AudioNervosa

Systemic Development => Amplification and Preamplification => Tubes => Topic started by: mresseguie on August 10, 2016, 11:07:44 PM

Title: Don Sachs Tube Preamp and Amplifier
Post by: mresseguie on August 10, 2016, 11:07:44 PM
Hello. This is a preliminary presentation of my impression from my visit to Don's home in Nelson, BC today.

Now why is it preliminary and not a full blown review? Well, thanks for asking. It's not going to be full blown until I get my new preamp into my system with my own speakers. You understand, I'm sure.

Don invited me into his home so I could get a really good idea of what my new preamp will sound like. You see, I ordered one about 10 days ago, and I was eager to know what my money had gotten me. Mine is only a little different (better) from today's preamp.

His system is such:
Source: Laptop with JRiver
DAC:     Schiit Gungnir
D Sachs Model 2 preamp
D Sachs KT88 amp
Joseph Audio RM25XL speakers

Everything is his system was new to me today. I had never heard these speakers before, and never heard the Schiit DAC, etc. Therefore, all I can tell you is how this system sounded. I cannot tell you what impact the amp and preamp had on the sound nor can I tell you how the speakers impacted my experience.

With that out of the way...

I got to hear some mighty nice live sounding - you are there - kind of music today. The instruments, the singers, the audience (in live recordings), etc. were so real sounding that I nearly pinched myself to see if I was dreaming. The sound stage was huge - at least 8' tall and wider than the speakers which must have been about 7  or 8 feet apart. There was depth as well.

Don played songs that he loves and songs that I love. They all sounded fantastic. The clarity was incredible and even after 4 hours I felt no fatigue.

What did I notice? I didn't hear that syrupy warm sound that I expect to hear from lower grade tube gear. I felt as though I were standing at an open window 10 feet from the musicians. The bass was tight and not soft or sloppy. His amp/preamp will play down to 20Hz because he uses really good power supplies.
[Edit] Acoustic instruments were very defined and clear. There was never any feeling of sluggishness or of muffling of voices, guitar, piano, drums, etc.

Don explained to me his amp/preamp design so much and in such detail that a good third of the information passed right over my bald head. He really knows his shit.

I can't wait to get my new preamp into my system in Oregon, and then, into my system in Taiwan.

Okay. This was a bit scattered, but I think you get it. I'll follow up in a few weeks once I'm back home and can set up my system for a thorough listen.

Michael


Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: richidoo on August 11, 2016, 07:15:12 AM
Michael, thanks for the pre-review! I've been watching the thread on AC and thinking about these pieces for myself. Looking forward to reading your impressions of your own SP14.

As I understand it the SP14 preamp circuit is designed by Roy Mottram, owner of tubes4hifi.com:
http://www.tubes4hifi.com/SP14.htm
Finished preamp  for $1300: http://www.tubes4hifi.com/pre12.htm#SP14
Kits for $240 - $950:
http://www.tubes4hifi.com/pre11.htm#SP14

Ultra-fi version custom built by Don Sachs: $1600+
http://www.tubes4hifi.com/don.htm
http://www.dsachsconsulting.com/custom%20line%20stage.html


I think Don's amplifiers are his own design?

Do you know who designed the amps they sell at tubes4hifi, like M125 monoblocks?
http://www.tubes4hifi.com/bob.htm#M125

Thanks!
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: mresseguie on August 11, 2016, 08:49:26 AM
Hi, Rich.

The SP14 was developed by Roy. Don has taken the original design and tweaked it in several places to create the D Sachs Model 2. I guess I'd call the Model 2 an evolutionary development/improvement/redesign(?).

If I recall everything I was told, the Model 2 has a thicker top plate, beefier toroidal transformer capable of producing music down to <20Hz, higher quality resistors, higher quality caps, better wiring, better quality XLR connections, better sounding tubes, and nice looking wood case.

Additionally, customers can customize their preamps by choosing from different brands of tube caps, power caps, balanced or not, etc.

I struggled with deciding which value caps to get to match what sort of amplifier - .33uF is standard, but .47uF to 1uF sizes can be selected. I say I struggled because I'm still not entirely certain which SS amp I want to have in Taiwan. I finally decided to go with .47uF as it will drive many SS and cost just $20 more than the .33uF caps. I selected Jupiter caps by the way. I decided that I just don't need the very expensive Deuland caps.

After spending four hours with Don, I came to the conclusion that he loves to tweak preamps and amplifiers. He took Roy's already good design and created a work of art. I told him he is undercharging for his work, but he is hesitant to charge more. He mentioned marketability and price points. Perhaps, once his preamps become better known, he may raise prices a bit.

When I get this to Taiwan, I'm going to take it to a couple guys I met last time. They are tube-heads and have great systems. As far as Don knows, my Model 2 will be the first one in Taiwan.   8)
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: mresseguie on August 11, 2016, 08:57:00 AM
Nick B posted in another thread, "Michael,
Sorry to be off topic, but I just ordered a custom phono pre from Don Sachs.  Tell him I said hello. I researched quite a bit and I know it's a gamble of sorts, but I have a hunch it will be excellent
Nick
"

Hi, Nick.

I figured it would be more appropriate to start an entirely new thread rather than answering in Don's WTB thread.

I can't tell you much about Don's phono pre. It wasn't in the room, and we listened to digital only. He did mention it, but I really don't recall what he said other than that it is excellent sounding.

I'd love to hear what you have to say about it once it is broken in.

Michael
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: mresseguie on August 11, 2016, 09:31:57 AM
A couple thoughts:

Now I find myself intensely curious about Joseph Audio speakers and about similar speakers. By similar, I mean MTM-like designs.

Five weeks ago I got to hear Prana Fidelity Fifty90 (and his Vayu/fs) speakers in Steven Norber's home. Steven insists they are not MTM btw. I came away from that experience really excited. That system was powered by SS amp/preamp. I can't help but wonder how the Fifty/90s might sound with Don's gear. The Prana Fidelity amp/preamp sell for ~$15k yet Don's amp/preamp sell for under $5000. I'll never know for sure, but I think they may be similar in clarity and oomph. [Yes. Oomph is an audiophile word.]

Interestingly, Steven was every bit as certain that SS gear was best just as Don was certain that tube gear is best. I'll stay out of that argument. Anyway, I'd love to someday hear the Fifty/90s powered by Don's gear.
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: Nick B on August 11, 2016, 09:41:37 AM
Hi Michael,
I expect to get the phono in mid September and ready for the audio club meeting at my home. I'll definitely let you know what my impressions are and I hope you'll report on Don's preamp as well
Nick
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: richidoo on August 11, 2016, 10:25:24 AM
Thanks Michael. I wrote to Roy to ask about M125, he said he designed the driver board, same as used in his Dynaco MK3 monoblock amp, and Bob put together the parallel push pull output stage and specified the kit parts and designed the chassis. Pretty nice looking kit. I'd want to learn the quality of the OPT.

Iirc you did not order a remote volume control for your SP14 preamp? Is there a remote option available from Don?


I was impressed by the Joseph Audio Pulsars when I heard them at CAF a few years ago. I remember thinking to myself, "I could live with these." Then he told me how much they cost. :roll: Brace yourself if you haven't seen the pricelist yet. ;)  But they do sound good. A local Pulsar owner said he liked the sound of my Kairos better, fwiw, but I think I remember the Pulsar having cleaner bass.
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: mresseguie on August 11, 2016, 12:03:11 PM
Rich,

Used RM25XL speakers (when available) can be had for less than $2k.  :)

I did order the Khozmo remote. Practically the only upgrade I did not get were the Deuland caps. I'll also buy one of Don's $109 power cords.  :thumb:
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: richidoo on August 11, 2016, 12:56:33 PM
Cool and cooler  8)
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: etcarroll on August 13, 2016, 06:19:19 AM
Michael -

Keep the info coming, I may have a preamp change coming in the future, so interested in your results.

Gene
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: mresseguie on August 13, 2016, 11:13:55 AM
Assuming all the parts of my preamp build come together before I leave Nelson, BC (where Don lives), I will take my shiny clean preamp to Kelowna, BC to hand off to Captainhemo (Jay). You may know him from the GR Research circle on AC.

Jay's got Gary Dodd's personal preamp, so I'll get to see/hear how mine stacks up to that.

Expect a report (from me) on the preamp paired with Jay's system by August 26th at the latest. I'll ask Jay to post his impressions over on AC when he has free time.
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: mresseguie on August 22, 2016, 09:41:33 PM
A little update:

I spent 2+ hours listening to Don's system with my new preamp this afternoon. Even though the tubes were not optimal (according to Don), and my preamp had played for a scant few hours, it sounded absolutely wonderful to me. I can only dream about how it will sound once it is fully broken in. String plucks, violins, snare drums, brushes on cymbals, piano, voices....incredible clarity yet not the least bright or artificial sounding.

After listening to my preamp with his KT-88 amp for 45 minutes, we switched out to my Nuprime IDA-8 100W Class D integrated amp/DAC. Holy shit. What a difference! The Nuprime is great for non-critical, background listening, or even for 2-channel TV sound. However, compared to Don's amp/preamp combination, the IDA-8 sounds flat, 2 dimensional, even tinny. Of course, I never expected much more from the Nuprime. After all, I got it for under $1000. No way can it compete against $5000+ in tube gear.

Now I can barely wait till I get back home to hook up my AVA 400R, Gustard X20u, my Adelphos speakers, and my Rythmik subwoofer....Just 10 more days....
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: richidoo on August 23, 2016, 06:57:24 AM
Thanks for the update Michael. Keep them coming. I'm very interested in getting his pre and amp for my next system. Nice that you were able to visit with him twice this year.
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: Nick B on August 23, 2016, 07:24:27 AM
Appreciate the updates, Michael.
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: mresseguie on September 04, 2016, 12:43:24 AM
I'm back in my (nearly empty) home again after being away for one year. I set up my system last night using my AVA 400R amp, AVA T8 preamp, Gustard X20u DAC fed by my Mac Mini playing my ripped CDs. [I deliberately used my T8 to reacquaint myself with its sound.]

My system sounded really nice after not hearing it for so long. I played mostly familiar songs, did some toe tapping, and repositioned my speakers a couple times. My listening room is our living room/dining room. It's approximately 14' X 29' X 8.5'h. The Adelphos speakers are on the short wall about 6' from the front wall. There is no furniture and no acoustic treatments in the room except for curtains on the front windows and carpeting on the floor. This is the best listening room in the house.

The speakers sound amazing when they are this far into the room. They are only six feet apart right now, but I'll likely pull them further apart tomorrow.

This morning I ran the T8 for about 90 minutes before replacing it with my new D Sachs preamp.

Now you want me to say something, huh? How about  :drool:.....or  :clap:....or I could bitch about how it took me a solid three and a half years to come around to the idea that a preamp can make this big a difference in my music enjoyment.

Yes. I am very much enjoying my new preamp. It's still breaking in. There was a song on just before I began typing this that sounded odd. It was "A Rose Among Thorns". I don't know who sings it - female though. For most of that song it sounded as though I had crammed everything into the boys locker room's bathroom in my high school. Yup. It sucked. Then, it was gone by the beginning of the next song. I assume it was the Jupiter caps breaking in since I have read many times that caps go through stages during their break in. In any event, once the CD had finished, I played the song once more and the locker room is gone. Weird stuff.

I'm floored by vocals, by piano, by how quiet the background is, by strings, by how loud I can play (but don't because it would hurt). I can't wait to retrieve my Rythmik F12G sub from Alan (Aldcol on AC) so that I can experience a full range of sounds.

And this on what Don calls 'sub-par' tubes! I'll get the best quality replacement tubes in about 3 weeks.  :duh Who am I to question?

more in coming days....
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: richidoo on September 04, 2016, 07:26:10 AM
Great!! Congrats Michael! Welcome home.
Are the "good tubes" the Treasure CV181?
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: mresseguie on September 04, 2016, 08:40:47 AM
Rich,

Both the good and 'bad' tubes are the CV181. Don had sent out a newly finished preamp with matched tubes just days before mine was ready. He didn't have other matched sets sitting around, so he sold me two good, and two used tubes that were sitting in a drawer. These two used tubes are the ones he referred to as subpar. As soon as he receives new tubes, he will mail the new tubes to me. He said that one of my tubes is slightly microphonic, but I'll be damned if I can hear it. I think Jay didn't notice it either.

His sales volume is low enough that he typically buys just 5 pairs of tubes at a time. Same goes for cabinets, caps, transformers, etc. He does not have a roomful of parts just waiting for the next 20 orders. It was hard for me to imagine that because this puts him at the mercy of holiday delays, supplier hiccups, bad weather, etc. I'm obviously not in his shoes, but if it were my business, I'd prefer to keep five to ten units' worth of parts in stock. [I understand that is a lot of money to tie up.]

At this point my preamp has fewer than 40 hours on it.

I am very curious about how Don's KT-88 amp, Bob Latino's VTA ST-120, or other similar amps sound compared to my 400R. Sure, I heard Don's a week ago, but my aural memory just ain't that good. I may buy an ST-120.
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: tmazz on September 04, 2016, 09:13:35 PM
Don't question, just sit back and enjoy!   :thumb:
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: hogg on September 05, 2016, 05:26:43 PM
Nice looking tube gear
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: dls123 on December 23, 2018, 07:42:34 AM
Hi
I saw this thread, so thought I would finally participate.   I have a new version of the preamp in a nice black aluminum case, with tubes on top of course.    There are a few subtle improvements to the design, and of course, I still build them in cherry or walnut. 

cheers,
Don
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: dls123 on December 25, 2018, 04:37:41 PM
Here is the matching amp to the preamp.  Of course the blue poly is removed by the user.  It protects the stainless transformer cans....
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: Nick B on December 25, 2018, 08:58:35 PM
Here is the matching amp to the preamp.  Of course the blue poly is removed by the user.  It protects the stainless transformer cans....

Very nice. Michael.....mresseguie....has a Kootenay and loves it!
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: mresseguie on December 27, 2018, 11:29:22 AM
DS Tube Porn!  :drool: My favorite.  :thumb:

Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: dls123 on March 03, 2019, 04:32:49 PM
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.

cheers,
Don
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: mresseguie on March 03, 2019, 08:50:47 PM
Hello, Don.

I return to Corvallis in 9 days. Iíve suffered without my amp and preamp for 3 1/2 months.  :duh

I may get all your upgrades later this year, but first I get to immerse myself in beautiful music. Iíll have my new DAC in two weeks.

Party in Oregon.
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: dls123 on March 26, 2019, 07:29:06 AM
Here is the newest version of the preamp in cherry.  It now has a drop in black top panel to mount the tubes.  More venting, runs cooler.....

cheers,
Don

Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: P.I. on April 02, 2019, 10:59:26 AM
Hello, Don.

I return to Corvallis in 9 days. Iíve suffered without my amp and preamp for 3 1/2 months.  :duh

I may get all your upgrades later this year, but first I get to immerse myself in beautiful music. Iíll have my new DAC in two weeks.

Party in Oregon.
Woohoo.  Par-tay!  We'll be in Tigard over the week of the 4th of July to catch the Blues Festival on the waterfront.  Any chance you and Melody will be there?  If no we can drive down there to Corvallis if you two are there.

Check out the lineup!

http://www.waterfrontbluesfest.com/artists/

Would be good to see you my friend!
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: mresseguie on April 03, 2019, 07:33:24 PM
Dave,

When are you two going to move to Oregon? You know you want to.

I'm pretty sure we'll be in Oregon in July - unless Melody dreams up a trip to places unknown.

I'll check the link. I'm trying to increase the number of concerts I go to. It's too easy to sit in my living room and listen. I gotta break that habit, but it's so hard.

Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: dls123 on November 25, 2019, 07:13:32 PM
Hi folks...
Here is the latest version of the preamp with the new OLED display.  It also has relay input switching.   Much shorter signal path:)

cheers,
Don

Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: Nick B on November 25, 2019, 07:29:06 PM
Hi folks...
Here is the latest version of the preamp with the new OLED display.  It also has relay input switching.   Much shorter signal path:)

cheers,
Don

 :thumb: Very nice
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: mresseguie on November 26, 2019, 07:47:09 AM
Hello, Don.

Thanks for posting the pic! That's sweet looking. Is the preamp in Jim's (Blueone's) system?

Does this newest version not have gain controls, or are they still an option? I really like my ability to dial down the gain.

I won't have an opportunity to do it this year, but I think I'm going to ship my Model 2 back to you for an upgrade next year - perhaps in April. Let's see....Polish caps, rectifier tube change, etc. to bring it up to 'top of the line' status.

Michael
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: dls123 on November 26, 2019, 08:50:31 AM
HI
Sure, send it whenever and I can improve it.  I have dropped the channel attenuators and gone to relay input switching because I can shorten the signal path by at least a foot.   Inputs go about 3-4 inches to the relay/attenuator and then only about 5 inches down to the preamp section.  The attenuators are not needed unless you need a balance control.  I worked with Arek to dial this khozmo version in such that the taper is perfect for this preamp, pretty much for any amp and speaker combo.   THere is only one resistor in the signal path for any volume setting on each channel.  Essentially like no volume control at all, except that you have one:)

cheers,
Don
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: dls123 on May 02, 2020, 08:50:43 PM
Hi all...
I am almost finished with the next project.  It is a tube integrated amp.  It will have the OLED Khozmo 64 step remote attenuator with relay input switching, exactly as used in the latest version of the line stage.   The case is wooden and it looks very much like the Kootenay 120 power amp with transformers and tubes on top.   Same epoxy potted Polish transformers in the stainless steel cans, but optimized for the 6L6 rather than KT88 tubes.   It will be 25-30 watts/ch and have the same auto bias and fully regulated power supply as in the bigger amp, but scaled down for the 6L6 tube.
 The input and driver tubes are 6SN7 types as in the big Kootenay amp.   The prototype was very, very good and it was only about 20 watts/ch using an off the shelf Antek power transformer.  Sounded like a 60 watt/ch amp on my 96 dB speakers.  The 6L6 is just a wonderful tube and I have always loved them since my Citation V days.  There is a great Russian version of the tube that I will supply with the amp.   The production version of the integrated has a custom wound toroid power transformer that is slightly smaller than the one in the Kootenay 120 amp, but will be 20-30% larger than it needs to be to drive the 6L6 tubes to clipping at 25-30 watts/ch.  I now have all the parts and expect to have the first production one completed within 30 days.   I will post photos on my site.   It will have 1 xlr input pair and 3 rca inputs, and the usual 4 and 8 ohm taps on the output transformers.  Not sure of the exact price yet because I need to see how long the build time is, but in the range of $3499-3799.   This integrated should give maybe 80-90% of performance of  the separates as long as your speakers are tube friendly and fairly efficient so that 25-30 watts/ch is adequate headroom.  Perfect for full range drivers, efficient box speakers such as the Zu speaker line, and of course the entire Spatial Audio line of speakers.   Really anything more efficient than 90 dB or so.  Stay tuned.....
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: dls123 on September 04, 2020, 03:22:22 PM
Well, Clayton Shaw of Spatial Audio speaker fame has listened to my first Valhalla integrated amp.  His impressions are at 1:16 of this zoom chat:
https://www.youtube.com/watch?v=Su41Ivt7VbA&feature=youtu.be

cheers,
Don
Title: Re: Don Sachs Tube Preamp and Amplifier
Post by: P.I. on September 04, 2020, 04:16:10 PM
Well, Clayton Shaw of Spatial Audio speaker fame has listened to my first Valhalla integrated amp.  His impressions are at 1:16 of this zoom chat:
https://www.youtube.com/watch?v=Su41Ivt7VbA&feature=youtu.be

cheers,
Don
I can't think of a better endorsement than that of Clayton's.  Good job, Don!

Someday..........

Also - a nice reference to Danny Richie's GR Research open baffle sure, which are amazing!