fripholm

Re: [BUILD] fripholm's TG1 Zener Limiter boards - support thread
« Reply #380 on: May 15, 2019, 03:43:50 PM »
Pots are wired hot= 1, cold / wiper = 2, drain = 3.

I'm not sure what you mean by that.

When done correctly, the output gain pot should get to full level when fully CW but *not* fully silenced when turned the other way.

When you look at the output gain pot from the front panel side with the pins facing down, the pot's rightmost pin is soldered to pin 1 (the square pad) of connector OUTPUTGAIN. The pot's middle pin goes to the pad in the middle of that connector and the remaining connection goes to pin 3.


ron_swanson

Re: [BUILD] fripholm's TG1 Zener Limiter boards - support thread
« Reply #381 on: May 16, 2019, 10:30:12 AM »
I'm not sure what you mean by that.

When done correctly, the output gain pot should get to full level when fully CW but *not* fully silenced when turned the other way.

When you look at the output gain pot from the front panel side with the pins facing down, the pot's rightmost pin is soldered to pin 1 (the square pad) of connector OUTPUTGAIN. The pot's middle pin goes to the pad in the middle of that connector and the remaining connection goes to pin 3.

Thanks for the reply fripholm!

Sorry, the I/P and O/P gain pots I have are numbered, hence my number reference.  Based on your response above, the numbers on my pots are in reverse to your instructions.    Also, 'yes' full CCW is not exactly 'no volume' .   

Does the installation instructions above also apply to the I/P gain control wiring?

So, after a quick re-wire to match your instructions, seems to work correctly now, but immediately ran into an issue where the right channel gain level was significantly less than the left channel .  The pot would sometimes be fully functional (matching the response of the right channel O/P gain volumes) and other times next to nothing.   Of course, the right channel was my channel of focus when trying to assess the reverse pot issue, so this volume cut in / cut out issue was probably muddying the waters.       

Gently tugging on the connecting wires, I noticed that would cut the volume in or out.  Thinking I had a bad solder or broken wire, I pulled the pot, measured just to confirm proper working order, re-wired  with new wire and again, wiggling the connecting wires resulted in the audio cutting in and out.  So, bad pot?   Ran out of time last night, but I'll replace that and go from there. 

Noticed a couple of other issues that again didn't have time to look into, but will work on that myself a bit before requesting assistance.  More troubleshooting fun ahead it seems!

Thanks again for the response!

~ Greg



Ilya

Re: [BUILD] fripholm's TG1 Zener Limiter boards - support thread
« Reply #382 on: May 16, 2019, 11:28:09 AM »
Bad pot is highly unlikely. They almost never break. Look somewhere else. If you can consistently reproduce a fault (for example, pulling a wire cuts out the signal) check for bad solder joints. These are more likely to cause the trouble than the pot.
PCBs, enclosures and build guides at www.rackneve.com

ron_swanson

Re: [BUILD] fripholm's TG1 Zener Limiter boards - support thread
« Reply #383 on: May 16, 2019, 12:06:56 PM »
Bad pot is highly unlikely. They almost never break. Look somewhere else. If you can consistently reproduce a fault (for example, pulling a wire cuts out the signal) check for bad solder joints. These are more likely to cause the trouble than the pot.

Hi Ilya,

Yes, that too is a possibility and something I will check into and keep in mind as well.   

That said, while checking this pot, I was able to stabilize the cable so only the connection to the pot and an inch or so of the wire connected to the pot could move.  A little tug / wiggle cuts in and out. 

I agree though, a damaged pot seems unlikely, but also easy to rule in or out.

Thanks for the response!  Much appreciated!

~ Greg

TwentyTrees

Re: [BUILD] fripholm's TG1 Zener Limiter boards - support thread
« Reply #384 on: May 16, 2019, 01:54:20 PM »
Bad pot is unlikely, but not impossible. Especially on the cheaper ones, too much heat (from an iron set too high) can wreck the connection between solder tags and carbon track - as I found out recently on a cheapo generic 6-gang one off eBay!

ron_swanson

Re: [BUILD] fripholm's TG1 Zener Limiter boards - support thread
« Reply #385 on: May 16, 2019, 03:33:14 PM »
Bad pot is unlikely, but not impossible. Especially on the cheaper ones, too much heat (from an iron set too high) can wreck the connection between solder tags and carbon track - as I found out recently on a cheapo generic 6-gang one off eBay!

TwentyTrees, 

Build pots are new Bourns from Mouser.    So, as you and Ilya have suggested, while the pot is a problem possibility, it  is only a suspect at this point. 

Thanks for the chime in!

~Greg

fripholm

Re: [BUILD] fripholm's TG1 Zener Limiter boards - support thread
« Reply #386 on: May 17, 2019, 02:48:56 AM »
Does the installation instructions above also apply to the I/P gain control wiring?

Yes, exactly.

You could try and temporarily connect the two circular pads of the input and/or output gain connectors. In this case there would be no attenuation at all and you'll be able to rule out a faulty pot and see if the level drops go away.


 

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