The correct Pots for volume control?

[dj0812]

Have just purchased the superb "Indiana Jones" Pachinko over the weekend. Today I noticed that the sound from the speakers was cutting out. I opened the frame to find the pot that had been fitted was smoking!

The duel linear pot was rated at 10k - I have used these myself on other pachislo's with no problems.

The question is therefore, is this the correct rating for this machine? Or is it just a faulty pot that was fitted?

Other techy details : Power rating: 0125W linear, 006W log. Max voltage: 200V linear, 150V log.

Thanks!

[Eddie]

Probably just a bad pot.

[Robocourier]

There's been many a discussion on this subject; trying using the search for info. Lumina frame games are well known for the problem.

As usual, I have a personal opinion and that is that I've never got on with carbon track pots. Regardless of the setting of the factory volume switch I've always managed to cook them in a relatively short time, plus there is the inconvenience of having to fit two so adjustment has to be per speaker. (The stereo ctp's seem to be of an even lower power rating).

Having tried L-pads I doubt I'd ever use anything else again. Their downside is that they are a bit large and therefore aren't always easy to place but I've found them available in stereo form so one dial adjusts both speakers at once. If you place the dial externally you can quickly adjust the volume at Fever time (to loud!). They can run a bit warm (at least, mine do) but I've yet to burn one out. Less repairs means more play.

That's my opinion and there'll be plenty here that won't agree.

[daverob]

10k is way too high a value to be used as a speaker volume control. All the useful adjustment is way down one end of the range, and so all the power dissipation is concentrated in a small fraction of the total track area which will tend to overheat.

Personally I'd use 500 ohm pots (or 1k if you can't get any smaller). I'd also go for cermet pots if you want the small preset ones, as the ceramic substrate tends to dissipate the heat much better than the other types.

Also make sure that the volume control switch on the pachi is set to it's lowest setting, as this will reduce the amount of power the pots have to handle.

[dj0812]

Had a quick drive to Maplin (An UK wide electronics store!) Purchased a couple of 1K Pots as recommended and replaced the duel 10K pot that was already fitted. Worked a treat with a lot more controlling range.

The only thing I can say though is that this frame must be pushing some power through to the speakers over other types, as again, if I tried to crank up the power levels to the speakers the pots started to smoke!

All as I can say is that those Pachi Parlours must be one loud place to hang out! I know they would break loads of English laws regarding sound levels....:lol8: .... I wonder if anyone has become deaf through to much Pachi' play?

What? Ehhh? You said what? Who....?

[fronzdan]

Yeah Luminas have been known to smoke volume controls. As daverob said, be sure you keep the internal volume setting at the lowest position or there's a good chance you'll smoke these new ones too.

[Trey314159]

I always need volume controls.. they aren't always potentiometers, though. Sometimes I just put clear packaging tape over the speaker grills. It isn't horribly ugly, and I can install it the same day I get a new machine.

[slothappy144]

As posted before much of the problems with failing pots I think are 1 of 2 things,
1 using too much heat and burning the POT
2 using 10K or other too large POT, and the 270 degree adjustment is too touchy for me
I prefer the 1k cermet 15 turn POT. for a set it and forget it adjustment.

[musky]

I don't use pots, I've had too many failures and to me they muddy the sound. I use L-Pads, and I will not start my preaching again.

[Chris]

Had a quick drive to Maplin (An UK wide electronics store!) Purchased a couple of 1K Pots as recommended and replaced the duel 10K pot that was already fitted. Worked a treat with a lot more controlling range.

The only thing I can say though is that this frame must be pushing some power through to the speakers over other types, as again, if I tried to crank up the power levels to the speakers the pots started to smoke!

All as I can say is that those Pachi Parlours must be one loud place to hang out! I know they would break loads of English laws regarding sound levels....:lol8: .... I wonder if anyone has become deaf through to much Pachi' play?

What? Ehhh? You said what? Who....?

dj0812 you may still have have issues with the maplin pots, i found i did with my indy. It still fried them, mainly during a fever round. I went through about 3 sets before i ended up giving up and bought some cement pots from the states. These are much better and i have not had any issues since.

[Robocourier]

You can get cermet pots from Maplins too, though their power rating will still fall a little short of the amp output so you'll still need to use with a little caution.......

[daverob]

You can get cermet pots from Maplins too, though their power rating will still fall a little short of the amp output so you'll still need to use with a little caution.......

Maplin cermet pots are only rated at 0.2w and are from the manufacturers 'low cost' range. They still run the risk of burning up on Lumina frames even with the frame's volume control set to the lowest setting.

Personally I now use good quality cermet presets which are rated at 0.5W (usually Bourne 3309P) and I haven't had any problems with them on any games so far.

Though technically they'll are still overloaded on Lumina frame's medium and loud volume control settings, I've tried them on medium setting and haven't had any burn out yet.