Correct wiring 2 x 12 fender red knob twin in series

[Jquijano]

I would probably need to change these ugly looking wires with better quality if i want my amp wired 16 ohms in series. Is this the correct wiring after setting the impedance selector to 16 ohms? If not please advise properly before i turn the amp on. Im heading to the chinese electronic shop to buy new wire and terminals. Speakers are 8 ohms each.

[The Dude]

Yes, that looks correct for series wiring.

[Jquijano]

Jajaja Pandora box with this used 1987 red knob twin. Scratchy pots, reverb sounding in both channels meaning reverb select switch not working. Where do we start? Just major cleaning of the pots with deoxit fader F5? What else do you guys think we should we check in this amp?

[The Dude]

Yes. Clean all pots, jacks, and switches. If pots are scratchy, it's quite likely the reverb select switch also needs cleaning.

[Jquijano]

Scratchy pots noise gone. Full response. What about the power resistors and grid and plate resistors?

[The Dude]

This has all been covered in your previous thread about the amp. I'm not sure why you started another thread about the same amp anyway, but there's no need to rehash information that has already been discussed in the other thread.

[Jquijano]

Just replaced all filter caps and power resistors. Low mode not working. Any clue?

[Chuck H]

I've never read about any common "low mode" failure for these amps. So the first thing to check would be voltages in circuit. The mode switch in and out first. Then upstream along the high voltage supply until you see a problem. If this is confusing you and you have any concern working with the high voltage circuits in live amplifiers you should take it to a qualified service technician.

[The Dude]

Just replaced all filter caps and power resistors.......

Of course you did.

[Jquijano]

I've never read about any common "low mode" failure for these amps. So the first thing to check would be voltages in circuit. The mode switch in and out first. Then upstream along the high voltage supply until you see a problem. If this is confusing you and you have any concern working with the high voltage circuits in live amplifiers you should take it to a qualified service technician.

Well if you can help me with this. I would kindly appreciate it. I really prefer fixing this myself as the only 2 techs that fix these amps in Panama are always busy and the waiiting line just to check the amps is 10 days.

If the amp used to work on Lo mode with the old cement power resistor and original filter caps what could have happened? I also changed the 4 power tubes with a matched set.

[Chuck H]

Can you please re link the schematic on this thread if you have one.

[Jquijano]

Can you please re link the schematic on this thread if you have one.

Yellow wire became loose. Ill resolder this back and revert. We need to move over to the reverb issue as the reverb selector swith is not closing the circuit on the channel that is not selected.

[Tom Phillips]

Yellow wire became loose. Ill resolder this back and revert...

This is a good example showing that it's not always failed electronic parts that cause problems.

Also note that your photo shows a push on mechanical connection that came loose. Just push it back in place. No soldering required.

[The Dude]

OP: So, you flag my post as "rude and counter productive"? I was actually taming it down on that post, but since you're going to flag me anyway, here's what I WANTED to say.

You asked for advice and were advised by multiple career/qualified/exceptional techs (and myself) not to replace parts that didn't need replacing and that it could cause more problems rather than fix any (see this thread: https://music-electronics-forum.com/...-knob-twin-pcb). You willfully ignored that advice and, as expected, caused more problems than you fixed. Then, you come back here and ask the same techs that you ignored to bail you out. These guys donate their time for free to help guys like you and you're intentionally wasting it. You wanna know what's "rude and counter productive"?............ THAT!

[Jquijano]

OP: So, you flag my post as "rude and counter productive"? I was actually taming it down on that post, but since you're going to flag me anyway, here's what I WANTED to say.

You asked for advice and were advised by multiple career/qualified/exceptional techs (and myself) not to replace parts that didn't need replacing and that it could cause more problems rather than fix any (see this thread: https://music-electronics-forum.com/...-knob-twin-pcb). You willfully ignored that advice and, as expected, caused more problems than you fixed. Then, you come back here and ask the same techs that you ignored to bail you out. These guys donate their time for free to help guys like you and you're intentionally wasting it. You wanna know what's "rude and counter productive"?............ THAT!

Man i already fixed my amp by myself using common sense. No problems whatsoever. Thanks anyway for taming it down.