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Hoffman Amps Forum image Author Topic: TOREVIBE PROBLEM  (Read 7221 times)

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Offline biker883

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TOREVIBE PROBLEM
« on: March 16, 2012, 08:33:01 am »
I am trying to fix the buzz problem in my torevibe. I have read several posts about proper grounding and layout, and mine is a big mess, because originaly it was only 6g15 and i added the vibrato layout. I am not an electronics expert so i was afraid to built a torevibe from the begining, it seemed very difficult to me. I thought it was safer to built the reverb first and if it was working to add the vibrato. Big mistake!!!  I ruined a good working reverb unit  :BangHead: Now there is a lot of buzz increasing by the MIX pot. Of course the other pots interact in this buzz. I can change the speed of the buzz, the tone... if you can understand what i mean. 
Anyway, i found out that there are a lot of things to improve. My first question is: if i isolate the input jack of the reverb pan from the chassis, then the grounds of this jack (in which i have soldered the wire of the O/T) should  be routed to other ground or not?  and the o/t just to ground only?   :w2:

Another thing that bothers me is that the heater twisted wires are too close to some caps of the vibrato cirquit (almost touching) I chose the orange drops which are too big and there is not enough room in my homemade aluminium chassis. I suppose this contributes to buzz/hum?

Any help is appreciated. Thanks in advance.
 

Offline biker883

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Re: TOREVIBE PROBLEM
« Reply #1 on: March 17, 2012, 03:32:52 pm »
The mix pot does not affect the vibrato. Even when it's full closed the vibrato is working normally, and there is no hum. suppose that the intensity does this job. The mix pot only mix the reverb, and the zzzzzz.....as well.
That's strange, because when it was only reverb unit, it had no serious zzzzzzzzzzzzz...
Also the mix pot buzz at all times, even with the footshwich closed.
 

Offline Willabe

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Re: TOREVIBE PROBLEM
« Reply #2 on: March 17, 2012, 08:43:59 pm »
Hi biker883,

It would help if you could post some _ good _ pics of the insides. There's a good # of guy's here that are eagle eyed as far as tracking down problems, once they can see the amps insides.


                      Brad    :icon_biggrin:

Offline biker883

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Re: TOREVIBE PROBLEM - FIXED !!!
« Reply #3 on: March 24, 2012, 12:06:24 pm »
I dont believe it! I fixed the hum problem. first, i separated the grounds of each stage, the first two filter capacitors grounds, the pots grounds (which were on the pot case), and soldered each one directly to a ground bus wire grounded on the output jack and running upto the speed pot.
I also moved away the heater wires of V4-V5 from the capacitors of the vibrato stage. 
also between the green wire from power cord and chassis i inserted the "trick" of 2 diodes, a 22 ohm resistor and a .01uF cap.  Now its really quiet even with the mix pot at high levels.
I did not isolated the input-output jacks neither the rca jacks to the reverb pan. No need for that now.
All information read in the forums. Thanks all who have posted.

However.... i created a new problem.  The vibrato footswitch is not working. It is a fender 2-button chrome pedal with rca jacks. when vibrato switch to on position it makes a terrible very loud buzz, i was afraid that i damaged the speaker....The strange thing is that it was working perfectly before i modified the grounding scheme.
Any ideas?
 

Offline biker883

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Re: TOREVIBE PROBLEM
« Reply #4 on: March 24, 2012, 01:14:57 pm »
UPDATE.

Just fixed the problem. i moved the wire of vibrato footswitch to the other side of the .01 cap that goes to pin 2 of V5. I dont remember where i read that.
I dont know why, but it worked.
Hood closed. Its perfect now. i learned a lot...


Offline Willabe

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Re: TOREVIBE PROBLEM
« Reply #5 on: March 24, 2012, 03:32:11 pm »
Wow! Nice job biker!    :bravo1:

How does she sound?

A few guys have posted sound clips using a Torevibe and I love the way they sound. I have to build one someday too.

Offline biker883

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Re: TOREVIBE PROBLEM
« Reply #6 on: March 25, 2012, 11:57:25 am »
the sound is amazing. Especially the reverb. It's so realistic!!!!

 


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