the 40v was the grid voltage. As I said no wiring has been touched at all. only components changed
Try to put a 1 ohm resistor in series for each cathode before the connection with trafo so you can check if the issue is around one 66With no output valves fitted v at pin 5 is 345mv which is correct.....
Hi, just a thought what about trying some IPA and an old toothbrush to give the valve pins and valve bases a clean, top and bottom. Obviously give things time to cool down and check voltages have decayed before attempting this. Probably wont work, as you have reminded us both amps are the same, but relatively quick and painless ( once Caps discharged. ) to try.
Sorry to nag, but do you have nice shiny metal under your earth tags?
Sorry to nag, but do you have nice shiny metal under your earth tags?
Check the pin 3 of 66 close to blue capCaps are 630v
Why there is a resistor to ground??????
Which KT66 are you using?
I've quite a few Sovtek 6L6WXT that are way out of specs, requiring over -17V in stead of the nominal -14V for a nominal Ia of 72mA.
Generally speaking, it's good to write down the numbers while you're tracing the circuit. The original Quad II schematic gives all the V's and mA's for debugging.
I've quite a few Sovtek 6L6WXT that are way out of specs, requiring over -17V in stead of the nominal -14V for a nominal Ia of 72mA.
Generally speaking, it's good to write down the numbers while you're tracing the circuit. The original Quad II schematic gives all the V's and mA's for debugging.
No resistor to ground. That's just perspective on the earth lift resistor.Check the pin 3 of 66 close to blue cap
Why there is a resistor to ground??????
all nice and shiny and measured very low resistanceHi, just a thought what about trying some IPA and an old toothbrush to give the valve pins and valve bases a clean, top and bottom. Obviously give things time to cool down and check voltages have decayed before attempting this. Probably wont work, as you have reminded us both amps are the same, but relatively quick and painless ( once Caps discharged. ) to try.
Sorry to nag, but do you have nice shiny metal under your earth tags?
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