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sonolink

Help with Fender Hot Rod Deluxe Crunch
« on: January 08, 2017, 02:22:29 PM »
Hello

A friend brought me a Fender Hot Rod Deluxe complaining that the clean channel doesn't sound clean any more and is always crunchy. I replaced the tubes for new ones but it still isn't really really clean like it should be.
Any suggestions as to were to begin looking at?
Could it be a hot bias? Any ideas as what the bias should be set for that amp?

Thanks for the help
Cheers
Sono
Why sleep when you can mix?
M.P.Stavrou


CJ

Re: Help with Fender Hot Rod Deluxe Crunch
« Reply #1 on: January 08, 2017, 04:35:01 PM »
maybe a stuck relay? there are a lot of them in there,

download the schematic, they have AC voltages listed at every stage,

If I can't fix it, I can fix it so nobody else can!
Frank's Tube Page: www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar Amps: http://bmamps.com/Tech_sch.html

Pip

Re: Help with Fender Hot Rod Deluxe Crunch
« Reply #2 on: January 08, 2017, 06:44:58 PM »
Check to see that all the negative feedback circuits and associated resistors are healthy. Also check plate voltages.
Pip
New York City
http://geosonixlab.com

sonolink

Re: Help with Fender Hot Rod Deluxe Crunch
« Reply #3 on: January 08, 2017, 07:04:16 PM »
Ok. Thanks for the input guys. I'll check and report back   :)
Why sleep when you can mix?
M.P.Stavrou

CJ

Re: Help with Fender Hot Rod Deluxe Crunch
« Reply #4 on: January 08, 2017, 07:56:31 PM »
check crunch sw also,  those guys are pretty cheap, just ordered some double decker stacked pushbuttons from Peavey for a Valve King, 2 bucks a pop , wtf, over? jus sayin...
If I can't fix it, I can fix it so nobody else can!
Frank's Tube Page: www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar Amps: http://bmamps.com/Tech_sch.html

sonolink

Re: Help with Fender Hot Rod Deluxe Crunch
« Reply #5 on: January 09, 2017, 04:29:43 AM »
Sorry I don't understand what you mean by crunch sw. Do you mean there's a crunch switch on the clean channel? Do you mean the "normal/bright" switch?

Thanks :)


 
Why sleep when you can mix?
M.P.Stavrou

Roly

Re: Help with Fender Hot Rod Deluxe Crunch
« Reply #6 on: January 09, 2017, 05:42:32 AM »
Hi

 I have dealt with a couple of amps from the hot rod series.
 In both cases, the channel switching had a mind of it's own.
 Here's a link that may help.

 cheers

 https://groupdiy.com/index.php?topic=59031.0

sonolink

Re: Help with Fender Hot Rod Deluxe Crunch
« Reply #7 on: January 09, 2017, 07:33:18 AM »
Thanks Roly  :D
Why sleep when you can mix?
M.P.Stavrou

sonolink

Re: Help with Fender Hot Rod Deluxe Crunch
« Reply #8 on: January 09, 2017, 07:39:10 AM »
Just a question: if the channel switch is the problem it would mean that both channels clean and crunch get mixed giving the impression that the clean channel is distorted right?

Wouldn't setting the Master Volume to zero discard that?
Wouldn't toggling the More Drive switch change the sound?

I'm asking because both things don't...
Why sleep when you can mix?
M.P.Stavrou

dax

Re: Help with Fender Hot Rod Deluxe Crunch
« Reply #9 on: January 09, 2017, 01:40:10 PM »
8 out of 10 distorted output on clean settings caused by failed plate resistor on PI stage in Hot Rod amps I see