Ken Fox
From:
Nashville GA USA
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Posted 1 May 2002 6:39 pm |
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I just posted this under another thread that started out on BW speakers in an Evans amp. Thought some of you might like to have this information on decoding the Accutronics tank numbers:
Just some notes on tanks from my Mojotone catalogue:
Accuctronics tanks numbers:
1st character: 4 = 17" tank, 2 spring
8 = 9" tank, 3 spring
9 = 17" tank, 3 spring
2nd character: input impedance at 1000hz
type 4 tank type 8 and 9
A= 8 ohms 10 ohms
B= 150 ohms 190 ohms
C= 200 ohms 1240 ohms
D= 250 ohms 240 ohms
E= 600 ohms 800 ohms
F= 1475 ohms 1925 ohms
3rd character: output impedance at 1000hz
type 4 tank type 8 and 9
A= 500 ohms 600 ohms
B= 2250 ohms 2575 ohms
C=10000 ohms 12000 ohms
4th character: decay time
1= short, 1.2 to 2.2 seconds
2= medium, 1.75 to 3.0 seconds
3= long, 2.75 to 4.0 seconds
5th character: connector arrangement
A= input grounded, output grounded
B= input grounded, output insulated
C= input insulated, output grounded
D= input insulated, output insulated
6th character: locking device
1= no locking device
7th character: mounting plane
A= horizontal, open side up
B= horizontal, open side down
C= vertical wall, long axis horizontal, connectors up
D= vertical wall, long axis horizontal, connectors down
E= vertical wall, long axis vertical, input up
F= vertical wall, long axis vertical, output up
The only vertical wall tanks that are avaiable from Mojotone or Antique Electronics catalogues are the 8DB2C1D. That is:
9" tank
310 ohm input
2575 ohm output
medium delay
input insulated, output grounded
no lock
vertical wall, long axis horizontal, connectors down
Hope that helps. I have an 8AB3C1B, short tank, long delay, works in tube amps. I test old Fender amps with it. It's a three spring, long delay. It has a very lush reverb. The trick is to get the three spring, long delay for your amp. Theses are recommended for vocals, keyboards, and steel guitar applications. I understand that the Rivera tube amps use the three spring, long delay and they sound great!
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Steven Welborn
From:
Ojai,CA USA
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Posted 1 May 2002 9:00 pm
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| Thanks for posting all that Ken. Very cool info. The tank in my '80 evansfet500hv is an(three spring) 8FB21F. 9in., highest input impedance, medium decay, vertical mount. So I guess if there was an 8(9") or even better 9(17")FB3B1B available then I could mount or set it outside the cab like on top(unless along the bottom/inside didnt produce too much hum). Its worth trying. [This message was edited by Steven Welborn on 02 May 2002 at 08:55 AM.] [This message was edited by Steven Welborn on 02 May 2002 at 08:57 AM.] [This message was edited by Steven Welborn on 02 May 2002 at 08:59 AM.] |
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Ken Fox
From:
Nashville GA USA
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Posted 2 May 2002 6:23 am
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| Steve, I'll try to find another site for tanks, maybe even Hammond themselves. It appears thet the Evans did use a 3 spring tank. I suspected it was a high impedance, input due to the transistor drive circuit. The older tube amps used a reverb transformer (looks a lot like a 25/70 speaker transformer) to step up the 8 to 10 ohm tank input impedance back to the typically 12AT7 drive circuit. The tank out of any old Fender tube amp would just not work on one of these transistor amps. It's mounting configuration and impedances are all wrong. [This message was edited by Ken Fox on 02 May 2002 at 07:25 AM.] |
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