Voltage regulation for Joule amps


I am wondering what if anything others are using for locking the AC voltage for their Joule amps. Based on the built-in voltmeter, my AC varies substantially, when I have the variac set for 89 volts and then the output tubes biased at 27-28, I find that it can be down as low as 82 volts as short while later, with the bias dropping down to 22-23!! I do not have the amp on a dedicated line and can try that next, after the XMAS lights are gone, but I'm betting it is a problem with the power delivered to my house. The difference in price between a Monster 2000 and an Exact Power 15a is almost $1K!! Any thoughts? TIA and Merry Kwanzachristmakah>
128x128swampwalker

Showing 2 responses by jsl

I own the Rites. Like yours, my voltage drops as it is warming up. After my amps warm up the voltage stabilizes in a range that doesn't affect sonics.

Reading your post, my guess is that you have the VZN-160s? Great amp! I have a suggestion that will get the most out of your amps:

When the amps warm up, turn the voltage up to the top of the recommended range. For a VZN-100 I think that's about 65 volts and for mine it's about 130 volts.

Next, bias the output tubes to read in the 29 range. Getting them stabilized in the 29 range will take a few passes through the buttons. I stabilize mine 29.5-ish...

Next, turn set the bias for your driver tubes right around 124. The bias will move a bit, but get it around 124.

Finally, sit down and strap in. You should get maximum harmonics and transparency at the same time.

The bias points will move around when the amp is warming up, so ignore all this when you turn things on subsequently. Keep your focus on the settings when the amp is good and warm and just drop me an email if you want to touch bases about anything.

Hope this helps

J
I'm sorry to be vague. I meant that I own the Rites of Passage monoblocks; the VZN-220s. I wasn't suggesting an upgrade, I guessed incorrectly.

The information in the previous post should still apply. Try setting the amp at the maximum recommended voltage and then set the bias points I suggested.

Best Wishes,

J