Is it possible to implement a mute feature without imposing a sonic price? I'm guessing that is no-can-do but it is a feature of my current setup that I find handy.
The remote control module that we are looking at actually DOES have a mute relay included, and that should not pose a sonic penalty if implemented correctly. If that were to go intermittent in many years, it would not affect the main function. And one relay could be replaced without too much trouble.
For me, personally, it sounds like too many features and compromises I won't use/am not interested in, and too few that I am. I'm old school in terms of a hifi in a listening room, not a desktop set up, not close monitoring, not using headphones (in fact, I really dislike headphone listening and barely ever use it). I don't care about small case size. In fact, I'd prefer a larger case size, more physically isolated power supply circuit inside the box, more RCA sockets and no TRS ins, no adaptors to use or new cables to buy or terminate. I'd be looking for something that can drive at least 6 feet or 10 feet of interconnects. I've lived for decades without a remote and while it would be a nice feature, it's not really of make or break consequence to me. But I'm an old, and legacy hifi guy. I get that the younger and future buyer might be more of a desktop system and headphone user, maybe with fewer input needs (though at the moment I'm down to two sources and it may likely stay that way with multiple digital sources going into a single DAC and switching between digital sources taking place there).
I’d agree about case size, not really a factor for me and I have no particular need for compact components.
Let's gauge interest, please, in a potential 8-series. We can talk about a "Potential" DL-8, Direct Line Preamp. High-Voltage J-FET single gain stage, non-inverting, low-impedance unbalanced output. 8 inch case, 2 external wall warts, true Dual Mono power supply, all RCA jacks for 3 sets of inputs, two sets of output (Class A, 10 foot) and (Class-AB, 30 foot) variable, 1 fixed output (Tape), a basic headphone output, and remote control with Volume Up/Down and Mute. Volume, Balance, Selector on front panel. $999. 13 inch case, as above except 4 sets of line inputs, with IEC power inlet (regular 3-prong power cord), built to UL/CSA standards but not officially certified by their organization. Optional Quasi-balanced (ground-referenced on negative-phase) XLR or TRS outputs (+$100). $1299. Thick natural-aluminum faceplates on the above, visually similar to our existing 5" chassis but with squared-off corners. A 'potential' future 'physically matching' MP-8 +40dB RIAA and a SU-8 +22dB Head Amp, each in similar case sizes (8" or 13"), and true Dual-Mono power supply, to the DL-8 mentioned above, could then make a physically matched set. Yet, an MP-7 and a future digital DAC companion DS-7 (existing outboard DAC and our electronics taking the signal directly from the balanced, voltage-output DAC chip, already working since May 2020 and very interesting) could feed a larger DL-8 line preamp with wonderful results...the latter's larger size being especially useful for sufficient I/O space. Mix and Match among the 5,6,7, and 8 series - sonically and design-intent-wise. Use a Darlington Labs Direct Line Preamp with your own existing basic Stereo Power Amplifier or Monoblock Amps or Powered Speakers...or use forthcoming Darlington Labs small Monoblocks and/or crossovers at least for your main speakers or High Frequency drivers. (Never say never, but we don't forsee competing in the 100W/8 ohm+ power amplifier market for a long while. Switching designs, conventional solid-state Class AB and tube amps appear well-accepted). A small HP-7 seems like a done deal from our perspective. Small case sizes in headphone amps are usual and customary, for travel and general convenience. But compromises are larger on a system-center Line Preamp in a small box. That would be a non-standard product; maybe useful to younger people in smaller living spaces.
These look fantastic although, for my own use, are perhaps more than I need for my simple, 2-source (DAC/MP-7) setup. Not sure how common that is. I'll never use a tape or headphone out and I never use the balance control I have now. While a small chassis is not a requirement for me, maybe it's all I need? A "High-Voltage J-FET single gain stage, non-inverting, low-impedance unbalanced output" with two inputs and high-quality remote volume (I always do volume tweaking after I put the LP on and sit down). I'm also fine with the larger chassis if it makes for better SQ (better isolation, etc.) but prefer minimal features. Not sure if that makes sense commercially. I'm imagining the minimal feature set of a typical passive attenuator/"pre-amp", but with buffered in/out and gain, Darlington-style. Had a monumental listening session last night with the MP-7, what a time. "MP-7 more forcefully picks the listener up and thrusts them into the middle of the musicians, completely immersing that listener in a powerful, dynamic live performance" from the FAQ pretty much nails it.
As a specialist relatively-low-volume (currently) manufacturer of high-sound-quality, high-value-proposition products, we have the ability to offer some customizing. For example, no balance control. A "passive preamp with extremely high-quality (and non-inverting!) gain", in a small chassis, may be a unique thing but we do think that it is an untapped niche and we have a circuit that can very much fit the bill. In comparison, truly "Passive Preamps" have all of the traditional drawbacks, and the buffered but zero gain units like the Pass B-1 are quite transparent, interface more easily, but still don't have any gain. Most high-value gain stages substantially impair the sound quality.
I'd like smaller boxes even if it means fewer inputs. I'd like wall warts to have a cord wart option, especially if there are to be two. I'd also like it tested with a single wart with a splitter or switch just in case I want/need to run with that configuration.
Line-Lump / "Cord-Wart" options are on the table. Ours are custom-wound and the minimum quantities are 500, quite a few for a 230V version that we'll sell relatively few of (for now). A Y-splitter to allow one wall cube or line-lump is an excellent idea. Our 5.5mm OD, 2/1mm ID cords are physically widely used in CCTV and other applications so pre-made Y-splitters are readily available. There is a hidden issue with 'phasing' of multiple adaptors though. If incorrectly designed (in the product), you invert one of the wall cubes (plug it in upside down) and they fight one another, eventually leading to smoke. And, the manufacturers don't guarantee AC phasing even if the user deploys them correctly. Of course, we think of--and plan for--these things ahead of time, but nothing is exactly quite as simple as one would like. A 24VAC, 2A Line Lump (which we've already quoted from a vendor) would enable an 8-inch "Mini-Monoblock Power Amp" of around 10W/8 ohms for clients operating on 120V (to begin). Remarkably clean sound. Potentially fully-regulated output power supply voltage. All discrete, no feedback. Is there any interest in such a thing? Such an small but high-quality power amp - which because of its power needs won't work with our regular wall-mounted 24VAC/500mA cube - is a clear driver of our moving into line lumps, which could then provide additional convenience for users of our existing products, and also then allow potential small-chassis-size, and easier dual-mono operation (without consuming an excessive number of wall or power strip spaces), for upcoming products.
Random thought; at least the LF outputs of the XO-7 or XO-8 should have the ability to drive long cables given they'll most often be connected to powered subs and often using well over 10' runs .
We're on it. Actually, the main difference between our existing Class-A output and a proposed Class-AB push-pull out is that the Push-Pull can easily drive a 600 ohm input and/or extremely long cables, whereas the Class A cannot. Both have low enough output impedance to handle a subwoofer or amplifier cable run in a house or listening room of 10' to 30', assuming a 10K or greater load on the receiving end. The combination of more than 1000pF of cable (usually >50 feet...pro gear considers up to 1000 feet...remotely-located satellite-uplink trucks, multi-building runs, etc), plus high audio frequencies, is when a very beefy output is necessary to drive the cable capacitance while maintaining low distortion. We tend to obsess about this type of question, figuring out the sonically most-transparent, simplest answer that can be reliably called up to do a great job. Comparatively, many manufacturers (even some audiophile ones) just slap a 5532 op-amp at the 'send' end, and call it a "Balanced high-current XLR out" regardless of whether it sounds transparent driving a short output cable or can even manage the 1000-foot run. Additionally, because the subtle tonal quality of a discrete Push-Pull output is ideally suited to this use, our crossover lower outputs will likely be a high-current push-pull unbalanced output. If there is sufficient demand, an XO-8 could feature optional truly-balanced, push-pull (on both positive and negative phases of the XLR or TRS outputs) on any output - LF, MF or HF.
Great question. First, let's clarify the "hum issue" - particularly as threaded-type forum discussions can be difficult to quickly and accurately interpret. The "issue" is that IF a user carelessly tosses the audio interconnects AND the wire from the wall-mounted power cube together, dangling behind the unit and in close proximity, AND then does a test where they intentionally crank the volume with no record playing, THEN you MAY hear a slight bit of background 'hum'. In no case have we actually had a user complaint of obtrusive noise, and we haven't shipped a formal owners manual yet (nor have we had a caution about the power cable routing in our FAQ until a week ago) so our assumption is that many existing installations haven't really optimized this interconnect spacing. The cure, if needed, is simply to "dress" the AC adaptor wire AWAY from the audio cables, crossing them at right angles and down the other side of the equipment rack to the greatest extent possible while avoiding excessive physical strain on any lead. This is good practice with all components from all manufacturers, whether those products use a wall cube power adaptor or a conventional 2 or 3-prong AC cord. Visually this separation has always been one sign of a thoughtful installation and this technique can assist with general signal troubleshooting. So having said that, what could improve the situation in a future product? 1) Simply a larger enclosure. Our current box is 5 inches wide, and so the power cable tends to coalesce with the audio cables based on gravity. An 8-inch or 13 inch box could natually have the AC coaxial power inlet, OR a 3-prong IEC power inlet, physically further away from the audio I/O. 2) Balanced input (for a Magnetic Phono Input or similar) as proposed by the above question. Yes, this IS possible. However, it is rarely done, for various reasons including: A) potential noise penalty - balanced inputs are often inherently noisier than unbalanced, for reasons we won't cover here, B) different distortion spectrum: Balanced Inputs tend to produce more third harmonic and less second harmonic, which goes against a naturally occurring "monotonic" distortion residual, whereby each ascending harmonic in the order decreases in contribution from the one lower to it. C) It may require tonearm and cartridge re-wiring, including termination the existing cables in an XLR (or non-standard Camac or mini-XLR) output rather than RCA. The grounds from the left and right channel MUST each be floating and not tied together, and neither channel tied to the metal of the tonearm or a metal chassis plinth. Our estimation is that less than 0.5% of all turntable users would be seeking a truly-balanced phono INPUT. Possible but rare, and not the "right way" to solve what is a simple installation issue. Balanced Input has sometimes been advocated for Moving-Coil usage, due to the very low signal levels involved. But induction from a power cable is arguably less common here due to the inherently lower coil resistance of an MC cartridge. Genuine ground loops, an altogether diiferent subject, would be a reason to consider special balanced MC inputs. Our first MC products will feature regular RCA unbalanced inputs. Balanced Output is possible on a future product, but this would be more of a market request based on "fashion" rather than actual noise reduction.
Thanks krichard. I had read that a truly balanced setup from tonearm to phono stage was no worse than unbalanced in short runs and superior for longer runs of cable. Allowing that the turntable had a balanced output - not an adapter. So for a short - 3 meter - run it may be worse? This is news to me.
From a purely interconnect-focused perspective, it shouldn't be any noiser. What we were referring to is from an electrical perspective and a circuit topology perspective. A balanced input stage is normally about 3dB noiser than an unbalanced. Electrically, you are putting the signal through two active devices rather than one, and they are not in parallel but in series and share the signal. Douglas Self has an excellent discussion of this regarding Balanced Line Inputs in his various books. See Small Signal Audio Design, 2nd Ed (2015), chapter 18, p. 489. Quote: "Balanced inputs are noiser than unbalanced inputs by a large margin, in terms of noise generated by the input circuitry rather than external noise. This may appear paradoxical; but it is all too true, and the reasons why will be fully explained in this chapter." He goes through a case study of where an unbalanced-input power amplifier was on the order of -120dB S/N, and adding a traditional 10K input via an op-amp raised the level more than 10dB. By using a number of op-amps in parallel, he was able to get the noise back down to close to the unbalanced figure. By the way, that same chapter makes the distinction between the three main ways in which an interconnection is suseptible to hum and noise, being 1) Electrostatic coupling, 2) Magnetic coupling, 3) Ground voltages. Back in the days of studio DAT (Digital Audio Tape) machines, the Panasonic SV-3700 series (a very popular deck), had ONLY balanced inputs. It used the traditional design where an op-amp debalancing input stage was present (usually with 4560 or 5532 op-amps). A popular modification was to bypass these extra electronics, and wire the + of the XLR to the 'real' input circuit, tying the "-" of the XLR to ground either directly or through a ~300 ohm resistor. We did the same on both the inputs and outputs to our Sony PCM-2600 DAT, itself a predecessor to the PCM-R500 which has both direct unbalanced RCA as well as balanced XLR. Balanced isn't always the best solution. Sometimes in reality, manufacturers are forced to include balanced I/O because giving the full explanation sounds like 'making excuses', and people tend to want "the best" and are willing to pay extra for it. We at Darlington Labs tend to be long-winded and prolific enough (and engineering-driven enough) to attempt full explanations behind our design choices, or at least allow a full understanding of design tradeoffs.
Houston, the Eagle has landed. Thanks to poor tracking updates the MP-7 spent the holiday weekend sitting in a parcel locker at the local post office. Picked it up today, added it to the system, and had the chosen test tunes waiting. I went with music that is by now part of my DNA...Treat from the first Santana for piano, back to Santana Abraxas for Singing Winds, Crying Beasts, Steely Dan Gaucho for Babylon Sisters, and then threw a percussion wildcard in with the Ray Barretto Acid title track. I wish I could play it cool and sound really knowledgeable with audiospeak...but W0w! I am still trying to think of how to explain it, but it comes down to the soundstage, wider and deeper. It really feels like the music can breathe now. And this is day one, 4 songs in, and this will only get better with time. When I closed my eyes I felt like the musicians were in the room playing. This is exactly what I bought the Rega P6 for and now know I don't need to upgrade the cart to get what I was seeking. Keith, thanks again for all the email responses and information provided. You delivered. Mind. Blown.
DLabs trivia time. When people say (with some regularity) "the MP-7 makes it sound like I am in the room with the musicians", first of all, we are deeply, deeply gratified as this was our primary design goal. But sometimes life meets a long-time sonic reference. Members of the Darlington Labs team just returned from a concert this evening where we saw a performer live that produced a disc which has been a reference for 31 years. It underscores the interplay between why many of us are in this business or pursue fine audio as a hobby or for pleasure. This evening, we heard two key tracks live for the first time...a hair-raising top-5 concert in your life experience. The album was "recorded on Mitsubishi X-850 and exclusively with Monster Cable" and likely primarily with API consoles. If gear can sort out this production and mix without exacerbating flaws, we've found the resulting gear to translate well. Don't fret, Harry James Direct-To-Disc LPs from Doug Sax are on constant rotation as well. And, we scored a new 30th anniversary LP pressing of the "huge radio album" that followed our reference disc three years later. It is phenomenal. Perhaps it helped that we listened through a production MP-7 but the sonics of the more-famous release were elevated greatly, especially the bass and soundstaging. Cut from what sounds like the master tape at Stirling's facility in Nashville. Every previous LP (including domestic record club releases and foreign releases) we've found was cut from a 1630 digital tape that produced the original CD, likely through that popular-in-1991-thru 1993-for-CDs-Aphex 700 Dominator tri-band limiter. Kudos to Joe Hutchinson this evening for an extraordinarily fine FOH mix, the smoothest sound we have ever heard from a digital Yahama Rivage PM3 console. Free gear (not kidding) to anyone who can score us a copy of the FOH audio or in-house video or something else decent from this tour. PS. We get the sense that Hoffman himself may also be a fan. A. Theater/Location B. QC Reference LP & Original Mastering Engineer C. 30th Anniversary LP & Reissue Mastering Engineer D. Artist
PRODUCT UPDATE ANNOUNCEMENT: AVAILABILTY OF A SHARP-CUTOFF SUBSONIC FILTER We have developed a fixed custom-slope low-frequency filter that is sonically transparent enough to be left in the circuit at all times, but is intended only for users who need it. We foresee three main scenarios where this could be of potential benefit: 1) Subwoofers with a gain structure optimized for digital sources, 2) Limited turntable acoustic isolation, 3) Moderately-to-substantially-underdamped tonearm/cartridge resonance. We now offer this fixed Subsonic Filter per client request at no cost. It is available for the MM-5, MM-6, and MP-7. As we expect relatively limited interest, buyers can place a regular order via our website and then email us with the order number. Products — Darlington Labs This filter is nominally a 12dB/octave low-cut (‘high-pass’) using a transfer function of our own design. It is optimized to provide good transient response, and minimum excess phase shift, while being musically unobtrusive. Specifications are as follows: 70Hz +0.05dB; 50Hz 0dB; 30Hz -0.5dB; 25Hz -1dB; 20Hz -2dB; 17Hz -3dB; 12Hz -6dB; 10Hz -8dB; 5Hz -19dB. The existing gain elements are used as buffering nodes to eliminate filter section interaction. This means NO additional active gain elements in the circuitry for the best sound quality. The curve is also unaffected by external loading, because the output stage does not contain a section of the filter. It can be deployed in our MM-5, MM-6 and MP-7 at user request and at no additional cost when ordered in a new unit. Current users may contact us for a retrofit quote.
I finally got my MM-5 back a couple weeks ago, I had forgotten Keith had reached out to me to upgrade my unit with a mono switch and a yellow LED. I’m quite happy with the results. They ended up just giving me a whole new unit and I’m impressed with the new faceplate. No more stickers! Looks very high end and like something you’d buy from a large company, not a small independent shop. I’m happy to be listening to my old beater mono records again in true mono, and the sound is definitely an upgrade to the internal preamp of my Yamaha A-S501. The LED even matches the Yamaha’s LED perfectly. Looks like they were made for eachother!
We've been quoted as saying that our current products could have been designed in 1974 (with minor semiconductor changes, and limited to a red or possibly a yellow LED).
Here's my guess: A. Theater/Location: Forest Hills Stadium, Queens, New York B. QC Reference LP & Original Mastering Engineer: Islands, Tony Arnold C. 30th Anniversary LP & Reissue Mastering Engineer: Red, Simon Heyworth D. Artist: King Crimson
