Sound distorted after volume control installed?

[Gadgetguy]

Hello all,

I have installed yesterday (50 ohm 10 W resistor) volume controls on my Marylin and Galaxy train machines.

The volume is down to a comfortable level, however it sounds like there is a distortion now in the sound which was not there before.

Is this normal? Will this distroy the amp on the long run? I understand that many (most?) of you use resistors (or potentiometers) to bring the volume down. Do you experience the same distortion? Is this (worse sound) something most people accept / get used to over time?

Thanks for sharing your experiences.

Regards,

Miklos

[Gadgetguy]

One more piece of information: the machine volume control is of course at "low", and the resistors are wire-wound.

I am not sure if that information matters - but maybe it does, so I wanted to add it...

I also did some more reading on this forum, and I found that what I did should be ok. So maybe I am just over sensitive, and will get used to the new (slightly distorted) sound?

One thing for sure: the 10W resistors should not overheat or burn up...

[fronzdan]

It's better to use LPads since it keeps a constant impedance on the amp. But as you said, many people use fixed resistors or simple pots with no issues with the amplifiers. I have fixed resistors on a Lumina frame with no problems, but probably about half the resistance you are using.

The distortion might be because the efficiency rating of the speakers require that they get pushed harder to sound good. I have a Fuji machine that's like this. It sounds much better when they are cranked.

It could also simply be that the sound isn't that good to begin with since in the real world, you can't really hear anything, let alone distortion...because the hundreds of machines around you are all blasting. Although I've always heard pretty clean sound from Lumina machines.

[Gadgetguy]

It's better to use LPads since it keeps a constant impedance on the amp. But as you said, many people use fixed resistors or simple pots with no issues with the amplifiers. I have fixed resistors on a Lumina frame with no problems, but probably about half the resistance you are using.

The distortion might be because the efficiency rating of the speakers require that they get pushed harder to sound good. I have a Fuji machine that's like this. It sounds much better when they are cranked.

It could also simply be that the sound isn't that good to begin with since in the real world, you can't really hear anything, let alone distortion...because the hundreds of machines around you are all blasting. Although I've always heard pretty clean sound from Lumina machines.

Thank you. So does it mean that if I use "middle" volume on the machine volume control it may sound better? Is that safe to try ( i.e. is it not going to blow up anything in my machine) how it sounds with volume on medium ( I know it will be louder - but I would be curious to test if the distortion will be less).

As far as the sound being generally not too good: you are right, but I think the distortion was less before I installed the resistor (but I may be wrong)

[Gadgetguy]

This was really bugging me too much. So I took the resistors out on one machine, in order to to a proper before / after comparison.

And ... I found it was me who was overly sensitive. Actually, the difference is quite slim (if there is a difference at all). There WAS distortion even without a resistor.

I am relaxed now, knowing that I have not made my cool pachi machines sound bad with the resistors...

[JohnD0406]

There will be more distortion with pots or resistors, and with the volume control on high. The only way to eliminate additional distortion is to use an L-pad. The resistors create a DC voltage offset, so half the waveform is getting clipped. If you install pots or resistors, you should definitely keep the volume on the machine on low. Also, the lower you set the volume on a pot, or the higher the fixed resistor value you use, the more the distortion. See my previous post here http://www.pachitalk.com/forums/pach...tml#post272363