Don Sach's pre amp

Pesky wabbit I agree with you that credit should be given to John Broskie for the buffer stage in the sp14 and the Don Sachs preamp.

I am aware of him crediting the SP-14, but someone with his knowledge of electronics would also be acutely aware that circuit is a straight copy of an Aikido. Given that this topology is well known, has been published in great detail, and has a name and an owner who supplies pc boards and kits for its construction I think it is rather disingenuous of him not to recognise it as such. By crediting the SP-14 as the inspiration for his circuit he sidesteps the issue completely

Pesky_Rabbit,

From a derivative stand point, Don Sachs has acknowledged that the inspiration for his preamp came from Roy Mottram's SP-14 preamp. Indeed, Roy mentions Don in his website so their relationship is very solid.  http://www.tubes4hifi.com/SP14.ht   Frankly, 90% of front end gear is a derivative design from earlier designs.

Don currently is a devotee of these 6SN7 tubes: Linlai E-6sn7 tubes.  I just ordered a quad of them. The quad cost ~$375 plus $55 for shipping from China.  

 

for the record the circuit used in the SP-14 is a direct copy of John Broskie‘s Aikido as published in the Tubecad Journal. This circuit has since been used by Don Allen. No credit has been given to Mr Broskie for using his design by either constructor.

Maybe ask Don Sachs if he's tried them?

Has anyone tried Grant Fidelity's Treasure Globe 6SN7-SE?

Also, just checked my pre's height and it looks to be under 8" tall with tubes (and some vibration control).  A little hard to check inside the cabinet.

@highstream Wish I could comment more about preamp options, but the DS pre is my first. Prior had run DAC direct from the PWD and DSD. Like you said, adding in a preamp is really a huge improvement. Counterintuitive as it may be. My reading did convince me that any relatively simple preamp circuit either based on 6SN7s or DHTs would be optimum. I suspect many of the simple 6SN7 pres (Supratek, the DS kit, deHavilland, etc.) would all be excellent and more similar than different.

Thanks, cal. Lots of variables. You’ve obviously put in a lot of work and money to find what works for you. I’ve been sticking to the easy changes, such as rolling tubes in the Lampi. I had a bad experience with the sale of my DSD, so I’ve got it back and am listening now with a PrimaLuna Dialogue preamp that came with old Mullards, while I await the return of my Lampi and think about whether or not to ditch the PL for something better. People -- developers and users -- were correct that although counterintuitive, sticking a good preamp between dac and active speakers, i.e., amp, improves the sound. Finding the right preamp for one’s tastes and budget is the trick.

Also, do note that input impedance to Don (or any other manufacturer). If the preamp design uses output capacitors you'll need 8uf caps to prevent any low frequency rolloff (https://www.v-cap.com/coupling-capacitor-calculator.php).  That'll limit your boutique cap choices unless you've got no budgetary constraints. If you were to buy the miflex copper caps yourself, it'd be $500 at partsconnexion... And they're huge, maybe too big to fit. 

I'm sure Don will have some options for you however. The mundorfs are smaller and cheaper. 

Can't answer all of your questions, but I'd say the DS pre is a touch on the warm side of neutral. A little tough to say because so much will depend on what tubes and output capacitors you have on it.

With the cv-181s and miflex copper caps, I found it pretty "modern" sounding. Extended and detailed. I liked it and definitely found that it improved the sound of whatever dac I fed it (ps audio perfect wave dac -> directstream dac -> audio mirror tubadour III se). 

I did eventually settle on vintage tubes (40s/50s rca grey glass vt231s and Sylvania Jan's) however. I lose a little extension with them, but gain refinement, tonality, and imaging. 

I also tried out a variety of output capacitors. The miflex had good tone, but were very 2 dimensional in my system. Mundorf Supremes added depth to the imaging, mundorf Supremes silver/gold in oil added even more depth and refinement but took away some bass, and v-cap tftf were too cold (tonally) for my system. I have some duelund tinned copper cast on the way.

All of these variables definitely change the sound, which I like to attribute to a quality, revealing circuit.  Does make it a little hard to nail down the pre's sound for a new buyer though.  

The pre does come with a remote by default. The newest modification gives you both volume and input switching but loses balance control. If you need balance control (not available on the remote) then you only get remote volume and muting. 

Final caveat, as always, these impressions are likely very system dependent. I need to update my dac description, but you can see the details on my system page.

If anyone is still around...

Giving a lot of thought to Don’s preamp. But do have some questions before I call him:

- Tonally: "neutral" or some degree of warmth (short of classical tube sound)? I don’t like what most people call neutral, which I find cool and uninvolving once the marvel at PRAT passes.

- I have a Lampi Atlantic TRP dac, which with some tube rolling I find much better than the very good DirectStream -- except that I have active ATC speakers that are balanced (10K impedance) and one set of my Lampi’s outputs are faux-XLR, i.e., unbalanced. I’ve had some mismatch problem running from those directly to the ATC’s in terms of hum/buzz. We’re working on that now. But if I add the Sachs preamp in between with its unbalanced outputs, should I expect to face the same problem?

- Is a remote standard?

- What does the preamp weigh? How tall is it with tubes?

thanks,

Guys,

I received my modified DS2 last week with Don’s latest Polish made Deulund copy oil caps and 6BY5 rectifier and it sounds amazing! I am hearing more transparency, better sound staging and imaging, more depth, lower floor noise, more air/ambiance. Bass is tighter, midrange is purer/more organic but you are going to be knocked over by its ”HOLOGRAPHIC” presentation; sounds emanating beyond the boundaries of my loudspeakers…

It is astonishing how you are immersed into the music with Don’s DS2 Tube Pre; his original DS2 is Amazing but the updated version is “UNBELIEVABLE”! For those of you who are in the market for a new pre-amp, I highly recommend that you put this pre on your short list. If you already own one of Don’s creations, get this updated version done ASAP!

I am not aware of any mods that can radically change the sound of a system for a very small investment. Act now and get your units in or orders placed soon… 

Wig :)

Hi all,
I have modified the preamp to take a 6BY5 rectifier because it sounds better and you can source 6BY5 tubes for $12 or less. If you own one of my preamps and pay the return shipping I will modify it for you and provide a 6BY5 tube for $75.   If you own an SP14 kit or any other version of this preamp, please DO NOT JUST PLUG A 6BY5 TUBE INTO YOUR PREAMP AS YOU WILL DAMAGE IT AND IT WILL NOT WORK!   This modification is something I developed for my customers only. I will NOT share the details and I will NOT modify any preamp that I did not build. Sorry, but this is what sets my gear apart from the kit versions.  I have gotten notes from a few people who have built the kit version and asked for the recipe.  No, sorry, but I do not share any of my mods.

rlb61,
We will await your comparison of Don's latest preamp to your BAT preamp, which even at pretty much twice the cost of Don's preamp, will be worthy comparison.  There is magic in his 6SN7 tubes!  I had a pair of Joseph Audio RM25XL speakers that for some odd reason I parted with, selling the to Don Sachs, actually.  

I heard the Pulsar's at an audio show powered by a Rogers tube amp and the bass response simply defied belief... similar in performance to the Dynaudio C1's, but with better LF response.

Asghar,
The upgrade of Don's new caps and the rewiring of the preamp to accommodate the more potent 6BY5 rectifiers is something your system would benefit from... it is an easy 10-15% improvement... the instruments much greater spatial definition.  I will be in touch with you after Don's tube amp is run in properly.  We will have fun comparing it to your fine Quicksilver mono block amps.  :-)

@gryphongryph ... thanks.

Thanks! Nice system you have there.

@gryphongryph ... I'm using Joseph Audio Pulsars and a Musical Fidelity A300cr amp (dual mono, 225 wpc).

@whitestix,.. Congratulations I already have the Dueland wiring and Jupiter caps , Don upgraded  my pre-amp last year so I will wait to get his new uprades !  this is one Unit that will stay in my system others may come and go , I am looking forward to listening to your KT-88 Kooteney , as I have been considering get one for a long time !

rib61 - looking forward to hear your impressions of the pre amp, can I ask what ss amp you are using and what speakers?
Thanks !

@whitestix  ... this is good news, indeed. I recently ordered a fully tricked-out Model 2 from Don with larger caps to drive my low impedance SS power amp and subwoofer. Had to get the black case because the larger caps won't fit in the wood case. Nonetheless, I am really excited about it, and am eager to hear the difference between the Model 2 and my beloved BAT VK-3i preamp, which I've used for the last 16 years. Hopefully, the Model 2 will be a huge upgrade. Thanks for the mini-review.

Don Sachs has relentlessly fashioned tweaks to his preamp since its creation, two of which I have had including an upgrade from Mundorf Silver Oil caps to Jupiter caps in the past which was marvelous.  I sent the preamp back a couple of weeks ago for three new upgrades:  one allows a more potent rectifier; another involved all internal Dueland wiring; and finally and most importantly, the substitution of sonically  equivalent caps to the extremely pricey but excellent Dueland output caps.  

I got the upgraded preamp back a few days ago and the upgrades are just astonishing and are likely not fully run in yet.  There is more pinpoint accuracy to the instruments in a wider soundstage and bit more hefty and control in the LF response.  Tons of air around the instruments, even more holographic than before.  Easily a 15% improvement overall, if I had put a number on it.  The cost of the upgrades was very reasonable, indeed, in comparison to the sonic improvement I am hearing. 

For around $2700, this is simply the finest preamp -- tube or solid state, that I have ever had in my system and I have had lots of them before I got this preamp 4 years ago, several significantly more costly.  If you are an owner of an earlier version of that which he currently sells, the upgrade to the new caps and the wiring modification in order to use the more robust 6BY5 rectifier is a very efficacious investment.  

In a weeks' time, I will receive his bespoke KT88-based amplifier to complete the front end of my system.   I heard the amp in my system recently and it was sonically far more three-dimensional than my wonderful Platinum-upgraded McCormack DNA .05 solid state amp.  Don's amp has all the control in the LF range and simply throws an expansive 3-D soundstage which is incomparable to the McCormack.  Tonally, they are quite similar, but the soundstage with Don's amp is vastly more realistic... the music just seems to float in the air.  

I'm considering the Sach's Custom preamp. I love the use of 6SN7's in the gain stage. The one thing I'm wondering is the use of a cathode-follower is like a double-edged sword; low noise and distortion, but this design usually has a modern tube sound; extended highs and a lack of warmth.
I like transparency and open sonics, but I've owned preamps that sounded similar to solid state. I don't like the dark "syrup" tube sound, but want a preamp that presents tube bloom.

Any comments on this by Sachs owners? I'm using an EL34 push-pull amp.

@porscheracer, , I just purchased a new PS audio Directstream DAC I do own a Schiit Gungnir ( which I use with my LCD-X and Audeze Deckard Amplifier, But PS Audio Directstream just blew  me away with the DS-2 , when I purchased it  I thought i'd use for 30 days and send it back  than may be try to get a Lampizator DAC, but the sound quality to my ears is so pleasing with this DAC that I changed my mind and decided to keep it . the DAC also can be used as pre-amp directly into the power power amp. The sound quality is pretty close, with DS stream having slightly bigger soundstage 

I ordered a pair of the Shuguang Black Treasure CV181z tubes to try out with the DS-2. The DS-2 needs over 100 hours of burn-in time for the capacitors chosen for the build anyway....so I will use them for the burn-in and see how they sound compared to my current 6SN7 favorite, the Raytheon VT-231 with 8 copper rods and flat black plates.

Those tubes will sound good after 50 hours but will need 200+ hours to fully burn-in. Looking forward on receiving my D2 and Kootenay 120 KT 88 Amp.

Wig

I tried them in a preamp and they didn't sound great.....I guess I will see as I have a paired ordered with my Don Sachs preamp.

@ porscheracer

It's all circuit dependent and my NOS tubes smoked the CV-181Z in my Line Magnetic SET Integrated Amp. A good thing for us is that we do not have to go out and procure these treasures, just choose the ones that best represents our listening pleasure.

The CV-181Z are quite special if used in the right circuit and this has been talked about by some serious tubes critics over the years.

http://www.tnt-audio.com/accessories/shuguang_treasures_cv181_e.html

Wig

@wig 

In my tests, the NOS tubes walked all over the CV 181-Z. If these tubes were as great as you say, the NOS 6SN7 market would dry up in a New York minute....

Since the website does not list specs, I have a question. Is Don's preamp using cathode-followers for the 6SN7 gain stage?

Also, if this is a single gain stage, is it sensitive to microphonic tubes? I assume you are all testing for low- noise?

I have the same selection of NOS to include WGTB and RCA 5692 and in a previous Modwright Sony 5400 CD Player which utilizes 6SN7s, the CV 181-Z walked all over my NOS tubes; not even close...

Wig

@a-shah,

I find that Yggdrasil sounds just a bit better through its XLR output. It's not a huge difference, but it is there. So I have ordered my DS 2 line stage with an XLR input. I will compare XLR and RCA in to see how the DS 2 sounds best in the chain.

Of the top of my head, I have these tubes:

Raytheon VT-231 (flat plates with 8 copper rods)
Ken-Rad VT-231 (both black and clear glass)
RCA VT-231 (grey glass)
Sylvania 6SN7W
Sylvania VT-231
Sylvania 6SN7GT (Bad Boys)
Sylvania 6SN7GTA

I have some more that I can't remember. I am on vacation and don't have access to my list.

I have tried the CV 181-z tubes in the past and found most of the above tubes to be better. I ordered a set with the DS 2 and will try them with that line stage.

Thanks for the update on Bendix. I'm partial to Tung-Sol but may order one to evaluate. Anyone have a reliable source?

Thanks,
Wig

Problem with XLR on DS 2 is that the whole chain needs to be balanced, although I am using it with Zu mission XLR  cables and Gungnir DAC, the rest of the chain is single ended,
So I find the SQ  of XLR  for my ears to be  comparable  to RCA's.
 XLR maybe good for long runs or if you have ground loop or hum  but for short runs it is insignificant !

Yes Bendix 5852 is just fine  !  DS 2 has 6 volt rails, I picked up 2 pairs from Ebay , very inexpensive  the seller claims that they are tested on Hickok 6000 tester although one of them turned out to be micro-phonic the rest are good this rectifier "does improve the sound of Pre-amp." which is noticeable.
You should get a quad of CV 181-z , but if you already have 20 matched pairs of WWII era 6SN7 you should try them out
could you list the 6SN7 that you have ? thanks !

Already done. The Bendix 5852 is fine in the Don Sachs line stage. It does take 30 seconds or so longer to warm up so you should turn the line stage on about a minute before the amp.

I would verify with Don before purchasing the Bendix; was informed when I bought a Lampizator Dac that the Bendix pulled twice the amount current than the standard 6X5GT.

Wig

@a_shah,

Mine will be walnut as well.

What rectifier tube have you been running? I am going to get a NOS Bendix 5852 to try.

For the 6SN7 tubes, Don is real high on the CV181z tubes so I am getting a matched pair of those from him to try. I have about 20 matched pairs of some real nice WWII era 6SN7 tubes I will be trying as well.

The  unit I purchased  is in a Walnut case , has both the XLR & the Tape Monitor,and 4 RCA  Yes that is what Don has recommended AudioCap thetas bypassed by Russian Teflon caps, but  Jupiters stay in,  I just get an extra 3.3 uf caps. for my 2nd output ! and new wiring on board & some inputs.

@a_shah,

I am confident I am getting all the best stuff. I was just curious if you thought of something I did not. I am not getting a tape monitor switch or inputs/outputs. I am getting one set of XLR inputs. The output caps are 2uf for my Pioneer M-22 SS amp. Don wants me to use AudioCap Thetas bypassed by Russian Teflon caps. He says these take 100 hours of burn-in to sound right and he likes them better than Jupiters and as well or better than the Dueland when they do.

I hope he finishes it early because I can't wait to get it and burn it in!

@porscheracer.   Best you talk to Don about it , in my case since I had purchased it from a AudioCircle member the unit was a year old  although it had all the Bells & whistles.  Don  recommended, that he could upgrade the power supply caps to better ones that he uses now and extra  output 3.3 uf Capacitors for my Odyssey SS (to get better bass) amplifier and change some of the board and input wiring to Dueland & Neotech to bring the unit up to date with his latest thinking , for me it was cost effective to do that , So I decided to go for it , in your case you probably will have his current Standard for the unit.
I can tell you one thing you wont regret it , I just love the unit !

What upgrades are you getting done and why? 

I still have time to make changes to my order so I would like to hear what you are thinking!

@porscheracer
Congrats ! you will like it , the pre-amp continues to delight me ! very happy with it , will be sending it back to Don for Certain upgrades , but even without those upgrades it sounds wonderful with my SS Amplifier

porscheracer,

Smart move!  Don's KT88 just arrived but I still have 4-6 weeks left for my preamp to be built.  Everyone I've spoken with that owns his equipment raves about the sound.  Speaking with Don sealed the deal for me.  

Congrats!

I ordered a Don Sachs preamp!

I am using a Schiit Yggdrasil DAC and love it. I have a Schiit Vidar amp but it does not measure up to the Pioneer M-22 so I am selling it. I just need a "reference" preamp and I think I am done playing with components and I can concentrate on listening to music instead of components!

Don himself using Schiit Gungnir upgraded to multibit, I have a delta sigma Gungnir  DAC  but use that with my Audeze headphone setup (audeze deckard and LCD 2), do not use DAC with the main system

Hi folks,

I have narrowed down my tube preamp choices to the Don Sachs Model 2 and the deHavilland UltraVerve 3. Does anyone have any comparative information regarding these two preamps?

I have heard great things about both. My speakers are 98dB efficient and I am using a Pioneer M-22 30 wpc all Class A power solid state amp. I am currently using a Schiit Audio Freya preamp which is fine but I am looking for fantastic! I know the DS Model 2 has enough gain. I don't know the UltraVerve 3 gain number.

Any feedback is appreciated! 

Hi all - wondering what DAC you are using with the DS2 SP-14 (if any), and if one DAC sounds better than the other in your demoing. I recently upgraded to Triton Reference speakers and am backfilling to upgrade other parts of the system now since the speakers sound so good. Considering doing a Sachs pre-amp with bells and whistles (remote especially), paired with a Sachs KT88, but I will need a DAC in there too as will likely stream Tidal MQA (maybe via a Bluenode 2?). Thoughts? Thanks for posting your opinions here and on other threads about the Sachs products, it has been valuable.

Also - is the remote control on the newer Sachs preamps something that can be programmed into Harmony etc? (maybe with the learning option?)

kalail, I suspect Don is too busy to have time for much internet posting.  I think it is a one-man operation, other than building the cases.  So I'll share what I believe to be the development.

First off he has a long-standing reputation for restoring and upgrading classic tube gear such as HK Citation, McIntosh, Marantz, etc.  Somehow he had the opportunity to examine the circuit for the VTA-SP14 and was impressed by the potential.  But he felt it could be improved by selective parts upgrades.  So he ordered the board and built one to test.  Being satisfied with the initial results he then refined that and began offering his own version, with the blessing of VTA.  After all, they reference Don's version on their own site.

Since then it has been word-of-mouth promotion.  That's how I learned about it and I couldn't be more pleased with my DS2 SP-14.