Capacitor question

[Anonymous]

Alright all you electronic techies. Try to keep it simple for me, ok? I want my Shay's sounds to be louder, I KNOW there has to be a way to do it. It only has a 3/4" speaker. Is it possible to eliminate the capacitor OR replace it with one of a lesser value in order to make it louder? That is, without doing any damage? I could go for an oval speaker that's a little bigger, but the smallest one I can find is slightly larger than the coal bunker, and won't fit. I don't really think JUST a larger speaker will do it. What are your thoughts? Thanks.

[Anonymous]

Caveat: I don't know beans about that area of electronics, but I can offer an idea.

First, if you're talking about replacing the capacitor on a board, I wouldn't, since that would void any warranty. Just changing it probably wouldn't do much anyway.

I'd suggest looking at Op-Amps and see if you can rig a simple amplifier that will boost your signal a little more. Op-Amps are small chips and you can probably squeeze one in somewhere.

For a start, take a look at:

http://home.cogeco.ca/~rpaisley4/BasicOpAmp.html

and

http://www.colomar.com/Shavano/intro_opamp.html

They'll give you some ideas you can play with.

Mike Tennent

[jfugate]

BigRed:

What's the decoder or sound board brand that's in the shay? Have you turned it up to max using the settings available in the decoder/board? And it's still not loud enough? Did it come with the sound installed or did you or someone install it later?

I have a hard time fathoming that max volume on a sound decoder/sound board would not be loud enough.

Are you sure nothing's touching the speaker cone and that there are holes through which the speaker's sound can escape? Is the speaker mounted in an air tight enclosure backing it? A speaker enclosure is a requirement for the speaker to put out adequate volume.

[Anonymous]

Good point, Joe. Play with the speaker first, then work on the signal.

It's surprising what just a small enclosure will do to boost the sound. You can place a small speaker inside a toilet paper tube stuffed with paper and double the volume. (Ask me how I know.. [:D])

Mike Tennent

[Anonymous]

Yes. I have adjusted the exhaust chuff all the way up. If the chuff was as loud as the air pump can be, I'd have no complaints. Actually, I think I've found a solution. I talked with Soundtraxx today. It's their brand decoder. They said with the Shay unit low sound volume is a common complaint since the speaker is only 3/4" in diameter. Yes, everything behind the speaker is ait tight. Yes, I have holes drilled in the coal load, as well as a spot ground out of the under side of the coal load, so the sound can escape that way, too. Actually, there's no difference in sound with the coal load in or out, so I think I did good there. No, nothing's touching the speaker. If you look at the three truck Spectrum Shay, the speaker mounts in the bunker, not the tender. The bunker IS the speaker enclosure. It's right small. They also said I could use a capacitor with a uF rating all the way up to 1000, and that would help with the bass response. The unit comes with a 50uF capacitor. I found a speaker that is oval. It is 1" by .563". I have a capacitor, so we'll see what that does. I don't know about an amplifier. I ain't sure I could squeeze anything else in that bunker.

[cacole]

Don't remove or change the capacitor. Putting the speaker into a baffle will have a more drastic effect than tinkering with the capacitor value.

There's not much room in the Bachmann Shay for a speaker and baffle; that's why the decoder comes with only a 3/4" diameter speaker with no baffle, but if you can find a plastic bottle cap that the speaker will fit onto and get it to fit into the Shay, sound and volume will improve.

[Anonymous]

I'll have to trim some off the bottle cap, but I'll try it before I change the speaker. I talked with two technicians at Soundtraxx today and they said I could use the different capacitor. Allan Gartner's site says the same thing, too. The guys at Soundtraxx said the only reason they include just the 50 uF capacitor is because os space limitations, but the decoder could handle the 1000 uF if I could get one to fit. I have one that will fit. They gave me all their reasons TO use the different capacitor. You just said NOT to use it. Any pirticular reason?

QUOTE: Originally posted by cacole

Don't remove or change the capacitor. Putting the speaker into a baffle will have a more drastic effect than tinkering with the capacitor value.

There's not much room in the Bachmann Shay for a speaker and baffle; that's why the decoder comes with only a 3/4" diameter speaker with no baffle, but if you can find a plastic bottle cap that the speaker will fit onto and get it to fit into the Shay, sound and volume will improve.

[nedthomas]

The capacitor is the block DC current from getting to the speaker coil. The value is not that important. A larger value may improve bass frequencies but with such a small speaker if will not help much.

[Anonymous]

I found a bigger speaker. It's like 1"x 9/16". We'll see. If I have some success, I'll let yall know.

QUOTE: Originally posted by nedthomas

The capacitor is the block DC current from getting to the speaker coil. The value is not that important. A larger value may improve bass frequencies but with such a small speaker if will not help much.

[Anonymous]

The higher value capacitor will improve the lower fequency response, but will not increase the volume at higher frequencies. You don't even have to remove the old capacitor, just attach the new capacitor across (in parallel) with the old one.

If you want to install an op-amp, you've got some serious work ahead of you.

1. Create a stable and smooth DC source. Op-amps require a positive AND a negative source, with a ground / neutral reference. There are other amps that do not require the dual voltage supply, but they require a series capacitor in the speaker leads. For the DC supplies you'll need a couple of small bridge rectifiers and small capacitors. Just be glad that the DCC signal is at a high frequency and basically a square wave.

2. Breadboard up the circuitry, and stuff it into your small space. A standard 741 op-amp is on a 8-pin DIP, and requires at least 2 resistors to make it work. It also wants 10-15 volts positive and negative. This may also drive the need for a couple of small voltage regulators.

So, how's your O-Guage train doing now??? :-P

Mark in Utah

[Anonymous]

You musta missed where I said "try to keep it simple for me".

QUOTE: Originally posted by mark_in_utah

The higher value capacitor will improve the lower fequency response, but will not increase the volume at higher frequencies. You don't even have to remove the old capacitor, just attach the new capacitor across (in parallel) with the old one.

If you want to install an op-amp, you've got some serious work ahead of you.

1. Create a stable and smooth DC source. Op-amps require a positive AND a negative source, with a ground / neutral reference. There are other amps that do not require the dual voltage supply, but they require a series capacitor in the speaker leads. For the DC supplies you'll need a couple of small bridge rectifiers and small capacitors. Just be glad that the DCC signal is at a high frequency and basically a square wave.

2. Breadboard up the circuitry, and stuff it into your small space. A standard 741 op-amp is on a 8-pin DIP, and requires at least 2 resistors to make it work. It also wants 10-15 volts positive and negative. This may also drive the need for a couple of small voltage regulators.

So, how's your O-Guage train doing now??? :-P

Mark in Utah

[SpaceMouse]

[:o)] You could get a FM transitter and run it through your stereo sound system.

[Anonymous]

COOL!!!!

QUOTE: Originally posted by SpaceMouse

[:o)] You could get a FM transitter and run it through your stereo sound system.

[howmus]

QUOTE: They said with the Shay unit low sound volume is a common complaint since the speaker is only 3/4" in diameter.

There is your main problem. The larger speaker will help some but you probably will still not find the sound is great. There are several reasons why the chuff does not sound good. It has a lot of low frequencies in it that: 1. can't be reproduced in that small a speaker unless the speaker is right at your ear. Try this. Put on a good CD then listen to it with headphones on then take the headphones off and just hold them. You will notice the big difference in the bass. They will sound very tinny. That is what is going on. 2. The encoding for the sound module is most likely in MP3 format which is severly compressed. As in all the sounds are clipped at 200Hz to lower the amount of space they take up. You may spend a lot of time and energy on a problem that really can't be fixed. My suggestion is to turn down the other sounds so they are at least in balance with each other. That may make it sound much more real.

Now before somebody flames me for being clueless, I am a retired music teacher (Eastman School Grad '68) have a Masters in Fine Arts, and own and operate a Pro Sound and Recording Company in retirement. I do professional on location recording for Schools and Churches (as well as many other clients).

[SpaceMouse]

QUOTE: Originally posted by howmus

Now before somebody flames me for being clueless, I am a retired music teacher (Eastman School Grad '68) have a Masters in Fine Arts, and own and operate a Pro Sound and Recording Company in retirement. I do professional on location recording for Schools and Churches (as well as many other clients).

Yeah, but are you 14?




Sorry, that just popped out.

Chip

Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.

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