Help! I think I f**ked something up...

Flames1950 · Post by **Flames1950** » Sun Apr 17, 2005 8:32 am

Dax wrote:We Need Pics!!! I don't think you need that jumper for a 50 Watter, i had to remove mine at george's request.

Dax

Dax, read through the whole thread again -- he didn't have a white bias wire coming in from the standby, so it was add a jumper or the wire. I recommended the easy route at this point.

Flames1950 · Post by **Flames1950** » Sun Apr 17, 2005 8:39 am

I plug the guitar in and get ... a loud hum. No guitar sound at all.

So is the loud hum only present with a plug in an input jack? If nothing is plugged in you can turn the knobs up without hum, or there is still a problem even without anything plugged in? Are the input jacks grounded with black wire to the ground buss on the back of the control pots? (Your earlier comment about touching the standby made me wonder.)

Trem Abuser · Post by **Trem Abuser** » Sun Apr 17, 2005 5:33 pm

Flames1950 wrote:
I plug the guitar in and get ... a loud hum. No guitar sound at all.
So is the loud hum only present with a plug in an input jack? If nothing is plugged in you can turn the knobs up without hum, or there is still a problem even without anything plugged in? Are the input jacks grounded with black wire to the ground buss on the back of the control pots? (Your earlier comment about touching the standby made me wonder.)

Flames, you are on it. Yes, I looked in and remembered that I had snipped the old buss connection grounding the input jacks when I pulled them out of the amp to rewire them.

So I soldered a wire connecting the old buss wire on the jacks over to the buss wire connecting the pots, and ground the input jack assembly. I only have two input jacks, and I used a diagram sent over by Dan to wire the input jacks. I have posted a picture for you guys to let me know if I did it right.

So after attaching the ground wire, I turn it on with nothing plugged in. No hum, no sound whatsoever, even turning the volume all the way up. I then plug in a guitar. SOUND COMES OUT!!! I can actually hear my guitar!

Unfortunately, it seems to only be putting out about 1 watt though. Fully cranked it is nowhere near as loud as my 6watt Champ. Also, I get no sound through the "low" input jack; I just get sound through the "high" input jack (the one on the left of the picture).

Dax-The-Ax · Post by **Dax-The-Ax** » Sun Apr 17, 2005 11:52 pm

I am no expert, Flames can help you here, but i think the Input Jacks are wrong? Here is a pic of the way i have always wired mine. Both green wires going to the board should be on the same jack, the top why, Wht, i don't know. I had no sound out of my amp and this was the culprit.

Flames1950 · Post by **Flames1950** » Mon Apr 18, 2005 12:00 am

Are those running as a high/low pair that will feed both channels?
I don't see the usual 1Meg resistor, and some connections don't look right to me.
Here's the standard high/low pair; the high is on the bottom with the 1Meg resistor, you're looking at it upside down as if you were about to lower it into the chassis:

Your ground would connect to the panel side of the 1Meg. There would not be a jumper between the two lugs on the panel side of the top (low input) jack. The green wires to the 68K resistors would go to the lugs on the top (low) jack; it doesn't matter which wire goes to which 68K.

Flames1950 · Post by **Flames1950** » Mon Apr 18, 2005 12:02 am

Good, while I was tracking down George's store pic Dax brought out his diagram, which is much more useful. Thanks Dax.
I still suspect we might have more problems if you're getting that little sound, but we'll eliminate this one first then move on and see where we are.

Yours shows a green wire connected to the panel-side lug of the right hand jack; where is it going off to?

Dax · Post by **Dax** » Mon Apr 18, 2005 2:49 am

The 1 Meg is buried on the left in the dark, you can barely see it. He just needs to move the bottom green wire to the bottom lug of the other jack. Will that ground function properly hooked to the top like that with that extra piece of buss wire, flames?

Dax

Trem Abuser · Post by **Trem Abuser** » Mon Apr 18, 2005 4:11 am

Guys thanks for the info. I have rewired my jacks to match the diagram. (The resistor on there before was some small value thing, I should have taken that off in the beginning; I have replaced it with a 1M resistor.)

(Flames, the wire you asked about was actually being used as a ground wire to the pot ground/buss wire. I have now wired another wire to serve as a ground wire, and it has to ground from the other jack.)

So that looks good. But now I'm cooking with an estimated 1.5 watts. On the bright side, I do not need to use my attenuator to achieve those bedroom level tones.

It doesn't sound half bad for such a tiny output, but what should I check next?

Flames1950 · Post by **Flames1950** » Mon Apr 18, 2005 7:59 am

Now it may be time for some bigger pics showing the wiring between the board and the controls/tube sockets, I'm running out of visible problems from staring at your board pics.

Billy Batz · Post by **Billy Batz** » Mon Apr 18, 2005 8:28 am

It is electronically no different if you have the wires going to the board on both pins of the right jack, or the left pin of each jack. The wire jumping the two jacks make both pins the same connection. Makes no difference but he has both wires to the board comming from eaither side of that jumper which is the same connection. So the hi jack will work normally and the lo will not work at all. One needs to go there from the tip of the lo jack which has nothing soldered to it now. Either way thats not the problem. Look at a schem. Wouldnt make much of a difference when plugging into the hi input. Move the wire going to the board on the right jack from the upper right pin to the upper left pin. Still that wont fix the problem only correct the input wiring. If Im seeing this jack wiring correctly it cant be the problem. Unless its a bad solder joint. Am I seeing things or is there no solder in those turrets?

Dax · Post by **Dax** » Mon Apr 18, 2005 9:50 am

Billy, doog eye, i didn't notice that. It looks like there is no solder on some components. That could be your cold solder joint problem!!!!

Dax

Trem Abuser · Post by **Trem Abuser** » Mon Apr 18, 2005 1:21 pm

Billy Batz wrote:It is electronically no different if you have the wires going to the board on both pins of the right jack, or the left pin of each jack. The wire jumping the two jacks make both pins the same connection. Makes no difference but he has both wires to the board comming from eaither side of that jumper which is the same connection. So the hi jack will work normally and the lo will not work at all. One needs to go there from the tip of the lo jack which has nothing soldered to it now. Either way thats not the problem.

I have rewired it to match the diagrams above. Both jacks work OK now.

Still that wont fix the problem only correct the input wiring. If Im seeing this jack wiring correctly it cant be the problem. Unless its a bad solder joint. Am I seeing things or is there no solder in those turrets?

There is some solder in each of the turrets that have a connection from the top of the board (in other words, other than just a wire coming up from the bottom). But if I have a connection on top of the board at a turret, do I try to fill the entire turret with solder?

Flames1950 · Post by **Flames1950** » Mon Apr 18, 2005 1:46 pm

If the solder flowed nicely and the components are secure when the solder cools filling in the turret isn't necessary, and actually can be a PITA later if you're trying to swap and fit new components.

Trem Abuser · Post by **Trem Abuser** » Mon Apr 18, 2005 4:55 pm

Flames1950 wrote:If the solder flowed nicely and the components are secure when the solder cools filling in the turret isn't necessary, and actually can be a PITA later if you're trying to swap and fit new components.

The components are securely held by the solder. But I can check continuity (for example, on the other end of the wire from the component) to make sure those connections are good.

Pics coming.

Dax · Post by **Dax** » Mon Apr 18, 2005 6:44 pm

Billy, i think i just called you doog eye!!! I mean good eye!!!!