Rowe Ami R-88 Volume control

[olidlavoie]

Hi, I bought an R-88 Jukebox from Rowe Ami (The 84, brown model) and there's no sound, except a "pop" from the speakers when I plug it in, i read a couple of posts only to see that there's supposed to be a volume control in the back of the machine, on mine there's only 3 loose wires hanging there, a black one, a red one, and an orange one, can anyone tell me how to hook them up on a potentiometer? I would prefer not to buy a 75$ service manual for 3 wires! I tried a couple things but it seems one of them could be a cancel button as the vinyl was ejected as soon as I touched some wires to the pot...
Thanks a lot,
Olivier

[Ken Layton]

From Victory Glass Company you can buy the manual very reasonably:

# 70-5765 (R-555) Rowe R-88 Field Service, Parts, Installation, & Operation manual, 135 pages, just $39.95

Strongly advise you to buy it because someday you'll need to order parts, repair something, or replace bulbs and you'll be glad you have it.

[ami-man]

I tend to agree with Ken, A few bucks now will save you a fortune in repairs for damaged parts or blown amplifiers or speakers.

Regards
Alan

Alan Hood
ami-man
UK

[olidlavoie]

You're absolutely right, and I will buy one when I can, but I really can't buy it right now, hence this post, I'll continue to look for signal with my scope then.
Thanks,
Oli

[ami-man]

Hello Oliver,

Forget the wiring above the amplifier compartment and make up a test volume control using a 10k log pot and plug into the volume control socket on the amplifier.

You can use the plug that goes to the connection above the amplifierdoor.

Link pins 1 & 5 and connect these to one end of the 10k log pot.
put a connecion into pin 3 and connect this to the wiper of the pot.

We use these to eliminate any faults in the jukebox wiring.

Regards
Alan

Alan Hood
ami-man
UK

[olidlavoie]

Thanks a lot!!!
I'll try this as soon as I get home
I'll give you some news, and probably a video when it works
Oli

[s-petersen]

I know it's an old post, but is there anything connected to the 3rd pin of the volume control?

[troubleshooter]

No, nothing is connected to the third (CCW) terminal.
These are 2-wire DC controls that control current through signal shunt diodes.  It doesn't need to be shielded, and can be ran some distance without hum issues.
Use a 10KΩ linear, NOT audio taper, but if you can get a REVERSE audio taper (C taper on some brands), that is the correct taper.
TubesAndMore/Antique Electronic Supply actually carries this taper in a solder lug panel mount!

The more you get towards linear and audio taper, the more you will get more rise of the audio at the END of the rotation (CW).
Reverse audio/ taper C, will give the original audio rate of rise with rotation.
There is no electrical issue, just how 'fast' the volume functions as you rotate it.

AMI apparently didn't document this beyond just an AMI part number, but I have measured 5 original vintage controls and all are ~10KΩ reverse audio taper...
I believe all the 2-wire VC that are wired on the 'top' two VC lugs are 10KΩ reverse taper.
This includes the 'bubbler' models AFAIK.
Mr K L