Help with an unknow reverb tank

Started by Mich P, February 21, 2016, 06:41:29 AM

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Mich P

Hello all, i have, since a while, a reverb tank from an old italian guitar combo from the end of 70's. Can remember model.
I wanna know if i can connect it to something like the stage reverb center or others to give it a try.
I made measurement of both coils with a component analyser who says this :
Imput   : R= 171.1 Ohms
           : L= 211 mH

Output  : R=157.2 Ohms
           : L=282 mH

Size 24cm X 10cm X 3.5cm

Thanks,
Mich P.










jatalahd

The reverb tank input/output impedance is highly dominated by the coil inductance. That is why datasheets specify the nominal input and output impedance measured at 1000 Hz. This image gives a hint to approximate the impedance at 1000 Hz using the DC resistance value which you have successfully measured: https://images.campyent.com/sites/default/files/tech_corner/reverbtank3.svg

According to that, the input/output impedance of your tank is around 2 kilohms, which to me seems a bit high for the Stage Center reverb. I built my Stage Center reverb using a tank with 150 ohm input impedance and it seemed to work well. The impedance of your tank is approximately 10 times higher.

Rod writes well about reverb tanks in his article: http://sound.westhost.com/articles/reverb.htm. According to that article, the high impedance tanks (which you have) need a higher drive voltage (where as the low impedance tanks need higher drive current). The with the Stage Center reverb you can get a max drive voltage amplitude of around 7.5 volts (15 volts peak to peak) from where the RMS voltage is around 5.4 volts. So to me it sounds that the Stage Center reverb will not directly work with your tank. If you somehow increase the drive voltage on the Stage Center reverb then I don't see no reason why it would not work.

But let's still wait and see what others have to say.
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I have failed to understand.

PRR

Some other tank-specs use 800Hz.

On that benchmark, the input is essentially 1K.

But it is NOT critical, because the impedance will be 500r at 400Hz to 2K at 1.6KHz.

It should work with basic opamp chips such as stage center reverb.

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Mich P