Tech: Please Help / NSM Firebird Jukebox Volume Issue

[postman516]

Hello, i just bought an NSM Firebird wallbox that had no manual & i am
not happy with the volume i am getting from it. I am using Yamaha
bookshelf 8 ohm speakers and have the neg hooked to terminal 0 and the
pos to terminal 5 on each side of the transformer. I would say the
Volume is pretty low and when i try to turn the volume up or down
using the volume on the control board it does nothing to help the
matter. I also noticed the 3 buttons on the bottom of the box also do
not raise or lower the volume. So basically, right now i am stuck with
a fixed volume. I tried hooking the wires direct to the amp bypassing
the transformer but this also did not help. Do you think i need a new
transformer and would this solve my problem? I see some newer boxes
have a 7 lug transformer as well. Would that one give me more volume
and would it work in my firebird wall box? Sorry about all the
questions but i am not sure what the problem is nor what the
transformers function truly is? The guy i bought it from knows nothing
about the box at all. Thanks for any help regarding this matter! Mike
in FL

[KR]

The transformers are probably the output transformers for the
amplifier. The taps represent wattage
levels, that are used to match speakers (or series/parallel groups of
speakers) to the amplifier and avoid overloading it. The transformer
probably generates a 70v / 100v line for 500 ohm PA type speakers too.
(these will have a transformer on the back of them with wattage taps
on them.)

I doubt that the transformer is a problem, the sound would probably be
distorted / overloaded. In other brands, I have NEVER had an output
transformer fail on a solid state amp. You can disconnect it from the
amp and run a speaker direct if you want, just to eliminate it.

The other possibility is blown output stage, this can result in low
volumes, but there would be distortion, and probably blown fuses to
the output transistors.

I don't know how the volume control system works on these things. If
it is done with buttons, it either drives a motorised pot, (this
should be visibly connected to the amplifier / preamp board) or runs
via the CPU or to the amp, and then to a "volume control" IC on the
Amplifier Preamp board. it may also run to the amp, and control the
volume directly via a special IC.

Either way, something along this chain is broken, you will need a
schematic or to identify and look up preamp the IC part numbers on the
web and identify how it all works and deal with it from there.

[postman516]

> web and identify how it all works and deal with it from there.- Hide quoted text -
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> - Show quoted text -

I have found a wire harness that was cut and left in the box
that has 4 wires in it brown, blue, green and orange. They connect to
the vol up, vol down & the cancel button at the bottom of the box but
i do not see anyplace that they would connect at? I was looking at
possibly St-206 on the preamp board as that is open on my box and has
four pins. Can anyone take a look at and let me know if i
should have a connector on at St-206 and what order the colors should
be from top to bottom, it would be much appreciated. Thanks alot for
your help! Mike in Fl

P.S. This box is the original firebird & has Es-IV boards in it

[McDuseldick]

> P.S. This box is the original firebird & has Es-IV boards in it- Zitierten Text ausblenden -
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> - Zitierten Text anzeigen -

check out this one

http://www.cdadapter.com/download/nsmcode4.pdf

regards

Ron

[angel-care]

> Ron- Hide quoted text -

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Mike,
The vol. control in the box connects to the central computer at ST
206. If you had a remote vol. control it would connect to ST 205,
with a 5-wire connection.

As for connections, pin 1 is orange, pin 2 - green, pin 3 - brown and
pin 4 - black. Don't have any Firebirds here, otherwise I'd take a
pic. but still have manuals.

Hope this helps,
Gene

[slim grossheim]

where are the pins located to hook up i have the wire but no plug on the end

[John Robertson]

You aren't likely to get an answer from the OP (Gene) from back in 2009.

However I suspect you are looking for a DIN style plug - that was what
NSM often used for audio connections including volume controls.

Expand a bit on your particular problem and include the model and
exactly what you are looking for if the above is not enough information...

John :-#)#
--
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John's Jukes Ltd.
#7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
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www.flippers.com
"Old pinballers never die, they just flip out."

[slim grossheim]

i have a firebird 2 and i have the wires which are hooked at the buttons underneath but i dont know where they connect to on the
board no plug just the wires orange blue brown and green