Does anyone care to ask an amplifier designer a technical question? My door is open.

PS:

the speakers could have have been changed to 8 ohms at re-coning. I kept them at 16. They are rated 101 dB efficiency.

The Futtermans are now about 45 Watts each. .

Since you listen at such low levels both amps are playing no power at all and thus both have very little distortion.

Are there some yes/no questions I could answer. It hard for me to see exactly what you are getting at.

Thanks for the reply!

I’m still trying to understand:

If my amps are being run at levels that do not bring on distortion, why do they still have that classic "tube-amp" character even at those low listening levels? If it’s not the clipping characteristics that are coming in to play...what is it that produces that classic tube sound as I described it?

You write that the low damping factor will come in to play across various speakers, so it seems that’s at least part of the factor. But does it explain everything? I’ve always associated low damping factor mostly with audible effects in the bass region. But with the tube amps there is also a sort of thickening and slightly softening of the mids and upper frequencies - it seems an across the board effect on the sound, not just in the lower frequencies. What other deviations may be coming in to play to alter the sound, even at low volume levels?

Also, I thought that impedance difference in speakers could cause audible issues in the high end as well - e.g. audibly rolled of highs etc.Which never really seems to occur that I can detect, across a broad range of speakers with very different impedance/sensitivity profiles.

If you can get a low impedance amp then you can hear what the speaker designer intended you to hear.

Ha! You trying to nudge me towards accuracy? How dare you! ;-)I’m more concerned with ending up with the sound I like, not in satisfying whatever the speaker designer may like. Normally when I audition a speaker it’s hooked up to solid state amps and I can get a very good indication as to the general sound and character of the speaker. Then I just nudge it a bit more in the direction I like. I’ve found the CJ amps preserve what I like about a speaker, while adding a bit more of what I like in to the equation.


As mentioned, I’ve used amps like the Bryston 4B ST, which would provide the type of low impedance/damping performance I presume you are alluding to. Every time I’d switch to the Bryston I’d hear that slightly more tight, taught, precise sound and think "well, that does some things differently and strikes me as more ’accurate.’ But I always found over time the whole system still had a sonic signature anyway, and I found the sound overall more organic, easeful and believable with my tube amps.

Such is personal preference.

Thanks again.

@unrecievedogma I also have settled on a remarkably similar system. I use Altec 604E’s  run full range from a pair of atmosphere M60s.  Then off of a second Output  on my preamp I run a dahlquist crossover to a pair of 12 inch subs.  I usually have it set at about 60 hz. 
 I also have a pair of fostex T 900 super tweeters augmenting the top end. 
 I have owned a lot of gear including high end Tannoy‘s, apogee Divas, reference 3a grand veenas.  I find this to be the most enjoyable and best for me. No plans on changing anything. 
 When I go to the shows I find my rig to sound better than pretty much everything there, to me. 

analogluvr,

I’ve been curious about the Atmospheres.

I have a 3 disc LP set of Theodorakis’s “Canto General” that Atmosphere produced, and I found the engineering to be disappointing. It has been muddy, and there has been no bass to speak of. I have yet to listen to it in the new environment with the sub. Maybe it will sound better.

As for setup, I run the signal through the preamp, then into the Velodyne servo, which splits the signal and sends above 70 to the Futtermans and below 70 to a 300 watt ss amp within the servo and then to the sub, which is also connected to the servo by another line that as I believe they say in their literature “digitally corrects for phasing” in order to reduce distortion from that source.

By cutting off the signal to the Altecs below 70, it gives them much less work to do and they sound clearer.

When I go to shows, the way I would put it is that I almost never hear anything that I would prefer, and never ever hear anything that I would prefer that’s within 300% of what I have spent on my system.

Nice to meet you. It’s nice to know that there is somebody out there who thinks and hears similarly. By hearing, I mean that my ears, from an early age, grew accustomed - maybe trained is the word - to hearing audio a certain way. My system no doubt sounds very colored to many, but it suits me fine.

Roger, I have two questions though the second is a doozy. 

1) What do you think of the Tungsol KT150?

2) What are your top 5 criticisms of the ARC Ref series components (i.e. the Ref 75SE or Ref 150SE amp and the Ref 6 preamp)?

I ask because I own and am proud to own the Ref 150SE and Ref 6 and more importantly, they deliver untempered joy and because while you said some negative things about Bill Johnson, you passed over the fact that Ward Fiebiger was the mind behind the latest designs.