Plug-n-Play speaker connect?

[Fred2179]

I just plugged a Revo 57002SS sound board in a Spectrum 2-6-0 (Gen-2) "Raton". It works fine, except there is no sound.
There is a speaker underneath, and a very prominent SPKR plug on the motherboard (see file attached.) If I connect a speaker to the spkr plug on the Revo, I get sound.

Anyone know why there's no connection between the Revo sound card sound output and the Motherboard SPKR plug?  Or is there something subtle I missed?

[Fred2179]

I did get the speaker to connect, by wiring the Revo wires to the motherboard pins along the side.
Still doesn't explain why I have to. The pnp spec says J2:1 and J2:3 are speaker output from the daughter board. Does Revo not use the spec?

[Greg Elmassian]

The Revolution was designed for Aristo locos.

Aristo almost never connected the loco speakker to anything. (there were a few locos where it was connected to J2)

The published spec never had connections on J2.

The Bachmann spec is different, similar but different, and J2 is used. I'm not aware that the interface is published as a spec anywhere, and there have been several slight variations from the K27 onwards.

So that explains why the Revo has no output pin for a speaker.

p.s. can someone get this stupid verification crap off this site? some way to get permanently verified? It is a pain.

[Fred2179]

I'm not aware that the interface is published as a spec

I have a document (attached) headed "Topic 0707092 Large Scale Plug/socket V2.1" dating from 2007. It clearly shows J2:1 and J2:3 are speaker connections. No idea where I got the doc, but obviously no-one is following it closely.

[Greg Elmassian]

Notice it was a "topic", not an NMRA approved "thing"

so if you look up the reference in your document, it references RP9.1.1 changes (as a topic)
then you can find that this has been moved to S9.1.1
and the sockets referenced are not any of the Aristo nor the Bachmann varient based on the Aristo

https://www.nmra.org/sites/default/files/standards/sandrp/DCC/S/s-9.1.1_decoder_interfaces.pdf

the Bachmann socket never got anywhere "officially" (as far as I can find) ... and looks like the one proposed and eventually implemented by Bachmann courtesy of Stan Ames

Again, the original question was about the Aristo/Crest Revolution decoder not having pins dedicated to speaker outputs. It was really only designed to fit Aristo locos.

[Fred2179]

bout the Aristo/Crest Revolution decoder not having pins dedicated to speaker outputs

At Stan's suggestion, I turned on the sound and checked pins J2-1 and J2-3 with a meter. There was varying voltage on the pins, suggesting the Revo card was outputting the sound signal to those pins. Guess Bachmann doesn't run a trace to the SPKR plug!

And yes, Mr. Bachmann. The Verification you've added is extremely onerous.

[StanAmes]

Peter

Sometimes I can make a mistake so I went out and double checked my D&RG 2-6-0 with both an ohm meter and with two different plug and play decoders and I can positively confirm that the speaker in the Bachmann 2-gen 2-6-0 is correctly connected to J2-1 and J2-3.

While it is possible that you have a defective board, I believe it is much more likely that you have measured incorrectly.  Remember once you soldered the Revo speaker outputs to the Bachmann board the Revo J2-1 and J2-3 are connected to the REVO speaker outputs when the Revo is pluged into the socket.

The best way for you to double check on your end is

1) use an Ohm meter (not a voltmeter measuring voltage))

2) remove the Revo board from the socket.

3) check the Bachmann board by using the ohm meter to check the connections from both the speaker output pins and the solder pads that you connected to the Revo speaker output.  You should find that pins J2-1 and J2-3 are connected to both of these two places.

Next with the Revo board out of the socket use an ohm meter to check the speaker output pins you connected the speaker to are connected to the Revo J2-1 and J2-3 pins.  If there is 0 ohms between these two connections the Revo should properly connect to the Bachman speaker.  If there is no connection, you must manually connect the speaker between these two products.

Please remember that while Bachmann publishes its connections to its non-proprietary plug and play socket, that by no means ensures that everyone who has products that plug into the socket follow that documentation.

Hope this helps

Stan

[Greg Elmassian]

Stan, it seems that you are telling the poster to check that the Revolution has the speaker connected to J2-1 and J2-3....

I do not think that is the case. Where did you find documentation that this is true?

I have a revo board, and I check in the absence of any documentation.

The QSI Titan does indeed have the speaker connected to those pins though, perhaps you are confused?

[StanAmes]

Stan, it seems that you are telling the poster to check that the Revolution has the speaker connected to J2-1 and J2-3....

I do not think that is the case. Where did you find documentation that this is true?

Greg

I believe you are correct that the Revo does not connect its speaker output to pins J2-1 and J2-3.  I can not positevely confirnm this as I do not have a Revo board to test.

Peter (Fred2179) believes that his Bachmann board is lacking a trace between these two pins and the speaker socket.  Unless there is a defect on his board (unlikely) I sent him a specific set of tests to confirm that the reason he had to make his own connection to enable the speaker is simply because the Revo board does not support this feature.

Stan

Stan

[Greg Elmassian]

I've put QSI in a number of Bachmann with the "new" socket and sound worked right off... it would be strange for those pins not to be connected in the motherboard, but I have not put a Titan in a 4-6-0 socket.

easy to test as you said, but it would be to no avail if he's putting a revo in the loco.

[Fred2179]

Stan, you may be right that I was back-feeding the J2 pins from my speaker output! I'll take a look with the ohmmeter.

I asked Revolution the same question:
"None of the speakers in the locomotive work when the Revolution is operating - I have to plug the speakers directly in to the 57002SS card using the supplied cable."
Today I got back the terse reply: "Please refer to the wiring diagram. The speakers are not plug and play." I take that to mean that the Revo board speaker output does not connect to J2-1/3.

Edit: I did check, as I have another Revo board handy. There does not seem to be a connect between the speaker output and the J2-1/3 pins. So the email from Revo was right - spkr is not plug-n-play!

[Greg Elmassian]

Yep, unfortunately, although I can show you some Aristo motherboards that have a speaker connected to J2... I don't remember which loco, but it was not consistent, and never documented by Aristo.

The entire time, J2 was just support for the board, it was indeed a waste of a connector.

[Fred2179]

While writing about the conversion (LargeScaleCentral.com, if anyone is interested,) I realized the 'chuff' trigger was probably set up the same way. The manuals say to connect the trigger on the Revo to the 'chuff sensor" pad on the motherboard.
Should work, but the loco is packed for sale so it will have to wait until the next one!

[Greg Elmassian]

remember that the bachmann chuff trigger logic was backwards on some early locos, notably the first K-27... since corrected.

[Fred2179]

the bachmann chuff trigger logic was backwards

which brings me to my next issue.  I was thinking I should test the 'chuff' trigger and see if it would synchronize to the wheels.
There are 2 pads on the board: "Chuff SW" and "Chuff Sensor". Why two? Anyway, there's a connection on the Revo for 2 triggers; one for whistle and one for bell/chuff. I initially wired the whistle wire to the Chuff SW pad, and got a constant whistle. Very noisy, as I was testing in my kitchen!

So I did the obvious - read the manual(s) and switched to the bell/chuff wire. The 2-6-0 manual says:
Locomotive Chuff
This locomotive has an optical chuff sensor in each cylinder that can be used to provide a prototypically correct chuff trigger for your sound system. A simple switch is used to select for two chuffs or four chuffs per revolution of the drivers. The switch is located in the front center of the tender
(see figure 21).

To use the locomotive's internal chuff, connect the sound board chuff connections to the main PC board solder pads "Chuff Sensor" and "GND."

So, with the correct wires from the Revo socket to the Chuff Sensor and Gnd pads (see attached pic) it should have worked. Well, it didn't. Anyone have any ideas?