Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: TIMBO on September 27, 2013, 05:12:44 pm
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Hi guys, Got a tricky one here. The reverb tank(long tank) in the Fi Sonic head had it mounted kinda vertical but jammed under the front transom as seen in the pic (ON rubber mounting). According to this http://www.amplifiedparts.com/tech_corner/spring_reverb_tanks_explained_and_compared (http://www.amplifiedparts.com/tech_corner/spring_reverb_tanks_explained_and_compared) this is not good, also it was mounted with the RCA connections at the bottom and the only reason I see for this is that it keeps the output transducer away from the PT as explained.
I was looking to right the wrong(if you guys think that having it mounted as I found it)is right, otherwise mounting it as per blurb it is such a tight fit in the head it inter fears with other parts.
Options are.....
Short horizontal tank fixed to bottom of head
Mounting tank in speaker cab.
Thanks
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Was there any problems with it as is?? i'm sure they made all the considerations before mounting it that way. Platefire
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If it works, don't fix it!
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The amp wasn't working when I bought it so I don't know. I was not wanting to mod the head cab or get another tank. So i'll try it in its original position.Thanks
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That could very well be the optimum mounting position for that tank. If it's an Accutronics tank, look at the model number and refer to the link you posted, specifically at the Accutronics numbering section.
If in doubt, don't mess with it.
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Thanks guys, Its a gibbs made in the US. Numbers stamped on housing is 6443 and a"C" under the springs, I think means that it is best vertical and has a DC resistance of 186.6ohms on the input coil.
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What Steve said. The accutronics numbering system will tell you whether its supposed to be a horizontal- or vertical-mount pan. http://www.accutronicsreverb.com (http://www.accutronicsreverb.com)
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This is similar http://www.hagstrom.org.uk/GA85%20Reverbunit.htm (http://www.hagstrom.org.uk/GA85%20Reverbunit.htm)
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Hi guys, I'm sad to say that the tank may be DEAD. I fired up the amp and every thing seemed to be working but no reverb even when tapping the tank I wasn't getting any boing. Checking the connection were good but measuring the DC resistance was 0 across the solder pads on the coil of the output. The input is 187ohm. So I believe a new tank is in order.Thanks
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Checking the connection were good but measuring the DC resistance was 0 across the solder pads on the coil of the output. The input is 187ohm. So I believe a new tank is in order.
Hmm. That's close to what a typical Fender tank would measure,,, IF,,, the input and output were reversed.
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Thanks Sluckey, The 4FB2A1C is a good match http://www.amprepairparts.com/reverb.htm (http://www.amprepairparts.com/reverb.htm)
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New tank fits nicely between transom and bead at the bottom.