Amp Tech Thread / Ask a tech Q

[Jake]

Hey, thanks Jake))). I'm aware of thems lethal voltages and a little askeered of opening it up. Are there some common failures? Could you perhaps list a few, from least to worst case scenarios? Will you come over and fix it? I give good backrub.

[RAGER]

Was there smoke or any weird smells.  if not maybe a fuse on the board?  Check easy shit first.

[Mr. Foxen]

B2 is solidstate, so not very high voltages, enough to make you learn to not touch thing things any more though, unless you have a dicky heart. Blown output transistors is what you get, but it might have thermal protection or somehting else that will kill it before hard bits are damaged. They are a proper ballache to get inside and see anything useful though.

[Jake]

Merci Beaucoup.

[liquidsmoke]

The swamp thangs shouldn't be distorted or fucking up at alll, they're ridiculously resilient

That's good to hear. They are rated at 150 watts each too. So far I love them. I may try to push em a little harder but as I was explaining weird pulsing tends to occur when I have too much bass dialed in. I am using a bass head but my Ampeg SS guitar head(would have worked fine for bass actually) had loads of low end to spare and could also create such strange bad sounds.

[RacerX]

The swamp thangs shouldn't be distorted or fucking up at alll, they're ridiculously resilient

That's good to hear. They are rated at 150 watts each too. So far I love them. I may try to push em a little harder but as I was explaining weird pulsing tends to occur when I have too much bass dialed in.

Sounds like the simplest solution to the "weird pulsing" is don't dial in "too much bass."

[liquidsmoke]

The swamp thangs shouldn't be distorted or fucking up at alll, they're ridiculously resilient

That's good to hear. They are rated at 150 watts each too. So far I love them. I may try to push em a little harder but as I was explaining weird pulsing tends to occur when I have too much bass dialed in.

Sounds like the simplest solution to the "weird pulsing" is don't dial in "too much bass."

[Lumpy]

So I bought a cheap guitar online... and it seems like the volume comes and goes. It will play normally for about a minute, and then for a minute the volume will drop (a lot). Then a minute later, back up to normal.

What could be causing that? It's not my amp, I tried it with a different amp. Same problem.

[RacerX]

Since the tech seems to be out, my Magic 8-Ball sez the problem is buying a cheap guitar online.

[VOLVO)))]

Shitty pots, honestly.

[Pissy]

So I bought a cheap guitar online... and it seems like the volume comes and goes. It will play normally for about a minute, and then for a minute the volume will drop (a lot). Then a minute later, back up to normal.

What could be causing that? It's not my amp, I tried it with a different amp. Same problem.

This might be pickup height.  Move them down a turn or two and see what happens.

[Pissy]

Actually, what is the pickup configuration?  Does it do that across all of the pickups?  If so, then it might be a string/nut/bridge thing - likely not pickup height.  Change the strings and see if it clears up - paying attention to the nut and bridge contact points on the strings and perform some freshening up there.  If not, then look at the pickup height.

The jack, and the pots can cause this too, but I'd look into the physical stuff first, then open up the control cavity and look for cleaning up opportunities (wire length, solder joints, contact cleaner in the pots, jack function, shielding). 

Hope this helps.  Cheap guitars can work great, but upon receipt, this kind of crap is the rule, not the exception.

[Lumpy]

The bridge is terrible, I think it's pressed metal. It has little divots where the strings ride (you get a choice of 3 divots per each string). The nut is also pulling up.

For pickups, it's two... Strat style, with no switch. Just a volume and a tone knob. I'm not even sure if I can adjust the height.

I will change the strings right away. Seems like they suck.

[Pissy]

I need new tubes in my record player console in the house. 6BQ5 which is equivalent to an EL84 I think. Any suggestions? I guess I want the highest headroom possible given its a home stereo.

?

[VOLVO)))]

Try EL84Ms.

[Jor el]

Where can I get case corners (protectors)??

I'm looking for brick and mortar retail stores -
The internets want more for shipping than the corners themselves.

[VOLVO)))]

Is there Ace Hardware up there? Any store that has grab bins of shit should have them.

[Jor el]

I forgot that ACE is the Place with the Helpful Hardware Man.
The local store has a couple store cats.

They had plenty of fancy brass.
I'm just looking for basic chrome. The search continues.

[VOLVO)))]

Bummer, what are they going on?

[Jor el]

I'm building a wooden cart for my buddy's work truck.
It's wheeled and will be loaded off and on the truck, as well as around whatever locations we end up at.

Just thought protecting the bottom four corners would be nice.

[RAGER]

Do the whole bottom edges in thin angle iron or galvanized.

[dogfood]

Q1) What Marshall circuit does the Traynor Bass Master most closely resemble?  I'm too spaced out on pain killers (another round of dental surgery) and Wild Turkey to google this shit. 
Q2) What are the differences in the circuitry and what is the sonic repercussions of said differences?

[James1214]

So I desperately want to move the standby on my earth Superbass from the rear of the amp to the front. What is the most effective way to drain the caps so as to ensure I don't kill myself? Anything else to keep in mind?

[VOLVO)))]

Bleeder resistor if they are huge. If not, alligator clips and a bit of wire, clip one end to the chassis, then touch the cap.

[RAGER]

Amp attached to speaker cab but amp not plugged into wall, turn on both switches for 15 minutes, speakers should drain caps.  This is prolly the least intrusive way but just to be sure I use a meter set to 1000vdc.  There's always just the screwdriver method.