Volume Control -- Revisited

[ssdcinc]

Hey Guys,

want to cut back on the Volume, want to try the Resistor Method,
I've seen it recommend to use a 50 ohm 10watt resistor.

Was looking at parts express and can not find a 50 ohm
they have 47's or 56's, question does it make a diff ?

which one would be better ?

..and when putting them inline should it be put on the + (positive)
side or does it matter ?

thnx Guys
this forum rocks

[coldluck]

they will work fine, value is close enough and even than you may have to alter to get the results you seek, just make sure the wattage is same. I still recomend using L-pads only. it's the most right way to do it!

[cwstnsko]

When I 1st started with Pachislos, I invested a lot of energy in coming up with fancy resistor neworks that would cut the volume without changing the nominal impedance that the amp sees. As I started looking more closey at some of the pachi's audio controls, I discovered that the factory volume control is normaly just selecting which one of several resistors to add to the circuit in series. It was aslo interesting to note that the factory resistors were usually 1/4 watt. I asked someone about this and I was told that since audio's spread across a wide range of frequencies, 10 watts peak of audio energy does not equate to 10 watts RMS DC load, and as you add resistance, you drop the current flow dramatically. Since then I usually just buy 1/2 watt resistors in the 33 ohm range and add them in series with the speaker. @ exceptions to theis rule are. Piezo tweeters in Sammy/Rodeo/Aristocrat machines. They need 1.5K-2.2k of resistance added, and the lower speaker in the same machines with the piezo tweeters. Get a power resistor for that one, it is driven HARD. I usually use the + lead on the odd chance that the - terminal on the speaker might be grounded.

Just my opinion, L-Pads are great too, just not my thing anymore.

[coldluck]

the 1/4 watt resisters you speak of may be at the begining of the cicuittry in the audio signal stage, once it gets thru the power amplifirers it's a differant ballgame. but a lot of owners seem to have good results using resisters I just don't want to have to deal with blown i.c. chips.

[cwstnsko]

Just looked at one of my machines, resistors are between the amp and the speaker. Might be 1/2 watt, but they are smaller than the 1/2 watts they sell at Radio Shack, closer to 1/4 watt size.

Assuming you start with a 8 ohm speaker, after adding the 50 ohm resistor as the original posted was suggesting, the power through the speaker will be greatly reduced.

[Sid]

Hey Guys,

want to cut back on the Volume, want to try the Resistor Method,
I've seen it recommend to use a 50 ohm 10watt resistor.

Was looking at parts express and can not find a 50 ohm
they have 47's or 56's, question does it make a diff ?

which one would be better ?

..and when putting them inline should it be put on the + (positive)
side or does it matter ?

thnx Guys
this forum rocks

Hi I use 47s on my dance night machine.. I just connect it to the positive wire and its good to go..
i have added clips to the resistors so they can be removed easily and the wire can be plugged back directly to the speaker should you want things back to normal...

[jdsabin1]

Excuse my ignorance but what is wrong with using the volume controllers that are at the top of this page?

I had planned to use these on my pachinkos and pachislos.

http://www.pachislo.com/pachislo/par...il/volume.html

They seem idiot proof which is exactly what I need .

[slotter]

http://www.pachislo.com/img/pachislo...ts/Volume3.jpg

jdsabin1... These little pots are great. Easy to install and work just perfectly. They are the best way to go for nearly all the machines, imo. Head on over to Syscom.com and pick them up. Shipping is lightning fast, too.


http://www.pachislo.com/pachislo/par...il/volume.html

[RKnarr01]

Go with what Slotter just posted easy to install and work great.

[Tulsa]

They are all I use.

[RKnarr01]

They seem idiot proof which is exactly what I need .

These are really easy to install, i doubted my ability at first but after the first one is done it was very easy.

Cut speaker wire
Strip ends of speaker wire
put wire ends thru holes on board
solder to the metallic part of the board and your done.

[slugflyer]

Caution: How many volume you need is depend on numbers of volume your machine have.


it says that on the afforementioned store, what does that mean ?

[chaz70]

It should say how many speakers you have.

3 speakers, 3 controls. 2 speakers, 2 controls .....

[RKnarr01]

that means u need 1 per speaker

[coldluck]

more reading before you decide...

http://www.pachitalk.com/forums/sear...searchid=92620

[dalto]

Hmm...I have been reading all the volume control posts for a couple of weeks and have some lingering questions.

1. If I decided to use resistors, should I very the resistance or the wattage. In other words if I put a 50 Ohm 10 Watt resistor in and decide it's too quiet should I switch it with a 10 Ohm 10 Watt resistor or a 50 Ohm 5 Watt resistor?
2. I have read that LPADS are not good options for certain speakers. Specifically for Piezo tweeters. How can tell the difference between a piezzo tweeter and a regular speaker?
3. What is the difference between an audio-taper pot and a linear-taper pot? More specifically, which one should be used for this application?

Thanks in advance.

[luckydog]

the 50 ohm 10 watt seems to be idea, then you have 3 positions on the factory volume to play with.

[chaz70]

Stick with 10 watts and varry the ohms. 50 ohms is what seems to work good on pachislo machines. My pachinko has a volume knob, but the lowest wasnt low enough for me, so I threw on some 10 ohm resistors just to quiet it down a little more.

[mike99gt]

Hmm...I have been reading all the volume control posts for a couple of weeks and have some lingering questions.

1. If I decided to use resistors, should I very the resistance or the wattage. In other words if I put a 50 Ohm 10 Watt resistor in and decide it's too quiet should I switch it with a 10 Ohm 10 Watt resistor or a 50 Ohm 5 Watt resistor?
2. I have read that LPADS are not good options for certain speakers. Specifically for Piezo tweeters. How can tell the difference between a piezzo tweeter and a regular speaker?
3. What is the difference between an audio-taper pot and a linear-taper pot? More specifically, which one should be used for this application?

Thanks in advance.

1.I use 47 ohm 1W metal oxide resistors and they stay cold during bonus. You want to vary resistance to change volume. Higher resistance will lower the volume. 10W resistors may be over kill but they are still fairly cheap. I haven't had a problem with 1W resistors for .13 each.
2.Not sure about the lpad thing but usually the upper speakers don't need resistors I just quiet the woofers down a bit but you can use 16ohm resistors in series with the upper speakers. I haven't seen a pachislo with tweeters.
3.Linear taper varies resistance evenly through the pots travel. It rises in linear fashion. Audio taper rises on the DB scale which is log fashion You could probably use either in this application but I would stay with linear at a high wattage.
Hope this helps

[v3550]

I ordered an L-Pad 15wt mono and 15 wt stereo for my Babel from Parts Express. Should be in today. Hopefully I will be able to figure out the hook-up. I think probably a test connction before final mounting would be in order.