Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Sonny ReVerb on November 15, 2016, 03:21:12 pm
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Just wondered about two changes from stock AB763 schematics.
Why did you choose an 0.0022uF for the cap off the plate of the reverb recovery (C19) instead of the usual 0.0033uF?
And why a linear taper pot for the tremolo intensity instead of audio taper?
Thanks
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I am seeing a .0033 here
http://el34world.com/Hoffman/files/Hoffman_AB763_2.pdf (http://el34world.com/Hoffman/files/Hoffman_AB763_2.pdf)
The notes on the library page show that this is a different trem/vibrato ciruit
It's a bias wiggle circuit, not a opto isolator circuit
http://el34world.com/schematics.htm#Hoffman_AB763_Two_Channel_ (http://el34world.com/schematics.htm#Hoffman_AB763_Two_Channel_)
Check out all the documents for the AB763 board on the page above
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The cap C19 is a .0022 on the single channel pdf and it's a .0033 on the two channel pdf. Blame it on Visio. :icon_biggrin: I really don't think it matters which value you use.
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Thanks, guys. I just wondered if that was a particular design decision to 'improve' the reverb.
As for the tremolo intensity pot, I noticed the Vibroverb 6G16 trem uses an audio pot and the Vibrolux 6G11 uses a linear pot. Hmm...
And yes, I'm looking at the one channel AB763 schematic:
http://el34world.com/schematics.htm#Hoffman_AB763_One_Channel_ (http://el34world.com/schematics.htm#Hoffman_AB763_One_Channel_)
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As for the tremolo intensity pot, I noticed the Vibroverb 6G16 trem uses an audio pot and the Vibrolux 6G11 uses a linear pot. Hmm...
You have that backwards. The 6G16 uses a linear pot.
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Sorry guys
I did not have time to dig into this
That's why I moved the post here
The guys here are more able to answer questions like this
I changed the single AB763 layout to a 0033, but like Steve said, that .001 difference does not matter
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You have that backwards. The 6G16 uses a linear pot.
You are correct, sir. Thanks.