Ruby reverb can: Resistance on Input coil?

[xraytheplan]

Hi all,
i have a 10 month old Ruby reverb can in one of my amps, but there is nearly no reverb hearable. Normaly there was more then enough reverb with the pot on 2 (goes to 10). I had a loud hum which disappeared kicking the amp a little bit. After that i had the problem.
With 2 older Accutronics cans everything is alright. My meter says only 2ohm on the input coil, 200 on the output. The accutronics have 60ohm and 200ohm.

On the Ruby website i cant find the exact unit, but there are resistence readings in a list. So i guess, my can is broken.
My question, has someone a Ruby reverb can "RRVL2AB1C1B" and can measure the input coil for comparison? Would be very nice.

thx in advance

[oc disorder]

Hi xraytheplan and welcome to the forum

I haven't got a Ruby tank but from reading
ruby reverb tank vs. accutronics [Archive] - The Gear Page
it would seem that they may be made in the same factory as the Belton tanks.
From here
Reverb Tanks
it states
.... Belton BL2AB3C1B = Accutronics 4AB3C1B
so Ruby RRVL2AB1C1B I would assume to be the same as the Belton

except digit 4 a "1" (between the B and the C) indicates a short delay time

see the Accutronics Type 4 part number specifications explaining the numbering system
which seems to be similar to the Belton.

http://www.accutronicsreverb.com/Type4.htm

BL2AB3C1B BELTON
Long Tank Long Delay, input impedance 8Z, out 2250Z, insulated input grounded output. Mount horizontal open down.
Used Hughes&Kettner, Marshall, Ampeg, Crate, Fender, Mesa Boogie.
TECHNICAL EQUIVALENT OF 4AB3C1B

Whem measuring with a ohmmeter we are actually measuring the DC resistance not the impedance.

Accutronics have a chart of typical DC resistance measurements of their tanks.

Accutronics Reverb by Sound Enhancement Products, Inc.
(also see attached)

From chart ..
Impedance of 10 or 8 ohms equals 0.81ohms DC resistance (read by a meter)
Impedance of 2570 or 2250 equals 200ohms DC resistance "

When you hold the probes of your meter together do you get 000 ohms or is it more like 001 (01.19 would be ideal in a perfect world ! ).

The meter is probably more accurate at higher readings.

Try another tank in its position. Its possible there may be something wrong with the send or return electronics.
If you rock the amp (or kick it - not recomended ! ) can you hear the springs crash or rattle?
Check the leads too.

[Enzo]

If you measure some resistance on each end, then the pan is probably OK by itself. The ends are just coils of wire, they don;t usually find themselves wrong valued. Mostly they are either open or they are fine.

Your pan may be the wrong type though. Your old Accutronics pans work, right? What numbers are on them? I would be betting they say 4EB2C1B - well, at least I am betting the second character is an E instead of an A.

Your Ruby pan measures like an AB pan - as in 4AB2C1B. That is the type used with a tube drive and a small transformer. The xEBxxxx is the higher impedance drive end as used with solid state drives. Your 60 ohm reading is consistent with this, and your low resistance reading on the AB type pan is consistent with the tube drive.

[xraytheplan]

wow, many infos from you guys, thx for this and for the welcome, too

First, i thought the very low reading on the input coil indecates the can is broken. AFTER my question here i saw the resistance list on the accutronics website for different cans with much lower resistance on the input jack. So, my readings and the can maybe ok, but my guess on a broken can maybe totaly wrong. My fault, next time, posting after reading

The can is the original one in a Koch Twintone II. And as mentioned, the reverb effect was hugh/big (sorry for my bad english, dont know whats right) with control knob just on 2! I bought this amp brand new and it was like this from the first day.

When the amp made this loud hum with more reverb, i dont actually kicked the amp , just a little beat with my fist on the top. The hum disappeard, a little bit later i noticed the change on the control knob. Even on the highest setting there is much less reverb then before on 2.

"oc disorder", you may be right and the send/return is faulty. But what makes me wonder, the accutronics can (from 1979) works fine.

I wasn´t aware there are so much different reverb cans with very different parameters.

Your Ruby pan measures like an AB pan - as in 4AB2C1B. That is the type used with a tube drive and a small transformer. The xEBxxxx is the higher impedance drive end as used with solid state drives. Your 60 ohm reading is consistent with this, and your low resistance reading on the AB type pan is consistent with the tube drive.

Very interesting. I dont have schematics from the Twintone II, so i cant say. But ur right, the old accutronics is a "4EB20IA" Im not 100% sure about the 0 and the I, the can is very rusted and the digits are stamped with ink.

But if ur right, and im sure you are, is it important to match the original can as required from the manufactorer and from the amp layout? If the send/return is alright, can it be damaged by a wrong can?

[Enzo]

It is important to use the correct type, but the brand doesn't matter. If your amp wants a AB type pan then an EB pan won;t work, and if you need an EB pan then an AB type won;t work.

If you see continuity through each end , then the pan is electrically OK, but the pan could still be mechanically defective.

SO, if the original pan was an EB, then your AB won't work.

Also, make sure the amp is working, and that the cables are connected to the corect jacks. Turn the amp on and turn the reverb controls midway. Pull the cables out of the jacks on the reverb pan. Touch the tip of the plug on each cable with your finger. One of them should make a loud hum from the speaker. That cable is the return cable and should be connected to the jack on the pan marked OUTPUT.

[xraytheplan]

...and that the cables are connected to the corect jacks.

oh boy. Enzo you got it
I changed the preamp tubes some days ago for a little sound experiments and i unplugged the cables from the chassis.
There is a sticker next to the reverb in/out jacks and i read it in the way "this jack GOES to the output" and not "this IS the output".

ok, im not going to disarm an a-bomb for the rest of the week. Thank you guys

[Enzo]

Connectors on our audio gear are generally marked with what their function is.