I too own the DS2 and it’s met all my expectations and more. Dealing with Don has been a real experience. I owned the SP14 with a lot of upgrades, but had a damn ground hum in the left channel that I couldn’t exercise for anything. It was driving me nuts.. I called Don to see if could maybe shed some light on it, and he had me send it in. I think it took him less than 10 min to ID it and fix it.. while he had it open, he squared it away with Duelund wire Mundorf silver oil caps, Black Treasure tubes, 6BY5 Rectifier Mod. I got it back and was blown way. So much that I bought the DS2 for my 2nd listening room. Again, blown away.. sound stage wide and bowling alley deep. As good if not bettter than my Citation that was twice the price. .. Both were enjoyed driving my Cary 200.2 Power amp. Ultimately, The one he squared away drives my Cary Audio SA-200.2 SS Amp and it’s just killer. The DS2 is slated to drive Don’s KT88 stereo tube amp.. I can’t wait. Don also has freely answered all of my questions, when her didn’t have to do anything more than tell me to “send it in, I’ll get ‘er done” I can’t recommend this dude and his Audio Works enough. https://i1007.photobucket.com/albums/af194/adlerburg1/0FD31DBD-EF63-4B92-9B07-7545F88AE98E_zpsigwapgwa.jpeg
I took delivery of the DS yesterday. Initial impressions ... more height and width to soundstage, more air around instruments and voices, lots of micro- detail, and more [email protected] to my system. No doubt, the "[email protected]" part (in terms of slam and impact) comes from the large output caps running my low impedance power amp and sub. Only have about 6 hours on the preamp, but I like what I hear so far. DS says the unit really opens up after about 50 hours, so we shall see. It's very different from the BAT, but I will not be in a hurry to sell the BAT, if at all. Evaluation periods can take some time.
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…
This thread made me visit Don's page again and I have to say it looks like beautiful workmanship for the money, and the general consensus is that it sounds great. But what really impressed me is if you own an older component of his and want it with current revisions, the price is more than reasonable. $75 for a rectifyer upgrade including tube? That's a bargain. Pay for only parts after warranty is up? You don't see that too often....I like his straightforward no BS attitude too. If I were in the market for a new tube pre or amp I would give him serious consideration.
Don Sachs here..
Tube life.. well it depends. All tubes in every piece I build are run very conservatively and not pushed at all. You should easily get many thousands of hours out of the 6SN7 types. The KT88 in the power amp should go 2000+ hours. The old American and Russian 6SN7 types will last a LONG time. The modern Russian and Chinese tubes.. well it depends. If you get a good pair, then they also go on forever, but some of the Chinese ones will get noisy. If you get 100-200 hours on a modern CV181 and they remain quiet, then they should go many years. Most problems seem to crop up in the first 100 hours. I play every tube set for 5-10 hours. If you get a noisy tube in the first 90 days, then of course I will replace it. To my ears in my system with my gear, the best sounding tubes are the Shuguang Black Treasure series. Even better than my Tungsol round plates, Sylvania bad boys, National Union black glass, etc... They have about a 5-10% failure rate in that they are noisy. So you just have to weed out the noisy ones, then they seem to last as long as any other tubes. The Shuguang Black Treasure CV181-T is about as good as it gets in my preamp and amp.
One other point. If you spend big dollars chasing down NOS or lightly used old tubes, you will find that a high percentage of them are noisy as well unless you buy them from a vendor who tests for noise. If you just get some off ebay that were tested on a regular tube tester they will work, but many will be noisy. Caveat emptor....