I have adjusted both my HR-1s and 944s, but I think the 944s sound great with my MKIII and MKIV. The HR1 has more sophistication to me, and improves on the 944's sound...but they are definitely family and the best Bob could make each design using the same front drivers and tweeters. The slightly less sophisticated character of the 944 is compelling to me too. For me, in both my rooms, I prefer both speakers less dark and tighter. But this is with Toriis in front....My 944s have no crossover coil different caps than the original (toning down the tweeter just a little), the mid/bass drivers slightly damped with resonance dots, and I have the plinth spaces plugged some, and they got a lot better after maybe 1000 hours, the tweeter now smoother, and the mid/bass drivers loosened up.

Tightening and smoothing the speakers with these adjustments does make them different speakers (to my sensibilities, notably better), but they both changed in the same ways and to my tastes, and to me sounded similar in many ways before, and perhaps more so now.

If I had to choose, I would choose the HR1, but I would be very happy if the 944s were my only speaker.

Dave, I was frankly trying to make you notice that there's good potential for improvement there for the future. Regardless of what you actually paid for those (none of my business), their specs are objectively at a higher level.

You probably already knew this, but I did not think mentioning it would cause such a wave. Sometimes being rational is anathema in this forum.

Enjoy your great setup.

What specs are you talking about FB, the prices of the two speakers? Or how speaker price relates to the price of the the Mystery amp or PS Audio components??? The HR-1 has to be notably higher than the 944 since it is so complex in shapes, and with its hand-made radial driver, but to me this does not make the 944 a less than stellar speaker.

It is hard to talk about the quality of speakers based on price or concept. I heard from a reliable source of the HR-1 comparing favorably to a 64,000 speaker, and I would say the 944 compares well in many ways against the HR-1 and my 944s were a bit over 900 delivered! Others on the forum got pretty worked up about your speaker with the new horn base at Decfest. All pretty subjective based on too many things, but I can say that in my opinion, the 944 is a world class speaker, especially after adjusting it a little to my spaces and tastes.

I guess I don't understand the rational of comparing speakers without hearing them, especially when they were both the "babies" of the designer and builder as he made them. I am guessing they both kick ass with the Mystery amp. At least with room and gear synergy!

I agree, it is all interesting to discuss, and are we ever lucky to have such amazing sounding gear to talk about!

Great news! I don't know why you would hate to say you really missed it, I think almost all of us here can more than relate. I know I can't wait for my day to be done and my parents in bed to come home and spend a few hours with my stereo, and when I wake up I don't lie in bed and doze, I get right up to seize another hour with my Torii before I have to go to their place and get them out of bed. And this when I have great sound at my parents' as well, with my C amp there and the CSP2 and ERRs. Some magic with the Torii and also hearing my selections, it's what helps make life a great thing.

I hope when you get it back it's silent and sounding wonderful.

I thought your buzz was related to using unshielded cabling picking up RF? I have that too, but was mostly resolved by rearranging my gear, as was yours.

LR,....what put me off track was...when I tried the ZMA only connected to my Speakers...no front end powered or connected, the ZMA is quiet.

MY logic was...then it is my Front End with IC's and maybe Spk Cables acting as antenna's, etc...RF noise happening even more so when you turn up the volume.

Now, with this revelation from your ZMA...their has to be something "Fishy" about my "ground scheme" too. Obviously, when turning up the volume knob....I should not be getting a BUZZ at the Listening Chair. All things being equal-my other two Zen Amps don't produce the BUZZ in the System. SO, that really tells me right there-it is the ZMA!

My SE84CS is quiet all rigged up with the volume full up. A slight hum with ear right in the Driver's I should say. But, certainly no Buzz or anything audible from the Listening position. The Transformer has a slight hum when your ear is right up to it.

My Super Zen CKC has no Tranny hum at all, with your ear right up to it. The cover's and density on this Tranny seem thicker too. The CKC is quiet at the Speakers.

I will call and send it back to be fixed. However, that sucks....I might have someone STAR ground it here and investigate the fuse issue.  

So, I will quit my frustration and get it fixed.  Steve makes great Amps. -S

Below are some observations/first impressions.  I have <30 hours on the amp.

1) Build quality is top notch.  The amp is meaty.  Not surprising, the amp is heavier in the back because of the transformers.  Right now I have 4 Herbie's Tender Feet (extra firm) under the amp.

2) Adjusting the bias and balance is simple and takes < 30 seconds.  I did have a couple random +/- 20 mA bias swings on the left channel.  I was listening and noticed the left/right imaging suddenly became unbalanced.  I checked the meters and the readings on the left channel had either increased or decreased by ~20mA.  This only happened a couple of times and seems to have stabilized.

3) If I put my ear up to the speakers I can hear a slight hum.  The hum does not change with volume until I get to about 80% of full volume.  Then the hum gets slightly louder until I reach 100% volume.  I think I am hearing some RF  (it is more apparent when I pass the 80% volume threshold).  I cannot hear the hum at my listening position.  In comparison, the SuperZen is dead quiet with the same setup.  

4) First things first.  The amp is musical.  I don't know what that means other than I just want to snap my fingers, tap my toes and dance.  

5) The ZMA has a lot more weight and bass than the SuperZen.  I think I will wait a bit before trying to describe the type of bass I am hearing.  

6) I did crank the amp a few times just to get some early impressions.  If you watch the meters you can start to see them bounce a little once the amp begins to clip.  If you push the volume further up the meters will start to dance.  At this point in the break in process, I find the amp to be slightly harsh/edgy when pushed.

Thats it for now.  Back to the music.      

Hi everyone!

For whatever reason, 000, 001 were definately built with a standard ground set up where the audio ground, chassis ground(shield) and earth ground are all bonded together.

This is how we build all of our amps so the difference in noise you hear between a 2 watt SE84CKC or a 6 watt SE34i.3 and the mystery amp is simply attributed to the difference in gain or in this case power.  If you took either of the two quieter amps and multiplied the power by ten times, the noise would increase by that amount as well.

That said, with the dual mono design and other unique properties of the Mystery Amp, I took #000 back to the bench and put the noise magnifier on it.  Once magnified enough, I was able to get the noise floor of the amp at idle in the headphones and then start playing around.  

Indeed you could hear an increase in the noise floor once the oppo was connected to the ZMA, and this happened regardless of volume position, and volume position had no effect on the noise floor.  This contradiction with user results is attributed to my testing with shielded cables vs. non-shielded cables.

In any case, you should not hear the noise floor change appreciably when another component is hooked up, and if you do, the component is either noisy or there is a ground loop.



With the Oppo there seems to be a ground loop, albeit with shielded cables and less than 94dB speakers you would likely never hear it, I was able to eliminate it by separating the audio ground from the earth (shield)  grounds.

The final results on 000 are zero noise or hum with the amp at idle, and no change when Oppo is connected with shielded cables, volume control makes no appreciable difference.  You can not tell that the Oppo is connected either OFF, ON or on pause.  

So for 001, I think we can easily modify your amp the same way and possibly without the need for soldering.  Email me at zen@decware.com and I'll elaborate.

Everyone else should be fine because we're building the ZMA's with a separated audio ground and earth ground to push the noise floor into blackness despite these higher power levels.

Hey, if it bothers you even a tiny bit, it bothers me twice as much.  I've always got your back no mater what it takes.   If 001 wants to send it back here rather than risk opening the amp I'll have no issues covering the shipping.

OK, That being out of the way, I am complexly pleased after reading the last few weeks of this thread to see the same results as I get here with the ZMA.  It IS a rather impressive amplifier.  In my room it has been competing with my completely modified Servo-Charged Acoustats and that should not be possible.

The real head bender was on the Reel to Reel when it surpassed the Acoustats by a lot.  What did I call it.... Liquid resolution?.. if not I should have... it's simply incredible when paired with my recent acquisition of the Otari MTR10 reel to reel mastering console.  I can't wait to write about the experiences I have been having with this amp using the "ultimate" source playing 15 and 30 IPS half track master tapes...  To be bluntly honest, my turntable doesn't suck.  But, I had no idea how good Decware gear actually was until recently, and the gap between the ZMA and everything else is getting larger.

The combination of this amp, and the master tape machine has finally achieved my goal of audio crack cocaine.  It's so good that you can't listen to more than one song without releasing energy by running around the building twice and mumbling things like holly crap over and over until you realize it's 14 degree's below zero outside... and the tape is still on pause.  Then you go in for song two, and bam... you're back outside in 15 below zero weather mumbling things like holly crap...  you get the idea... there IS a pot of gold at the end of the rainbow and I firkin knew it...   just took over 20 years.

Now on a related note, we have had some interesting experiences with the new TORII MK IV using Siemens 7DJ8's or Russin 6P23P-EV tubes and had a night where that combination also surpassed the Acoustats...  

Hear's my thought...  If you guys want to to "ferret out all the nuances" between the TORII MK III, MK IV and Mystery Amp, and or ALL other Decware Amps, I would invite you to come over, get a hotel, start around 5 p.m. and go till you drop.  Recover and then document the experience.  There is probably at least a thousand people who would like to know what the specific differences are from someone other than myself.  My shop is your shop.  Weekends are also open for this if you're game.

I will even attend the event with master tapes in hand.

-Steve








 

Quote:



Well, I'm in obviously - but this is probably going to ruin me for source. There is no way I'm going to get *Back* into reel to reel - let alone *master tape* reel to reel. LOL I'd really like to hear what the ZMA can do - and I'm getting the feeling I know why the OTL amp looked like it was recently in use when I last stopped by. I'm sure a Master Tape on the OTL was pretty mind bending.

If some of you somewhat local guys want to take Steve up on his offer, just pick a day and I'll do what I can to come down as well with my ZMA - an impromptu mini-Decfest. I'm really curious what the ZMA does with such a great source!

I would also be interested.  I am about a 5 hour drive from Peoria, so a weekend would probably be better for me.

My reply #767 above... .

On second thought...I better not open her up Steve. Those CAPS scare the crap out of me. Even if I let them drain for several days, I would still need to alligator clip/ground with wire one end and test positive ends of caps for charges with the other clip. I could do it....butttttttt?.....I better not. (....with a resistor in the wire and the test clip on a chop stick).

However, please do email me (I sent you an email last night to the address you gave), on how to/schematic.....separate audio ground from earth ground in the ZMA. I will have a Tech do it here.  -S

My ZMA landed today.

I disconnected the Torii3 and put the ZMA in.  I put 6 hours on it so far.  Still trying to understand everything I think I heard.

Right out of the box, it sounded tighter, cleaner, more controlled in the bass and I guess overall.  I think it's faster.   My superzen and torii were trade offs.  zen was faster, crisper.  torii is fuller, powerful, but slower.  strings plucks aren't as crisp as a superzen.  

Well, this zma seems to sound fast like the zen, but powerful throughout the spectrum.  

I listened to several songs I know well, including my bass torture tests.  I was immediate focused on the bass because it was so present and so articulate.

I moved one channel and speaker cable over to the Torii, and set foobar2000 to output in mono.  This way I could compare zma and torii simultaneously single channel just by the volume controls.

the torii3 bass control can make the torii sound much leaner or much boomier than the zma.

And on my HDT's, the treble control can make the torii sound too dull or too bright relative to the ZMA.

I found it curious that the ZMA sounded very similar to where I tend to leave the bass and treble controls on the torii.  The ZMA has a good balance all on its own.  The torii3 allows for way more adjustability than you need.  

I was concerned that the single driver HDT's would pitch up like they can on the torii at full treble.  They don't on the ZMA.  It's a little brighter than I'm used to, but it also seems less offensive, I think because it's "cleaner" or faster.   something about the clarity of the treble makes more of it tolerable.  it's weird.

it was obvious the speed difference when they were side by side.  notes and instruments are rendered by the ZMA very distinctly.  things are very clear and separated.  on the torii, I noticed some bass lines blurred a bit.  There's a long suspained low piano note at the end of a song...  it sounded like a decaying note on the torii.  on the zma, I think I heard wavering or some other detail I didn't quite understand. it just seems "more like a real piano".    It's strange how you don't realize your bass is getting blended a bit until you hear something else that doesn't do it.

I went back and forth for a long time wrapping my head around the speed and clarity differences I was hearing.  I do realize at times I thought the torii sounded better even though it wasn't technically as clear.   On some cd's there was a trade off between accuracy and listenability.   The torii is lush in it's presentation.  on some cd's, it's better.  I realized that good cd's sounded better on the ZMA, but the torii play more of my cd's in a pleasing way.   some were not fun to listen to on the ZMA.  

This made me think of photography.... sometimes you need to blur or soften an image for it to be most pleasing.  sometimes you want the sharpest image you can get.  there's a time and place for different amounts of "accuracy".

I started thinking of the torii and zma in these terms.  I also wondered.... if I just heard "better" because of a speedier amp, wouldn't my old solid state amp do even better?  have I fooled myself into loving tube audio for it's softness, while now I'm back on a quest for speed?   I hooked up my Myryad MI-120 side by side with the ZMA.  The amp was fast and powerful as I remember it.  I forgot though that that crisp dryness also causes listening fatigue within 1 or 2 songs.  I back on the shelf for another few years for that one.

So, the zma is fast..but not too fast. I guess.

I'm also redefining what I thought were well recorded cd's.  what sounded good/bad on the torii, isn't the same on the zma.  some cd's I don't like on torii, are tolerable on zma.  and the other way around.  haven't figured out why yet.

volume knob seems to have more usable range on zma.  music doesn't get loud until more than half way, then the power really comes on, and never strains.  The torii seems to get louder faster. (I use less of the volume range).  

Anyway, this is just my first impression, first day.  I'll let it burn in for a while and try all this again.   I forgot what it sounded like back in October.  it's nice. very nice.  I like how it presents notes and instruments very clearly.  I'm preferring that over the smoothness, lushness, listenability, of the torii.





I listened to a few tracks and liked what I was hearing.  The increase in control is definitely apparent.  bass notes are crisp.

WHEW! Good news.

Seems like there may have been a few here on the forum saying something similar. I think that is true even if used with fantastic sources, the CSP2-CSP3 preamps are just wonderful tools for listening.

I was of the same mindset with the preamp as well...until I bought a CSP2+ and now it will never be taken out.  Really allows me to fine tune my "sound".

Are you new Mystery Amp owners using preamps or running directly from source?  Anyone listening to vinyl through it?
Thanks

JD

Hi,

So am I as SteveC comment. ZMA provides a excellent resolution and speed but without analytic feel, dry and fatigue. For this kind of Amp, source is very important or first priority to be considered. It will give high reward with ZMA.

Sorry that I misunderstood about EMF You are correct that non-conductive materials cannot block EMF. Then the case of fabric wrapping the power cord do not have any effect on EMF. But the sound improve because of power cord position changed in distant to IC cables, Second commend of text books, it makes subtle change in sound, i have try A/B comparison many times. But it may comes from anti-vibration of shelves, not EMF.

However I would share my trick again, it may like woo doo magic but it does not cost any thing more, just try and see the result.

Using clear plastic or acrylic material to block wave frequency to get through CD open/close tray as in picture (vibration reducing). It improve pin point image or focus of instruments in sound stage.

Well, I have no regrets selling my Torii III. The ZMA kicks it to the curb...the IV too, from what SteveC has described. I have no regrets not owning a PS Power pooper regenerator either. The ZMA does not need one!

I canceled my HR-1 order. My vintage Polk LS 90 Speakers, vintage Polk SDA 1 and soon to have in, Golden Ear Triton 2's will be all anyone could ever need with the ZMA (nice rotation in the Listening Room).

I am having my ZMA STAR grounded. It will then be a SZMA!
************Super-Zen-Mystery-Amplifier**************

It will be done by the time I get back from Vegas. Vegas Baby-Vegas!

Goodnight, good luck and enjoy.     -S

Congrats! Here in this thread a few weeks back Steve explained the bias method. . . I haven't found it yet but you may be able to. . . .

Thanks Dave! I even had trouble finding that post - here is a cut and paste of it:

To set the Bias

So, you drop the KT66s in, power on - Steve has the "bias window" set so the amp will come on in the ballpark of the tubes we would be using. (this is a great design/safety feature)  Using this image for reference -

https://www.decware.com/newsite/images/DSC_0014big.jpg

The two tiny white knobs behind the voltage regulator tubes are the bias knobs - one for each channel. Dial them in till they are close to 60ma, which is what Steve said is right for the KT66.

Now, say the tubes are pretty damn close right off the bat; you dial the bias in and it comes to 58 on one tube and 62 on the other. You use the bias balance next to the volume knob to sweep them closer or further - in this case closer so they both line up to 60ma. Do the same for the other side.

If you sweep the balance knob full left or full right and can't get the tubes to match, they are out of range and need replacing (or rematching in extreme cases I would assume).

As the tubes warm up you can tweak as needed to keep them on track. After an hour or so, they should have settled and and you can simply leave that setting till next time. Or, you can tweak, tweak, tweak and dial them in as they warm up...but they will eventually end up in that same spot after an hour.

Tubes can and will drift with age - so the bias when the tubes are new will most likely be different as the tubes age, and are aged.

I can dial in my tubes in about 15 seconds - and after 4 hours, they were within .5ma still.

I hope that helps out!

Edit to add: I find that once set, I don't need to mess with bias at all unless I physically change something, like swap tubes (or mix them up if they aren't well matched), or I did have to re-bias when I got my PS Audio P10 as it regulates the voltage to a proper 120v 60Hz vs whatever mess was coming out of my wall. Once dialed in, I've left the bias untouched for two weeks and it didn't need tweaking at all, it's very stable.

I'm using the outermost speaker posts. I don't remember exactly, but I think I remember that was 8ohms from Decfest.  frankly I haven't tried the inner ones.

Their is no fatigue from this Amp and it just keeps getting better and better. I think the Jupiter Caps are now coming into their own at 191 hours now! Plus, I was reminded my Kimber Select 3035 Speaker Cable's are still breaking in...from just being purchased back in early November from the Cable Co.....wonderful coupling with my Kimber 1030 RCA IC and the ZMA! They certainly make my vintage Speaks' overachieve.

Welcome Farmboss!  Do post your impressions with your ML ESL's.
I keep telling myself to make a bigger commitment to Vinyl...nice Table your VPI Classic. I have a Pro-Ject Debut Carbon III out in my Living Room Rig though...and it is great fun (certainly not the caliber of your VPI Classic).

Well, Steve sent me the Mod for the separation of audio ground from earth ground. It is easy (with Cap draining resistor's)....I just have to get myself from enjoying the Amp and do it.
I can do it without making the Darwin Page.
http://www.darwinawards.com/

However, no hurry, the noise has to be below audible that is being picked up by the IC inputs that are connected to earth ground...because of the way this Amp is making Music.....fast, liquid & no fatigue.

I decided not to do the Star grounding....it would have been overkill and cost me a pretty penny.

My ZMA is now passed 100 hrs. And it makes my system closed to below article. What is great sound quality?

The value of well produced music
Listening to music is one of life's great pleasures. Close to our sense of smell, music has the strongest power to evoke mood changes and bring back memories. We have all had the experience of hearing a song we loved in our youth. Immediately, we may think of a first love, a holiday or special event, friends we knew and experiences we haven’t remembered in years.

Listening to music actually causes the brain to release dopamine, the “feel good” hormone that restores logic and enables us to focus and concentrate. This can literally change your life. For example upbeat, high tempo songs raise energy levels if you feel lethargic. Classical music or jazz will often help you unwind properly after a busy day. It is interesting that when Dame Kelly Holmes won Olympic gold in the 800m and 1500m, she had a theme song in her head for the training and events. Where would films be without music to capture the mood so much better?

Why have great sound quality?
The actual quality of sound reproduction can have a very strong influence on our enjoyment of music. Why is this though? Surely if you can identify the song it's good enough? Ultimately the answer to this lies in defining what exactly is “better” sound quality? To be clear about this, leads to understanding the issues  and making correct choices.

What is Great sound quality? The ear and brain enjoy particular aspects of music. The order of priority is different from person to person but all of the following are present in a great system.

Dynamics:  The ability to reproduce the full energy of a note without loss of impact.  Loss of dynamics  are usually manifested by an artificial softening of bass notes, lack of speed,  blurred treble etc. The sound is essentially dull and boring in comparison with a dynamic sound. Dynamics are akin to the acceleration and braking performance of a car. You should put a big flag on the fact that measurements of dynamics are never included in loudspeaker specifications! This is not to be confused with dynamic range which simply states the range of frequencies that a speaker produces. Neither are efficiency / sensitivity figures a proper measure of dynamics.

Timing / musicality:  Live music is coherent, liquid and integrated – For example, the bass does not lag behind due to sluggish speed or overhang.

Tonal balance: Too much treble emphasis soon causes listening fatigue. Conversely a bass oriented sound  will become heavy and oppressive.

Separation / clarity / definition / transparency: This creates interest as it enables you to “see” into the mix and latch onto each individual strand of the music, whether it be vocals, drum beat, keyboard etc.

Natural Sound:  The ear does not like distortion introduced by resonance, electronics or phase issues.

Freedom from Coloration: Cabinet resonance, cone breakup and ringing are often present in loudspeakers. These are a bit like artificial additives in food and detract from music by causing distraction, usually at a subliminal level but there nonetheless.

Ability to create an “out of the box” 3 dimensional sound image: This is really a result of good definition and tonal balance because if these are present you are halfway there, but imaging is also related to cabinet shape and driver dispersion.

Because the brain knows what it likes and expects to hear from music, it is constantly “filling in the gaps” for reality. In other words it imagines it is hearing the real thing. This is a form of “error correction” that is going on all the time. Visual cues sometimes make this easier. For example one of our staff was at an exhibition and noticed that watching a video of a singer and band  as it was played through a reasonable system made the effect much more real. As soon as he closed his eyes the flaws of the music reproduction were immediately apparent. Closing your eyes is not something we recommend but the point here is that the brain fills in for reality.

There is one caveat here and it is a big one. The error correction process that goes on, is work for the brain that it prefers not to do. Eventually it gets tired and your level of enjoyment does not last anywhere near as long as it would with a better system.