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someone please educate me on installing a spring reverb
Posted: Sun Nov 17, 2013 6:58 pm
by space6oy
i have one i'd like to install in my univox U-1011 head but don't know how to wire that up. the tank has simple RCA in & out jacks, but that's all i know...

Re: someone please educate me on installing a spring reverb
Posted: Sun Nov 17, 2013 9:16 pm
by space6oy
also it doesn't have reverb/send return jacks, but it does have a pot for reverb adjustment and foot switch jacks for reverb & tremolo.
Re: someone please educate me on installing a spring reverb
Posted: Mon Nov 18, 2013 1:05 pm
by new05002
does this amp have a reverb driver circuit?
Re: someone please educate me on installing a spring reverb
Posted: Mon Nov 18, 2013 1:33 pm
by Dr Satan
I'm seeing all sorts of pics online of that amp and the jacks for the reverb are on the left, kinda behind the preamp tube section. The tank is either mounted on the side or bottom. Unless someone took the reverb out, it probably just needs a new tube for the reverb drive/recovery circuit. The reverb will only work on channel 1. Schematic here-
http://music-electronics-forum.com/atta ... 1011-2.gif
Re: someone please educate me on installing a spring reverb
Posted: Mon Nov 18, 2013 1:37 pm
by Dr Satan
Also, the drive/recovery circuit is designed for a specific tank with a certain impedance. You can't just swap out any old tank and expect it to work. And the tanks themselves, despite only have a couple of RCA jacks, aren't as simple as they seem. They are designed to be mounted specific ways, the input and output jacks aren't always wired the same- some share a ground, some are isolated, some only the input is shared with the housing some only the output, etc.
Re: someone please educate me on installing a spring reverb
Posted: Mon Nov 18, 2013 2:00 pm
by space6oy
wow, thanks! see the pic is hosted in photobucket, where did you find that though? i haven't run into that searching, but i was only looking specifically for the U1011. awesome that there are jacks in there afterall, i hadn't even looked around beyond the back plate where i ASSumed they'd be.
the guy i bought it off on here (delta IIRC?) included a tank with it, made by a company named "accutronics." has what i'd think is a serial number but not a model number, "8EB2C1B."
Re: someone please educate me on installing a spring reverb
Posted: Mon Nov 18, 2013 5:53 pm
by Dr Satan
I just did a google image search for univox U-1011 reverb tank and found one that looked close then in the related images I found some better ones, like the one I posted. 8EB2C1B is indeed a model number and all the info about it can be found at the Accutronics website. It's a flash based site so I can't link directly to it, but that would be a "type 8" reverb tank. Copypasta'd straight from their page:
Designed for applications in which the overall sound quality is important and a compact package is required. Small in size, this three spring reverb approaches the rich textural quality of our larger reverb units. Outer channel dimensions are 9.25” Length x 3.375” Width x 1.313” Height.
PART NUMBERING SPECIFICATIONS FOR TYPE 8
EXAMPLE: 8EB2C1B
DIGIT #1 - REVERB TYPE
8 for Type 8 or 9 for Type 9
DIGIT #2 - INPUT IMPEDANCE
A = 10 Ohm
B = 190 Ohm
C = 240 Ohm
D = 310 Ohm
E = 800 Ohm
F = 1925 Ohm
DIGIT #3 - OUTPUT IMPEDANCE
A = 600 Ohm
B = 2575 Ohm
C = 12000 Ohm
DIGIT #4 - DECAY TIME
1 = Short (1.2 to 2.0 sec)
2 = Medium (1.75 to 3.0 sec)
3 = Long (2.75 to 4.0 sec)
DIGIT #5 - CONNECTORS
A = Input Grounded / Output Grounded
B = Input Grounded / Output Insulated
C = Input Insulated / Output Grounded
D = Input Insulated / Output Insulated
E = No Outer Channel
DIGIT #6 - LOCKING DEVICES
1 = No Lock
DIGIT #7 - MOUNTING PLANE
A = Horizontal Open Side Up
B = Horizontal Open Side Down
C = Vertical Connectors Up
D = Vertical Connectors Down
E = On End Input Up
F = On End Output Up
Not exactly sure how to figure out the proper impedance based on the tubes and whatnot. Maybe someone else who knows more about that will chime in. It seems like if the impedance was too low, that it would overdrive the transducer on the input and possibly damage it, but if it's too high that it wouldn't drive the tank at all. I know that the tanks you see in cheaper/newer solid state amps tend to be 8 ohm input impedance and are very easy to drive, but the older stuff (even in solid state amps) takes more to drive. I suppose it's possible to put an resistor inline with the input to the tank to protect it, but again, I'm not entirely sure that would work.
Re: someone please educate me on installing a spring reverb
Posted: Mon Nov 18, 2013 6:00 pm
by space6oy
WOW. i

you dr. satan.
also i have been a grinch and stuck w/ yahoo since it's been my search engine forever but you are tempting me to succumb to google...
