Hey guys,
About two years ago I did the JC18 with the ideas to make it some more gainy. I tweaked it to taste and added some stuff.
The only thing im encountering now is that when I push the gain it starts to develop some noise, and with the gain knob on three quarters I hear it make kind of a 'swooosh' sound when turning it to full. Also sometimes some HF noise.
Any ideas? I lowered the cathode resistor in the first stage from 2k7 to 1k5 and did a.68 bypass cap. on the second stage I made the cathode resistor switchable between 3k and 10 with .68 bypass. (This way on the 3k/.68 setting you have this plexish vibe going on when going in the low input) Also raised the plate resistor on the first stage to 220K. Did the depth mod in the nfb loop.
The problem noise came after I put back the treble peaking circuit before the second stage. before that I've had the v1a plate res. up to 300K with no issues. but it lost definiton, so I lowered it and put back the treble peaker/attenuator.
left out the bright cap on the gain pot.
It sounds super tight, punchy and fat. With just the right amount of gain.
Any tips to get it a bit less noisier, or maybe some tweaks?
Thanks in regard guys!
Jesse
