5F6A + 'blocking' distortion & Grid Stopper trials

[Gaz]

Hey! That was the first time I was able to help somebody!

[BackwardsBoB]

I think its time I invested in a scope to eliminate some of the guesswork in future builds.

I got a Velleman PCSGU250. They're really cheap for a new scope. 2 channels plus function generator, computer controlled, 12 MHz bandwidth, it does frequency response, spectrum analysis, bode plots... and it doesn't take much bench space as long as your computer is nearby.

You can paste scope shots into your posts.

[jmaf]

I recently(delivered last week) built a 5F6-A clone that had cracking sounds exactly as described. It was a long plate Sovtek 12AX7LPS on V2.

When I made the long plate into the inverter and swapped a quieter JJ into V2 the amp was just fine.