For those of you running the ZMA, how hot do your transformers get?  My inner transformers get hot enough that I can't keep my hand on them for more than a couple of seconds and after several hours the top plate gets very warm.  My ZP3 and CSP3 run relatively cool.  Some of the ZMA heat may just be heat soak from the KT-66s which run super hot.

Thanks for any input.  Also, you guys must have incredible hearing.  I find my ZMA phenomenal right out of the box!  One thing though.  At very high volume I had really bad feedback due to induced vibration of the ZMA from the (very solid) platform that it sat on.  I built a separate isolation platform using springs and the feedback was eliminated.  I built similar platforms for under my ZP3 and CSP3 and all induced vibration is eliminated from the components.  (Doesn't isolate the airborne vibrations -- of course.)  I pick springs with natural frequencies well below the audible range, say 10 Hz.

LR:  The inner transformers definitely get hot.  I'm running off of a Hospital grade Triplite. I don't notice any transformer buzz on the ZMA but the ZP3 and CSPS have audible buzz.  Steve seems to have fixed any noise issues.  With everything turned full up I can barely hear anything with my ear against the speaker.  I have the red caps like you.  Maybe the difference is the CSP3 or that I've been playing LOUD a lot?  It all sounds so good I just can't help myself.  :)

Steve told me that the transformers should NOT be running as hot as mine seem to be.  He said you should be able to touch them for a minimum of 10 seconds.  He told me to set my bias at 50ma and let him know how things are.  So far, at 50ma, the transformers are running warm to the touch.  We shall see what they are in a couple of hours.

Stone -- With my CSP3 and 91 db Monitor Audio speakers I can get the volume up well beyond what I consider too loud.  I haven't tried the ZMA without the CSP3 so I don't know how loud it would get or if I'd notice a change in sound.  When I ordered I got the capacitor upgrades on my ZP3, CSP3 and ZMA but I did not get the stepped pots.  My motivation for the CSP3 was the flexibility of having two outputs to the ZMA but there are other obvious benefits!  Steve gave me an input/output knob setup that is different from the description on the CSP3 product page.  He suggested having the ZMA volume full up and the input knobs, which are closest to the CSP3 volume knob, full up and then to set the other knobs (output level) to normal listening level with the CSP3 volume set at the halfway point.  Of course for headphone listening, the setup would be different.

I picked up my ZMA Thursday from Steve and had it in the system in time to put about three hours on it that night.  Initial impressions:

1.  Heavier for sure than the Torii.  Ugh!

2.  Love the looks, including those red caps.

3.  Initial bias was indeed easy.  I haven't had to fiddle too much since.

4.  I actually thought running hours were put on this unit it sounded so good out of the box.  Steve says, "no, that's the way the amp sounds".

5.  Based on everyone's feedback on the improvements in sound to come, I'm pretty excited.  There is just a bit of edge to the sound that needs to be shaved off.  I know this will come with time.

6.  Love the power switch in the front.  No more on my knees to turn on and off.  Thank you Steve for that change.

7.  I haven't pushed volume yet but there is no doubt this amp has the goods.  Dynamics clearly have more attack, like a rim shot getting more force than before.

8.  Bass.  Ah, bass.  Yes, its there in spades and oh so tight.  I played some Count Basie where the stand up bass with the torii was in the background.  The bassist with the ZMA has taken a few steps forward and again, much more tight.

9.  I'm not a fan of the placement of the bias knobs behind the regulators.  I have short fingers and this was a PITA.  I may have to keep some longer needle nose pliers handy.  I got it ok but this is my only ergonomic issue.

10.  Quiet as a church mouse.  I could hear the faint hum from the transformers on my Torii.  Nothing with the ZMA.  I hope it stays this way as it breaks in.

So far I'm thrilled with this.  A great amp and still a relative bargain.  My JansZens are happy to have a new mate.  This combo is great.  I know David has raised his prices some but these are superb speakers that really ignite when fed a quality signal.  He will be advertising a new stand mount model soon using the same technology but with less size, fewer drivers, and lower cost of course.  I'm so happy I got mine before the good reviews hit and price increases became inevitable.  I kind of feel the same about the ZMA.  Steve can raise the price any time now that I have mine.

Edit:  I do not have the ZMA's gain at full tilt.  If I did, my preamp's volume control would be too sensitive and not have much swing.  I like to get into the best sounding range of the preamp with is between 1/3 and 2/3 of its full gain.  This requires that I keep the ZMA gain lower.  Just a thought for those looking to get a preamp with their ZMA.

Scott

Since I don't have the CSP3 yet...or any experience with it...I thought this is what you meant Archie. Thanks for the clarifications. Enjoy!

Cool Scott, you're up and running! Enjoy!

Quote:


Thanks for reminding me about this. My typical temps are right in the 110 to 115 range as well. I've had the amp on since yesterday at about 6pm. I'm cranking the ZMA with some Keith Jarrett right now (Oppo at 100% ZMA at 90% or so), dialed in at 60ma with the gauges sightly bouncing, I'm at 122.0F on the right power transformer, and 123.2 on the left power transformer. My IR thermometer is a decent $45 one, so I'm sure it's accurate, assuming no operator error. I can put my hand on the power transformers for 10 seconds before it's uncomfortable.

Piano is the best I've ever heard on any amp.

Steve, thanks for these further comparisons.

I'm using the KT-66 in the Torii Mk III for the first time this week. There IS a difference, but I'm sure the power supply differences between the two amps are making a large contribution to the differing characters of the amp. Would be very interested to hear what you hear though.

Hey that's cool!

I was surprised that the KT-66 sound softer to me than the 6CA7 I was using. I'll probably put the 6CA7 back in soon for a comparison and because I'm missing a bit of something that I think is the result of the Hazen Grid not being in play.

Archie,

It's a non-issue. These transformers are actually running quite cool compared to other amps I've had. The ZMA is actually quite efficient.

I was just watching a movie with the volume cranked, temps were the same, about 122F on the right, 123F on the left.

Yeah, no worries - I've actually had guitar amps that got so hot, they cooked the labels off the transformers!

Just enjoy your amp! I look forward to seeing how you feel about it after 125 hours or so.  

I hear you Archie!

I have 277 hours on mine and I hate to shut it off and go to bed.

You know it LR!
January 22nd...the Eagle Landed.

5.036 avg per day hours x 55 days (as of yesterday) = 277

Even allowing for 1 or 2 days a week not having it on....some week nights & weekends I have it on 6 to 11 hours straight at Listening Levels you can hear up in my Kitchen making dinner with the GF and a glass of wine or two.

I am following the Direct Stream DAC thread over on the PS Forum. I am figuring out a way to get one by the Fall. First, the CSP3 and some tube rolling with KT120's...... .

PS Audio room 434 at Axpona Chicago April 25-27.

Billing it as the first show with Direct Stream.

I'll be checking it out.

NOW YOU'RE TALKING!

I just E-mailed Brianne to see if she's OK with me going. I don't recall why, but something was making it difficult for me to attend...a wedding or something maybe.

That said, I still have some PTO days I need to burn, so I can take that Friday off and start early.

If she green lights me, I'll go with you, and I will genuinely see if Paul would mind a few minutes to try the ZMA and the DS together, even if it's an off hours visit.

I am so jealous Palomino! I remember you mentioned you were going to Axpona. I will be with my Son at Stanford for an Admit weekend and for his housing in the fall, etc... (he gets his mega brains from his mother-I can't take credit).

I would be there Palo...if for not this Trip. I don't spend enough time with my son as that goes/he is 18 now. Besides the cool stuff at Stanford and area...we will hit up a Giants game...they are in town that weekend.

However, LR & Palomino, I am only 5 hours drive from Chicago Land. Seriously this Fall, if I get one...{will see what Palomino thinks about it/especially under show conditions that usually suck-and without a Decware Amp....are you going LR(?)}..... . We should get together and I'll bring my CSP3/ZMA/Speakers/Wires....and of course the Direct Stream DAC!  Unless, Palomino buys one before me!

Yes, Paul needs the ZMA/CSP3 combo with DSDAC for the show!  

Cool LR....you're going too and if you got after hours with your ZMA! Wow.

Lon, I know you have mentioned you're not into this sort of stuff. But, I think I can speak for the other guys....you know you are invited. Especially, over from Ohio now...not traveling from Texas.

Stone,

Enjoy your school visit.  That's a special time. Raven and I will hopefully figure out what this DAC is all about. And if you want to come down for the next Chicago Decware Appreciation Society meeting our doors are open.

If you guys want an opinion on anything else at axpona let us know. I have not had my ear that close to the ground so this new DAC is the only thing on the dance card thus far.

I typically don't like shows like this. Too much noise, poor room setup, douchbags with entitlement issues pushing their way around - just not my thing. I don't plan on staying long, but I'll try and poke my head into as many rooms as I can in a short amount of time. I'll probably buddy-up with Palomino so we keep each other on task. We tend to attack tasks/issues the same way.

+1 on the douchbags.  You'll want to shower when you get home.  Its a carnival barker environment in some of the rooms.  And the prices....don't get me started on that.

I will just say this...you will come home appreciating the Decware value proposition.

Maybe I will start another thread.  I would like some input on what might be worth checking out.

What link at the bottom of the ZMA page?

Nice! Looking it over now.

I'm in trouble right on the second page!

3. Never leave this amplifier powered
ON while unattended or at night
when sleeping.

Edit to add: This is already the *best* Decware manual yet! I now see why Steve wanted help to update all the manuals!

Second Edit: One misspelled word and a couple typos - beyond that, this is very well done. I like it!

A couple notes - I notice Steve is recommending 50ma as the bias point rather than 60ma.

I notice KT120 was dropped from the list, but that was probably for brevity, rather than to list *every* tube that would work - or maybe because Steve is trying to save the power transformers from abuse.

I also notice it takes a 6.8 amp fuse as standard.

That was just a quick skim.

This is the end of my comparison testing.

1. Side by side, using kt66's in the ZMA and Torii3, the ZMA still does the tight defined bass trick much better than the Torii3.  If I turn the bass control all the way down (tighter), the torii3+kt66 will approach the bass tightness of the ZMA, but there's a lot less of it.  And it still doesn't have that razor sharp attack that the ZMA does.  It really doesn't compare.  I think maddog said he can get his torii3 to sound like a torii4 or zma by tube swapping, and I agree.  The kt66's in the torii3 make it sound more... leaner? crisper? tighter?


2. The torii3 sounds better using E34L (mine are E34L's not EL34's) than kt66s. I agree with Lon, there's some vocal and presence magic that's gone from the torii3 with kt66. (because of missing Hazen Grid mod?)  EL34's sing.  Through swapping configurations, I ended up just listening to the stock torii, and I was tapping my toes with a big smile.  It's a damn good amp. Very fun to listen to.

3. Using a Bottlehead OTL headphone amp as a preamp made both the Torii3 and ZMA sound much better.  That was an aha moment for me.  I need better source.  I could make the sound thinner or fuller riding the gain.  I hear it. I get it now.

4.  no more playing around.... The torii3 is just fun to listen to.  The ZMA is just powerful and accurate and right.  I give up. They are both great, and different beasts.  I won't be giving up my Torii3. (Which mean, I'll probably be getting more speakers. 2nd system. sigh.)

5.  no more playing around... because I removed one voltage regulator in the ZMA when I was doing side by side single channel comparisons.  when I put it back in, ZAAAAAP.  big pop. big arc. change of underwear.  And funny enough the zma manual says... don't do that.   I did this a couple days ago, then noticed that balance was off.  one side was quieter, and bass was missing.  I had a horrible sinking feeling for a few minutes. Did some left right swapping to troubleshoot it.  finally swapped the voltage tubes after letting the caps drain (unplugged while it played out).  This fixed it.  Assumption: was bad contact where it arced.  It's fine now. channels balanced, bass is back, etc.

no more playing around. I'm just going to enjoy it. well, both of them.  :)

Steve,

Wow, thanks for all that deailed comparisons, I learned a lot.

Now, just sit back and enjoy and try to decide what speakers to get for the second system.

I don't have power gen. I'm just using a triplite isolation xformer.