Hello,
I have managed to hold of a 60s carlsbro reverb that needs fixing. I get sound through it but no reverb. I can get a picture of the insides for you if necessary. But if this is a common problem maybe someone could help me without a picture. The pots are pretty dodgy so i'm going to replace those, what type and value of pots would they be?
Thank you,
Oscar.

:wink: If you take a good pic outside too and some info if there is model number or something like that there might be some info somewhere, I have followed some surf/instro/eleki etc. links and those guys are reverb and echo fanatics and maybe some info might be found. I know a collector who would be happy with good quality pics inside and outside...

These in general are relatively simple circuits, and you have good chances to get it working. And if it is bad sounding one in original condition and in bad shape but good looking, you can maybe replace the circuit or the sproing with better one ...

If teh pots have no markings you can unsolder the wires temporarily (make a drawing before you remove anything) and measure the value between outside lugs

here are some pictures.
http://www.jga.u-net.com/reverb.html
Thanks,
Oscar

Nice pics and looks very cool and neat construction, not too fancy but clean retro look. This might look cool with old tape echos and Vox AC30.

Someone said "if it is not broke don´t fix it". Maybe you could test first if the reverb spring assembly works. Does it give any amplified sound from the spring  when you give some movement to the unit, or if you can touch carefully the spring and listen the output (dont get shocked, watch the mains voltage!). The circuit amplifying the echo output may be the fault, you could temporarily connect the output to some other preamplifier. Or if the input driver coil of the spring assembly is burn dead, you should first measure the dc resistance to get a quess what the impedance is. Perhaps you could drive it with some other signal while listening the output with some preamp that works for sure. But not so easy find the input and output impedance and optimum drive level...

Not very much components on the board, so maybe you could replace all electrolytics with new ones with same specs, maybe not so big fault there because you get some sound (maybe it is not "true bypass" or direct sound straight from input to output). And maybe semiconductors are easily replaced too. You should measure pots with digital ohmmeter and you could see if they are lin or log by measuring how the resistance changes when you turn the pot.

Peter Snowberg posted few days ago a good link to a rev tank manufacturers site, there is good info about some reverb tanks and their input and ouput impedances, and suitable drive and recovery circuits. There has been many good threads about spring reverb in this forum, do a search and you find info. And Stage Center Reverb is in good reputation, if you need to make whole inside in new order...

Not much info around but maybe good pre- and post eq and filtering and good spring unit and suitable drive level are crucious design points, or a matter of taste...

www.accutronicsreverb.com is a good site for reverb tank info

Thank you for the help so far.
I do get an amplified sound from the spring if i tap the box, so where do you think the problem could be in this case. Also the guitar sound i get is a bit low in volume as well as having no reverb.
Thanks,
Oscar

Maybe you could temporarily unconnect the reverb driver from original circuit and try to feed it with some other signal, maybe an opamp stage or headphone output (be careful not to burn the coil with too hot signal, check the link Smoguz posted). And measure the coil if there is total open or short, and the impedance/resistance.

If it works you can then start debugging the circuit, pots and jacks wires etc.