System phenomenon when playing loud


Great Friday Greetings All,

I'm experiencing a phenomenon which I’ve never encountered before.  When cranking some tracks to an admittedly on the loud side level, sometimes the highs and mids become suddenly muted.  Not gone altogether, but very muted.  It occurs like a switch being flipped, no fade-out, it happens in an instant.  My system is:
Triangle Volante 260 speakers 
Parasound JC-1 mono block amps 
Sonic Frontiers Line 1 preamp
Recent purchases are a Panamax power conditioner and a Yamaha Cd-S2100 CD player.  Please note, I have experienced this phenomenon several times before acquiring the conditioner and the CD player, so it’s not those.  Can anyone guess if it’s the preamp, the amps, or the speakers that’s the culprit?
When I turn the volume down, the upper spectrum returns like nothing happened, and I can turn it back up some, but I’ve been shy about going back to the level it was at when the phenomenon occurred.  There are no attendant noises the happen with the suck-out, and there doesn’t appear to be any distortion when playing at that level, and I have listened for it. It’s not like the amps are clipping, audibly.  The tracks that this has occurred on are pretty intense rock tracks.

Puzzled, I think I’ll have a Martini.  Any thoughts appreciated,

Dave
dprincipato
My suggestion is try a different preamp. Or, your attenuator on the SF pre might be corroded a bit, causing the problem. If you can access it easily, you could try cleaning it with some contact cleaner/enhancer.

Hope you get it fixed, regards,
Dan
Much thanks, George!  I’m imagining that the hard part will be determining the value of the inductors.  Unfortunately, in my experience, they don’t often have a handy label on them when factory installed.  
Last night as I played with volume levels, I could find the point where the phenomenon occurred, back off a bit, bring the volume back up, etc.  I discovered that the phenomenon did have a fade in/out, not quite the “flipped switch” I described earlier.  But the fade was very quick, just as I’m imagining the saturation effect might be.  
Much thanks guys!
Dave
A lot of the reasons why music becomes congested and distorted and compressed at moderate or louder levels have to do with things that go bump in the night, as your humble scribe has intimated over on the other loudness and congestion thread currently in play.

A lot of the reason are not (rpt not) related to the system per but to our perception (hearing) of the sound and the effect of the local environment on our sensory perceptions, especially the perception (hearing) of sound. You could say it’s mind-matter interaction. 🧠 It’s not physical or electronic. It occurs in the subconscious.That’s why this phenomenon occurs even when audiophiles are careful to address all of the usual (physical and electronic) suspects - you know, vibration, absorption, diffusion, break-in, fuse direction, cable direction, RF, sufficient power, time of day, etc.

“There is nothing wrong with your television set. Do not attempt to adjust the picture. ... We repeat: there is nothing wrong with your television set. You are about to participate in a great adventure.” (Outer Limits) 🤗
I’m imagining that the hard part will be determining the value of the inductors.


Many decent multimeters can do inductance and certainly resistance, and can be as low as around $50, you’ll work it out.

Cheers George