Bad Relay?

[JammyDodger]

Hey All,

I have a 183 version that I completed in 2009. Was as everyday user until about a year ago. I played through it last week and noticed a strong static sound when I played a note or chord hard. The head sits atop a 2x12 cabinet. It was loud enough and strong enough that I turned the amp off after about 5 minutes. The sound was similar to if you put your finger on the end of a guitar cord.

I brought the head home from our studio and opened it up this weekend. At home it seemed to work fine. I was touching / pressing the main board looking for an intermittent connection. I accidentally hit the OD relay and it made a loud pop and became static sounding again. Tapped it again and it went away.

Has anyone every experienced a relay going bad? I guess I will get a new board and relay (probably replace both). Strange huh?

Cheers, Mike

[wjdunham]

Don't assume that because you tap on the relay that's where the problem is. Of course, it could be the relay, but I have seen many amps where tapping on once place excites a problem in another. From your symptoms I'd check the FX loop jack first - plug a patch cable from the FX send to return and see if that helps. The contacts that connect the input to the output when there are no effects plugged in can oxidize or otherwise get flakey with the symptoms you describe. Electrical contact cleaner can be your friend here.
Bill

www.sebagosound.com

[tubedogsmith]

What is it mounted to? It could be a cold solder joint or dirty contact if it's just plugged in to a socket.

[JammyDodger]

Fx loop - I'll give that a try.

Cold solder joints? maybe. I can pull the board up and reflow these.

Great suggestions, thanks!

Cheers, Mike

[Structo]

Check the FX loop jacks but the relay thing bothers me.

When I built my amp I ordered triple the relays I needed so if one went bad.

I would pop in a new relay if possible.

If you have a Fry's nearby, they carry those small relays.

[Guitarman18]

To check whether you have a relay issue just swap it with the PAB relay.

Paul.

[JammyDodger]

Paul,

Swapping the relays might do more harm than good. I am afraid that un-soldering / re-soldering the wires might pull the pads of the relay boards. I may just go ahead and replace the boards and the relays together. Is anyone selling the relay boards these days?

Cheers, Mike

[vibratoking]

I think Paul may have thought that you had the relays in a socket, which many of us do. Swapping is easy in that situation. I like the socket for the relays. You can still remove a soldered relay. You just have to be careful with the board and you may have to destroy the relay to get it out. In short, save the board not the device.

[ampgeek]

Jammy,
Doug Hoffman sells relay boards here:

http://www.hoffmanamps.com/MyStore/perl ... D=!ORDERID!


It may not be a drop in replacement for what you are currently using. But...might work in a pinch!

Good luck,
Dave O.

[Guitarman18]

vibratoking wrote:

Paul may have thought that you had the relays in a socket

Exactly right!

I would really recommend modifying any relay board set you end up with to include the relay socket. That way you don't have to risk destroying a relay or a board if you suspect the relay of malfunction. Saves a huge amount of time and frustration with fault finding and allows you to move on to the next suspect without delay.

Cheers,

Paul.

[JammyDodger]

Paul,

I agree about the relay sockets. I think I will replace both boards and get new relays and sockets for them.

I did check out the effects loop and it is solid. I've tapped all around the boards and leads in and out of the pots with little noise. Tapping on the relay gives a good 'thunk'

Cheers, Mike

[DonMoose]

Pick a socket you can get a tiewrap under - preferably one with gold contacts. Plated is better, but flash is good.

Something like this: http://www.digikey.com/product-detail/ ... ND/3313525 but I'm not 100% positive your relay pins will fit.

Hope this helps!