Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Bangy on February 08, 2017, 08:56:56 pm

Title: blackface Fender Pro reverb AA165 tremelo ticking
Post by: Bangy on February 08, 2017, 08:56:56 pm

My 67 BF Pro reverb has a ticking that follows the speed set, however nothing else effects it except disengaging the via the footswitch. Once disengaged its silent. Back on, If I turn the speed dial up the clicking increases tempo with the trem speed.

Intensity on 10 or 1 - same level of ticking
Volume off or on any volume no change in volume of the ticking.

2 prong AC. I have done nothing as the circuit is 100% original.

Roach gone bad? I think DOUG sells them, right? Im looking. . .

anybody?

Bangy

Title: Re: blackface Fender Pro reverb AA165 tremelo ticking
Post by: sluckey on February 08, 2017, 10:06:41 pm

Probably not the roach. Maybe lead dress. Maybe circuit board is conductive around the roach. Try this...

Title: Re: blackface Fender Pro reverb AA165 tremelo ticking
Post by: Bangy on February 08, 2017, 10:44:16 pm

HUm. . . But its worked fine for 52 years. Seems odd but Ill do some testing in the am. . . Thanks Sluckey

BAngy

Title: Re: blackface Fender Pro reverb AA165 tremelo ticking
Post by: Willabe on February 08, 2017, 11:10:11 pm

Change that 2 prong AC cord to a 3 prong before you get stung.  :w2:

Title: Re: blackface Fender Pro reverb AA165 tremelo ticking
Post by: tubeswell on February 08, 2017, 11:56:37 pm

And if a 0.01UF snubber don't work enough, 0.02uF will probably be enough to slug it.

Title: Re: blackface Fender Pro reverb AA165 tremelo ticking
Post by: Bangy on February 09, 2017, 06:53:19 pm

Thanks all. It seems in 68 or so Leo or whomever was CBS's guy at the time sent out a service bulletin which said this is a common occurrence and the fix is exactly what Mr. Sluckey (Why do I ever question the man???) posted.  @Willabee Ive been stung a few times (not with this amp) however, this one will never see a three prong its a looker not a player, like a time capsule BF. I am offloading a few of my finer ones.  So these type of buyers want everything original.

Anywho. . . When I took pics of the amp I was through a brown box, and a diff outlet, the problem came through my variac. I havent had a chance to recreate the before issue scenario (dif AC outlet and brown box)--but I will.

I was told by a super smart Fender tech this am that this is a well-known and frequent occurrence on BF Fenders, and is dependent more on the AC than anything.  I sold my last brownbox so I cant totally recreate the before until my new order is filled.

Thanks for chiming in everyone. . . BAngy

Title: Re: blackface Fender Pro reverb AA165 tremelo ticking
Post by: robrob on February 09, 2017, 10:43:00 pm

This is how it looks in the AB763:

https://robrobinette.com/AB763_Modifications.htm#Tremolo_Ticking (https://robrobinette.com/AB763_Modifications.htm#Tremolo_Ticking)

(https://robrobinette.com/images/Guitar/Deluxe_Models/AB763_Tremolo_Circuit_Board.jpg)