Bottlehead Forum

Bottlehead Kits => S.E.X. Kit => Topic started by: Happy Ghost on October 14, 2021, 06:14:15 PM

Title: C4S voltages
Post by: Happy Ghost 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

Title: Re: C4S voltages
Post by: Paul Joppa 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.

Title: Re: C4S voltages
Post by: Happy Ghost on October 14, 2021, 09:29:47 PM

Thank you so much Paul!