What is the “Darlington Labs Sound”?

It is the sound of resistively-loaded Single-Ended Class-A amplification implemented in a unique topology. Our designs combine dynamics, liquidity, transparency, natural soundstaging, and bass and treble extension that is hard to accomplish with traditional tube designs. Our clean and musical sound also lacks the usual harshness, etch, glare, and listening fatigue commonly present in transistor, differential J-FET and op-amp designs.

With our products in their system, our clients report that they are able to listen longer, and at louder volumes, resulting in greater satisfaction. They notice previously obscured details, and can now follow complex instrumental threads in the middle of a dense mix.

Unlike some of our competition, our products are not ‘colored’ or ‘warmed over’. Yet, they remain eminently musical. Even on worn discs with excess surface noise or relatively poor recordings. Many listeners report: “it doesn’t sound bright at all, yet now I’m hearing much more detail that I expected.” We let a natural and musically-appropriate treble region through without editorializing or smearing.

Our electronics retrieve more information from your records than you knew was there. This is especially noticeable in an all-analog amplification system. They’re a rare blend of ‘Just Right’….and almost impossible for our competitors to achieve with conventional solid-state transistor, BJT/FET or IC-op-amp approaches.

Mid-priced vacuum-tube units usually suffer from a notable lack of dynamics and sound ‘rolled-off’ at the frequency extremes, often times combined with a upper-midrange glare. People praise their ‘plusses’, but often go back to Solid State, getting back on that upgrade wheel searching for superior overall results.

High-end tube units using feedback often still do not provide the same level of tight bass response, soundstaging, dynamics, and natural upper-midrange.

Our proprietary single-ended High-Voltage J-FET technology, combined with extremely sophisticated Power Supply regulation of our own design, allow us to deliver more marvelous analog LP sound in your home than most people have yet experienced, whether you are listening to an RCA Shaded Dog or Snoop Dogg.

We know the majority of historical and competitive units’ circuitry encyclopedically (see our extensive database in the “Audio Encyclopedia” for an overview).

Our truly unique technology allows us to achieve an inherently-balanced high level of performance. Unlike most companies who try to compete using more “typical” tech, whether vacuum-tube or discrete transistor (‘solid state’) or IC’s, and look to bring in products at a certain pricepoint, we don’t need to make large sacrifices in any one particular area in order to achieve gains in other areas.

Doing so leads to the glut of products that excel in certain genres of music or for only some listeners, but are not well suited to a wide variety of music. These are the products that tend to have big divisions of supporters (“I love it”, “You need to hear it!”, “Seek it out”) vs. their numerous detractors (“Nothing special”, “I sold it”, “Not for me”, or even “Terrible”). Our return rate (15-day return option from date of receipt) is unusually low.

We consider these weaknesses of other products the basic definition of “audible distortion”, whether subtractive (for example, a typical cost-effective-tube design) or additive (low and mid-priced transistor/IC designs).

Users also report how their spouse or partner is suddenly noticing that vinyl purchases (new and used alike) in the household have significantly increased. Clients have said that our sound is “enveloping and immersive” but rarely offputting…”tolerant of difficult or worn program material”…but “able to shine” on the best, most well-engineered discs.

For various reasons, our tech is not easily amenable to mass-production nor foreign cloning, and frankly we’re grateful that those characteristics are inherent in our preferred J-FET approach…and that we have developed implementations to build on strengths and minimize weakness. Still, however, we are following the “Botox” (and longtime high-end FOH analog console) prescription of ‘trade secret’ rather than ‘patented’, at least for now.

Our building reputation in the hands of current clients best tells our story.

"“The MP-7 puts me in the room with the musicians”.

“I realized that I don’t need a new cartridge after all.”

“Your product has such a rightness and natural immediacy. I could tell on first listen, after having searched for something like this for more than 30 years.”

Our small footprint (5 inches wide) is either an advantage, doesn’t matter to you, or is the only possible real compromise — if you would instead prefer a giant impressive-looking enclosure. (Note: the small box is extremely well-built, nicely-finished-in-an-understated-way, very solid when you hold it in your hand, and all-aluminum, rather than steel, for the best sound).

You have a 15-day return option for a refund (10% restocking fee) to decide if you, too, can benefit in quality of life from the reviews that you are reading.

Is it true that your units actually tend to reduce Surface Noise?

Yes. Near-universal client feedback says that our designs particularly benefit their less-than-perfect vinyl, by reducing the audible impact and annoyance of surface noise, while bringing all of the music to the fore. 

This, we believe, is a combination of two things: (1) Most competitor units actually accentuate​ the noise, due to their feedback architecture and low-overload-margins, and (2) Our design with its high headroom and zero feedback circuitry subtly "rounds off" and reduces the impact of those otherwise-large voltage excursions above the normal playback level. 

Our design has NO very-low-frequency time constants in any direct gain stage. This is not true of most all op-amp designs, which use a large electrolytic capacitor to control DC offset OR must use an active DC servo. Our design also differs from most vacuum-tube units (and other FET units) which have either Cathode bypass capacitors, or Source bypass capacitors, respectively, or those that rely on Balanced or Differential operation in order to achieve a usefully-low level of distortion.

We know of no other company employing our dynamically-adaptive, frequency-selective instantaneous attack-and-release pre-emphasized limiter and clipper approach, via our entirely-directly-coupled first gain stage with a tailored frequency vs. saturation level. Our technology is similar to those employed for many years in analog FM broadcast processing to control peak modulation without undue audible side effects.

The surface noise peaks that aren’t ‘almost completely eliminated’ are modified in effective-frequency content, sounding “lower” in tone, and are passed through the rest of our circuitry including the very-high overload-margin output stage.

The music, and reduced-but-not-eliminated surface noise, is then passed intact to the rest of your system. Your preamplifier and amplifier are typically never overdriven with the remaining peaks because your downstream system, in practice, always includes a volume control which is run with significant attenuation below “maximum output” and power amplifier clipping.

Our extremely “stiff” low-noise power supply (itself differentially-controlled and without VLF time constants) allows almost no disturbance within each stage, or between channels, in our preamplifiers during conditions of large transient compression, while maintaining clean amplification of the music.

The end result is that our combined approaches allow our units to handle large ticks and pops cleanly. No level shift or time-based transient distortion is present, allowing the soundstage to remain fixed tightly in place while surface noise ‘comes and goes’ in microseconds or milliseconds. This, we believe, is highly contributory to people’s perception that our designs allow the “music” to remain separate from the “surface noise”, the latter of which is no longer distracting for the combined set of reasons described above.

Your updated models offer many adjustments. How do those work? Does a user need to solder?

No soldering! We use removable “DIP headers” which are designed to be pulled off and moved with your fingertip and/or fingernail. You may use a appropriately long needle-nose pliers if the unit is fully powered off and the capacitors have discharged. These headers were used in many older computer motherboards to set BIOS options and master/slave IDE settings on on the back of IDE hard drives and CD-ROMs.

We invite you to take a look at the photos on our SU-7 listing.  We provide extra jumpers in the box, and they are color-coded for easier visual discernment. The top cover of the unit is removed with an (included) 2.5mm hex key wrench, and your own client-provided Philips screwdriver. 

The unit may remain connected in your system and nothing needs to be disconnected as long as you have reasonable visibility to the top when it is in place/in use.

Why don’t we use ball-point-pen-operated switches? Reliability! Those switches are notorious for intermittency and are hard to internally clean or repair. Relays are the only worse solution in our opinion. Our method is nearly foolproof, because as you remove them upward the pins are effectively self-cleaning.

In decades to come, you could replace the female portion if needed (we provide extra, but they should remain commercially available on eBay for the foreseeable future, as they are fairly widely used today in other electronic gear). While the uprightspins are gold-plated and inherently resistant to corrosion, as are the mating connectors, If needed, the user could clean those upright pins with a pencil eraser or a Q-Tip and 99% alcohol. The unit would need to be fully powered down for a period of minutes first.

In short, we build not only for incredible sonic performance now, we do so while intending to remain widely accessible to the serious upper-middle-class audio enthusiast. We also strive to appeal to the fiscally prudent upper-class consumer for their second, third, or other auxiliary and remotely-located system(s).

No matter the initial purchase transaction, we build for decades of trouble-free use and think innovatively now and for the long term, to deliver the best, longest-lasting, most thoroughly enjoyable experience to our clients.

We believe that this philosophy has contributed to our increasingly fervent and resilient client base, routinely expanding at an accelerated rate, since our founding in 2020, all with zero formal advertising and no paid sponsors or influencers to date.

You’ve recently introduced new models. Do you offer upgrades from older models?

Yes. Since early 2020, we’ve had a history of working with existing clients and treating them fairly, as you would expect for a company which has, as of yet, done zero formal advertising.

*Here is how Upgrade pricing works:

YOU MAIL US YOUR OLD UNIT, WE REMOVE AND DISCARD THE INTERNAL PRINTED CIRCUIT BOARD, AND REPLACE THE PCB WITH A NEW UNIT, REUSING YOUR CHASSIS, AND REAR PANEL INPUT/OUTPUT JACKS. We will strive to duplicate your existing LED configuration to the extent possible.

Therefore the update is the level of electrical and sonic performance OF the higher model but with your existing configuration. (Changes to configuration such as upgrading of jacks can be done at the same time as the PCB exchange, for additional cost).

Turnaround time expected: 4 to 6 weeks and is not guaranteed.

UPGRADES: Pricing in $USD as of 1/16/24. **CHECK OUT OUR NEW TAB UNDER THE PRODUCT LISTING.* Easy to do; no need to email us. You pay to ship the existing to us; Return shipping TO you is not included but is not excessive at flat USD + $20 for domestic USA clients, and we include new factory box packaging if needed.

MM-5->MM6B  $270

MM-5->MP7B $420

MM-5->MP8B $630

MM-5->MM5B  N/A

MM-6->MP7B $350

MM-6->MP8B $530

MM-6->MM6B  N/A

MP-7->MP7B  $240

MP-7->MP8B $360

MP-7+SU-7 to a single-box unit: N/A

Please note: The LOMC capabilities of the MP8B and MP7B ARE NOT INTENDED TO REPLACE THE SU-7 AND OTHER HEAD-AMPS. They contain very good LOMC step-ups inside, more than competitive with those offered by other vendors. However, because of the space and power supply limitations, we expect the SU series outboard head amps to provide a lower noise floor and superior overall sound quality. We do not offer a trade-in your MP7+SU7 to a ‘single chassis’ unit. (A SU8A is expected to be introduced at AXPONA 2024—ideally paired with an MP8B—and this will sit above the SU-7 in our product line).

Your units have internal separate MM (Moving Magnet) and MC (Moving Coil) units. That’s a rare approach.

We do this to provide you maximum value for your dollar. Our new MP7B and MP8B now feature an integral LOMC stage inside the box; but they also retain our extremely high quality and specialized +35dB to +40dB stage. This way, if you use an outboard SUT, or simply want to get the very most out of your high-level cartridge, we have you covered. At the same time, if you run a Low-Output Moving Coil (LOMC), our MP7B and MP8B give you an excellent soution in the same box. We don’t “crank up the gain” of our basic +40dB circuit, as do so many of our competitors, and try to advertise that we are giving you “something for nothing.”

If you have an outboard head-amp, such as our SU-7, the LOMC circuitry in our new units are not intended to replace the outboard SU; they are designed to complement it, OR, for new clients, assure them that they have everything they need in one box to “go LOMC”. If later they want to get a third-party SUT, or buy an outboard head amp (such as the SU7) to get an even lower noise floor, and even better sonics, they can do so.

DLabs Vs. Standard Op-Amp or DIfferential Discrete J-FET MM/MC Competitors

The standard competitors’ combo (MM/MC) circuitry is generally a textbook implementation of low-cost op-amps, such that it can’t truly be “optimized” for either MM or MC. An op-amp with certain tradeoffs is selected, and there are typically two separate op-amp gain stages per channel.

In the MM mode, each gain stage runs at 30dB with passive RIAA sandwiched in-between. Gain in their MM Mode is approximately: +30dB in the input stage - 20dB passive RIAA loss +30dB gain in output stage = +40dB overall gain at 1kHz.

In “MC Mode”, each gain stage is increased by 10dB, to a total of 40dB per block (which is very high for a typical open-loop-op-amp-bandwidth of 100Hz). The result: +40dB input - 20dB passive RIAA loss + 40dB gain in output stage = +60dB overall gain at 1kHz. A low-valued resistor is placed in parallel with the 47K input load and then they stencil “MC mode” across a DIP switch pattern on the bottom. (This also explains odd- and often little-used-settings which fall in between 40dB and 60dB).

Ergo, you have developed a combo MM/MC unit which is particularly easy to advertise, cheap to build, and you can suggest that it is “ready for any scenario” (even a very unlikely one, like an average user suddenly buying a $2500 LOMC but really wanting to keep their old plain-vanilla preamp). However - and very importantly, we suggest — it results in only modest audio performance for either the MM or the MC mode.

Our unique design does NOT rely on Balanced or Differential operation in order to achieve a usefully-low level of distortion.

DLabs vs. “External Power Supply Chassis”

Sometimes a competitor will provide a “separate power supply box”. While it may appear impressive, the external box often features a relatively small power transformer inside. Without our advanced power supply regulation circuitry, the result still leads to compromised dynamics.

The real reason for some external power supply chassis is undoubtably the deadly trap awaiting the average designer beause they weren’t able to squeeze a low-noise MC input into the same box with any ‘real’ power supply circuitry. When they don’t use an external power supply chassis, you will note they often run an 18 or 24VDC DC wall wart (ours is an AC step-down transformer) - with minimal “real” rectification and filtration, thus further compromising their already-present overload and distortion issues.

We run an internal +/-20VDC supply on the SU series, with a very low audio noise floor, even though our fundamental MC gain approach is more sensitive to power supply disturbance than theirs. To be fair, it did take us five years and over one-thousand hours of R & D dedicated to the Step-Up line. Thus, each of our units is self-contained in terms of power supply, using a simple externally-mounted AC-output step-down transformer. We can therefore dedicate all of our resources to do the necessary job to an incredibly high standard.

Interestingly, even though our MM/MP and SU series use the exact same type of wall cube, the internal power supply approach (MM/MP vs SU) is completely different. This is an additional reason for our “separates” approach - there isn’t as much internal overlap as you might expect.

To put it simply: once you hear our results, you’ll appreciate and understand the dedication, passion, and ingenuity we deployed to our design approach. Then go and buy some records with the significant cash you have left over.

Jack Panel Upgrade Option

Our new MP8B includes our best jacks at no extra cost.

For the MP7B and MM6B, you can purchase upgraded jacks: The smaller gold jacks on the right in the photo (below) are the ‘stock’ units. These gold-plated jacks are reliable and represent a big step up over the plastic and tin-pressed jacks commonly found in consumer equipment.

The jacks used by most of our competitors can shear off or break with little applied force, easily develop intermittent connections, and—with so many subtle variations—are a challenge to replace. Failure of such inexpensive connectors often means the gear has prematurely reached “end of life” and is discarded.

Our ‘upgraded’ jacks (the left ones in the photo) are larger and stronger with more robust grip on the attached patch cables (i.e., interconnects). These are patterned after a high-end ‘805’-style jack, and we hand-select each one to ensure proper fit and performance. Pricing for the upgrade varies by model.

We don’t claim dramatic sound differences between the jacks, but the upgraded units do exhibit improved connection characteristics. They also provide a visually enhanced look to the rear panel.

Does Darlington Labs practice an intentional strategy of planned obsolescence?

No. It's important to note that we did not "attempt to hold anything back" in spring 2021 with the MP-7, even though this strategy was recommended to us (and on good authority) based on the car industry going back 100 years. 

Our first products were based on four years and 4000 hours of work, and were more than marketplace competitive. Our new updates are the result of 2000 hours more R&D, good luck, good fortune, and the experience of four years in business. 

Peer review of our current power supply topology and other circuit enhancements by industry veterans with over 60 years experience leads us to believe that we really are innovating new cutting-edge technology in this form factor and achieving unprecedented sonic value.

Do you sell through dealers (for example, in Europe)?

We sell direct to the end-consumer in all parts of the world; and currently do not use resellers, distributors, nor dealers, in Europe or the USA or elsewhere. 

The reason is this: 

Distributors typically require a 20% markup in our business, and retail dealers often employ a 50% markup.  We also still need to get the products there (from us to you).   Therefore, if we were to offer it through these traditional channels, is it likely that our prices would be 20% to 70% higher.  

Our products are very reliable, and require almost no service.  However, if you do purchase from us in the USA and then have a warranty issue outside the US, we will pay for shipping both ways on a repair. This almost never happens, again due to our reliability. About 10 to 15% of our business is international. 

Would the MP7B or MP8B offer significant enhancement over the MM6B even if I use an MM (or other high-level output) cartridge? How does the EQ Trim feature work?

In addition to overall audio performance enhancements compared to the MM6B (which itself remains excellent, especially in the new configuration) the MP7B and MP8B have extreme adjustability compared to many of their peers, including a user-variable EQ function (called LF and HF EQ trim).  Our all-analog implementation is unlike most any other known unit in existence.

These features can be used to compensate for your cartridge's frequency response, SUT characteristics, overall system response including speakers, room and/or furnishings,, tonal quality of the associated turntable, or your individual taste or ear’s/hearing frequency response.  

We see six major potential use cases:

(1) MM cartridge optimization

One potential use case of the EQ Trim is the following scenario involving popular Audio Technica MM cartridges (VM95, VM 540, 760).

Many users of AT cartridges tend to have a love-hate relationship with the quality of the treble produced by those units, and many seek to ameliorate some of the mid-treble harshness via lessening the capacitive loading and/or adjusting the resistive loading. 

With our MP7B's very flexible resistive loading, combined with its flexible capacitive loading options, you can lower the cartridge capacitance, taming a mid-treble peak, and then regain the lost brightness electrically through judicious use of the EQ trim. The end result is a marked increase in phase linearity and a clearer, cleaner impulse response to transients.

(2) Step-Up Transformer Optimization and Compensation

You may also compensate for deficiencies in your associated Step-Up Transformer (SUT) at the frequency extremes; or flatten out your cartridge response (possibly in conjunction with a test record and instrumentation).

(3) Cartridge Frequency Response Compensation including LOMC

Note: our EQ trim can even be adjusted separately by channel! Many cartridges have small but measurable interchannel high and low-frequency frequency response anomalies. Many MC cartridges have excessive HF response rise from cantaliever or tip resonance, and these can be flattened to a remarkable extent by our EQ trim.

(4) Speakers, room and/or furnishings compensation for your analog reproduction chain. Keep your analog chain all analog! With EQ Trim you may be able to bypass your digital room correction.

(5) Compensation for the tonal quality of the associated turntable and arm. Many people believe that different turntables and arms sound different, even when using the exact same cartridge. Slight EQ adjustment in the phono preamp, such as our EQ Trim, can optimize your full complete analog chain without adding any additional or unnecessary circuitry, and without subjecting your precious analog signal to unnecessary digital conversion or degradation.

(6) Compensation for human ear’s response. It is a fact of life that the human ear’s response changes over a lifetime. Particularly acute is high-frequency loss, associated with age or exposure to loud noise. Our signal path is so clean and clear, you can achieve a remarkable treble increase while maintaining an open sound and avoiding harshness. Between the LF and HF trim, you can even add a tiny bit of extra boom and sizzle, like one recent reviewer asked for, with minimal drawback. Try it and see.

If you are a tweaker, then the MP7B or MP8B will be a powerful tool for your overall system and potentially your satisfaction, including growing and changing with your system needs in a unique and high-performance manner.

If you tend to be more of a "plug it in and forget it" type of person, AND are certain that MM cartridges are the way to go, then the simpler MM6B represents a truly excellent value and may meet continue to meet, and hopefully exceed, your expectations, both now and long into the future. 

Should you change your mind about LOMC needs, you can add an SUT or one of our SU units, or contact us to consider an offer to trade in your MM6B (whereby we would exchange the internal circuit card for a compatible higher-end model in our lineup).

Another common example question on Value Perception - using a $1900 Decca Super Gold (high-level 5.0mV) cartridge:

From a client on 2/7/24 who initially looked at the MM6B (and is international, with customs/import duty to consider):

>>Okay...what about sound differences\features between MP7B and MP8B???Or just a more complete Phono preamps then MM6B with loading options for MC cartridge and different set of gain and capacitance???.....Please, I am owner of MM cartridge, not MC....worth the extra money for me???Thanks.

Our founder’s answer follows. Quote:

“The question of value is one that you will have to consider. 

The basic sound quality does go up.  I just auditioned a new MP8B as it left our facility (on my reference MM cartridge, a retipped Stanton 881), and it was breathtaking.  The best we have ever produced.  The openness, solidity, coherency, was just phenomenal.  The MP7B sounds like a very good preamp by comparison.  And the MM6B sounds entirely musical and remarkably better than others anywhere near it's price range.  

I listen to all of our models and am intimately familiar with them, in combination and consultation with our engineering staff, consultants and others who have input.  Is the MP8B worth more than double the MM6B?  I can't answer that.  But I do know that each is better as you go up the line; but even the MM6B is a fine instrument which should produce thousands of hours of true musical enjoyment when fed by a cartridge like your Decca.”

Do you ship internationally (to Non-US addresses?)

Yes, we ship internationally. As of 1/21/24, we’ve added international address support to the website so non-US users should now be able to check out directly on the website. We have moved to a flat-rate international shipping charge of $60 for one unit and $90 for two units ($30 base order charge plus $30 per model).

This provides predictability and allows automatic online ordering which is consistent with the functionality provided by our SAAS back-end website providers.

We also added United Parcel Service support (UPS) for domestic USA orders to be optionally chosen by clients instead of our traditional USPS service.

INTERNATIONAL CLIENTS WHO WISH TO MINIMIZE CUSTOMS FEES:

There is one additional option that is available to minimize customs cost into Canada, the UK, and the EU. Under our “Upgrades” section, choose the “Customs Mod.” We will remove the front panel and include it separately in box, together with a hex key wrench, and instructions on how to remount it. With your client-supplied Philips driver, it should be pretty simple for most users. Customs reduction is not guaranteed but works more than 90% of the time and is legal and above-board. We are converting it to a Non-Retail-Saleable item by this method. You reconvert it to a Retail item by the reassembly.

What about International AC Line Voltages?

Because our units do not employ a switching-type power supply, our remote wall cubes are necessarily different to accommodate multiple line voltages around the world.

We can provide a 230V EU-style or UK-style or AUS/NZ adapter. Please confirm with us your voltage needs and plug needs (EU or UK) via email after your purchase (referencing your order #) if your needs differ based on what would be expected from your shipping address.

Users in parts of Japan with 100V local supply should use an international converter to step their voltage up to 120VAC for use our regular 120VAC adaptor, or secure a local 100VAC->24VAC wall cube with a 5.5mm OD (Outer Diameter), 2.1mm ID (Inner Diameter) male coaxial connector which fits our unit.

Do we set up a preamp with Custom Settings for a client?

Sorry, no. As we have streamlined production, it is no longer practical for us to keep track of client individual requests for custom settings of the jumpers.

The user can adjust them without any soldering, by following the directions in the instruction manual. If a user is having difficulty, we will try to assist.

MP8B, MP7B and MM6B units are shipped out with MM mode, 47K, 100pF, +40dB, Unbalanced Out. We do try to match the client’s preference for LED brightness on the final QC.

Why are prices different on eBay?

eBay collects United States sales tax in all states. We only collect Massachusetts state tax on our website since that is where our LLC is registered. Additionally, the MM6B and MP7B are higher on eBay to compensate for the greatly increased sales fees they charge.

The MM5A is only available on eBay. It is a simplified MM6B with no internal user adjustments and is our committment to main a unit offered for $199.

What are the differences between your models?

We strive for neutrality in all of our designs; attempting to let the intent of the original performers and engineers shine through directly to you. They have a balanced, musical sonic signature that doesn’t short-change any one type of music.

The conventional measured specifications are similar between units. Given our preferred design methodology, the specs support our claims of high headroom, low distortion and an overall technically well-executed design.

We take an integrated approach to the variations between units. This means that each has their own blend of circuitry and power supply in order to deliver what we feel is a “well-balanced” sonic presentation that represents a high value at each particular price-point, and taking into consideration the typical systems to be paired with each unit.

A non-audiophile might say that they hear “more notes” in the music and this is even more true in going up our model range to the highest-end models, on a relative basis.

What cartridges do you recommend?

Our units are designed to be neutral, musical and transparent so that you do not need to “match” them to a particular type of cartridge.

Users have reported excellent experience with current cartridges including the Audio Technica (AT) AT-95, VM-750 and variants, the AT OC9 LOMC series, Ortofon 2M series (Red to Black), Nagaoka MIs including the TOTL MP-500, Denon HOMCs (DL-110, DL-103), Soundsmith MI or LOMC (similar to the B&O MMC/MI design), Grado (MI), Hana, Stanton and Shure. LOMC cartridges in use include Audio Technica (AT), Hana, Grado, Koestsu, Benz, Dynavector, Lyra, Van den Hul, Decca, and others.

How is your mono switch configured electrically?

Our mono switch places the positive inputs from the cartridge in direct parallel (this parallel junction is accomplished in series with a 1 ohm resistor intended to damp any possible parasitic effects in the input leads). No additional circuitry is added. When not in use I.e., ’normal stereo”, there are no additional circuit elements including switches are in the signal path.

It is the equivalent of wiring a stereo cartridge to mono right at the headshell.

Ours is completely silent in its sonic operation and can be switched while listening to a record, without muting your system or worrying about transient “pops” like some of our competitors.

Step-Up Transformers are completely unaffected and our mono switch works perfectly.

What about loading effects? Not to worry. The resistive input load with our channels in parallel declines to 23.5K and capacitance increases to 200pF, but now the cartridge has its’ own coils effectively “in parallel”, meaning that the source impedance is exactly halved.

Therefore, the cartridge high-end resonance point and frequency response is unaffected and no changes to loading are necessary nor desirable.

If a user is operating an active MC Head Amp ahead of our MM-5, MM-6 or MP-7, they should use any mono switch available on the MC head amp itself.

The Mono switch is physically configured as “Mono=Up”, “Stereo=Down”.

What is Darlington Labs warranty?

The warranty of parts and labor is 12 months on each unit, from date of original purchase, to the original purchaser. At our option, we will repair or replace any unit determined by us to be defective as a result of manufacturing defect. It does not cover abuse, neglect, externally applied damage (such as excessive power spikes or the use of non-approved power adaptors), and any product which has been modified by the user without the consent of Darlington Labs, or units which have been serviced by technicians not approved in advance by Darlington Labs.

Warranty, in this context, refers to a performance level originally associated with the date of manufacture and does not cover any running changes made as part of our continuous improvement plan.

Any implied warranty relating to Darlington Labs products is limited to the duration of the warranty period. Darlington Labs LLC shall also not be liable for any consequential or incidental damage resulting from the misuse of its products. Some states do not allow the exclusion of consequential or incidental damages. Our warranty gives you specific legal rights that vary from state to state.

We reserve the right to modify the design of any product without obligation to purchasers of previously manufactured products and to change the specifications of any product without notice or obligation to any person.

What is the meaning behind the “MP” prefix vs the ‘MM’?

MP stands for Multi-Purpose - truly optimized for four different scenarios. We optimize for 1) High Quality MM and MI cartridges via the main +40dB stage, 2) Low-Output Moving Coils via our unit’s own internal active LOMC step-up stage, 3) Outboard Step-Up-Transformers (SUTs), or 4) Separate external active Head Amps (like our SU series). Our MP units feature incredibly wide-ranging loading and gain options with resistive and capacitive loading to suit almost any situation, and a great number of gain settings. This combination, based on our review of competitive products is, we believe, a rarity among quality preamps.

Are these kits?

No. The units are entirely plug-and-play, fully complete with an external AC transformer (available in 120V or 230V).

Do you offer a Black Enclosure (a Black front panel, rather than the standard Silver panel?)

Yes. Since April 2023, we have offered Black front panels as well as Silver front panels. Our pricing is now the same no matter the color of front panel you wish to choose. The rest of the enclosure (Top, Bottom, and Rear) is always black.

Is it true that some high-end competitor units are not well suited to Moving Magnet (MM) cartridges?

Yes. Counterintuitively, some of the highest-end solid-state designs are not well-suited to Moving Magnet cartridges., due to excessive fixed gain and/or input capacitance. Those designers consider the Moving Coil user their intended client. Expensive MC cartridges can also be a source of lucrative profit for dealers. If the minimum gain is 46 to 50dB, it may be a MC-optimized unit masquerading as a true MM preamp.

Darlington Labs seems to take a dim view of conventional feedback. What about the classic tube preamps and some high end FET units which appear to use it successfully?

Marantz 7, McIntosh C22, EAR 834 and both Audio Research and Conrad Johnson from the ‘70s into the ‘90s, as well as FET units including the Threshold FET-Nine and FET-Ten use feedback and are well respected.

Our primary objection to high feedback designs are those using un-degenerated differential BJT transistor input stages, either made from discrete transistors or in the input stages of BJT (Bipolar) op-amps, which represent the vast majority of our competition (purely from a price, but not performance, standpoint).

The tremendous headroom in most high-end tube units lessens the impact of negative feedback. In general, we do believe that passive RIAA is better in performance-oriented tube units and that active feedback tube RIAA has been used as a cost-saving measure but can still perform well if properly implemented.

Barrie Gilbert, a (recently passed) top-flight engineer with more than 60 years’ experience including at Tektronix and Analog Devices, pointed out that:

“…there is significant odd harmonic distortion even at frequencies well below the unity-gain crossover; and that the phase angle is not only a function of frequency, but also of amplitude -- that is, the op amp generates a peculiar kind of amplitude-to-phase modulation, something which one should not expect of a linear system.

But, then, an op amp is by no means as pristine in this respect as the textbooks suggest, and that gm cell has very strong open-loop distortion for even quite small inputs.” (Barrie Gilbert, "Are Op-amps Really Linear?", Electronic Design magazine, June 10, 1998, available online at https://linearaudio.nl/sites/linearaudio.net/files/Are%20Op%20Amps%20Really%20Linear.pdf

I’d prefer an IEC power cord instead of a remote-mounted AC wall cube. And why don’t you just use a modern universal (120V/240V) switching supply?

We agree that wall warts aren’t necessarily the sexiest addition to a product at first glance. If you’ve already read our section at the top of the FAQ about upgrading the existing power cube, but still have more questions such as “why not a computer-style IEC power cord and a built-in power supply?” then this additional information may be useful.

Outboard wall warts are an important enabler of the value proposition on the 6, 7, and 8-series products. They allow us to utilize every inch inside of our enclosure with active circuitry and power supply rectification and regulation, without inducing significantly audible noise. Because of its high performance, our design is especially responsive to the quality of the power supply rails.

A large proportion of our design effort went into the discrete power supply regulation topology, one with truly exemplary line and load regulation, and low impedance, combined with low noise. In fact, it is specifically optimized for use with wall warts. Therefore, no external high current supply is needed to achieve excellent sound quality. This is part of our ‘Integrated Design Philosophy’ and is one reason why such substantial R & D resources were expended.

Our outboard linear AC power transformers have no active parts to fail (such as capacitors found in DC wall warts, nor the surface-mounted complexity of combo 120V/230V switchers), and they produce an orders-of-magnitude reduction in hash and noise compared to typical switching DC power supplies.

Around one-third to nearly one-half of our PC board space is dedicated solely to power conditioning using sophisticated all-discrete final stage power supply regulation. This is simply unheard-of in any other compact-form-factor product. However, it allows us to provide class-leading dynamic reproduction, freedom from strain, and natural sound-staging with a previously unheard-of price-to-performance ratio.

If you travel internationally, we can supply both a US 120V and an EU 230V wall wart, as well as physical travel adaptors, so that you can use them nearly anywhere in the world.

Tell us more about your company logo.

The pits represent a CD i.e. digital reproduction, the bottom of the circle represents a phonograph record i.e. analog reproduction (including tape), and the VU meter in the center represents professional audio applications. The 'Labs' portion indicates that we have engineering expertise in-house, rather than being a provider of products whose design is outsourced. While we introduced phono preamps first, our product roadmap contains Line Amplifiers, Headphone Amplifiers, Electronic Crossovers, products which interface to D/A converters, and more.

Are Darlington Labs units usable with digital phono preamps?

Yes! If a user needs the digital equalization and other features offered by such a preamp, we highly recommend the use of one of our products to properly increase the gain of your cartridge, and RIAA equalize the input signal, before feeding the output of our units to a digital preamp in a Line-In configuration.

Doing so will dramatically increase the overload margin of a digital preamp. If a digital preamp uses strictly digital EQ, at typical +40dB MM/+60dB MC gain, representative samples have been measured to enter gross overload at 20mV in, a level produced by most cartridges by regular program material (music) on a heavily modulated record, not to mention peaks above this level which result from the inevitable presence of surface noise.

Allowing basic RIAA correction to be done in the analog domain, ahead of Analog-to-Digital Conversion, can produce 20 to 30dB or more of increased headroom in the real world, leading to notably improved sonic results.

Why do we not incorporate Remote Control?

Remote control? It’s cool. But remote control typically means relays, and we have found them to be among the least reliable electronic components. We build for long-term projected reliability as being paramount and equal to our sonic priorities. Our engineering team’s background stems from professional and broadcast audio, where equipment failure or interruption can have very serious consequences.

Many audiophiles regularly use gear that is more than 40 to 60 years old. Most of those long-serving pieces do not contain relays of any type; if they do, it is almost certain they are not going to be still-in-service originals. A single relay failure in a piece of equipment containing many of them, will, for most practical purposes, result in the equipment being considered “end of life”.

Even if one could find the problem unit and replace it yourself (by soldering), most people would be tempted to replace ALL of them at the same time - an expensive proposition in parts and time. Much more likely is that the average person will be faced with prohibitively exorbitant repair costs. If the manufacturer used relays which are plug-in (extremely rare), the mating sockets themselves will contribute to sonic degradation and lack of reliability.

In our SU series, we use gold-plated DIP headers with computer-motherboard-type pin connectors which are adjusted by hand. They have proven very reliable, and are self-cleaning through simple use.

Can Darlington Labs product feed into a Balanced Line Input?

Yes! Darlington Labs high headroom designs mean that we don’t need to use a true balanced output stage, with its attendant limitations, in order for you to have compatibility feeding a Balanced Line Input from our unit. A user CAN connect any Darlington Labs unit directly to a balanced-input (XLR) with standard studio-style wiring practice (consult the factory for directions if needed).

Can Darlington Labs products interface with Balanced Output turntable?

Yes! Just because we use single-ended gain stages, by preference, does not limit the interface that a user can accommodate in his system. A user CAN connect a balanced-output cartridge/turntable combination to any of our units with standard studio-style wiring practice (consult the factory for directions if needed).

Do you offer Balanced XLR out on the Darlington Labs preamp?

No. XLRs are not currently a factory option.  While they could be added by an end user, the resulting grounding will then be inferior to our recommended method (see papers on Neil Muncy and the ‘Pin 1 Problem’ in a 1995 AES preprint).

Our solution involves custom interconnects that terminate in RCA (XLR pins 2 and 3) and spade lugs (XLR pin 1) at the Darlington Labs end, and male XLRs at the receiving end (your line level preamp, or A/D, or studio tape machine). Directions are in our owners manual and elsewhere on this website. 

Jumpers are moved internally on our unit to select the balanced out connection. The ring of the RCA then floats above ground at audio frequencies, providing an impedance-balanced out to both phases of the receiving side input. To our knowledge, our solution is entirely unique in the industry, rejects excess noise in special applications, and is sonically transparent, unlike the traditional actively-electronically-balanced XLR out.  

Why do we use a Single-Ended Input Stage?

Two reasons: First: for the same level of electronic circuitry, a Differential or Balanced Input is 3dB noisier. This is because the signal is shared between the two halves of the gain devices. Second: The distortion spectra of a Balanced stage is typically predominantly 3rd order (odd-order) distortion, which our research has determined to be detrimental to the ear’s perception of quality.

For a real-world example: Most cherished balanced in/out studio gear from decades past is passively balanced at the input and the output by physical transformers. Check the used price of recording consoles with electronically balanced inputs vs. transformer-balanced and related single-ended gain circuitry - the associated three-decade depreciation is often 20X to 60X. An Actively-Balanced In/Out Soundcraft console that sold for $90K in the early 1990s might fetch only $1500 today. On the other hand, Neve and other serious consoles using balancing transformers and internally single-ended circuitry have retained a much greater proportion of their original value. (Note that you don’t need to use transformers to interface our gear with balanced outside I/O).

We believe this is related to the ear’s response, based on over 80 years of research, which indicates that type of distortion is equally important to overall level. Note that Darlington Labs equipment, with proper interconnection by the end user, can both Receive a balanced-in signal, and handle it with low noise; as well as provide Output which is to be subsequently received by a following Balanced Line Input.

I still want a truly balanced internal architecture for a LOMC step-up.

Here is a more concise overview of the above.

While our units are fully compatible with a fully-balanced turntable and cartridge setup (whether XLR out or Mini-DIN), and they are also fully compatible with the ability to feed balanced line inputs, and reject a significant amount of externally induced noise while doing so, we realize the inherent disadvantages with using balanced or differential circuitry inside the unit.  Simply put, a higher noise floor by roughly 3dB, all else being equal, and a distinctly unmusical distortion residual high in odd-order output, even if at an overall low level. We can do it; we just choose not to. These problems are inherent in an electronically balanced internal design; few successful “classic” units are truly balanced inside the box.

Compare a Neve recording console with a Soundcraft console in the used market where the electronically balanced mic input version took a 100:1 hit in resale; the unbalanced-inside-Neve being far more highly valued and respected. Other vendors are vexxed with the same problems but are unlikely to tell you in as much honesty as we will. In fact, our most well-known direct competitor introduced a Balanced Phono Preamp in October 2023 and was quoted on video as saying that they did so because people “were asking for one”, not because “those clients actually needed one.”

While physical SUTs have their problems, if you are set on a "truly balanced" step-up, then we suggest that you consider having a vendor custom-wire a SUT (preferably with a floating internal shield), with XLR in and out rather than the customary RCA.

Can you make a Flat RIAA preamp version so that I can do RIAA in my computer software digitally?

Doing RIAA in the computer digitally is, in our studied option, a highly suboptimal solution, and therefore we do not offer this option. Different is not always better; you will send up with at most 10 to 12 bits of effective resolution for signals below 2kHz, and to preserve transients correctly you need a conventional analog phase response in the RIAA deemphasis, not a linear-phase IIR digital filter as some would have you believe.

Additionally, if you were to use an unequalized phono preamp, peak transients will tend to severely overload the front end of your A/D, exacerbating any residual TiM/SID. Our history before starting our commercial company was in professional audio and live recording, where we needed to deal extensively with digital conversion.

We can highly recommend our products feeling a regular A/D in the normal configuration. You should choose an A/D with an input impedance of 10K or greater for best compatibility with our Class-A output stages.

How generous are Darington Labs Overload Margins?

Ours is 30dB as specified on the MM/MP series and greater than 60dB (not a misprint) in our SU series. Competitors are often at least 10dB worse. Our greater overload margin equates to more freedom from audibly-distracting surface noise, pops, ticks, and clicks, as well as cleaner-sounding peaks and a generally more relaxed presentation.

Tell me about Power Supply Differences - DLabs and others:

Our high voltage rails (68V on the MM6B and MP7B, and 70V on the MP8B) are used directly and fully by each Pure J-FET and, separately and fully, by our supporting BJTs for more native internal single-ended headroom. Our J-FETs are individually hand-calibrated in all our MM and MP series in order to maximize their use of the rail.

Competitors employ “auto-bias” techniques in order for them to obviate the need for hand-matching or hand-calibrating the J-FETs used for primary gain (J-FET parameters vary, sample to sample and batch to batch).

A clue to our more efficient use of the power supply rail is the following example: One competitor who operates on what they advertise as a 64V rail (internally it is +45V/-19V) specifies a maximum single-output of 10V RMS, this using a combination of BJT+FET, not the DLabs method of Pure J-FETs.

Using our 68V or 70V rail, we specify a maximum of 17 to 19V RMS or between 48 to 50V peak-to-peak on our high-headroom single-ended out, demonstrating that we have more efficient use of the rails. This is part of our Inherent Linearity Topology which tends to reduce odd-order harmonic distortion (the kind not cancelled through differential operation).

Quality of the internal regulation OF those rails is also key:

We use exceedingly sophisticated Discrete Power Supply regulation in all of our units. Compare the PCB space dedicated to our power supply cleaning section with that of our competitors; and if you can, “probe” our power supply rails with an oscilloscope and compare them to the competion. You will likely find that our rails are nearly noise-free while others may have excessive AC noise and ripple, be polluted with mains rectification and bleedthrough, or present too high of impedance or an impedance which varies significantly with frequency - all of which tend to “color” the audio that passes through the associated gain stages.

I’m looking at the MP8B (or MP7B) but I use a LOMC (Low-Output moving coil cartridge) with an output of 0.3mV. I know that the MP8B includes a built-in head amp. Should I consider adding your SU7 or a Physical Step-Up Transformer (i.e. bypassing the built-in head amp in the MP8B, or MP7B)?

Yes, for most optimum results we suggest using an outboard Active Head Amp (like our SU7) or a physical third-party Step-Up Transformer. 

While the MP8B does include an internal head-amp (max total gain of 72dB), and is a capable, even reference-class product operating in it’s MM mode, the best sonic experience with an LOMC cartridge will be with either one of our separate Active Head Amps (the SU7) or by using a third-party physical step-up transformer driving the MP8B in MM (+40dB) mode.

What about total price? If you are trying to keep the budget around the same as the MP8B ($999), then we recommend that you consider combining our MM6B ($369) and our SU7 ($569). The MM6B has taken some technology from the MP8B. If you can spend a little more than the MP8B, consider our MP7B+SU7 combo. This will give you significant sonic adjustability that the MM6B lacks, as well as increased sound quality.

Note that prices above for the MM6B and MP7B include basic jacks and no mono switch, whereas the MP8B includes upgraded jacks and a Mono switch. 

For a typical LOMC cartridge of 0.3mV nominal output and an internal impedance of 10 ohms, we ship an SU7 with +23dB gain and 220 ohm loading (20X the cart's internal impedance).

Our best current offering is the MP8B+SU7 combo.

Do you still have a B-Stock program?

The B-Stock program has been decommissioned at the present time.  Our chassis have now been arriving in consistently good condition. While our products are hand-assembled, and therefore have slight minor variations, everything we ship is knowingly ‘A’ quality based on our assessment. (In the past, a small number of outer chassis had cosmetic blemishes primarily received during transport to our facilities). 

I’ve seen pictures of older models which have non-silk-screened surfaces. Tell me more about history?

Since March 2022, all front and rear visible surfaces are professionally pad-printed with high quality ink using expensive Italian machinery by a subcontractor north of Boston, then specially heated for days to cure the colored ink.

Early production models from Oct. 2020 to June 2021 had a color DLabs Logo and model number via a front adhesive-mounted panel applied to the aluminum base. Early models from Oct. 2020 to March 2022 had rear panels which were marked in red and black, via adhesive-mounted panel applied to the aluminum base. Current black front logos use the same light-grey silkscreen as is used on all rear panels; silver fronts use all-black for the DLabs logo..  (Any owner of a first-run pre-June-2021 stickered-front-panel unit may contact us and we will provide a B-stock silk-screened front panel and assembly hardware free of charge (it is user-installable). A-stock panels are available for purchase on the website or contact us directly via email.

The model number and serial number and QC date are currently inscribed on the bottom, by the final QC engineer, in permanent marker (which can be chemically removed and replaced if you are returning a unit to us for model update). The model number is not listed on the front but is referenced on the bottom. If you upgrade to a higher model, we assign a new model number and serial number and they are placed on the bottom surface.

Upcoming Product Roadmap:

We are expanding! We’re in the process of setting up a second primary design center in the central US (northern Iowa), in addition to our primary facility in the Boston area. This will enable us to collaborate more closely with a greater proportion of our staff, provide hand-carry capacity to our primary annual audio show (AXPONA), and in the long term, provide maximum production efficiency and cost inputs for the healthiest long-term company consistent with our reference-sonic-quality at accessible-prices-approach.

We will ship production units from both places; for service, or if needing to return something to us, please do not assume that the appropriate return address is the one from which it was mailed and check with us first.

AXPONA 2025 preview:

We are planning to have a headphone demo at our booth in the Expo Hall. 

This will be our planned public launch of the SU8A head amp; and we expect to have one or more MP8Bs, MP7B, MM6B, SU-7 and the new SU8A available for audition with the ability to mix and match for audition.

Initial plans are a Technics SL-100C TT with swappable cartridges upon request including an AT33PTG/2 LOMC, a Nagaoka MP-500 MI, an AT VM750SH MM and an Ortofon 2M Blue MM, via a prototype DLabs headphone amp and AKG K701 headphones.

Production Update: As of 11/13/2024:

Order status: 15 orders outstanding. Oldest order received 10/26.

Inventory: MM6B available in quantity; small number of MP7Bs and SU-7’s available from stock; MP8B and MP7Bs being resupplied during November.

New order timing: MM6B 1 to 2.5 weeks, SU7 1 to 2.5 weeks, MP7B 2.5 to 4 weeks, MP8B 2.5 to 4 weeks.

Please email us if you have questions.

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Sales Consultation:

EMAIL is the fastest and most preferred method of communication. We typically respond to email within 24 hours. See our Contact Tab on this website.

If you are having trouble reaching us through email, please leave a message at x617x459x7080x - removing the x’s. and provide your contact information. If needed, we will work with you to schedule a call at a time that is convenient to both you and our staff.

(Also, please do not use DMs on audio boards or the Message function in our eBay listings - unless you are actually talking about an existing eBay transaction - to reach us. They are not consistently monitored and we don’t want to miss your message).