I just looked into other threads and see that I am not alone, although the thread is about the non select amp that I own.

I should also post some more info about system and set up.

I run two 20 amp dedicated lines, the amp is powered with a Shunyata PythonCX, into a Shunyata Hydra two and now into a Furman IT 1500 balanced power conditioner and into a short 10 ft 10 guage run to the panel.

I tried the the furman just recently to see if this would help.
It didn't.

I have run other amps in the same power set up and no hum, so it has to be just in the Decware amp.

I will try moving the breakers around and see if this helps.

I listen about 9 feet away from the speakers(Ref 3A Grand Veena,Nordost Heimdal speaker wires,IC,Manley Steelhead, Audio Aero Capitole CD, Rega P9, Hydra 8, Shunyata Annaconda Helix power cords ).

The hum is not heard from the listening position, but it's there if you put your ear to the speakers.

The asnwer is if it hurts when you do this don't do it, but,, any noise is bad noise and I know it's robbing me of something.

I am glad I looked at the posts for the other DecWare amp and feel more reassured that this isn't just my problem with my amp.

I thought i would post this again so that others would see that an isolation or balanced transformer and extensive power conditioning won't solve the problem.

I believe it to be internal not external, and so far the fellow with the cap mod might be onto something of a fix for these amps .

If that's the case, maybe a quick fix is all that's needed, but I don't want to destroy my warranty by having it done outside of the company.

I hope this helps, and I hope someone has the answer.

Thanks 4K, I have done everything and it comes down to just the amp.

Even wallplugging the amp doesn't diminish the hum, and neither does any of the other power conditioning and power cords.

I should mention that the hum is the most pronounced from my mid range driver, and not from the tweeters or the two bass woofers.

Now this may be specific to my speakers in that this very same driver is direct connected to the power amp by it's design , no crossover, it's full range, and then a simple crossover kicks in for the bottom end and the tweeter and super tweeter.

I may experiment sometime and take the amp to a friend and see what happens, but I don't think his old Spendor 2.3 are a very nice match to the Zen.

Anyways I have nothing but praise for the sonics of the amp, I really like it.It has bested quite a few amps more expensive than it is.

The only drawback is the hum.
My other amps, a pair of Red Dragon Mono blocks are dead silent.

If I had experienced the same hum with other amps in my system I wouldn't be concerned, and just accept it as a fact of life.

But in this case after isolating all components and not connecting anything to any of the two inputs on the amp, with only the speaker wires connected to the amp(plus power cord) the hum persists.

And only from the mid driver which is connected directly to the amp, not from the bass driver or tweeters.

It's a low 60 hz type of hum that neither gets louder or softer in volume when you fool with volume pots.

It takes a few seconds for the hum to begin,I guess as the amp charges up, but it doesn't stop as the hours go by.It only ends when the power is turned off on the amp.

I may try some different rectifier tubes,but it was there with the stock tube and the amp is still only a few months old.

I've lived with it this long, and it's not a deal breaker, but if I could find a way to rid myself of the hum, I would be 110% satisfied.

It was small comfort to find out that I am not alone in the hum situation.
I am curious to find out what systems set ups are hum free.

Maybe it would be nice to hear from all the hum free folks and find out what gear they have been successful with.

I wonder if there is anything I can do at my speaker end to fix the problem.

I have tried running a ground wire from the screws on my speaker's connection plate to no avail.

I tried lifting the ground at the amp with a cheater to no avail also.

So I am open to all suggestions, short of selling either the amp or speakers.

Thanks again.

Lon,

 That is a great idea about the tube. Something like that often gets by me when I am tracking down a problem. My system also has a little hum, and it is all solid state for the time being. The reason that this worries me is that I have on order the FRX drivers, and with them being very efficient(like ZENs), the hum will only increase. I'll keep ya posted.

I still haven't solved my SE84C+ hum problem (another thread on the SE84C+ forum), but I just started another thread on the General forum asking if anybody's had success with isolation transformers, power regenerators, etc.

But my hum level isn't a show-stopper at all.  However, it would be nice to know if there's something external to the amp that could reduce the level of hum somewhat.

Mark Blair

Well I thought I would try a different tube for the input .

I replaced the very good Russian tube with an older gold pin Seimans 6922.

I believe the hum is not as pronounced,but again it's win some loose some.

The bass has bit less puch and impact, but in return, the mids and highs and the overall clarity of the amp has improved.

This amp is a source of wonder for me.

It's like a chameleon.

Do some tube swapping and change the sound.

My advice to anyone who is thinking they need a change  and are contemplating selling their Decware, is to just do some tube rolling.

The rectifier and the input was where I started to notice differences.

I wonder if switching to EL 84s would be a step forward or back?

It's normal to have always a slight hum. The main reason must be the input tube. There's also the design of the amp. As far as I know, a SET amp is going to have more hum than a push-pull amp or an amp which has negative feedback.

Glad you're enjoying your Premier! I've had mine two weeks now and it's transformed my listening. I have really bad power here. It's more dramatic a change than tube-rolling. I obviously have been experiencing my system at far less than "all it can be."

I've not yet used the Premier without an isolation transformer, but the isolation transformers I've used have really improved my sound and I've seen no indication it's doing anything detrimental to my sound with the Premier. I've seen cautions to not use computer related isolation transformers/uninterrupted power supplies, but haven't heard of problems with audio-suitable isolation transformers as long as they can provide enough power for the system.

I just plug my Premier directly into the isolation transformer, and I plug everything else into the Premier. Works fabulously for me, but then again I don't have quite the power requirements that your system will have!

It's 500.

Somewhat to my chagrin, I forgot that I had thrown a bid on a used PPP on fleabay. It was a trade-in with an audio dealer by someone who was trading up to the more current models. Anyway, it's supposedly in mint condition, and it's in black, and I wanted another one anyway. And it was a few bucks less than the B-stock on Music Direct. We shall see.

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That's exactly what I told my wife! Must have worked. Now I have a black and a silver one.

Personally, when it comes to the hum issue, I cheat.  I primarily use my Decware amps in bi-amp configuration driving the horns of my Klipsch speakers.  No hum whatsoever, as it's completely filtered out.  No restrictions on dynamics, wheather it's Mahler or Metallica.

Even run full range with the Zens, the hum is only noticable within a couple feet of the speakers (pretty sensitive at ~99db/w).  Hum has never been a real concern or prevented the goosebumps from happening.