Zyx Universe. O.24 mv vs .48 mv with low eff spkrs

Doug wrote

If you feel like taking the time, it would be instructive to hear how the UNI2 behaves with your Salk speakers. My guess (only that) is that it would slightly improve the perceived lack of dynamic headroom.

Doug will do
maybe I mislead everyone somewhat, I have headroom with the Van Alstine, just wanted to see if it was worth getting more as I was on the upper range of my Doshi volume knob. Hence the .24 vs .48 mv question

The Atmasphere will not work with low efficiency speakers

I will add in one piece at a time, most likely the ZYX will arrive first

perfect indoor fun for the hot summer that hasn't quite hit New Orleans yet

I cleaned 30 lps with my Kl Audio ultra sonic yesterday evening in preparation for the anointing

yes Mehran is the best!

Audiotomb, there should be no issue if the volume knob is near the end or all the way up. Usually, all that a volume control does is attenuate the strength of the incoming signal, which the preamp circuit then amplifies by a fixed amount of gain. The only concern with the preamp circuitry should be the level of the signal input, the fixed (maximum) gain of the preamp, and the preamp's maximum output level.

If the signal going into the input jacks is 6V and you use the volume to reduce the input level to 1/10 (0.6V), or if the signal going into the input jacks is 1.2V and you use the volume to reduce the input level to 1/2 (0.6V), both are the same thing to the preamp circuitry. Whatever the input signal level ends up at, the preamp circuit will amplify that by its fixed (maximum) gain, which does not change with volume position.

I know that many audiophiles show a psychological adversion to having the volume turned all the way up, but as long as the preamp output isn't clipping or distorting, the physical position of the volume is a needless worry.

kind regards, jonathan

PS. There may be one or two unique preamps (such as Ayre's KX-R) where the volume does alter the internal gain, but such designs are quite rare.

My guess is that once you hear the Atma amps w a suitable speaker, your only argument will be w yourself, for not doing it sooner. IMO, the Salk speakers are beautiful, real craftmanship, but clearly designed for high power SS amps. A high(er)/flat impedance, high(er) efficiency speaker designed for tube amps is the way to go w the Atma amps. My own experience is that you do have to be somewhat concerned about hum and noise when you go to very high eff speakers; the higher eff the more careful you have to be; there's a reason why many low power amps (likely to be mated w high eff speakers) have hum pots!

Swampwalker, I am guessing you've not heard our amps in a while! At the Munich show we did not use the jumper plugs as described on our website, yet to hear any artifact from the electronics at all, you had to have your head inside the horn of the loudspeaker, which was 107 db. Even then it was a gentle hiss.

My apologies to all, but esp. to Atma. My last post was poorly worded. The reference to being more concerned w hum and noise was based on two things. One, just an electrical/acoustical fact of life. A higher eff speaker will reproduce the inherent hum and noise in a system at a higher SPL than a lower one. At least I think that's a fact of life. Second, my recent experience w both push pull and and PSET amps (but not w the Atma OTLs). When switching between two speakers of differing efficiencies, I always heard more tube rush or hum or noise from the higher eff speaker. I was not in any way trying to say that Atma amps were noisy when mated w high eff speakers. My bad.

Since I generally can't stand horn speaker distortions, listening with my head deep inside the horn is often the only way I can tolerate them. Swampwalker's advice and Ralph's clarification are spot on!

<:-)