Help needed the Pre-3 CF CSS Config.

[G Willis]

Thank you for the offer but its working fine now and I'm happy withbthe sound.

(CSS is a typo - I am a software developer and CSS crops up)

[bob orbell]

Looking at Grahams problem with the CCS, I am now building one, and I think the problem may have been caused by Graham fitting the wrong valve. With the ECC83 he would have had about 50 volts DC into the ground, this would have found its way to the collector of Q2 / 12 via VR2 / 12 and R7 / 17, it may have damaged Q2 / 12. With the correct ECC88 6922 this would not have happened. May be John C could comment. Bob

[bob orbell]

Just finished mine and the set to CCS, switched on and measured the CCS voltage and adjusted with the trimmers to the recommended 0.84 volts with no problems, I suggest Graham tries again with the correct ECC88 valve, if it still does not come up to the correct voltage then it must be a malfunction. I did offer to have a look at it and the offer still stands. Bob

[John Caswell]

The Pre3 CF uses an ECC88/6DJ8/E88CC and the like and is a different pin to the ECC81/2/3 range of valves.

John

[bob orbell]

Yes John, indeed, but read post 7 and that will / should jog your memory, Graham states in post 7 that he used a ECC83, and that he could not get the voltage up to the 0.84 volts with CCS configured. Bob