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Re: Gibson reverb question


 
3/4/2005 2:42 AM
Denny
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Re: Gibson reverb question
Alex, what does the input and output impeadance measure on that new tank?  
 
Denny
 
3/4/2005 4:03 AM
Ray Ivers
Denny,  
 
IMO Rick's recommendation of the " target="_blank">http://www.tubesandmore.com/new/scripts/silverware.exe/moreinfo@d:/dfs/elevclients/cemirror/ELEVATOR.FXP?item=P-R4AB3C1B"> 4AB3C1B (2-spring) tank is right on the money, and FWIW, the " target="_blank">http://www.tubesandmore.com/new/scripts/silverware.exe/moreinfo@d:/dfs/elevclients/cemirror/ELEVATOR.FXP?item=P-R9AB3C1B"> 9AB3C1B 3-spring tank may have a slightly fuller and richer reverb with less 'springiness', if that's what you're after.  
 
 
A 12BZ7 reverb tube might improve the reverb a bit as well, if you can find one.  
 
Ray
 
3/4/2005 6:59 AM
Denny
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Ray,  
 
I think that would probably be the one IF i also had a fender reverb transformer. I think with this Gibson GA-17RVT they had a different input and output impedance reverb tank than Fender. I may have to go that route though, can't seem to find a match. Thanks for your input.  
 
Denny
 
3/4/2005 7:47 AM
Ray Ivers
Denny,  
 
Well, between you and Alex you've pretty much tried the higher-input-impedance tanks and found they don't work well, so what's left? The low-input-impedance tanks. The whole point of using a (costly) reverb drive transformer is to get a low-impedance drive to the tank, and if your reverb transformer had a higher-impedance output the tanks you and Alex tried would probably have worked fine. If you have a spec sheet for the RV4C-1 Gibson reverb transformer that's another matter entirely, and in that case definitely use the Accutronics tank that matches the output impedance of that tranny as close as you can.  
 
Ray
 
3/4/2005 11:11 AM
scott
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hi all,  
 
i just found this thread and it is a problem i am trying to solve as well. i have a gibson ga15rvt and think i screwed the reverb transformer. i snapped one of the leads off. the transformer is marked GIBSON, INC. E-6400 9966523. how do i find the specs on this particular reverb. tried gibson, accusonics, etc. no one seems to know. the reverb was fine until i snapped the lead (imagine). the tube is good, tank good. reverb still there but way off in the background. any ideas ?  
 
thanks,  
 
scott
 
3/4/2005 11:52 AM
scott
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sorry i meant the specs on the transformer.  
 
thanks,  
 
scott
 
3/4/2005 5:06 PM
Ray Ivers
Scott,  
 
If it were my amp, here's what I would do, FWIW;  
 
a) Try to fix your transformer. I've pulled more than one transformer apart, repaired a broken or burnt winding or lead-in, then put it back and had it work fine. If yours can't be fixed (potted, etc.), then...  
 
b) Replace it with a Fender-type reverb transformer. If for some reason you don't want to do this, then...  
 
c) Get a Hammond 125A or 125B tiny universal output transformer from Antique Electronics, and set it for the highest impedance ratio it has; it should work fine, maybe quite a bit better than stock.  
 
Ray
 
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