[[email protected]]

I know that the specific application that I am asking about isn't
relevent to this group, but I am sure that someone here will know the
answer.

have a 'Fruit Machine' which is designed for commerical use and is VERY
loud.. It does have an electronic volume control with 5 steps varying
from LOUD to MY EAR DRUMS HAVE BURST!!

On the LOUD setting, its just about fine, but the device also makes a
very low 'whoosing' sound which changes as the lights flash and this
can be quite annoying.

Its been suggested that I try a 47ohm resistor inline with the
speakers.. I have tried this and it worked perfect, but not as
dramatically as I hoped. The 'whooshing' is a lot quieter, but now the
volume has only reduced by one setting (Now what was the bottom
settings is +1)

I would like to drop the volume even more and am going to experiement
with some smaller resistors.. I am hoping that 30ohms will do the
trick.

But is there a problem doing this? I am sure that I am chaning the
impedence of the system and whilst this isn't a hi-fi product (and the
quality of the sound isn't important) I don't want to do any damage.

If this is OK, are metal film resistors OK to use, or should I be using
'Wire Wound' types?

I look forwards to your thoughts

Best regards

Jon

[GregS]

In article . com, wrote:
I know that the specific application that I am asking about isn't
relevent to this group, but I am sure that someone here will know the
answer.

have a 'Fruit Machine' which is designed for commerical use and is VERY
loud.. It does have an electronic volume control with 5 steps varying
from LOUD to MY EAR DRUMS HAVE BURST!!

On the LOUD setting, its just about fine, but the device also makes a
very low 'whoosing' sound which changes as the lights flash and this
can be quite annoying.

Its been suggested that I try a 47ohm resistor inline with the
speakers.. I have tried this and it worked perfect, but not as
dramatically as I hoped. The 'whooshing' is a lot quieter, but now the
volume has only reduced by one setting (Now what was the bottom
settings is +1)

I would like to drop the volume even more and am going to experiement
with some smaller resistors.. I am hoping that 30ohms will do the
trick.

But is there a problem doing this? I am sure that I am chaning the
impedence of the system and whilst this isn't a hi-fi product (and the
quality of the sound isn't important) I don't want to do any damage.

If this is OK, are metal film resistors OK to use, or should I be using
'Wire Wound' types?

Does the 47 ohm get hot? Try higher ohms..

greg

[Laurence Payne]

On 25 Jul 2006 06:01:03 -0700, wrote:

Its been suggested that I try a 47ohm resistor inline with the
speakers.. I have tried this and it worked perfect, but not as
dramatically as I hoped. The 'whooshing' is a lot quieter, but now the
volume has only reduced by one setting (Now what was the bottom
settings is +1)

I would like to drop the volume even more and am going to experiement
with some smaller resistors.. I am hoping that 30ohms will do the
trick.

But is there a problem doing this? I am sure that I am chaning the
impedence of the system and whilst this isn't a hi-fi product (and the
quality of the sound isn't important) I don't want to do any damage.

If this is OK, are metal film resistors OK to use, or should I be using
'Wire Wound' types?


If the resistor is really inline with the speaker, you need a higher
value to further drop the volume, not a lower. Note that the resistor
will be passing the same current that goes through the speaker. A low
wattage resistor will overheat and/or fail. Don't be too frightened -
it's only doing what a fuse would do. But while experimenting, make
sure the resistor is mounted somewhere where it wouldn't be dangerous
if it got very hot.

There are better ways to do this than with a series resistor. Someone
who knows the numbers may sketch out a circuit for you. Anyone?

[Richard Crowley]

jon.p.weaver wrote ...
I would like to drop the volume even more and am going to experiement
with some smaller resistors.. I am hoping that 30ohms will do the
trick.

You want a resistor with MORE resistance (higher
number of ohms), not a smaller resistor. If 47 ohms
gets you part way there, try something like 100 or
even 200 ohms and see what you get.

But is there a problem doing this? I am sure that I am chaning the
impedence of the system and whilst this isn't a hi-fi product (and the
quality of the sound isn't important) I don't want to do any damage.

Not any really definitive way of answering this without
knowing what kind of amplifier is driving it? Only you
can evaluate the risk/reward in your particular situation.
I would likely not worry about it too much, but YMMV.

If this is OK, are metal film resistors OK to use, or should I be
using
'Wire Wound' types?

It doesn't really matter what kind of resistor you use in
this application, as long as it has sufficient power rating
(which translates to physical size).

[[email protected]]

Laurence Payne wrote:

If the resistor is really inline with the speaker, you need a higher
value to further drop the volume, not a lower. Note that the resistor
will be passing the same current that goes through the speaker. A low
wattage resistor will overheat and/or fail. Don't be too frightened -
it's only doing what a fuse would do. But while experimenting, make
sure the resistor is mounted somewhere where it wouldn't be dangerous
if it got very hot.

OMG. You are right.. I rolled my eyes when I read this, thinking that
you were just being pedantic about my use of bigger/smaller.. But
suddenly, I realised that I am being stupid.. 0 ohm = no resistor, so
my 20/30ohms resistor is closer to a short circuit than the 47 ohm I
have in there now and the volume would have got louder, not quieter.

Doh!! I am so glad that you pointed this out to me, as I would have
just wasted my time and then spent hours beating myself up, trying to
work out why 20 ohms was louder than 47!!.. I am going to put my
20/30ohm resistors back and grab something a little 'more resistive'..

Thanks for that..

Jon

[James Lehman]

wrote in message
ups.com...
I know that the specific application that I am asking about isn't
relevent to this group, but I am sure that someone here will know the
answer.

have a 'Fruit Machine' which is designed for commerical use and is VERY
loud.. It does have an electronic volume control with 5 steps varying
from LOUD to MY EAR DRUMS HAVE BURST!!

Why is there any speaker or electronic sound system at all in a "Fruit
Machine"?
What is it for?

James. )

[Arny Krueger]

"James Lehman" wrote in message
. ..

wrote in message
ups.com...
I know that the specific application that I am asking about isn't
relevent to this group, but I am sure that someone here will know the
answer.

have a 'Fruit Machine' which is designed for commerical use and is VERY
loud.. It does have an electronic volume control with 5 steps varying
from LOUD to MY EAR DRUMS HAVE BURST!!

Why is there any speaker or electronic sound system at all in a "Fruit
Machine"?
What is it for?

I suspect his 'Fruit Machine' is a gambling device. IOW, something like an
electronic slot machine.

[[email protected]]

Why is there any speaker or electronic sound system at all in a "Fruit
Machine"?
What is it for?

James. )

Sorry.. I am using "UK" language.. What we know is a "Fruit Machine" is
a what you call a 'Slot Machine'...

The once in question are actually Japanese and called "Pachislo".. They
are very hi-tech and have an array of sound and light, but since they
are for a commerical market, the sound is VERY loud.

I have now fitted a 180ohm resistor, which has made the inbuilt volume
controls work from "Quiet" to "Loud", just as you woudl expect it to
work.

I will keep an eye on it and see if I can see any sign of the resistor
getting too hot.

Many thanks for everyones help

Cheers

Jon

[Walt]

wrote:
Why is there any speaker or electronic sound system at all in a "Fruit
Machine"?
What is it for?


Sorry.. I am using "UK" language.. What we know is a "Fruit Machine" is
a what you call a 'Slot Machine'...

The once in question are actually Japanese and called "Pachislo".. They
are very hi-tech and have an array of sound and light, but since they
are for a commerical market, the sound is VERY loud.

I have now fitted a 180ohm resistor, which has made the inbuilt volume
controls work from "Quiet" to "Loud", just as you woudl expect it to
work.

I will keep an eye on it and see if I can see any sign of the resistor
getting too hot.

Assuming the speaker is 8 ohms and the output power before the mod is in
the range of 10 watts, you'll need about a half watt resistor a 180
ohms. I'd use a one or two watt resistor to be on the safe side.

Thanks for the vocabulary lesson - I was unaware of the term "fruit
machine" or Pachilso, even though I own a Pachinko machine myself.
Which, thankfully does not have a sound system.

//Walt

[Don Pearce]

On Wed, 26 Jul 2006 10:28:21 -0400, Walt
wrote:

Thanks for the vocabulary lesson - I was unaware of the term "fruit
machine" or Pachilso, even though I own a Pachinko machine myself.
Which, thankfully does not have a sound system.

//Walt

A pachinko machine doesn't need a sound system - it already sounds
like a demolition site.

d

--
Pearce Consulting
http://www.pearce.uk.com

[[email protected]]

Assuming the speaker is 8 ohms and the output power before the mod is in
the range of 10 watts, you'll need about a half watt resistor a 180
ohms. I'd use a one or two watt resistor to be on the safe side.

Thanks for the vocabulary lesson - I was unaware of the term "fruit
machine" or Pachilso, even though I own a Pachinko machine myself.
Which, thankfully does not have a sound system.


thanks for that.. The resitor I have is quite large.. I would guess
1/2-1W.. Now that its in and working, I am tempted to get a larger
Wire-Wound type to do it properly.. But then again, its hardly loud, so
I am sure that the resistor I have already will be fine.

You have a Pachinko?? Which one do you have??

I have just bought 'Star Wars' and whilst I can't really understand
what the big deal is, its an impressive bit of kit.. You should check
out Pachislo.. Its basically the other Japanese craze which is very
similar to Pachinko, but it uses Tokens and has 'reels' instead.

I personally prefer them over my Pachinko, although I appear to me in
the minority!

All the best

Jon

[GregS]

In article . com, wrote:

Assuming the speaker is 8 ohms and the output power before the mod is in
the range of 10 watts, you'll need about a half watt resistor a 180
ohms. I'd use a one or two watt resistor to be on the safe side.

Thanks for the vocabulary lesson - I was unaware of the term "fruit
machine" or Pachilso, even though I own a Pachinko machine myself.
Which, thankfully does not have a sound system.


thanks for that.. The resitor I have is quite large.. I would guess
1/2-1W.. Now that its in and working, I am tempted to get a larger
Wire-Wound type to do it properly.. But then again, its hardly loud, so
I am sure that the resistor I have already will be fine.

You have a Pachinko?? Which one do you have??

I have just bought 'Star Wars' and whilst I can't really understand
what the big deal is, its an impressive bit of kit.. You should check
out Pachislo.. Its basically the other Japanese craze which is very
similar to Pachinko, but it uses Tokens and has 'reels' instead.

I personally prefer them over my Pachinko, although I appear to me in
the minority!

All the best

Jon


A quick calculation gives about .02 watts dissapation for 2 VRMS signal.
I would use a small resistor size.

greg

[plew@csus_abcdefghij.edu]

On 2006-07-26, wrote:

Assuming the speaker is 8 ohms and the output power before the mod is in
the range of 10 watts, you'll need about a half watt resistor a 180
ohms. I'd use a one or two watt resistor to be on the safe side.

Thanks for the vocabulary lesson - I was unaware of the term "fruit
machine" or Pachilso, even though I own a Pachinko machine myself.
Which, thankfully does not have a sound system.


thanks for that.. The resitor I have is quite large.. I would guess
1/2-1W.. Now that its in and working, I am tempted to get a larger
Wire-Wound type to do it properly.. But then again, its hardly loud, so
I am sure that the resistor I have already will be fine.
......................

Why not a pot? I got a potentiameter many years ago for the "ambient"
rear speakers for the old Sherwood receiver. I was able to vary the
sound output of the rear speakers depending on the type/loudness
of the music; may suit your purpose also.

[James Lehman]

wrote in message
...
On 2006-07-26,
wrote:

Assuming the speaker is 8 ohms and the output power before the mod is
in
the range of 10 watts, you'll need about a half watt resistor a 180
ohms. I'd use a one or two watt resistor to be on the safe side.

Thanks for the vocabulary lesson - I was unaware of the term "fruit
machine" or Pachilso, even though I own a Pachinko machine myself.
Which, thankfully does not have a sound system.


thanks for that.. The resitor I have is quite large.. I would guess
1/2-1W.. Now that its in and working, I am tempted to get a larger
Wire-Wound type to do it properly.. But then again, its hardly loud, so
I am sure that the resistor I have already will be fine.
......................

Why not a pot? I got a potentiameter many years ago for the "ambient"
rear speakers for the old Sherwood receiver. I was able to vary the
sound output of the rear speakers depending on the type/loudness
of the music; may suit your purpose also.

Pots usually don't handle much power. If you want a knob, put an L-pad
behind it. That is what they are made for.

James. )

[[email protected]]

......................

Why not a pot? I got a potentiameter many years ago for the "ambient"
rear speakers for the old Sherwood receiver. I was able to vary the
sound output of the rear speakers depending on the type/loudness
of the music; may suit your purpose also.

I have pots/L-Pads fitted to my other machines as they don't have
volume controls as standard.. But since this machine does and has 3
speakers, adding pots will not only make balancing the sound tricky,
but it will mean that there are 2 ways to adjust the sound.

All I wanted to do was reduce the volume by a fixed amount (mainly to
get rid of the "whoshing") and then I can use the inbuilt volume
controls to change teh volume depending on my mood.

I have found that by adding a 180ohm resistor, not only is the
"whooshing" almost entirly gone, but now I get the same volume at level
3, that I used to on Level 1... So, I now have the ability (using the
inbuilt volume control) to go from "Quiet" to "Loud", rather than
"Loud" to "Ouch.. My ears are bleeding"

Jon

[TimPerry]

James Lehman wrote:
wrote in message
...
On 2006-07-26,
wrote:

Assuming the speaker is 8 ohms and the output power before the mod
is in the range of 10 watts, you'll need about a half watt
resistor a 180 ohms. I'd use a one or two watt resistor to be on
the safe side.

Thanks for the vocabulary lesson - I was unaware of the term "fruit
machine" or Pachilso, even though I own a Pachinko machine myself.
Which, thankfully does not have a sound system.


thanks for that.. The resitor I have is quite large.. I would guess
1/2-1W.. Now that its in and working, I am tempted to get a larger
Wire-Wound type to do it properly.. But then again, its hardly
loud, so I am sure that the resistor I have already will be fine.
......................

Why not a pot? I got a potentiameter many years ago for the
"ambient" rear speakers for the old Sherwood receiver. I was able
to vary the sound output of the rear speakers depending on the
type/loudness
of the music; may suit your purpose also.

Pots usually don't handle much power. If you want a knob, put an L-pad
behind it. That is what they are made for.

James. )

i would suspect that there is an audio gain control in addition to the
"step" control somewhere in the system. i have seen plastic variable "L"
pad attenuators melt when used on home stereo speakers.

[Bucket]

If you put too high a resistor in the audio output you risk damaging the
output transistors/IC. It will not like working into a high impeadance load
(much above a few tens of ohms). There must be a input level control to the
amp somewhere inside the thing.

If you can't find an input level preset and cannot see any way to fit a
volume pot on the input of the amp, then what about sticking a sheet of
cardboard over the speaker or unscrewing speaker from case and putting a bit
of soft cloth or foam padding gently over cone?

bucket

[Eiron]

Bucket wrote:

If you put too high a resistor in the audio output you risk damaging the
output transistors/IC. It will not like working into a high impeadance load
(much above a few tens of ohms).

Totally wrong.

--
Eiron

No good deed ever goes unpunished.

[Mark D. Zacharias]

Bucket wrote:
If you put too high a resistor in the audio output you risk damaging
the output transistors/IC. It will not like working into a high
impeadance load (much above a few tens of ohms). There must be a
input level control to the amp somewhere inside the thing.

If you can't find an input level preset and cannot see any way to fit
a volume pot on the input of the amp, then what about sticking a
sheet of cardboard over the speaker or unscrewing speaker from case
and putting a bit of soft cloth or foam padding gently over cone?

bucket

The vast majority of solid state amps have no problem running into a high
impedance or open circuit. An old SS amp with deteriorated components will
occasionally oscillate into such a load, but in such a case, that is a
malfunction, not a feature.

Mark Z.

[TimPerry]

I have pots/L-Pads fitted to my other machines as they don't have
volume controls as standard.. But since this machine does and has 3
speakers, adding pots will not only make balancing the sound tricky,
but it will mean that there are 2 ways to adjust the sound.

by 3 speaker do you mean woofer, mid. and tweeter? or 3 separate full range
speakers?

if 3 full range speaker are used you might rewire then in series instead of
parallel... that would cut the total audio power down. and no worries about
a resister overheating.


All I wanted to do was reduce the volume by a fixed amount (mainly to
get rid of the "whoshing") and then I can use the inbuilt volume
controls to change teh volume depending on my mood.

I have found that by adding a 180ohm resistor, not only is the
"whooshing" almost entirly gone, but now I get the same volume at
level 3, that I used to on Level 1... So, I now have the ability
(using the inbuilt volume control) to go from "Quiet" to "Loud",
rather than "Loud" to "Ouch.. My ears are bleeding"

Jon