Phono II looses right channel

[Greg.]

Thanks for all your suggestions. You know I'm not green so much you've advocated I've been over already. I spent some more time on it today. Resoldered every component and valve base junctions etc. I repeated voltage checks which remained correct. I carried out continuity checks on the whole circuit board and all was fine and there was no visual sign of a broken track. With the work I've done, I'm satisfied that the problem is a poor contact within the valve socket. As this is a sealed ceramic unit, it's not servicable. Furthermore, the board is so well used with hard wired links all over the place, it's not worth the hassle (it's a big hassle) of replacing the valve socket.

To my rescue comes Clive who within the generous ethos of this forum, is sending me free of charge his obsolete Phono II circuit board. Thankyou Clive. Hopefully, in a couple of days, my both channel vinyl sound will be back to normal.

Best wishes,

Greg

[NickG]

Err, Greg, not wanting to argue with you. But...

If there is a bad contact with a valve pin, how do you believe the voltages can be all correct?

the problem I've had is losing a channel with a phono pcb, it went if I touched a phono lead, lifted the amp, twisted the chassis, pressed the top of the chassis. I found a wire connection to a cap brocken in the insulation but it was a decoupling cap. This was after ages messing with phono connections.
The phono on the pcb was only used for wire connections and it was the earth from this lump of ally that had parted with the pcb the half width of a hair and when measuring I was useing some pressure.
Check the earths

[Richard Higgins]

Hi Greg
If its any help, I rebuilt my Phono II using two tag boards and raising the valve bases so that the valves poke out though holes in the top of the cover.
I've got my version of the layout somewhere if you decide to hard wire it.

Regards Richard Higgins

[Greg.]

Thanks for all the help and advise.

Nick, I don't understand either.

Will, checked all the earths to no avail.

Remember, throughout the circuit, continuity is measured as good.

Richard, I've often wondered about doing this as I've done Pre II albeit hardwired on matrix board. If I did it I'd want to keep the valves enclosed within the chassis which I achieved in Pre II even mounted vertically, but if space is an issue I see no reason why these small valves can't be mounted horizontally. Certainly I'd be happy to see your lay-out either here, by PM or email.

Anyway, with Clives spare board (free of charge including delivery) I'm up and running again and once more loving my vinyl sound. Thanks to all and especially to Clive. Yet another example of the generous and healthy ethos this forum continues to promote. You can't beat it. The best you can do is, whenever the opportunity arises, join in and contribute. To be sure, give and take balances out over the passage of time.

Best wishes,

Greg

[Basil]

Hi

To get an idea of a hard mounted version have you seen the link below, it shows the valves mounted vertically within the original case:

http://www.triode-systems.com/module...p?articleid=13

Basil