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Are genuine bias pots available OR120

Posted: Sat Jun 16, 2018 2:56 pm
by LD50
I have a couple of mid 70s OR120s, one is in need of lots of TLC and I need a new bias pot (and ideally heater balance pot) of the original type with plastic cover and correct rating to fit on the board (Labelled Orange OR80/120 Mk ii).
The 100R heater balance pot is presumably 10-15v rated and several amps. The bias pot will need to be 100v rated but only 200mA rated?
Does anyone know of a source for these?
Many thanks in advance.

Re: Are genuine bias pots available OR120

Posted: Sat Jun 16, 2018 3:48 pm
by bclaire
An amp tech could source them for you in a few minutes.

Re: Are genuine bias pots available OR120

Posted: Sat Jun 16, 2018 4:42 pm
by Gladmarr
IF the same style is still available, it would be a matter of searching far and wide for them. You’d have to see if you can see any company-identifying markers on them. I really doubt you’re going to find the EXACTLY correct pots, but I do know the ones used in the 90s reissue amps are still available.

Re: Are genuine bias pots available OR120

Posted: Sun Jun 17, 2018 4:42 pm
by fiveightandten
Your best bet is to measure the lead spacing and search around on www.mouser.com for something that is correct spec and fits. It is likely a tall order to fill.

-Nick

Re: Are genuine bias pots available OR120

Posted: Mon Jun 18, 2018 11:42 am
by LD50
Thanks Billy - but, as the other gentlemen with an interest in vintage Oranges these things are no longer stock items and, as I suspected from my general enquiries, seem be pretty hard to source.

I have replacement ones with correct spacing to hand (old style wafer with metal slot, but was after the correct original type if they are still available from some obscure store!

The 90s reissue ones might be the nearest thing?

Re: Are genuine bias pots available OR120

Posted: Mon Jul 23, 2018 2:15 pm
by LD50
Good news.

I found some.

An e-bay seller: hmss

Listing number: 232841513742

He ahs both 100R and 100k and other values. These are the correct RS pots. You will see on listing there are two types, the common lug has a thread for a nut, the other type (the ones I need) are just hollow solder lug. Obviously NOS and the lugs needed a polish but exactly as the originals.

Re: Are genuine bias pots available OR120 - yes!

Posted: Mon Jul 23, 2018 2:16 pm
by LD50
LD50 wrote:
Sat Jun 16, 2018 2:56 pm
I have a couple of mid 70s OR120s, one is in need of lots of TLC and I need a new bias pot (and ideally heater balance pot) of the original type with plastic cover and correct rating to fit on the board (Labelled Orange OR80/120 Mk ii).
The 100R heater balance pot is presumably 10-15v rated and several amps. The bias pot will need to be 100v rated but only 200mA rated?
Does anyone know of a source for these?
Many thanks in advance.

Re: Are genuine bias pots available OR120

Posted: Tue Jul 24, 2018 12:07 am
by Gladmarr
LD50 wrote:
Mon Jul 23, 2018 2:15 pm
Good news.

I found some.

An e-bay seller: hmss

Listing number: 232841513742

He ahs both 100R and 100k and other values. These are the correct RS pots. You will see on listing there are two types, the common lug has a thread for a nut, the other type (the ones I need) are just hollow solder lug. Obviously NOS and the lugs needed a polish but exactly as the originals.
Excellent news! 8)


(Except on further investigation, I can’t find that auction/item number OR that seller’s ID anywhere)

Re: Are genuine bias pots available OR120

Posted: Tue Jul 24, 2018 9:33 pm
by LD50

Re: Are genuine bias pots available OR120

Posted: Tue Jul 24, 2018 9:45 pm
by LD50
LD50 wrote:
Tue Jul 24, 2018 9:33 pm
Sorry hmhss is the seller

https://www.ebay.co.uk/itm/Potentiomete ... 1438.l2649
Image

Re: Are genuine bias pots available OR120

Posted: Thu Jul 26, 2018 4:16 am
by Gladmarr
Right on!! How did you find these? I never have the patience to find this kind of obscure stuff on eBay.

Re: Are genuine bias pots available OR120

Posted: Wed Oct 17, 2018 1:42 pm
by jontheid
Just bought 2 x bias pots and 2 x hum pots. Turns out the seller lives about a mile away from me! Lots of other interesting stuff for sale too.

Re: Are genuine bias pots available OR120

Posted: Sun Oct 21, 2018 3:59 pm
by LD50
Lots of other interesting stuff - do tell!