trinityamps.com

Hey gang,

So I've got the VRM installed and it seems to be working. Plenty loud when full up and most definitely quiets down when lowered. I didn't write down the B+ voltages but I think 350-ish down to less than 100 (IIRC). My question is this - should the amp clean up at lower voltages? I would think that at lower voltages the amp would distort sooner, but I'm seeing the opposite. For example - to get the same breakup with the volume at 3-4, VRM full on I have to turn the volume up to 9-10 if the VRM is all the way down. Is that how it's supposed to work? Also the distortion at lower voltages seems a little...blatty? Hard to describe but it's not very smooth and I find myself picking a lot harder.

Whatcha think? Did I break it?

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~fredster

Tone shouldn't change much with the VRM installed.

What's your min and max B+? Do those 1M grid leak have a good ground point?

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http://pdfelectronics.com

Thanks for the reply! With a JJ 5Y3 I get 356 down to 78. The ground points are grounding lugs on the tube socket, and they pass a continuity check up to the resistor lead. One thing I did notice though, may not mean anything, but the voltage on the filter caps drop very quickly when I turn it off. Whether I unplug it, turn off the power or just the standby, the voltage drops from 358 down to less than 5 in seconds.

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~fredster

Hey, I think I got it! While I was in there looking around I turned the amp off and back on, heard a bzzzap and there was the most lovely smell of electricity and fizzled dreams. I also saw some arcing on the VRM board on the B+ In terminal. I re-soldered the connection, checked all the voltages again and it's all good! The breakup level is consistent throughout the range of the VRM, and it sounds great!

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~fredster

I'd say you got lucky the VRM is still working. takes a lickin' and. Keeps on tickin' !

sounds like it's working properly now. It can get 'Blatty' at really, really low voltage though.

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Stephen
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