Tube stereo sounds -smaller- after being on


Ok here is a weird one. I’ve been into tube audio for the last 20 years or so and I have one system I leave as is and one system I mess around with and change things out. For the most part, these days, I’m happy with both. Except I’ve been noticing something I thought I was imagining. Which is my experimental system starts out sounding great and after being on for a couple of hours sounds worse. Small soundstage, compressed highs and lows. Just over all enh. I have two turntables -

Gates and an EMT 930. The mixer is a great sounding one hand built in Austrailia called a Condesa Lucia. The amp is a Line Magnetics 2a3 amp LM 217. The cartridges are an EMT and a Denon 102. The tt preamps are by sun valley and auditorium 23. The one thing I can think of is the amp is a 220 version and goes through a power converter. Perhaps this is a sonic wrecker when it gets hot. Any other ideas? Thank you. 

yaluaka

Thanks everyone for your thoughts. I only thought about the line voltage being an issue when I wrote the above post. The amp came with a Chinese made voltage regulator that doesn’t seem to be adjustable and shows 217 volt output on the led screen. I always thought that was pretty weird. But since it came with the amp from China I didn’t question it. As for other possible issues, the mixer, being Australian made, could also be in some voltage netherworld. It comes with a separate power supply set up for the US which gets very hot. I can take that out of the loop easy enough and see if that’s the issue. Plus I probably should just buy a different regulator for the amp. 

@yaluaka Sorry when you say Mixer what component are you referring to? A mixer as in pro sound? And you're using it as a preamp?

The mixer is a great sounding one hand built in Australia called a Condesa Lucia.

If you are "adding" EQ with your preamp/mixer it's possible that doing so is overtaxing the 3 watt amplifier and/or the step-up TF you are using.

What speakers are you using, or are you using headphones (I know ZIP about headphones)?

Just throwing this out there for thought/discussion.

Interesting LM amp which I was not aware of (like the tube compliment and the soft start feature).

 

DeKay