Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: MatGir on September 08, 2024, 10:14:21 am

Title: Fender 75 lead channel bleed trought reverb
Post by: MatGir on September 08, 2024, 10:14:21 am
Hi Guys,
I had intermittent problem that became permanent on that amp. So the lead channel bleed trought the reverb when reverb activated and lead is not. I suspect that the vactrol are not working properly. Do you think that i can remove the vactrol to confirm that they are faulty. Do i need a resistor to ground the reverb pot wiper ? any lead on something else that could possibly cause those symptoms ?
Title: Re: Fender 75 lead channel bleed trought reverb
Post by: Latole on September 09, 2024, 09:22:12 am
Why don't you use the original schematic ?

Title: Re: Fender 75 lead channel bleed trought reverb
Post by: MatGir on September 10, 2024, 05:06:00 am
Quote from: Latole on September 09, 2024, 09:22:12 am
Why don't you use the original schematic ?

I found the handdraw one easier to read.
So if i disconnect the lead volume pot and the reverb pot to footswitch jack, i should hear only reverb  right ?

regards
Mat
Title: Re: Fender 75 lead channel bleed trought reverb
Post by: Latole on September 10, 2024, 05:41:31 am
Quote from: MatGir on September 10, 2024, 05:06:00 am
Quote from: Latole on September 09, 2024, 09:22:12 am
Why don't you use the original schematic ?

I found the handdraw one easier to read.
 

regards
Mat

Yes easy to read 'cause incomplete and is it accurate ?
Title: Re: Fender 75 lead channel bleed trought reverb
Post by: pdf64 on September 10, 2024, 07:02:13 am
Quote from: MatGir on September 08, 2024, 10:14:21 am
... the lead channel bleed trought the reverb when reverb activated and lead is not. ...
I'm not sure quite what you mean, could you have another go at describing the issue?
Title: Re: Fender 75 lead channel bleed trought reverb
Post by: Latole on September 10, 2024, 07:49:21 am
Quote from: pdf64 on September 10, 2024, 07:02:13 am
Quote from: MatGir on September 08, 2024, 10:14:21 am
... the lead channel bleed trought the reverb when reverb activated and lead is not. ...
I'm not sure quite what you mean, could you have another go at describing the issue?

You are right, It is not easy to understand what he mean .
Title: Re: Fender 75 lead channel bleed trought reverb
Post by: MatGir on September 10, 2024, 01:13:13 pm
Quote from: pdf64 on September 10, 2024, 07:02:13 am
Quote from: MatGir on September 08, 2024, 10:14:21 am
... the lead channel bleed trought the reverb when reverb activated and lead is not. ...
I'm not sure quite what you mean, could you have another go at describing the issue?

I was trying to says that when lead channel is off and reverb is on, the reverb pot act like adding more volume and more distortion to the mix with very little reverb. it's like the reverb pot control the lead channel. both lead volume and lead master are at zero during this time.

Sorry for my bad english, i'm french BTW.
thanks you for your reply and help!

regards
Mat
Title: Re: Fender 75 lead channel bleed trought reverb
Post by: Latole on September 10, 2024, 02:32:20 pm
Quote from: MatGir on September 10, 2024, 01:13:13 pm
Quote from: pdf64 on September 10, 2024, 07:02:13 am
Quote from: MatGir on September 08, 2024, 10:14:21 am
... the lead channel bleed trought the reverb when reverb activated and lead is not. ...
I'm not sure quite what you mean, could you have another go at describing the issue?

I was trying to says that when lead channel is off and reverb is on, the reverb pot act like adding more volume and more distortion to the mix with very little reverb. it's like the reverb pot control the lead channel. both lead volume and lead master are at zero during this time.

Sorry for my bad english, i'm french BTW.
thanks you for your reply and help!

regards
Mat

Bienvenue sur le forum , je parle français du Québec.

Je me sert souvent de:   https://www.deepl.com/fr/translator

Gratuit
Title: Re: Fender 75 lead channel bleed trought reverb
Post by: AlNewman on September 10, 2024, 09:16:43 pm
Have you tried cleaning all the connections and grounds at your jacks?