Pan pot for a Trident Series 8T 16 Channel Mixer

[tomheavybeats]

HI
I have a faulty pan pot on my trident series 8t desk (stock photo attached) and I am wondering if anyone can recognize the pot from the photo and knows what I can buy as a replacement please? Long shot and I emailed Oram and got no reply. Couldn't find a schematic and there's no marking on the pot itself.
Any help much appreciated!

Tom

 

[Bo Deadly]

Trident is alive near as I can tell so you should start by asking them. While your waiting for a reply, use a hot air station to get it out (or use a braid and a lot of flux if you don't have a hot air station) and then measure it carefully to figure out the taper and pinout. Then search mouser. It looks like an Alpha RV112BF might work but you might find something even closer to that metal shell on a PCB. Don't trust pictures though. Look carefully at the part codes and match them with proper drawings. There are lots of mistakes about such things on parts sites.

 

[Ike Zimbel]

...and while you're in there...maybe touch up the soldering on LED-34. It could just be no flow-through from the underside of the board, but that sure looks like a "no-solder" joint on the lead on the right.

 

[tomheavybeats]

...and while you're in there...maybe touch up the soldering on LED-34. It could just be no flow-through from the underside of the board, but that sure looks like a "no-solder" joint on the lead on the right.

oh yeah well spotted, getting a few issues on these last few channels so thats worth re-soldering

 

[tomheavybeats]

Trident is alive near as I can tell so you should start by asking them. While your waiting for a reply, use a hot air station to get it out (or use a braid and a lot of flux if you don't have a hot air station) and then measure it carefully to figure out the taper and pinout. Then search mouser. It looks like an Alpha RV112BF might work but you might find something even closer to that metal shell on a PCB. Don't trust pictures though. Look carefully at the part codes and match them with proper drawings. There are lots of mistakes about such things on parts sites.

Many thanks for the info and pointing to the Alpha pot, looks pretty close. I emailed trident/oram with no reply a few months back but will try again. Have braid but no flux so will look to removing and following your advice. Thanks!

 

[Whoops]

I've seen those pots in some gear in the past but I'm not remembering at the moment where.

You should remove that Pot from the PCB and measure it, if you get readings then you know the value to look for. If it's a PAN pot it's probably a Linear taper, but measuring is better to be sure.

 

[abbey road d enfer]

Are there components on the underside? Most often pan-pots are dual linear taper, which require two law-steering resistors, connected between the wiper and the signal. Their value is tpically about 30-36% of the nominal pot value.
In the absence of these resistors, you could assume it's a log-antilog pot, which is more difficult to source.
However, most of the times pan-pots are 5k or 10k, so if you find a 5k or 10k dual linear taper pot that fits the footprint, you can certainly make it work, with the addition of the correct law-steering resistors.

 

[pucho812]

Trident is alive near as I can tell so you should start by asking them. While your waiting for a reply, use a hot air station to get it out (or use a braid and a lot of flux if you don't have a hot air station) and then measure it carefully to figure out the taper and pinout. Then search mouser. It looks like an Alpha RV112BF might work but you might find something even closer to that metal shell on a PCB. Don't trust pictures though. Look carefully at the part codes and match them with proper drawings. There are lots of mistakes about such things on parts sites.

this is a john oram trident piece, far different than trident owned by PMI even though it bares the trident name and john claims all kinds of things. PMI owned trident will probably not help here.

I will guess and say the pot will have the value on the other side, you would have to remove it to get it. If you can do that, nothing stopping you from sourcing another pot that would fit and wire leads to and from it,

 

[tomheavybeats]

Thanks for all the replies, had already taken the desk apart to see if anything written on the other side but there wasn't. Emailed Trident and they confirmed desk has nothing to do with them, Oram illegally put his name on the desk or something, don't really understand the history here, very strange.
Anyway, I emailed Oram and they just asked for my name and address, hope thats just preliminary before they send some information.

 

[Whoops]

If you can do that, nothing stopping you from sourcing another pot that would fit and wire leads to and from it,

I was going to suggest that also

 

[pucho812]

Thanks for all the replies, had already taken the desk apart to see if anything written on the other side but there wasn't. Emailed Trident and they confirmed desk has nothing to do with them, Oram illegally put his name on the desk or something, don't really understand the history here, very strange.
Anyway, I emailed Oram and they just asked for my name and address, hope thats just preliminary before they send some information.

The history is trident went under. A company thst bought and owned the ip was not enforcing ip. This went on until pmi audio purchased the ip.

 

[Whoops]

Thanks for all the replies, had already taken the desk apart to see if anything written on the other side but there wasn't.

Did you measure the removed pot?

 

[tomheavybeats]

No I meant I removed the PCB from the metal mixing desk frame, I haven't taken pot off yet, thats the bit I am nervous about, I have always got into trouble removing a component with that may pins before and end up ruining the tracks.

 

[Bo Deadly]

I haven't taken pot off yet, thats the bit I am nervous about, I have always got into trouble removing a component with that may pins before and end up ruining the tracks.

There are three techniques for removing a part like that:

A) The best is a hot air station. These are actually not that expensive and if you're going be hacking on a big old desk like that, it's a worthwhile investment.

B) Use solder braid and a flux pen. Put a bunch of flux on the braid and then try to wick out the solder around all of the pins to the point where the part literally just falls out.

C) Cut the part out and then remove the pins one by one. To remove the pins, add some solder and then use a jumbo solder-sucker where you hit a button and a spring loaded piston sucks the solder out of the hole taking the pin with it.

Depending on the board, you should never try to pry parts out. For example, when removing an electrolytic capacitor, the instinct is to lever the cap while heating a pin and then lever it the other way and go back and forth until it's out. This is a very bad technique because the levering pushes the levering pin into the PCB which can easily lift the wirepad off the PCB and break the trace.

So use the right tools or find someone else who has the right tools.

 

[Ike Zimbel]

Depending on the board, you should never try to pry parts out. For example, when removing an electrolytic capacitor, the instinct is to lever the cap while heating a pin and then lever it the other way and go back and forth until it's out. This is a very bad technique because the levering pushes the levering pin into the PCB which can easily lift the wirepad off the PCB and break the trace.

So use the right tools or find someone else who has the right tools.

+1. The other issue with using any kind of force to pry parts out of the board is pulling "vias" or "plate-throughs". This is the copper which is inside the holes that the leads go through and it's function is to connect the traces (and hence, the circuitry) on one side of the board to the other. This is probably the #1 way that inexperienced people damage circuit boards. This can be a very insidious fault because, unlike a lifted or missing pad, there is no visible evidence of it. A really good habit to get into when removing parts from double-sided boards is to look at the leads on each part you remove. You should see nothing but the lead. If you see a lead that has a little collar of copper around it, you've pulled the via. The "fix" for that is to solder the lead of the new part on both sides of the board. The downside of that is that if this is not documented, you've created a land mine for whoever works on the unit next and has to change that same part.

 

[tomheavybeats]

There are three techniques for removing a part like that:

A) The best is a hot air station. These are actually not that expensive and if you're going be hacking on a big old desk like that, it's a worthwhile investment.

B) Use solder braid and a flux pen. Put a bunch of flux on the braid and then try to wick out the solder around all of the pins to the point where the part literally just falls out.

C) Cut the part out and then remove the pins one by one. To remove the pins, add some solder and then use a jumbo solder-sucker where you hit a button and a spring loaded piston sucks the solder out of the hole taking the pin with it.

Depending on the board, you should never try to pry parts out. For example, when removing an electrolytic capacitor, the instinct is to lever the cap while heating a pin and then lever it the other way and go back and forth until it's out. This is a very bad technique because the levering pushes the levering pin into the PCB which can easily lift the wirepad off the PCB and break the trace.

So use the right tools or find someone else who has the right tools.

great tips, thank you. I've always gone for option C in the past. I have solder braid and was never that successful with it, I guess the missing element was the flux! Definitely looking into the hot air station as I have load of other equipment with repairs to do too.

 

[Whoops]

This is what I always do and have great results,
a litle bit different than what Bo Deadly suggested so I will put as option D.
But a D that always works well for me:

D: use a solder sucker desoldering pump. Reflow all solder joints with new solder before desoldering . (use 60/40 solder)
Reflowing all solder joints before desoldering will not only refresh the solder there and make it more easy to move but will also pre-heat the solder pins and solder.
Then go each pin one by one, touch with the soldering iron, make the solder liquid and without taking the soldering iron away suck it with the Pump. (this is a quick movement). Move on to the next Pin and so on.
If there's any solder left in any hole or pin, use solder braid to clean it.
I never ever use flux and never need it, I just use flux with SMD stuff.
60/40 solder has already a mix of flux in it.

my 2 cents,
good work

 

[grid_stopper]

I use a method similar to whoops, specifically i use an Engineer SS-02 Solder sucker, which is a vast improvement over every other solder sucker ive used. Very handy in cases like this.

 

[Whoops]

I use a method similar to whoops, specifically i use an Engineer SS-02 Solder sucker, which is a vast improvement over every other solder sucker ive used. Very handy in cases like this.

That looks quite Hi-Tech, would love to try that.

I use this model, that is not so expensive but works great:



I don't like the other cheaper alternatives, they're crap

 

[tomheavybeats]

I use a method similar to whoops, specifically i use an Engineer SS-02 Solder sucker, which is a vast improvement over every other solder sucker ive used. Very handy in cases like this.

Looks great, time for an upgrade I think. On multiple pin removals like this, there always seem to be a few that stick and go cold again, I saw a technique on YouTube where someone ran the soldering tip quickly and evenly across all pins for a while until they all heated up and then they just popped the part out but I could never get pins hot enough. I guess this is where desoldering guns shine but I just saw the price of a Weller one