(Topic ID: 272200)

Stern v.1 audio potentiometer

By Caucasian2Step

1 year ago


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  • 13 posts
  • 6 Pinsiders participating
  • Latest reply 49 days ago by seshpilot
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#1 1 year ago

What is the rating on a potentiometer for a Stern made in 1980.

I'm looking for a speaker too.

What are the specs for these items?

Thank you.

c2s

#2 1 year ago
Quoted from Caucasian2Step:

What is the rating on a potentiometer for a Stern made in 1980.

From memory the potentiometers are 25k ohms logarithmic.

Speakers are 8 ohms.

#4 1 year ago
Quoted from KenLayton:

This Jameco Electronics # 140514 will work fine:

Ken, that's for Bally. They use the pot directly on the amplifier output to the speaker - hence the low ohms and high wattage.

Stern is different - their sound boards have a MC3340 volume attenuator chip with the 25k ohm pot in the cabinet connected to it. No audio is carried on the cabling to the pot hence there's no noise picked up via the cabinet cabling.

#5 1 year ago

Oh, I thought Stern was doing it like Bally since Stern copied so much of Bally's designs. Sorry.

I just noticed in a Meteor schematic, Stern does NOT even mention a value of the pot. It just says external pot.

#6 1 year ago
Quoted from KenLayton:

I just noticed in a Meteor schematic, Stern does NOT even mention a value of the pot. It just says external pot.

No worries, check the Hot Hand schematics for the SB100 sound board - there it's mentioned as 25k ohms. The SB300 sound board uses the same volume attenuator chip.

About 6 months ago I measured the pot on a Catacomb (uses a SB300 sound board) and it was a standard 500mW logarithmic 25k ohm pot.

6 months later
#7 8 months ago

Need to replace volume control potentiometer 25k assuming 5watts rated.
Would be using as replacement for Hot Hand & Seawitch
Found these
https://www.parts-express.com/25k-linear-taper-potentiometer-1-4-shaft--023-630
Didn’t see anything @ Marco, PL or PBR.

Looking to get one with long shaft.

Can someone point me in the right direction?

#8 8 months ago

Thinking of picking up a couple of potentiometer for classic Bally’s
Would this work
https://www.parts-express.com/100-ohm-linear-taper-wire-wound-potentiometer-1-4-shaft--023-604

Not sure what tapered wire wound means on performance

#9 8 months ago
Quoted from Madmax541:

Need to replace volume control potentiometer 25k assuming 5watts rated.
Would be using as replacement for Hot Hand & Seawitch

Presume that's a typo, but Stern only requires 0.25 watt potentiometers.

Quoted from Madmax541:

Not sure what tapered wire wound means on performance

Wirewound potentiometers are how they are constructed to be higher power. Lower power potentiometers use carbon.
That potentiometer is labeled as "linear taper" which is contradictory. Either it's linear, or its tapered. Audio equipment volume controls are logarithmic, but in a set once and forget scenario like this it's not going to matter too much if it's linear.

#10 8 months ago

Quench thanks for confirming, thought while ordering would pick up a few

6 months later
#11 59 days ago
Quoted from Madmax541:

Quench thanks for confirming, thought while ordering would pick up a few

What did you end up getting? Did it work out ok?

#12 53 days ago

No one ever followed up on this post, but I believe this product checks all the boxes: https://www.mouser.com/ProductDetail/652-PDA241SRT02253A2

Going to order one and can confirm if needed.

#13 49 days ago

I can confirm that the pot I listed above works! Buy with confidence.

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