DRRI & intermittent problems

[lorand55]

I'm a newbie on this forum. I came across it in searching for answers to my drri which is driving me crazy.
Problem 1 -- after playing for about an hour, the sound changes and is muted/dirty. It stays that way until the next session. Turning off and letting it cool for 15 minutes or so during a break doesn't seem to make a difference.

I've had it back to the shop for warranty repairs where they re-soldered a tube socket claiming it had a hairline crack around the solder. It cleaned it up somewhat but still does the same thing only not as noticable. I took the unit back into the shop where one of the guys played on it for about an hour and he claimed it was all good.

Problem 2 -- from day 1 I've felt the unit was microphonic (although I'm not sure if that is the correct description). We play in a basement that is relatively small however, the drri always seems to be affecting anything that will vibrate. The snare on the drums, a light fixture...anything that will vibrate. The other guys in the band have no problems with this. 1 plays a Rivera Chubster, another plays a Peavey Classic 30, and Fender Bass.

Problem 3 -- the vibrato and reverb sometimes works off the switch and sometimes it doesn't. I've checked the switch and it's fine (it's very simple).

I've changed the rectifier tube and the pre-amp tubes with no change in the above symtoms. I have not changed the power tubes however do not think it is a tube problem. While I love the 6v6 sound I'm looking at options as I don't want to sink in any more money into the amp unless I know it's going to work.

So, question is... is this a bad amp from the factory.

Sorry for the long winded description. Again appreciate your feedback.

[52 Bill]

If you are unhappy with the earlier repair, either go back to the store that serviced the amp and discuss the problem with them or try a different warranty station.

The toughest amp to fix, is one that takes a while to act up. If you can go in and make the amp do what you say it does, it may help them to understand what you are describing.

It's tough to have a tech play an amp for an hour to see if it will fail. I can set up the amp with some sort of signal running through it, but it may not put the same stress on the amp as you playing it at whatever volume levels you play at.

At least try changing the power tubes and see what happens. Then take notes as to what causes the problem to occur.

[lorand55]

Taking it in for warranty

Hi Bill,
Thanks for the quick response. I'm taking it in this afternoon. I would have tried new power tubes but they didn't have any in stock and am waiting for their next shipment. The guys at the shop have been super to deal with so it's not a matter of fighting to get them to look at it.
The tipping point for me was when the reverb and vibrato became intermittent -- sometimes they would work and sometimes they wouldn't.
After checking the footswitch and the connector, I plugged it back in and pushed on it while playing. The reverb would go on and off amongst some crackling. Without taking the board out, it sounds like poor soldering.

My concern is after repairs to the circuit board and now this, that the problem is a poor pcb from the factory. Chasing cold solder joints could become a nightmare.

[52 Bill]

Fender, like most manufacturers have their share of badly soldered pc boards.

I wouldn't worry too much about it, once the problem has been sorted out, you should be set to go.