Need Help by e80cc tube premp

[pl802]

Hi Audio... What's your Htr PSU? Series 12.6V or Parallel 6.3V ?
Wiring doesn't reflect your text? Or am I missing something.

 

[audiorado]

...Hi,heater PSU is 12,6 volts DC series!!!

 

[pl802]

I worry about the Valve at start up when the heater is cold....a diode spanning grid and cathode is your friend.BTW this scheme reminds me of ccda...constant current draw amplifier Tubecad Blog0161.
Hope you sort it.

 

[DF96]

Hi,is no coax wire,its only a piece of silver wire , that goes from tourret tag to pin 2!

OK. The black stuff around it looked like coax insulation.

Anyway, huge input caps (just visible at top of picture?) mean large stray capacitance so room for unwanted feedback.

 

[Ketje]

If the tube resembles the 6N3P the gain is 25x or more.It probably saturates giving bad sound.
Mona

 

[audiorado]

...hi,Mona.....
...the tube that I use is one piece E80CC per chanel.I say already I have 3 pairs from this tubes from Valvo,Philips and tungsram,and with all this tubes the problem is tha same,I try the ecc82 to,becouse many people use in the way of ecc82 than E80Cc and it work perfectly,but in my preamp when I use ecc82 pait of tubes the problem is the same.I have now put the 1kohm of grid resostors in the input socket pin(pin2) and the problem is the same.
Have maaybe someone out there some good schematic for line preamp with E80CC tubes???

 

[pl802]

tubedata.org is your friend....see highlighted area in the attached

 

[audiorado]

Hi....thanks for the help,yes Im thinking to go this way now,to use this lower values of resistors to see what will happen.I have no another idea how to solve the problem with this parts right now.I will report back in the next few days.I must buy the resistors first.

 

[Ketje]

Try it with these values, based on the 6N3P data.
Mona

 

[maxst67]

Hi audiorado, have you tried the circuit with the resistance values updated for e80cc? how are you ? it works?. Thank you

 

[Hificat]

hello everybody. i do have ciruit to run 12au7 at 8ma/420v B+/ra=30k, are e80cc still able to work that conditions?