Last rehearsal my 2/90/2 began feeding back horribly, at the end of a song luckily. I took it home to check out and found that V2 and V4 had both failed at the same time. That seemed weird to me. I replaced those tubes and it works mostly ok now. But while making sure it would work with the new tubes, with the top still off, I noticed that the heater on one of the power tubes was rather weak compared to the others. Also noticed that that channel fed back more. I had noticed the feedback before but didn’t realize it was only on one side. I just assumed it was the gain I was using in the preamp. I don’t have the proper equipment to bias it as shown in another post, and don’t know of any decent techs in my area. I’d like to send it in for a checkup, especially after those two tubes failing at the same time and seeing the weak heater. How can I do that? And what is the timeframe?
My rig for this band is a two amp rig. Two Syn 2s using the 2/90/2. And we play loud.
Hi Dub,
Is this an out-of-warranty repair? If not, let me know your approx. location and when and where you purchased the unit from.
After you let me know your location, I might be able to suggest somewhere, but if not Fryette works with legitimate repair shops; you can follow these steps, Can I get my Fryette product repaired at a local repair shop? It is usually easier to take it somewhere locally than ship it to LA.
Let me know, and we can take it from there!
Hi Dan,
I purchased it from ZZounds in July 2022 but didn’t receive it until that September, so I assume it is out of warranty, especially for tubes. I am in Fort Worth, TX. I only know of one tech in this area anymore, and I’ve had nothing but bad luck with him. Maybe you know someone in this area?
Thanks.
Hi Dub,
Well, it’s worth checking with them the warranty length before we proceed!
Dan,
The card that came with it says there is a 5 year warranty, of which I have two years left, on manufacturing defects in materials and workmanship, but tubes are only warrantied for 90 days. I’m assuming that it is a tube issue, though it was odd that both stage driver tubes failed at the same time. And the one power tube having a weak heater I would assume is the tube. But I could be wrong.
Are you saying that I should email Fryette itself to see if this would be considered warranty work?
Thanks
Hey Dub
The chances of two tubes failing at the same time could be a coincidence, but the changes of two random uncorrelated events occurring simultaneously is unlikely. It hints at a possible underlying issue. As for heater brightness, I always find that hard to estimate, but let’s chalk it up as another factor.
Zzsounds are an official dealer, so please contact them for a warranty repair/service, if it turns out to be tubes, then you will have to pay, but if it’s turns out to be something else then they should cover it!
Let us know how you get on!
Hey Dan,
Thank you for your help. I’ll contact them about sending it in. With my luck it will all be coincidence, but at least it will be working properly again.
One more question…should I reinstall the 12AU7 tubes I replaced before sending it in so that it is seen with the original issue, or just make a note about it when I send it?
I think either is fine, you can even send them this forum link so they have the history we have discussed.
Hey Dan,
Thanks again for your help! I have emailed them and am waiting on a response.
Cheers!
Well Dan,
I contacted ZZounds and they weren’t any help at all. Here is what their reply was…
“Thanks for the email. zZounds does not offer any warranty nor do we perform warranty service for manufacturers. Please contact the manufacturer to make a warranty claim on this item. We suggest contacting a local repair facility. Please let us know if you have other questions or concerns.”
Hi
I’m checking on this, please wait for accurate info…
Hi Dan,
I haven’t heard anything yet so just checking in. I know I’m not the only one you are dealing with, so no rush or worries. I have a couple of heads that will hopefully work for upcoming gigs and rehearsals.
Hi Dub,
Sorry for the delay; I was talking about you yesterday with the shop. There is something I need to check. Will reply on Tuesday.
Hi Dub, I’m jumping into this conversation to hopefully help get this resolved. Your first message indicated that you had bad feedback issues then when you got the unit home you determined that both the V2 and V4 tubes had failed. In the tube layout chart, those tubes are the 12AU7 Voltage Amp/Driver Stage tubes. How were you able to make this determination with certainty? Do you have a tube tester? I’m asking this because there are other factors that could create the appearance of those tubes having failed, yet that may not have actually been what occurred. Since you have owned the 2/90/2 for 2+ years, it is quite possible that one or more of the power tubes are beginning to fail. And when the amp cools down, like after you brought it home that evening, the power tubes may function but in a weakened state so things don’t sound so good. The odds of the two 12AU7 tubes failing at the same time highly unlikely and that is why I am suspecting another explanation. Please take a clear picture of the inside of the chassis from about 12" above and post it so we can also check for any other obvious issues. I’m leaning towards recommending that you replace the power tubes with new matched pairs as this is one of the most likely solutions to the problem. Here are the power tubes we recommend;
https://www.tubesandmore.com/products/vacuum-tube-6550-jj-electronics
Thanks! Gil
Hi Gil
Yes, I used a tube tester which showed that both 12au7 tubes had failed. Both 12ax7 tubes tested good. Once I replaced them it began working mostly fine. I did not test the power tubes, but I did notice that the heater on one of them was weaker than the others. I don’t have the chart at the moment, but it is the second tube from the right if looking at the front of the amp. That channel did still want to feedback on certain notes played, and only on certain notes, but the other channel worked great. I agree that the power tubes, at least that pair, need to be changed. But it’s odd that both 12au7 went out at the same time. I’ll send the picture later when I get home this evening. Thanks
Hi Gil,
Since I haven’t heard anything in a while I’m checking in. When I took the pictures I didn’t notice anything unusual. Maybe y’all saw the same? I know that it’s possible, though unusual, that both 12au7 tubes would fail at the exact same time. Maybe you’re chalking it up to coincidence since I haven’t heard back and just didn’t let me know? Obviously the power tubes would benefit from being changed, at least the one side. But it’s both of the other tubes failing at the same time that has me wondering. I’ve already purchased another power amp, that I couldn’t afford, to cover upcoming gigs. The heads I had hoped to use didn’t work out. It would be nice to know if I should send this in to get checked, or if I should just keep using this (after changing the power tubes) to see what happens. By the way I’m not upset, only curious. I needed a backup power amp anyway.
The new power amp I bought as a backup is the LXII. No feedback issues at all with it like I’ve been having with the 2/90/2. Anyway, could you please let me know where I stand with this issue so I know which direction to go? Thanks.