Tube Lab

What happens when you have too many tubes and not enough amps? This!
Link to our online store: valvesnmore.com/
Link to Mellow Tone Kits: valvesnmore.com/?page_id=13253

[@thermionic1234567]

I have a lot of amps and adapters. That’s my Rube-Goldbergesque solution.

[@davidkclayton]

Hey you guys , you might do well to hire a hand model for your videos.😁

[@airgead5391]

nice! I have about 170 pcs 76 tubes lying around.

[@thermionic1234567]

Nice tube. I have a lot as well.

[@masterazlan6999]

Triode.. Hmm.. Peace!

[@CollectingRetro]

Very cool testing setup! Did you use the 2P4T rotary switch that you sell?

[@tubelab194]

Correct, and interestingly the rotary switch we eventually settled on is a Chinese copy of an old Soviet mil spec switch, which was originally silver plated. I brought in a whole bunch of the surplus Soviet switches and often found the silver had oxidized and many had contact issues. The Chinese copy just uses tinned brass contacts (tried and true) and it has proven to be reliable and overall an excellent rotary switch. Most people who buy amps and kit amps look closely at the specs, design, chassis and never realize how important something like a good switch is for both quality sound and the longevity of the amp.

[@thermionic1234567]

Why not just use adapters on these 7N7s? I’ve been lucky and haven’t had any mechanical or electrical issues.

[@tubelab194]

We started with adapters, but found the same issues that killed the base type are still a problem - difficult to insert and remove and poor pin contact. The solution was to rebase as octals and that has been a huge success. And interestingly the locals sound better rebased - I know it doesn't make much sense, but Charles thinks it has to do with the resistance/impedance change rebasing gives.

[@thermionic1234567]

@@tubelab194I agree. They probably do sound a bit better as they probably have better, lower-impedance connections. Normal pins probably have 100% more surface area.