Kat34 component replacement

[FoxJT]

Hi,

I have completed the mods to my amp. It is now a Kat34 with the input attenuators, rec balancing resistors, 470R cathode resistors for the EL34s and new 100uF. I also replaced all the valves with the match set from Watford valves. The volts around the amp are much closer to the design volts, so that the components will hopefully have a much easier time . I just need to fashion a wooden front plate to complete it.

OK it was a rather wholesale upgrade but the change to the sound is more than marginal! . It all seems quite a bit more open. I haven't added Acorn's bypass caps yet, though.

During the mods, when I was testing, I used my older valves and was rather puzzled when one of the EL34 cathode volts were 0V. My initial suspect was the new components I had put in, or c**p soldering. However, Moving the valves did seem to move this, so it appeared that valve(s) had gone open circuit inside; ie valve not conducting. My other suspect was that perhaps the valve base was no longer making a good connection to the valve pins.

Putting the new valves in cured this. I wasn't looking forward to replacing valve bases! However, is there a possible problem with bases after a lot of insertions?

Thanks all for the helpful assistance and suggestions.

Cheers,

Jeremy.