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Hoffman Amps Forum image Author Topic: Hoffman AB763-Twin BOM/Schematic question  (Read 2330 times)

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Offline clarkleach

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Hoffman AB763-Twin BOM/Schematic question
« on: December 27, 2021, 08:23:05 pm »
I was going through the BOM, putting together a price to retrofit a '65 TRRI, and noticed what I think is an error.  If it is not can someone explain?
The BOM lists C26 as "not used" in the notes column.  According to the schematic, this is the feedback coupling for the tremolo oscillator.  Surely it would not oscillate without it.  Right?

Offline SILVERGUN

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Re: Hoffman AB763-Twin BOM/Schematic question
« Reply #1 on: December 27, 2021, 08:40:19 pm »
It is always helpful to post links to the info you are referencing.

Offline clarkleach

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Re: Hoffman AB763-Twin BOM/Schematic question
« Reply #2 on: December 27, 2021, 08:47:20 pm »

Offline sluckey

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Re: Hoffman AB763-Twin BOM/Schematic question
« Reply #3 on: December 27, 2021, 08:50:13 pm »
Trust the schematic.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline pdf64

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Re: Hoffman AB763-Twin BOM/Schematic question
« Reply #4 on: December 28, 2021, 04:36:14 am »
I was going through the BOM, putting together a price to retrofit a '65 TRRI, and noticed what I think is an error.  If it is not can someone explain?
The BOM lists C26 as "not used" in the notes column.  According to the schematic, this is the feedback coupling for the tremolo oscillator.  Surely it would not oscillate without it.  Right?
Correct, the ‘not used’ seems to be in error.
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Offline EL34

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Re: Hoffman AB763-Twin BOM/Schematic question
« Reply #5 on: December 28, 2021, 08:00:53 am »
I was going through the BOM, putting together a price to retrofit a '65 TRRI, and noticed what I think is an error.  If it is not can someone explain?
The BOM lists C26 as "not used" in the notes column.  According to the schematic, this is the feedback coupling for the tremolo oscillator.  Surely it would not oscillate without it.  Right?


The BOM line was probably copied and pasted and the not used did not get erased
The schematic is correct

Offline clarkleach

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Re: Hoffman AB763-Twin BOM/Schematic question
« Reply #6 on: December 28, 2021, 12:50:56 pm »
... The schematic is correct
Is there a document available with turret spacing dimensions?
This would be helpful in selecting components.

 


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