Some work, some don't

[jockman]

Hello all,

My Park 1273 combo, 2 x12ax7's and 2 xEL84's, has a strange 'problem'. I have, like most, bought a lot of valves (12ax7) to try for my holy grail of tone. The valves would 'maybe' work in one spot but not the other, and may not even work at all, naturally, I thought it was duff valves. But I recently had a Fender hr deluxe, and as usual, i tried some valves, EVERY SINGLE one worked, no noise no crackles nothing, try them in the Park, and...as above. Can anyone maybe through some light on this, couls there be a voltage problem? ? ? ?

Jon

[rjgtr]

You might just need to retention your tube sockets. Do the "bad" tubes feel loose in the Park?

[dartanion]

RIchard has a good point.

Also, some amps are just really fussy and certain tubes will just not sound good in them. Other amps, the tubes may be fine. It just depends

[Plexi]

is this amp a PC board..or the sockets mounted on the board? If so.. its probably a loose solder pad on the heater circuit. If its not a PC board amp,and has the tube sockets..make sure there isn't a loose connection to the socket. Got a pic?

Richie

[jockman]

Many thanks for the help, The valves seem tight enough, the inside of the amp..

As i said, they ALL worked in the Fender, and some work in the Park, could be V1 could be V2, just think its very odd, especially as, if the one that works in V2 will give a very QUIET output, as in, nearly no volume, put it back in V2, fine??
Does the voltages on the preamp valves have to be set up??

Jon

[teletroy]

Many thanks for the help, The valves seem tight enough, the inside of the amp..

As i said, they ALL worked in the Fender, and some work in the Park, could be V1 could be V2, just think its very odd, especially as, if the one that works in V2 will give a very QUIET output, as in, nearly no volume, put it back in V2, fine??
Does the voltages on the preamp valves have to be set up??

Jon

as someone mentioned above- retension the tube sockets

[merlin]

Hello all,

My Park 1273 combo, 2 x12ax7's and 2 xEL84's, has a strange 'problem'. I have, like most, bought a lot of valves (12ax7) to try for my holy grail of tone. The valves would 'maybe' work in one spot but not the other, and may not even work at all, naturally, I thought it was duff valves. But I recently had a Fender hr deluxe, and as usual, i tried some valves, EVERY SINGLE one worked, no noise no crackles nothing, try them in the Park, and...as above. Can anyone maybe through some light on this, couls there be a voltage problem? ? ? ?

Jon

Send me the schmatic of your Park, and I'll take a look.

-g