Broken amp pot

[Taff107]

Chaps, do we have anyone who knows anything about electronics? I've been given a TP3116 amp board however, the 'Bass frequency' potentiometer has been snapped off the board. I'd like to get some use out of it and solder in a new one. Problem is that I don't know which to get. I can find other 6mm shaft, 6 pin pots however I don't know what resistance to get. Anyone able to help?
(As you may have guessed, my knowledge of electronics is at caveman level)

[Hotspark]

That's probably a two channel pot'. Basically provides two separate resistive readings that are identical, but isolated for different parts of the circuit.

If you have a multimeter, spin the shaft full deflection left, probe between the middle and a pin to one side of it. Measure the resistance and take note. Now probe the middle and opposite pin and take note. This should give you the min and max range.

Probing the other channel pins should produce the same readings.

Don't forget to view the channels as a bank of three if that makes sense

If you struggle probing the pins, you 'may' have luck by desoldering another, maybe two to confirm, pot's and measure from those in the hope that they are identical and the filter capacitors are selected accordingly.

Edited by Hotspark on Friday 17th April 09:59

[curlyks2]

Are there any markings/writing on the pot at all?

Looks like it's one of these (with other similar on other auction/import sites at the same c. £15 price point) although sadly no obvious schematics to assist.

[Who me ?]

They'll will be information on the body. It's how to read it that matters. The technical side is of two frames. One is the value of the resistance , the other is whether pot is LIN or Log. The value of the resistance will be something like 2k2/ 4k7/10Ketc. And after that, usually, but not always is the type. Lin, means that the resistance increases in a linear fashion. Log means that it will increase in a ( usually a Napier series) value as the pot is rotated. I'd suggest that if all fails I'd suggest that pot will be a Log TYPE.
Stick up some photos of the writing on the body for more info.
Next Q- how competant are you with a small soldering iron, and a solder sucker/ desoldering braid. A lot of the PCB of this type are not tolerant of attempts to clean out the holes.

Edited by Who me ? on Friday 17th April 12:33

[Taff107]

Thanks chaps.

I can't see any writing on the side of it but unless it is miniscule. I'll give it another go with a magnifier when I get home.If I do see anything, I'll put it on here for you guys to see.

I'll try what you suggest also Hotspark if I see no writing

WRT my ability to de solder the holes, well, I have done it before (once!) but not on these type of boards. I'll just take it slow and gently. It doesn't really matter if I do make a hash of it as it is no good as it stands Who

[xtruss]

If i remember correctly from when i played around with one of these TPA3116 boards it used a B50k dual pot - Ebay linky for reference
https://www.ebay.co.uk/itm/RK097G-15mm-Audio-Shaft...

[megaphone]

Have a look on the aluminium front, may be marked there.

[Taff107]

Gents you are stars! Took a magnifying glass to it and it does say

B502
B503

On the top and right at the very bottom on the back,

B50k

Bingo!

[Who me ?]

Taff- an old trick if you damage a track ( and I've used it on home made boards that got over etched) was to find some very fine stranded wire and bridge out the broken parts of the track. If the track lifts ( usually caused by excess heat in desoldering) it's possible to use something like Araldite to stick the track down and solder/solder a wire over any breaks. ( tip- the heat of an iron can be used to speed up the setting time)

[jet_noise]

£20 from Amazon...
...for the whole thing!

How are you going to power it?

A little digging suggests the B in the numbers is lin(ear).
You might find something on internet auction bay long lead times from China.