Resoldering help...

[Walker]

Two of the GEQ sliders on my Ampeg Pro were banging and popping when I played certain notes. So I took the GEQ PCB out and noticed that the solder points on the two sliders were moving, therefore making and breaking contact. I carefully warmed them, sucked the old solder off and applied a good drop of fresh shiny solder.

Works fine and is now solid as a rock. A couple of questions...

1. Were they what are called 'dry joints'
2. Did I do it correctly / should I have done anything else / differently?

Thanks!

Chris

[iiipopes]

Yes, and Yes. Great job!

[icastle]

Yep - that sounds pretty much right to me.

[bremen]

I had to do the same to my SVP (among others, including about 100 assorted pots and jacks on my A&H mixer). Board-mounted controls and connectors are really prone to this.

[flyfisher]

Could have been a dry joint, though I tend to be a bit suspicious of such diagnoses unless the equipment is fairly new because, in my experience, dry joints tend to manifest themselves at the young end of a product's lifetime.

But, I had a similar problem with a power resistor in my Ampeg combo. It's a large component and was only secured to the PCB by its soldered legs.

The soldering was fine but years of vibration had resulted in the PCB track developing a small crack allowing the soldered lead to move about in the PCB hole, resulting in an intermittent connection.

A b*gger to find, but very easy to fix by cleaning the PCB trace and soldering some tinned-copper wire across the hairline fracture.

Of course, simply re-flowing such a joint would probably fix the fault but probably wouldn't be as robust a fix as it could be if there is underlying PCB damage.

Might be worth bearing such things in mind when dealing with ageing amps.

[Max Normal]

Ampeg soldering is CRAP. I have a Korean SVT3pro. It actually sounds very nice indeed, very loud and SVT warm (I understand these can be a bit hit and miss for volume and tone). The first few months when I took it in the van to gigs it was constantly going wrong due to dry solder joints. It was in M J Still in Hove about 3 or 4 times getting them redone. Seems to have settled down now, hasn't gone wrong for about a year despite some bumpy van rides. I use the Markbass at the rehearsal studio now just to save moving it and tempting fate though, and just save the Ampeg for gigs. I'd buy a Markbass instead as they are light and punchy and reliable, but there's something extra about the Ampeg I just can't let go of....