Steve Deckert
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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
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