I have an old cream coloured Roland Cube-60 which came to me with reverb issues.
Initially it had no drive going to the spring tank input, that was due to a pin sheared at pcb level on the driver ic. With that sorted there is sound going in but nothing coming out unless you twang the springs. So I'm guessing a new tank is the best bet but does anyone know what spec I need ie input/output impedance and delay length?
Thanks
Don't guess, pull the plugs off the pan, and measure resistance at each jack, is either end open?
Bad choice of wording perhaps Enzo but input is sub 1 ohm and output is 180 ohm. This situation has also been proven by temporarily fitting another reverb to the PCB sockets which results in a working system. I just want to be sure that the reverb tank I purchase has the right impedances.
If the input coil reads under 1 Ohm then there is a short as the drive coil would be somewhere between 30 Ohms and 100 Ohms,, Drive Z is dependent on the circuit that drives it. You may have to research what tank Roland used for that drive circuit.
Before I'd replace the tank I'd be checking the inside of the tank, yes the coil might be fried but I'd wiggle those little wires that lead to the coil and see if they have not shorted as it maybe a simple issue to fix.
Phil.
Like Phatt said, that is likely too low an input impedance for a solid state amp.
It is probably defective, or possibly someone has installed an incorrect type.
Are there any numbers on the tank?
An AB style pan will normally measure about 1 ohm or less on the drive end. The amp may or may not desire and AB, but the fact remains.
Quote from: Psabin8951 on September 12, 2017, 02:27:58 AM
I have an old cream coloured Roland Cube-60
I have two of these Cube 60's. Initially I dispensed with the rev tanks and took a feed from pin 10 of the SIP tank driver IC via a 10k as an Aux send and ran an effects loop using a Chorus Echo 301. I fed the return from the Echo unit into the rev return point. I eventually made a better version of the "send" function which I still use although these days I'm using the RE-20 Space Echo twin pedal instead of the tape based Space Echo.
Just gives you another option.
I can post a schema of the send mod patch if you're interested.
Nominal 8 ohm input tanks have DC resistance about 1 ohm, just check Accutronics/Belton site.
Typically transformer driven by a 12AT7 1W power amp in old Blackface/Silverface Fender, in fact you could test reverb drive by hooking a speaker there, but I remember Roland used same "speaker impedance" tanks driven by a Car Stereo type chip amplifier, just look at the schematic or inside your chassis, you will find it.
Modern SS amps use mid impedance tanks (some 200 to 600 ohms impedance, DC resistantce 10X smaller) which can be driven straight from a humble (cheap) TL072 .
https://www.tubesandmore.com/products/reverb-tank-accutronics-8db2c1b