Intermitent Ampeg B2R problem

BassTim · #1 05-25-2011, 07:22 PM

I have an Ampeg B2R. Its been a great amp. However, in the last couple weeks, its started crapping out.

It plays fine and then....nothing. The cab seems to be fine. The input from my bass seems to be fine. But I get nothing from the amp. (No blue smoke but also no sound.) Then, its starts up again. No reason why. Usually within a couple minutes. I think there is a faint click as it starts up again. I'm afraid its going to act up during a gig. Ideas?

Jerrold Tiers · #2 05-25-2011, 08:23 PM

Click is probably the relay closing. The thermal sensor or relay driver may be having a problem.

Are the lights on while it is "off"? Does he fan seem to be going fast when it has shut off?

The fan and relay are linked to the thermal sensor. The fan speeds up as the amp gets hotter (or if the sensor thinks it has), and at the limit temp, the relay opens to remove the load so the amp will cool down.

if the sensor is acting as if the amp is hot, the fan will be going fast, AND the relay will open.

If the relay circuit has the problem, the relay may open but fan won't be going faster.

yet another cause can be a DC on the speaker out.... This normally would cause a fairly loud "pop" when the relay opens, but if it opens while you are playing, that may give a "pop" also.

BassTim · #3 05-25-2011, 08:35 PM

Is it possible this is a speaker cable gone bad? It just happened again. I switched to my other speaker cable and it worked - granted may have been coincidence.

The fan does not seem to be going any faster than normal.

floridagatorfan · #4 05-25-2011, 08:46 PM

sounds like the same problem I'm Havng with my 4 Pro, excep my fan does speed up, im gonna get mine checked out by a tech tommorow and when i find out what the cause is will let u know, maybe its the same thing on yours

BassTim · #5 05-26-2011, 11:38 AM

More info. When its off, the lights are still on - even the limiter seems to be functioning - just no sound.

The fan is running but I don't notice it running faster.

Guess I need to take it in and have it looked at.

Any other suggestions or ideas are very welcome!!!

RickenBoogie · #6 05-26-2011, 11:43 AM

Yes, you need to take it in to see your local amp tech. Hope it works out.

Jerrold Tiers · #7 05-26-2011, 09:48 PM

Quote:

Originally Posted by BassTim

More info. When its off, the lights are still on - even the limiter seems to be functioning - just no sound.

The fan is running but I don't notice it running faster.

Guess I need to take it in and have it looked at.

Any other suggestions or ideas are very welcome!!!

Well, then....... that would be the relay opening. If the amp is otherwise functioning, the issue may be the relay circuit malfunctioning. Protection circuits can fail like anything else.

BassTim · #8 06-01-2011, 07:02 PM

Impressive trouble shooting! I just got off the phone with my amp tech - the heat sensor relay has gone bad. The fan is running high and the output is shutting off because the amp thinks it is over heating. They'll repalce the circuits. Do a once over to solidify all the sodders in her. Clean her up and its back to me. ($150 to $200 lighter.) I'll give you an update when I bring her home and give her a test run.

BassTim · #9 06-04-2011, 06:13 PM

Well, I played an in house gig last night with my refurbished B2R. Worked beautifully. Not sure it sounded any better that is always had (and I wouldn't really expect it to) - but no cutting out and the tone sounded just the way I want it too.