Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Misc Schematics and Layouts => Topic started by: 2deaf on April 29, 2019, 11:38:51 pm

Title: '70's Fender Twin Reverb Trilogy of Schematics
Post by: 2deaf on April 29, 2019, 11:38:51 pm

I was never a fan of the '70's Fender drawing style, so I drew my own. 

Title: Re: '70's Fender Twin Reverb Trilogy of Schematics
Post by: sluckey on April 30, 2019, 06:40:40 am

Very nice! Easy on the eyes. I put all 3 in a single pdf and tucked it away. Thanks.

Title: Re: '70's Fender Twin Reverb Trilogy of Schematics
Post by: BrownIsound on November 16, 2023, 07:43:37 am

Hi, I see an error in your schematics (unless you are correcting an error on the original fender schematics?), it looks like there is a feedback feed from the output of the LTP V6A, a 220k ohm resistor connected after the 0.1uf coupling cap on the Fender schematics, yours is connected to the 68k top 6L6s input grid load resistor and the bias balance pot.

This would lower the feedback, and maybe this was an intentional effect for your schematics?

But otherwise very nice schematics!  I have a late 1971 quad reverb and a Super Six, all the date codes on the transformers in both other than the chokes match exactly.

Title: Re: '70's Fender Twin Reverb Trilogy of Schematics
Post by: sluckey on November 16, 2023, 08:56:57 am

Quote from: BrownIsound on November 16, 2023, 07:43:37 am

Hi, I see an error in your schematics

So it seems.

Title: Re: '70's Fender Twin Reverb Trilogy of Schematics
Post by: Lambertini on December 10, 2023, 09:10:46 am

@2deaf:
Thank you for these easy-to-read schematics.

@BrownIsound:
Thank you for noticing the 68k resistor placement error.
I've updated the 2 schematics I'm interrested in. Can you please check if the fix is ok?

Title: Re: '70's Fender Twin Reverb Trilogy of Schematics
Post by: BrownIsound on December 10, 2023, 06:01:25 pm

Looks good, I just checked the one w/o MV.

Title: Re: '70's Fender Twin Reverb Trilogy of Schematics
Post by: Lambertini on December 10, 2023, 06:30:53 pm

Did the same update on both. Thank you!