C4S voltages

Happy Ghost · 524

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Offline Happy Ghost

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on: October 14, 2021, 06:14:15 PM
Hello!

I had built my S3X 3.0 + C4S during the Covid days. The left tube always had a faint hiss. So I finally replaced the tube with one I brought separately. I re-measured the voltages afterwards. OA is still good ~ 69 V, OB is now higher ~ 86 V. While both are still in range, I wonder if I should put in a matched pair of tubes instead? The amp still works and sounds great (no hiss though!) .. But OB being close to the edge is a tad worrying.. Is it a problem?

Rgds,
Atul

Atul


Offline Paul Joppa

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Reply #1 on: October 14, 2021, 08:27:50 PM
It's not a problem - the circuit is very flexible about that particular voltage. Plus, there's a good chance it will come down after a few weeks of use, if the tube has been unused for a few decades.

Paul Joppa


Offline Happy Ghost

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Reply #2 on: October 14, 2021, 09:29:47 PM
Thank you so much Paul!

Atul