ECL86 reverb design issue

[Bob-I]

I'm having an issue with my ECL86 reverb in a Dumble clone.

I took the reverb xformer B+ off the screen node on the power supply rail, into a 10k / 20uF filter isolation stage which gives 210V B+ on the pentode side. Rk/Ck is 180R/25uF and measures 4.6V. This seems to be about 70% dissipation on the pentode, but it depends on the data sheet you read

Last night after several hours of playing the 10k resistor burned open. I replaced it and measured the voltage drop across it. It's dropping 260V about 6 watts. I put in a 5 watt resistor.

If I move to a later node on the PS rail I'll be dissipating more across the rail changing all the voltages. I can increase the voltage on the plate but only to 250V, max design spec for this tube.

Any suggestions on getting this more reasonable?

[tictac]

Remember this is not a power amp! You only need 1 watt or so to drive the reverb tank. There's no need to operate at 70% disapation.

I've used a 1k cathode resistor and used a 27k with a 22uf / 450v cap to lower the screen voltage with this type of tube.

TT

[tictac]

Remember this is not a power amp! You only need 1 watt or so to drive the reverb tank. There's no need to operate at 70% disapation.

I've used a 1k cathode resistor and used a 27k with a 22uf / 450v cap to lower the screen voltage with this type of tube.


TT

[Bob-I]

Remember this is not a power amp! You only need 1 watt or so to drive the reverb tank. There's no need to operate at 70% disapation.

I've used a 1k cathode resistor and used a 27k with a 22uf / 450v cap to lower the screen voltage with this type of tube.

TT

Well damn that was easy. Worked perfectly and still plenty of depth to the reverb. Thx