Jono_L
New member
My Laney LC15R has been acting up lately. Its cutting in and out - it jumps from its normal volume to approximately half volume, depending on its mood. If I was lucky, it'd stay at normal volume, but just cut out once in a while. Now, it stays on at around half volume, never jumping back up to normal volume. 1 of the 12ax7s in there are new, the other one around 2 months old, and the other is REAL old, but was working when my friend took it out of his amp. By half volume, I literally mean that it is half of the percieved volume, and whereas I used to run the master on 2, I now run it on 4.
I used to suspect a problem with the phase inverter slot, as wiggling the PI tube got it to cut in/out, however, no matter which 12ax7 I stick it in (new or old), its staying at half volume. Opened up teh amp, and I didn't see any sign of a cold solder joint, nor did I see any loose wires. Now, no matter which tube I stick in the PI slot, its still at half volume.
Power tubes are approximately 1 1/2 years old, but this amp is hardly ever cranked. Both power tubes are working afaik; I pulled one tube and tested the amp, had the tonal difference of and slight volume drop of running one tube less, and pulled the other; got the same result. (For more info on running amps on 1 tube; http://www.londonpower.com/faq.htm) In this case, would this mean that the PI is fully functional too?
Any pointers/suggestions? As far as I know, there are no guitar amp techs in the country. If it gets sent anywhere, it'll have to be sent right back to Laney in the UK - and paying the shipping for that would be a b*tch. The Laney dealer/distributor don't really know sh*t either.
I'll have a buncha spare/old tubes to screw around with in a couple of days, but right now, I have the stock power tubes, 2x EH 12ax7EH in both preamp slots (one is brand new, other is a couple of months old) and a Ruby Czech Selected ECC83 in the PI slot (very old, but no matter what tube I substitute it with, I still get the same problem)
I used to suspect a problem with the phase inverter slot, as wiggling the PI tube got it to cut in/out, however, no matter which 12ax7 I stick it in (new or old), its staying at half volume. Opened up teh amp, and I didn't see any sign of a cold solder joint, nor did I see any loose wires. Now, no matter which tube I stick in the PI slot, its still at half volume.
Power tubes are approximately 1 1/2 years old, but this amp is hardly ever cranked. Both power tubes are working afaik; I pulled one tube and tested the amp, had the tonal difference of and slight volume drop of running one tube less, and pulled the other; got the same result. (For more info on running amps on 1 tube; http://www.londonpower.com/faq.htm) In this case, would this mean that the PI is fully functional too?
Any pointers/suggestions? As far as I know, there are no guitar amp techs in the country. If it gets sent anywhere, it'll have to be sent right back to Laney in the UK - and paying the shipping for that would be a b*tch. The Laney dealer/distributor don't really know sh*t either.
I'll have a buncha spare/old tubes to screw around with in a couple of days, but right now, I have the stock power tubes, 2x EH 12ax7EH in both preamp slots (one is brand new, other is a couple of months old) and a Ruby Czech Selected ECC83 in the PI slot (very old, but no matter what tube I substitute it with, I still get the same problem)