Larry and Lee are two of my favorites for easy to consume jazz fusion.  They both always bring plenty of punch to the recording and make good demos when you want to show off your system.  I will need to get that album.  I wish they pressed on vinyl though.

I'm about 150 hours on the ZMA, and 10-15 on the P10 Power Plant - it's starting to level-up again! I played some choral music last night, and for the first time, I could clearly hear the different sections! (rather than one amorphous blob of voices) I think I'm starting to see what the P10 is supposed to be doing! Followed up with some Beatles albums I've not listened to in years. While I didn't have the "I heard things I've never heard before" thing happen, I was clearly hearing some wonderful depth and detail that I didn't have previously.

I still have to work out the buzz issue I have. I spent more time on it last night and got nowhere - was up till 12:30am working on it and up for work at 5:05am. Oppo suggested running a cable without a ground pin - but I'm having this buzz issue even when power isn't applied to the Oppo!

I made some progress on rebuilding my garage/workshop last night as well; so I'm a little bit closer to starting to build my Big Ass Diffusers. when I get back into town, I hope to get further along on the garage and maybe be able to start cutting wood for my prototype diffuser this weekend!

This buzz is driving me nuts, Lon. I'm really good at dividing and conquering issues. Usually I can narrow it down and come up with a plan in no time, and this one issue is taking me weeks!

I'm really going to have to start swapping components to figure out the exact source, so I can find an exact solution. When I get back home later this week, I think I'm going to swap in my old copper chassis Denon CD player and see if the problem persists.

For what it's worth the best trouble shooting procedure for noise, hums, buzzes, ticks etc., is to start with the speakers and work backwards.  

Hook the amp to the speakers and plug it in with nothing hooked to it's input jacks.  Let it warm up, and see what you hear.  Whatever you hear is the base noise floor you have to work with.  You can raise or lower this base noise floor somewhat with tubes, but essentially it should be so low that you don't care.  

Then hook the source to the amp while the amp is still on, but the volume is down, and see if anything changes.  If it does, you have three possibilities.  A) cables  B) the source itself  C) ground loop.

Under A) cables - we would also include the following scenario;  Unshielded interconnects picking up a square wave being broadcast through the air from a solid state module in todays light dimmers.  This would cause a buzzing sound.

Steve, I sent this to you in E-mail, but wasn't sure if you got it -

Here is the shop that rents reel to reel tapes - they also have upgrades for Otari and some other machines.

http://www.tapeproject.com/

There was another group renting out masters, or 1 generation away from masters, but I can't find them anymore, I think they dried up.

Also, Stone of Tone says he's having what sounds like the same buzzing issue I am with the ZMA - I'm going to do more testing tonight if I get out of work at a reasonable hour...

Those are cool trees.

And I just discovered why an engineer I know smells so bad.

Steve, I ordered my ZMA with the balanced option. What do you think between the RCA and the XLR? Any sound difference?

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Just a little food for thought based on what happened to me. In my case the "little buzz" was in the 60 Hz region due to a grounding problem. For almost a year I put up with it thinking it might just be normal.

During this time frame I was using an HSU Mid Bass Module and it produced very good bass through the 50 to 150 Hz range it was designed for. I had the MBM volume knob set at about the 10 O'clock position. Any higher and the Bass would start to get a bit boomy.

Finally one night I decided once again to try and root out the source of the "little buzz". Turns out I found the problem and the "little buzz" was completely gone, my system was dead silent. On top of that I was able to increase the MBM volume knob from 10 O'clock to 1 O'clock and it was wonderful, closest thing to live bass I have ever had in a living space. No boomy tendency at all.

In retrospect I think the actual noise floor of the amp is below what is audible. Only the 60 Hz "little buzz" was audible, an abrupt peak on the noise floor. Then when amplifying a music signal anything in that 60 Hz region rides on top of that peak creating a boomy effect to the ear (similar to a room induced peak) if the Mid Bass Module volume setting were too high.

Point being the "little buzz" may prevent you from getting the most out of your Sub and or Mid Bass Module as it did in my case?

my ZMA is now 'on the bench' ... woohoo!

Steve.... I asked the question months ago if I should get the balanced option.. and everyone said no, don't do it, just a waste.

and then today my mystery is 'on the bench' and you come out with this..

anyway to add the balanced output option at this point? will this find the same improvement with my balanced xlr dac output...

need advice asap.

Sarah said my amp hasn't shipped yet because they are still waiting on Pelican cases.  I think it's REALLY because Steve and team are still listening to master tapes on the ZMA/R2R combo.  

So, is both balanced and single-ended outputs available for this amp both on one amp?  I thought not. . . .

Yeah, I noticed the ZMA really warming up and wowing me around the 100-125 mark as well.

I'm still putting on about 25 hours a week with mixed music and TV/Movie watching. So I'm at about 150 now, give or take a little.

Cool! I thought you could only get one or the other.

I'm looking forward to your thoughts on all those tubes. I'm just going to keep trucking with what I have.

Speaking of which, I don't see the Super Cryo 23P on the page anymore.

I thought I remembered someone bringing them up recently.  :)

I guess I should do a small update as well.

~175 hours on the ZMA

Brought it over to Palomino's house for the 3rd meeting of the Chicago Decware Audio Enthusiasts (or whatever the hell he called us LOL).

Last time I brought the amp over to Palomino's listening room, it only had 25 hours on it and Palomino's Rachel sounded scary good - the ZMA sounded better after an hour of warming up, and as he said "never looked back" from that point.

This time, the ZMA smoked his really excellent sounding Rachel right from the get go, no contest, not even in the same league. Listening to the Rachel by itself is awesome, but having an amp like the Mystery amp in the same room simply made the Rachel sound anemic.

We did a lot of A/B testing with the limited gear we have, and our notes were exactly the same all throughout - here are some highlights:

#1 My MG944 are *way better* than I realized. The room treatments that Palomino is constantly adding and adjusting in his room, plus his excellent sounding Rachel proved that. I'd say their only drawback is that they are a bit beamy and very room dependent - if the room isn't balanced, and your head isn't in a vice at the sweet spot, your imaging will be off. His room sounds so good, we were hearing imaging off by inches due to something in the room. (the room was that good and the sound that detailed!)

#2 I knew this already, but it still shocks me when you listen to a well treated room - the quality of sound in his his room, before/after room treatment, is on the same level as the difference between the Rachel and the Mystery amp - his room treatments were as big of an improvement to his *existing* gear, as dropping $4600 on the ZMA! Keep in mind, he's got less invested in his *whole setup* room treatments and all, than I paid for the ZMA alone! The room and room treatments are that good, and that important.

#3  The Mystery amp in a well treated room, is truly amazing. We both agreed, this was the first amp we've ever heard, that truly gets Piano right. We also heard guitars in recordings, that sounded *live*, like they were right there in the room with us. I've said this in almost every post about the ZMA, the dynamics and harmonics - this amp makes the music truly come alive.

#4 The PS Audio P10 power plant easily added 25% quality improvement to Palomino's setup. I completely agree with Steve now, that with the big caps on the ZMA, a Power Regenerator is *less* necessary, but on the Rachel it brought it up to another level. I still firmly believe the Power Regenerator makes an improvement to the ZMA, just not as drastic as what we heard with the Rachel. I can now see why you guys say these things are game changers. While we agreed that it was a 25% (huge!) improvement on the Rachel, I think it was more like a 5% improvement on the ZMA. But at this level of quality, every percent counts!

Side note: when I got home I put my little 2 watt Zen amp on the P10, and *wow*, that was like buying a new amp! It even sounded louder! Zero regrets on the expenditure of the P10 now - I'm very happy with it!

Lastly, the negative - part of our audio play date was to help me suss out the buzz issue I'm having between the Oppo and the ZMA - we easily recreated the issue, and basically ran through all the elimination tests I did at my house - I do have *two* different buzzes - #1 being the ICs picking up noise like antenna, which with proper equipment and cabling layout is minor and almost inaudible at the listening position (even in Palomino's small room). #2 The buzz between the Oppo and ZMA, it's there, no doubt about it - as soon as you plug in the ICs, BZZZZZZ, goes up and down with the volume control.

But, as soon as we plugged in the Rachel, it's *dead quiet*. All things being equal, only change was the Rachel, dead quiet. In fact, it was so quiet, I actually said "is it on?".

I'm in Peoria today for work, but there is a big storm rolling in - I'm going to call Steve and see if I can swing by tonight with the ZMA and Oppo and see if we can figure out what's going on. I *really* like the Oppo, it does just about everything I need it to, and I really can't afford to replace it. So I'm going to see what Steve can do to help out. Right now my worst fear is that there is something off about the Oppo's design that will be inherent in any Oppo I get - I don't want to get rid of it, so I'm hoping we find a solution. I *need* to get the dead quiet I heard coming from the Rachel.

Calling Steve now to setup an appointment.  

Just spoke with Devon and Steve - Devon said roads are pretty impassable right now - so I'm hoping to drop off the Amp and Oppo with Steve tomorrow if the roads clear up. Being without the amp for a week makes me sad, but I know it's in good hands. Wish me luck and cross your fingers!

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LR:  Is it also true that you can connect your Oppo to your Super Zen at home and there is no "Buzz #2" ???

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If you only get "Buzz #2" with the ZMA (not other amps) then I would suspect the Earth Ground on the ZMA. If the ZMA has a higher resistance to Earth Ground than it should then the path of least resistance will be through the interconnects to the Earth Ground of the Oppo.

I'm sure if you get to Steve's he will sort it out in short order. I'm South of you in Springfield, IL and the ice is bad here. Be careful on the roads.

Very cool & constructive LR, Palomino & DBC. I look forward to Steve's further insight.

I'm still forming my opinion but I feel the ZMA is SET on steroids. All the imaging plus more detail pushed out by those massive caps. This is not just raw grunt or low end.  It's across the frequency range.

Maybe Raven can chime in on the "cymbal" experience we had.  That cymbal has always been heard in that song and Rachael plays it crisply and clearly. But the ZMA plays it more fully and you can hear the full cymbal resonating and as the sound wave expands to the full circumference of the cymbal it gets deeper.  We just looked at each other and said "now that sounds like a real cymbal."

Same thing for the dsd violin music we listened to.  You didn't just hear the strings, you heard the bow rubbing against the strings *making* the sound.

So when Steve says liquid honesty I think he's saying all the lifelike detail and none of the "edge."

Note: I'd like to hear some comparisons to the Torii.  Maybe it is too big a jump from a Zen or Rachael and you can get some of this with a Torii III or IV.

I was bowing and paying homage to the ZMA/P10 combo

What power cord was used on the Rachael, Mystery Amp and P10? Did you use any tube damper items on the Rachael? Just curious. Thanks

Eric can comment on the p10 power cord.  I simply called it "the python."  

Rachael had the DIY audiophile power cord recipe from DIY audio.  Basic shielded power cord.  We had herbies tube dampers on the input tubes.

Hi,

I am the owner of 4th ZMA which someone mention before. (Mr. Veerachai from Vietnam). I would like to share my experience of ZMA. I am new in tubed audio amp. The ZMA is my first tubed audio amp and first Decware amp. My objective to buy ZMA is to replace my Pass Labs X150 SS amp. I want to try tubed audio amp. However my worry is that
1) Short of Watt power to drive Avalon Avatar speakers which have 85 dB sensitivity. Tubed audio need to match with >90 dB sensitivity speakers.
2) Short of dynamics or bass to play hard rock musics.
The result of 50 hours played with ZMA is
1) It can drive Avalon Avatar loud enough for my listening level ~83-93 dB. Wife does not allow > 93 dB. Once I can get 96 dB for music and movie or home theater system.
The different of ZMA to Pass labs is that ZMA can still keep holographic sound image and layers of music instrument while Pass labs cannot when play at 93-96 dB level with complex instrument musics. For Pass labs, the louder you play, the noisier you feel. It is less musical and messy or fighting between music instruments. But ZMA keep all music instruments in line.
2) Bass, now I hear bass different. It is much more articulate and details, details and details. With ZMA, I can hear drum skin resonant and bass string resonant.  This feature is one of my happiness to buy ZMA. I can play without sub. Normally I must use sub with Avalon Avatar speaker.  
Dynamics, No dynamic problem at all with ZMA. It is very liquid transition from quiet level to loud level, no delay and no over shoot, no canny sound.  

I am very happy with ZMA now. It is worth every dollar for buying ZMA.

I will use V-Cap capacitor sound characterizing from Clive Meakins for sound characterizing of ZMA as following.

My immediate and lasting impressions were of dry tight bass, clear treble and very broad stage width. Bass is strong, laying a carpet of bass in the room. Treble very clear at the top-end (of my hearing), vocals are meaty. Famous Blue Raincoat / Jennifer Warnes; not only does this reference recording sound impressive, the V-Caps deliver a strong bass foundation, excellent treble extension and impressive vocals.

I provide my system information because different system provide different sound.

Player is SACD player DP77 Accuphase.
MIT Oracle RCA.
Decware switch box.
MIT Oracle RCA.
ZMA
MIT Oracle speaker cable.
Avalon Avatar speakers.
Shunayata Hydra 8.
Power cord to Hydra 8 is Kubala Sosna Emotion.
Power cord to ZMA is Synergistic research Tesla precision reference.
Power cord to Accuphase DP77 is Siltech.