Don Sachs Model 2 Preamp

jdjohn

Just secured this used Don Sachs Model 2 preamp for pickup in a week or two.



Based on the venerable VTA-SP14, info on these units found here: http://www.dsachsconsulting.com/custom line stage.html
The one I'm getting has the volume remote upgrade, upgraded pair of Shuguang Black Treasure CV181-Z tubes, and upgraded Duelund CAST PIO-Cu output capacitors. I may send it in for further upgrades after I play around with it first.

Anyone here familiar with Don Sachs equipment? Looks like he started with Vacuum Tube Audio/Tube4HiFi kits, and then applied his own improvements. His stuff seems to get rave reviews on the interweb.

Faustin

Nice looking pre. Not familiar with his products. I will be interested in what you think once you have a chance to play with it a while. I think my next pre will be one that uses the 6SN7 instead of a 12A series tube.

mhardy6647

Faustin wrote: »

Nice looking pre. Not familiar with his products. I will be interested in what you think once you have a chance to play with it a while. I think my next pre will be one that uses the 6SN7 instead of a 12A series tube.

Or go for the gusto with a single-triode 6SN7 precursor -- 6J5, or maybe even a 56 or a 27

http://vinylsavor.blogspot.com/2014/02/tube-of-month-6sn7.html


They're all good, and good sounding, tubes, if that family has enough "mu" for one's porpoises purposes.

joecoulson

Looks good Jody. Looking forward to your impressions.

Nightfall

Faustin wrote: »

I think my next pre will be one that uses the 6SN7 instead of a 12A series tube.

Why?

jdjohn

Will be interesting for sure. My previous in-home experience with tubes is limited to incorporating an Eastern Electric MiniMax BBA into my system...which may become for sale if things work out well

EDIT: I want to throw a tube-pre hard against a class-D power amp.

joecoulson

Should be a very interesting combo.

pitdogg2

That is very sexy Jody. I like!

jdjohn

My big limitation for testing is a good DAC. I will really be limited to vinyl/analog except for a Logitech SBT, or a CD player.

Faustin

Nightfall wrote: »

Faustin wrote: »

I think my next pre will be one that uses the 6SN7 instead of a 12A series tube.

Why?

To my ears the 6SN7 has a better soundstage and is more musical than the 12A family of tubes. And the price of NOS 6SN7 tubes is not as ridiculous as 12AX7,s and 5751's etc. Side note: I recently bought some nice quality adapters/converters for my Bottlehead 300B monoblocks, to go from the the miniature 9 pin 5670 tube to a 6SN7. With the 6SN7 I have noticed better bass extension and an overall better sound.

msg

jdjohn wrote: »

My big limitation for testing is a good DAC. I will really be limited to vinyl/analog except for a Logitech SBT, or a CD player.

Beautiful looking piece there, Jody. Curious to hear your impressions, as well.

Re: the DAC, I say nothing to worry about in your plan there, since you'll be testing this new piece with other components you already know.

mhardy6647

The 6SN7 is a hifi tube, even though it wasn't designed for hifi. IMO, of course. Only medium-mu, though, so it's not exactly a blanket replacement (functionally, that is) for high-mu twin triodes like a 12AX7 or a 6922.

I am with @Faustin, FWIW -- I am always a little perplexed, amused, and saddened when I see the knee-jerk use of 12AX7 and 6922 in modern hifi designs, especially when said designs aren't phono or tape head preamp/EQs The 6SN7 and 6SL7 (and their kin), by and large, just gots mo' musical soul to me.

Westies closeup by Mark Hardy, on Flickr

EDIT: of course, the crowd I run with are smitten with things like 27s and 56s
(The 27 and the 56 are a bit lower mu, single triode precursors of the 6SN7; you'll see a couple of 'each front and center acting as voltage amps in the photo of Alan's PP 2A3 amp below)

Nightfall

Man, my preamp sucks now too. Will my stereo ever be good enough?!?!

mhardy6647

Nightfall wrote: »

Man, my preamp sucks now too. Will my stereo every be good enough?!?!

why, what's wrong with it?

If it makes you feel any better...

Line level preamps (with gain) are hard IMO -- I haven't (ever) heard very many that I really liked. I've been using a 'passive front end' for years now. I really, truly could use some more oompf driving the Simple 2A3 amp, but I've yet to find an even close-to-affordable preamp that didn't make everything sound just a little more distant.

FWIW, I thought the Tubes4HiFi(?)/Vacuum Tube Audio SP14 6SN7 preamp wasn't bad at all when I played with one. Price is fairly reasonable, too (last time I looked). This one was tarted up a bit

DSC_7135 (2) by Mark Hardy, on Flickr

Nightfall

mhardy6647 wrote: »

why, what's wrong with it?

It's got 12AX7 and 12AT7's in it.

mhardy6647

well... 12AT7 isn't so bad, at least


paramours 112413 by Mark Hardy, on Flickr

Faustin

I have an interesting story about my pre and the 12a family of tubes. I do not want to highjack this thread, so I will start another one. Somewhere, someplace. Maybe. Anyway, I still want to hear some thoughts and impressions in regards to the Don Sachs pre.

jdjohn

I picked this up a few days ago, and the sound is promising...probably needs some fresh tubes. The unit is 3+yrs old, and the tubes are still stock, so probably showing some age. I don't know how many hours the previous owner put on them. I did notice (after proper warmup) a little random static every few minutes. The noise only lasts a few seconds, and isn't especially loud. Again, it is only every few minutes (like it's cycling), and I can only hear it at idle (i.e., no input, volume at zero); it's probably not even audible with music playing. I emailed Don Sachs about it, and he highly suspects it is a tube, or tubes. I'll try to narrow it down.

Except for that random noise, this seems to be a very quiet tube pre-amp. My initial listening has been through a PSA SG S300 Class-D power amp, which is very revealing. Considering this, and that it is still this quiet, it's kind of impressive IMO.

As I mentioned before, my tube experience is quite limited. My listening impressions are that it sounds...tubey It is SO different than what I'm used to with SS, and especially class-D, I'm still processing it all. The WAF is high, as she was immediately impressed with the harmonics. We both agreed that a rug is needed in front of the speakers since the floor is hardwood, and the room is pretty lively. To me, the tubes add a faux room acoustic, which can be a bit overwhelming in a 'hot' room.

Generally, I found the tube 'kiss' sounded good with digital formats, but *might* be a little much with vinyl. Microphonics could be coming into play here with the cartridge, so I'm trying to be realistic in expectations.

I'll need to chase-down that random static and see if replacement tubes are necessary before I do more serious listening and provide more impressions.

BTW, Don Sachs is consistently suggesting the use of CV181 tubes instead of 6SN7...just sayin'.

marvda1

try rca vt-231

jdjohn

msg wrote: »

jdjohn wrote: »

My big limitation for testing is a good DAC. I will really be limited to vinyl/analog except for a Logitech SBT, or a CD player.

Beautiful looking piece there, Jody. Curious to hear your impressions, as well.

Re: the DAC, I say nothing to worry about in your plan there, since you'll be testing this new piece with other components you already know.

I have to say, Scott, this preamp really does justice to the lowly SBT DAC analog output. FLAC files on the microSD card, in particular, are fantastic. I can only imagine how a better DAC will sound.

I'm currently still chasing down a complement of tubes to suit me. I'm finding that "matched tubes" is a relative term for sellers.

I am generally digging the sound of this preamp into the PSA class-D, but tubes are high maintenance to be sure.

jdjohn

As nice as it is, I think I will be trying to move this pre-amp on in the near future. I just don't think I'm a tube guy.