Installing On/Off switch and Volume knob?

[Mooly]

Its a bit hard to see the detail in the picture. A normal volume control has three pins per "gang". A stereo pot is called a dual or twin gang pot. Does you old pot have that number of connections ?

If its different then we need to see a clear picture of the old pot that shows the connections.

 

[cudnot]

there is 3 pins on top 3 pins under them then 3 pins under them then 2 pins on the bottom with holes in but are not soldered

 

[AndrewT]

that looks like a stereo vol pot + single pole single way switch.

For the sake of helping to avoid interference I would not bring mains voltage to the switch.

Maybe consider using the switch to turn on a remote relay using well smoothed DC to the switch.

 

[godfrey]

The connections are like this:
(This is the third pic from post 22, cropped and rotated)

 

[Mooly]

there is 3 pins on top 3 pins under them then 3 pins under them then 2 pins on the bottom with holes in but are not soldered

Thanks. It looks as we thought, that they are normal pots. Godfreys post shows clearly how to wire them so I would say that if its not working (both channels the same ?) then something untoward has happened during the repair.

 

[cudnot]

where can I I get another switch from

 

[Mooly]

Switches on pots tend to be a bit unique. I don't think you would turn one up. Only chance would be a similar type pot that you could swap it from... and even then it may not be possible if there are rivets etc securing it.

Are you thinking of trying the old one to see if it works. If so then just short the on/off switch out to test it all.

 

[cudnot]

so the green switch should do the same as the old switch maybe not soldered joints properly thanks for all the advice much appreciated

 

[Mooly]

Be sure with the switch, but yes it should do the same job. The black one has two extra pins pointing down which you say are not soldered.

So yes it should be the same. Just short the two wires that go to the switch together to overide it and refit the old pot to test.

 

[javy]

Hey Mooley, noticed you helped someone with similar issue, expcept his POT looked different.

How would you wire the following up?

2x8W Amplifier

Amazon.com: 2x8W at 4 Ohm TPA3110 Class-D Audio Amplifier Board: Electronics

This POT is not the one I'll get, as I'm reusing the one I have but it looks just like this one. Also, is this POT OK for the amp above? Not sure if this POT will work with the STEREO side of the AMP. Not sure if it even matters.

500K Audio Taper Potentiometer with Switch 1/4" Shaft


I want to wire this guy up to the AMP and the POT so that it turns it on and off along with the AMP. I know I'll need a ground loop isolator too.

http://www.amazon.com/Logitech-980-...1411755033&sr=1-1&keywords=logitech+bluetooth

Thanks a million man!

 

[Mooly]

I'm not so sure 500k is a good value tbh, that's a throwback to valve gear and high impedance circuitry. Yes it will work but you could find a couple of issues, one that the "law" of the pot would be modified greatly by the input impedance of the amp. That would mean all the action happened in the last few degrees of rotation. Second, 500k forms a low pass filter in conjunction with the input capacitance of the amp. If you take 250k as a value and just 220pf (pico farad) capacitance then you make a filter that rolls off at just 2.9kHz. No good. Typically a volume control needs to be in the 10k to 47k region.

Ground loop isolator... not sure why you think that is needed. They are more to solve problems caused by poor wiring architecture or problems that arise in say a field installation where a quick fix is needed without major rework.

 

[javy]

You are absolutely right. I have it wired up now and only in the last 50% does volume start appearing. Secondly, the ground loop isolator thought was only because of what I was trying to combine based on my previous post. Wanted some guidance on how it could and should be out together.

 

[Mooly]

I'm not so sure you'll find a 10k to 47k switched pot these days, you would have to do a search and see what comes up.

That is what you need though, value wise. Can a separate on/off switch be fitted ?

 

[javy]

I'm not so sure you'll find a 10k to 47k switched pot these days, you would have to do a search and see what comes up.

That is what you need though, value wise. Can a separate on/off switch be fitted ?

I'm starting to feel that I have no choice. I really wanted to keep the functionality of original radio Volume/OnOff knob in the front, even if it meant retrofitting a more modern POT, but I keep striking out. My final picture of this radio is getting pretty muddy. Wa Wa Wa.

Now I see why everyone else who is doing this to Vintage radios is just shoving Jam Classics in the chassis and walking away. Grrrr

There has to be a safe and better way to keep everything intact. Sorry Mooly, just going nuts and the Cafe Shop closed!! LOL

 

[javy]

How about this little guy Mooly?

http://www.amazon.com/dp/B00C4N410G...UTF8&colid=ZF0TIU0HMOX3&coliid=I3AUSDLLBABPSE

its a 6W Amp that has a POT already on it. I'm sure that POT functions well. If I can retrofit that into my current knob, even with some trickery, it should work right?

If you say yes, beware, more questions will come, LOL> Is there a donation button for your help?!? LOL

 

[Mooly]

That's a 50k pot, and yes it will work. You might struggle taking it off the board though if you are not used to desoldering parts. If the holes (vias) are plated through and particularly if the board is double sided then its not easy.

Donations. Top line of this page. Every little helps keep the show on the road

 

[javy]

Morning Mooly, thanks for Donation button, I'll donate 20% of my final build cost once I get this squared away, which at the moment is far exceeding my initial budget.

My father n law will be shadowing me with the desoldering. He's a master welder. Bentsnake is helping me compose a proper configuration for a good final and proper radio. What I'am finding out is that the 6wAmp has limitations. I have one here and I put some small speakers and the volume didn't go up very much, I mean, I could barely hear it. Volume up on the POT and on the IPHone. I was experimenting, I'm sure its a wattage or OHM thing. amp was for 4ohm speakers and the speakers were 4ohm, yet they were 60w. So I'm thinking of going up to another Amp, which unfortunately don't have POTS.

Would you be able to tell me where I can get a POT that has an on / off switch and volume control that I can adapt say to this module?

Amazon.com: 2x8W at 4 Ohm TPA3110 Class-D Audio Amplifier Board: Electronics

or this guy?

Amazon.com: 2x15W @ 4 Ohm TA2024 Class-D Audio Amplifier Board: Electronics

Thanks.

 

[javy]

BTW this is what the POT looks like, this is off a testing radio I'm using that was pretty beat up.

 

[javy]

Ah what the heck, donated a starter now!

 

[Mooly]

Ah what the heck, donated a starter now!

Excellent

A 6 watt amp can be surprisingly loud,
http://www.diyaudio.com/forums/mult...much-voltage-power-do-your-speakers-need.html

I suspect your probably not feeding enough voltage into the amp tbh. The only other remote possibility is that you have the speaker wired incorrectly... but it should all be clearly marked on the board. Try the amp with a proper source such as a CD player if you can.

For a pot + switch you would have to search the component catalogues from suppliers in your part of the world. That's going to be Digikey and Mouser I suspect. They are not common items these days.