I purchased a fryette lxii on july 26th. I had been using a single synergy syn 2 preamp on channel B into a 16 ohm palmer pdi 03 loadbox/speaker simulator , the impedance selector was set at 16 ohm. I just recently got a second synergy syn 2 preamp that i had then plugged into channel a and then output A was plugged into a second 8 ohm palmer pdi03. The impedance on channel A was set at 8 ohms. Almost immediately i started getting intermittent audio cut outs on channel B. Now channel B has completely stopped working. I have checked and changed out all cables and and the fuses on the front. Can you please advise me what I should do next. Is there anything else i should check, or should it just be sent for service? I have not yet called the place i purchased it from , but it is about 60 days passed the exchange window. Thanks
Hey @S_everett good to see you again,
Just to check the obvious things, you are in Stereo mode and you are using the “use first” speaker sockets?
I cannot see any problems with what you have done.
There are a few things you can try:
- Swapping in different tubes
- Ask dealer for a warranty repair
Unfortunately, the tubes are now out of their 90 day warranty period. So that is why I suggest you try replacing the tubes yourself.
Regards,
Dan
Thanks for the reply. Yes I thoroughly checked all the settings, stereo, impedance switches etc. And i made sure i had it hooked up into the use first jack.I thought it could maybe be the 12ax7 tubes? Do you recommend i change all the tubes , the 6l6 and 12ax7? Also is there anything in particular i should be looking for when buying tubes, like particular brands etc ? Will any 12ax7 tube work? For what its worth all of the power amp tubes looked like they were working fine, but i know that doesn’t really mean anything.
Hi!
I would take a scientific approach:
- Do the 12AX7 first, check if that solves the problem
- Then change the 6L6s
When you open the LXII do you see any information indicating the target plate current? This will normally be a number written on a Fryette sticker saying I_p.
My PS-2 has Sovtek but you could also use Psvane or JJ.
Regards,
Dan
Ok. So i switched the two 12ax7 tubes from there original position( switched A to B, B to A). When i did that i got no sound on either channel. I then replaced both of those tubes with 2 other 12ax7 tubes i had and was back to having only channel A working. I then changed the tubes back to the original 2 that came with it. When i turned it on , the tube on channel B started glowing bright blue quickly so I just turned the amp off. As a side note: i noticed the blue transistor that is next to the presence and depth control ( the same one that was bent over that i emailed you guys about when i first got the amp) , looks kind of like there could possibly be a crimp or break in it. I was advised at the time to very gently , slightly bend it away, which i did at the time and it still worked at the time. I hope i didn’t break it by doing so. So what can you advise at this point? If its something i did , i dont care to pay you guys to fix it. If i did it then its my fault. If its something covered under warranty and i need to pay to ship it to guys thats fine too.
Hi !
Ok so your swap experiment tells me that you have a bad preamp tube. Nothing should change when you make that swap. It does not rule out 6L6. But it is a start.
The blue capacitor looks fine to me, it would be very hard to damage that by just pushing it.
What do you want to do next?
Im going to buy a complete set of preamp and power tubes and put those in and go from there. I will make sure they match brand and model numbers. Just out of curiosity if its a bad preamp tube, what are the odds of the same channel not working when i put the other set in?
If there is also a power tube issue then maybe. This is a Bayesian probability problem - I give up!
So i turned the amp back on without the cover so i could watch the tubes. The phase inverter/preamp tube for channel B didnt come on at all this time. I then switched it out again with another 12ax7. The tube came on but still no sound on channel B. Just to make sure, i went ahead and switched the other original phase/preamp tube and still no sound on channel B. However i noticed that while all 4 6l6 power tubes had a normal looking orange glow, only side A had a slight blue glow that appeared as soon as i turned off the stand by switch. So i switched the side A and side B 6l6 power tubes and then i finally had sound on channel B but not channel A. So it would appear i have a bad preamp and two bad power tubes on channel B. Would you agree with my conclusion? Im going to still change All the tubes ASAP . Im hoping this will fix it. That only begs the question of what happened that would cause the preamp and both power tubes on channel B to blow all at once?