Congrats on the Purchase!

I've played with a few Dynaco amps over the years, and was tempted to build one from scratch using the Triode parts (they are Chicago based). The ZMA is for sure in a different league than the Dynaco stuff. Your ST-70 will be quickly relegated to your "second system" LOL

I look forward to hearing what you think of the Mystery Amp when it arrives. I swear every 100 hours the amp bumps up a notch - so you'll have a lot to look forward to.

Smile...

In the very early pre Decware days during the 17 years between my first wife and my second wife, I did my serious listening every night from 10:45 P.M. to 2:45 A.M.  During this time, my corner horns were my primary reference speaker and were on either side of a 6 foot opening into another room of equal size which opened up to a third room of equal size. The speakers were a mere 13 feet apart putting me at 6 feet back due to the 45 degree toe in. Of course with an opening in front of me with some 30 feet of optical depth I certainly didn't feel like I was sitting that close.

Just to mess with my brain, I put a baby grand piano in the second room behind the speakers... that was fun.  It was especially fun when listening to piano music.  The typical recording put the piano right where it actually sat.  Good stuff

I learned about negative feedback in this place.

The first time I lifted the feedback on a tube amp in this room I almost pissed my pants. You see the stereotypical soundstage I was used to went 6 feet behind the speakers (on a good night). With the feedback removed the sound stage suddenly exploded back into the back wall of the third room. That was 30 some physical feet but it sounded like 90.  

This illusion became an obsession of mine that lasted for several years where the depth of the sound stage became the ruler by which one amplifier's stripes were measured against another. I can remember many times when two amplifiers were tried and... same frequency balance, same bass, same dynamics, same sound but one went back to the third room and one didn't.  Winner!

It doesn't really take a lot of math to understand that it takes a finite amount of time for the signal to pass through an amplifier and during that process it gets delayed more at some frequencies than others aka phase shift.  

So if you take a signal from the output of the amplifier that is delayed and no longer in-phase relative to the input at most of it's frequencies and feed it back into the input... the end result is smeared time and smeared phase. It's so smeared in fact that the low level ambient information that contains the sound stage depth cues is completely destroyed. Add to the casualty list: transparency, openness, presence and micro detail and of course ambience.  

Taking the momentum of this thought a bit further, imagine taking the tube circuit poisoned with negative feedback and exchange it for solid state with 10 times as many parts and 4 to 10 times MORE feedback. hmmm yummy. Then invent CD's. Take away the last hope and make us listen to our miserable crap on an equally miserable format. After all, since CD is missing some 40 percent of the music, and solid state amplifiers gross amounts of negative feedback kill about that same amount, no one will even notice.

Frankly I was mortified.  Decware was born from that disgust.

On a happier note, despite the corner horns having perhaps the best bass ever... and extension to the mid 20's...  Imagine the following:  The house was over 150 years old. There was a basement. I build a concrete horn in the basement that wrapped around the furnace.  It has a throat that was 3 inches x 48 inches and a mouth that was 10 feet by 48 inches with a total length of 18 feet. The wall thickness of the horn was 4 inches on one side and infinity on the other being underground. I estimate it weighed over 3000 lbs for just one side wall of the horn.  (grin)

With a single 12 inch woofer I cracked my basement in 72 places in on the very first test. The bass from this sub when you were upstairs in the listening chair was so fast you perceived the kick drum coming out of your chest.... agh the good old days...  when i was still crazy.

Happy listening!

No doubt... . I can't enjoy a 75 watt per channel push pull Amp like the Audio Research because of the Negative Feedback in the VSi75.
http://www.audioresearch.com/VSi75.html
....the negative feedback and not Steve's Topology. I also did my best to enjoy this one.......
http://www.audioresearch.com/Reference75.html

....nope....the CSP3 & ZMA win... . ...not about the money either...if the AR stuff was better (either one)...I would have bought it. Being able to also dial in the Voltage output to my ZMA for my Anthony Gallo Reference 3.1's...is a shat your pants factor too.

Welcome Dave! I am sure you are going to be impressed with the Mystery Amp!

Welcome Dave!

I am glad to read you have great Speakers & Cables! You will get to hear what the ZMA can really do...(like me). I use a pair of Gallo Acoustic Reference 3.1's currently an Kimber Select 1030 IC an Select 3035 Speaker Cables.

I remember a gentlemen at the 2005 DecFest that was a Dealer for Art Audio...and he was there to hear if Decware was hype. He left knowing these Amps can compete with Art Audio.

I am very pleased with my ZMA & CSP3 combo!  I am now looking at your choice in Speakers! I am always out for improvement... .

....Morning Jam Session with the CSP3 an ZMA combo. I am pounding the ZMA right now at 88db SPL...and peaks of 92! The beautiful tube compression with no ear fatigue an such clarity of focus!  

Cheeeeeeeers, an Happy Spring!  

402 hours on the ZMA as I type...an 42 on the CSP3...+/- only .5 hours.

Has anyone here done any tube rolling? I just tried some cryoed KT88 Gold Lion tubes. I liked the sound but didn't continue because I could not adjust the bias to the 50 mark. It seems I'm bottomed out on my adjustment at almost 70 on gauges. Thought I would check with you guys while I'm waiting for a reply from Steve.

Lance

Hi Ilance,

tube rolling for ZMA. Yes, I have done with Siemens E88CC ($370 for quad), RCA 6L6GC ($380 for quad) and RCA JAN OA3 ($18 for pair).

The sound quality of ZMA with stock tubes is unquestionably superb
. But I need more in lush midrange female vocal, sparkle treble and powerful bass or bass slam.

My first plan is to burn in ZMA with stock tubes for >300 hrs first to know the sound. Then do tube rolling step by step to observe sound quality changing. But ZMA with stock tube's sound is so good that I imagine what if I put Siemens E88CC tubes in, how much is the sound improvement?  
I cannot wait, I change plan to put in Siemens E88CC tubes first 3 days ago. Midrange sound is more lush, both high end and low end extend more, more holograph sound stage. But speed is slower than stock tube.  The fun or PRAT is reduce a little. But overall sound improvement is very satisfy. I replace KT66 with RCA 6L6GC next day. There is more dense sound and more bass. Now speed come back, PRAT is same as stock tube now. But bass is little boated, not well control. Then I put in RCA JAN OA3.
OMG, it is the last jigsaw. RCA JAN OA3 make over all sound dense, coherent and PUNCH SLAM bass!  Boated bass disappear and very well control now.

Now I get all, lush midrange female vocal sound to die for of tube amp reputation, sparkle high and PUNCH SLAM bass!  Playing with heavy rock music, you can feel wavy air movement of bass. It is very very scare realism! If you run at 56 ma, it likes discotheque. If you run at 52 ma, it likes stadium rock live concert. The strange is that you just listen at normal SPL 80-93. It is scale down at any SPL, no need to get loud of 100 SPL to get rock live concert feel.

Is it worth to change tubes as above? In my system, the answer is absolute yes!  I will report more when have more hours on these tubes. It is improving.

You can read more on page 66.

LR, #1062, ....I don't know if the ZMA has plateaued? I have the CSP3, now in its 46th hour....and the involving music with this Pre, I am getting-does keep getting better. No hyperbole...I was not a fan of the Torii III...so I sold it. .......the CSP3 & ZMA combo is truly a musical journey every time I turn them on.

LR & Palomino, have fun at Axpona! I would have been there to meet you guys... . I will be partying in Northern Cal gentlemen, being a Stanford dad!

Cheers, enjoy!

I'll just leave this right here.

I wonder that Otari MX5050 sounds compared to the master tape console.

So I've had my first real listening session since getting the XLR inputs on the ZMA, and I had some friends over for a listen. One friend I've been on this listening journey with since I bought my first amp from Steve back in 1998. The other friend was curious what this audiophile thing was, and is a pretty smart dude (in general) who loves music, so I invited him to join us tonight.

Long story short, I played some of my favorite audiophile tracks, plus some classic stuff like Pink Floyd and Crosby, Stills, and Nash just to prove my setup does more than female voices and jazz (which it seems to be what 98% audiophile tracks seem to be), then took a couple requests, and finished up the night by playing some of the Twins Soundtrack (a copy of Steve's Master), and...get this, Allied Electronics commercials from April 1959 that came in a box of tapes I picked up off Craigs List.

I have to say, this was the *best* the ZMA has *ever* sounded! I thought I was done with the "wow, I've never heard *that* before" thing when playing old favorites, but there is was again! Another level of detail and depth and soundstage that I didn't have before. My friend Jason was just like, Wow, that's the best I've ever heard Pink Floyd's The Wall - and I pointed out it was the MFSL 24k CD (FLAC) that he never liked compared to his standard copy. We both heard details we'd never heard before. And my friend Nate who'd never experienced anything like this before...well, I think the ZMA was too much for him...he was stumbling over his worlds just trying to say WOW. He was pretty flabbergasted.

Now, my friend Jason who's been listening with me for 15 years, he heard the ZMA when it was still pretty new...not quite 100 hours I think, and we both thought the high end was a bit edgy and dry, and I caught him looking at me like "you spend how much on this..." Now that the got 400+ hours (and XLR inputs) he was floored - he said he couldn't understand how I heard this potential in an amp that sounded that rough when it was new. He said everything I described to him 3 months ago was there now; the detail, the rich harmonics that bring voices and instruments alive, and the dynamics that just make everything pop.

And the new guy was like...wait, there's only two speakers playing here? No center channel, or surrounds? He'd heard of soundstage before, but this was the first time experiencing it.

So after such an amazing digital show (all from the Oppo via XLR, controlled by my cell phone), the tape only floored them all over again. The Twins soundtrack was so dynamic and live. Neither one of them could put their finger on how or why the tape sounded so much "better" than the digital tracks "it just did". I still have a lot to learn about tape, and Steve's copy isn't 100% right IMHO, but it was a good showing. With some tweaking on my part, and a slightly better recording, this could be a whole lot better. And my friend Jason who's a very science geek said that he was very skeptical of tape, that he really believed that CD was already to the limits of what we could hear, but that special something that comes from Analog really changed his mind.

And to finish up the night, we all got a great laugh out of these 55 year old commercials for Allied Electronics. It was just some typical late '50s jingles and an announcer with a great voice, but it sounded so live and present, like he was here in the room with us trying to sell us a stereo (only 149.50 and only $5 down!). That was certainly a great way to end the night, and just blew our minds how a 55 year old tape could be so fresh and present.

Sorry to ramble and gush so much. It's just that I thought this amp was done, it's at its final plateau and will sound this good forever.  I really believe these XLR with my Oppo took it up another notch.

Gear tonight was -

Oppo BDP-105 with 2T Passport hard drive playing FLACs ripped, FLACs downloaded, and DSD purchased.

Morrow Audio 1.5m XLR cables (I have no idea which ones, they cost me $135 at the audio show) to Zen Mystery Amp

10AWG Zen Styx clones (soon to be replaced with 8AWG versions)

MG-944 on spikes

Also, Otari MX-5050 playing 2 track tapes with my own DIY 26AWG Zen Styx style wire XLR cables

I found like six version of it from my usual sources - which album is the correct version off of?

Awesome story Eric!

We had friends over a couple weeks ago and my friend’s boyfriend was showing some interest in the stereo equipment.  I think it was the blue lights/screens on the PSA gear that initially caught his attention.  He then started looking around and asking questions (why are the speakers so far into the room?, etc).  He isn’t into audio and had never seen a tube amplifier which further intrigued him.  I asked him if he wanted to listen.  He said sure and I sat him down in the sweet spot.   His reaction was very similar to what was described below:

And the new guy was like...wait, there's only two speakers playing here? No center channel, or surrounds? He'd heard of soundstage before, but this was the first time experiencing it.

He initially said, wow, this would be great for movies because he thought I had a multi-channel setup going.  When I told him that all of the sound was coming from the two speakers, he couldn’t believe it.  He pointed at my diffusion panels and said “those aren’t speakers”?  I think it really blew his mind.  He couldn’t stop talking about it for the rest of the night.  It was pretty entertaining.  

Dave, Sounds like you have a good setup for that. My imaging and soundstage are the weak points because of my L-shaped room and the fact that I've not finished building my diffusers. I think I'll be at that happy point that Lon is  at once I get my room better dealt with. I just need to redesign (make more simple) my diffusers, or come up with a better way to mass produce them error free.

Zygi, I saw a box like that when I visited Steve, but I wasn't really paying attention to it. I was more focused on Tape Stuff than the XLR ports, but now I'm seriously looking at the XLRs, as it's the only explanation as to why the ZMA has really taken a step up. Honestly, I thought I was done with the "I've never heard that before!" thing. I'm giddy all over again, like I got a new amp.  :)

In this case, I thought my PS audio DAC also has XLR outs, why not give it a try. It was uncanny good. Everything you said changed in your system, I concur with. So go back and try using the RCA's again and let us know if it has as much to do with the Steve's version of an XLR converter or was it really another stage in your Mystery amps break in?

My ZMA has the XLR inputs and I still haven't tried them.  Been dragging my feet on XLR cables for weeks.  This really is the motivation I needed.  I hope they sound as good as the little black box with my PSA DAC  :)

MG-944 on spikes

Do these make an improvement?   My 944's are sitting on carpet at the moment.

Dave1210, my biggest improvement recently was to get my speakers off of the carpet. I recently acquired a pair of JanZen zA2.1's and they didn't come with carpet spikes. I finally got around to ordering Mapleshade speakers platforms with brass spikes and now those speakers sound incredible with the ZMA. It was a huge difference. I do have the dreaded L shaped room so nothing's perfect.

lLance...I will look into the MapleShade speaker platforms.

LR...what are you using to isolate the 944's?

in regard to xlr connections.  i had a wonderful cary 120S big tube amp for a good while.  when i changed from single ended to balanced, the sound was so much better that i never considered going back.  on that amp, the balanced impedence was different and i think it just worked better with the preamp and speakers which accounted for the change. must have allowed them to work in more comfortable ranges.

I'm curious now, Steve. I'm going to write Oppo and ask them exactly what kind of XLR output I have. I'm positive this isn't placebo, but I have no idea if it's just an Op-Amp.

Looks like my Oppo is differential.

--------------------------------------------------------------------------

NOTE
􀁸 Balanced audio connectors are used mostly in professional audio electronics, such as high
quality microphones and inter-equipment connections. The BDP-105 utilizes the 3-pin XLR
connector (shown below), which transmits a pair of differential signals (positive /negative). The
amplifier extracts the voltage difference between differential signals, thus the common noise can
be rejected and the signal integrity is improved.
􀁸 In some audio systems the position s of "hot" (positive) and "cold" (negative) pins are switched.
In this case please set “ XLR

Right, they couple rather than decouple. And sometiemes that's the ticket!

In terms of coupling or de-coupling, I think variables make it pretty complex, each foot material, design, and size acting and sounding different. And finally it is the sound that wins. I agree though that decoupling, in my case, with Herbie's isocups, can be quite good for gear, especially with some balls of different materials to fine-tune tone with. But I have used hardwood cones under my DAC for a long time, almost always preferring this DAC sound over any other feet I have. And I tend prefer the sound of Synergistic Research MIGs (small metal bowls) under my Oppo. I also like weight on top of components, solidifying the sound further.

In the case of metal speaker spikes, though it is not decoupled, it is considerably less connected to the floor than with the plinth right on the floor. So the plinth is freed up for the most part, apparently a part of the sound of a speaker beyond deflecting passive bass outward. And the speaker can drain vibration to the point of the spike and floor, while floor vibration effects on the speaker seem minimized by the spike point being the connector. This is how it appears to me anyway, and I think the sound reflects this minimal coupling.

Herbie's gliders do decouple the speaker though, and it is a better sound to me, in this room, and with this floor. They have done considerable work on materials and design trying to get a neutral sound though.

I find feet fascinating. I think I use six different kinds in my system at this point, all having different characteristics vibration-wise and sound-wise.....nicely useful for a given component or speaker. But I really enjoy experimenting.

I've been experimenting with vibration isolation the past few years. I've used a variety of 2-shelf racks with different shelving materials with only limited success at best. Recently I purchased Maple Platforms with Isoblock footers from Mapleshade and have been very impressed with the sonic results.



My problem was always with vibration from the floor being transmitted through my equipment rack & shelves to the audio gear. The Main Maple Platform (18" wide, 15" deep, 4" thick, 25 pounds) is very stable compared to the floor when I'm cranking the system. The Second Maple Platform (15" wide, 12" deep, 2" thick, 10 pounds) is stable as well.

You guys and your whimpy little 4" thick maple stands.
My Torii sits on a 5" thick slice of maple tree trunk! It has about 1/8" of shellac over the top and sits on a mahogany base.
I cut the wood with a chainsaw, planed it level, sanded until it was shiny and then started shellacking until I went through 2 cans of Bulls Eye.
My sub sits over in the corner on another hunk that is more like 6" thick
Sounds better? Probably not, but it sounds good enough for me.