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?
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?
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.
Quote from: Greg Elmassian on June 27, 2025, 11:39:47 PMI'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.
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.
Quote from: Greg Elmassian on June 28, 2025, 11:01:23 PMbout 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.
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
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?
Quote from: Greg Elmassian on June 30, 2025, 02:45:05 PMStan, 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
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.
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!
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.
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!
remember that the bachmann chuff trigger logic was backwards on some early locos, notably the first K-27... since corrected.
Quote from: Greg Elmassian on July 14, 2025, 04:58:18 PMthe 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?
Of course...
Since this has the updated electronics...
The first thing is to be sure the stock bachmann motherboard is powered, otherwise none of the chuff electronics work.
Then try your voltmeter on the chuff sensor (and reference minus with the other probe)
I think you may find that the Bachmann sensor goes POSITIVE when it should "chuff"
Most sound board electronics were designed to detect NEGATIVE when it should "chuff"
This has been changed over the years in Bachmann locos, so you need to determine yourself.
did you actually test the Revo independently? You stated "it should work", but you did not explicitly verify that connecting the 2 pads on the revo made it chuff...
I don't remember, but I thought there was also a setting in the Revo to switch from autochuff to triggered chuff.
Greg
The K27 board has chuffs that go positive when a chuff is made. (Note we now have a replacement chuff board that goes negative)
All the Bachmann Locomotives since the K27 that have a chuff circuit that goes to ground when the chuff is trigerred.
I suggested 4 steps for Pete to take
1) ensure the revolution chuff is configured correctly by taking the revolution chuff trigger input and touching it to ground. You should get a chuff each time you make a connection to ground and no autochuff.
2) As you suggested make sure there is DC voltage on the Bachmann's B+ and ground connections.
3) if 1 and 2 are successful try bending the revolution pin J1-5 so that it does not make a connection to the Bachmann main board. This may not be required but I have no idea if JK makes any connection to this pin
4) Connect the revolution chuff input pin to the Bachmann Chuff Sensor on the main board ensuring that the connection does not overlap to any other solder pad.
Hope this helps
Stan
Yeah, good safety idea on pin 5, I have a revolution, so I might check that myself, but there were abortive attempts at Aristo to control the smoke unit... remember the Digitrax what DG583 or some similar number?
Also good catch on making the ground common between boards.
Greg
Quote from: StanAmes on August 10, 2025, 06:26:20 PMmake sure there is DC voltage on the Bachmann's B+ and ground connections
It actually has a battery squashed behind the motherboard, connected to the battery input, and the loco and chuff work fine - except the chuff isn't synchronized.
I will try grounding the chuff trigger, but I think the trigger wire from the Revo is connected to the Chuff Sensor pad and nothing changed. See my photo on post #14.
I looked, and I thought there was a menu setting for autochuff vs triggered chuff.... but I don't see it in the manual...
something does not make sense, as there should be a setting I think...
try just "flicking the chuff wire to ground... also the other wire should do the whistle..
Quote from: Fred2179 on August 13, 2025, 04:15:17 PMQuote from: StanAmes on August 10, 2025, 06:26:20 PMmake sure there is DC voltage on the Bachmann's B+ and ground connections
It actually has a battery squashed behind the motherboard, connected to the battery input, and the loco and chuff work fine - except the chuff isn't synchronized.
I will try grounding the chuff trigger, but I think the trigger wire from the Revo is connected to the Chuff Sensor pad and nothing changed. See my photo on post #14.
Please follow all 4 steps I posted providing the answers for each step. You need to check the voltage at the B+ and Ground Battery input 1 is connected to J1-1 and J1-12 only when you have the battery switch on. It is not connected to B+ and ground. I believe the revolution provides this voltage but best to confirm.
In step 2 you need to disconnect the solid conection to the Chuff sensor and simply "flicking the chuf wire to the locomotive ground" as Greg suggests. Each time you flick the chuff wire to groud you should get a single chuff. If the revolution is in auto chuff mode then you might get a whistle of bell sound.
You need to disconnect the chuff wire to the sensor when you do this, If there is no voltage on B+ to ground you will get no chuff and if the Revolution is not configured for sensor chuff you also will get no chuff.
Your photo shows how you connected wires to the Bachmann board. I believe this is a revolution issue and not a bachmenn locomotive issue.
Stan
Quote from: StanAmes on August 10, 2025, 06:26:20 PM1) ensure the revolution chuff is configured correctly by taking the revolution chuff trigger input and touching it to ground.
OK. Yes, that works.
Quote from: StanAmes on August 10, 2025, 06:26:20 PM) As you suggested make sure there is DC voltage on the Bachmann's B+ and ground connections.
Yes, there is power between the GND pins and B+.
Quote from: StanAmes on August 10, 2025, 06:26:20 PM4) Connect the revolution chuff input pin to the Bachmann Chuff Sensor on the main board
And that worked - we have 4 chuffs per rotation [I was going to type 'revolution' but that might be confusing.] Thank you.
What is confusing is the Revo talks abut the 'common' trigger pin, but there is no indication whether that is the same as motherboard GND or not.
Quote from: StanAmes on August 10, 2025, 06:26:20 PM3) if 1 and 2 are successful try bending the revolution pin J1-5 so that it does not make a connection to the Bachmann main board
It doesn't look to be connected, so before I snipped it off, I figured I would continue testing, which had the required results.
Thanks for all the inputs and help. Pity the Revolution isn't completely plug-n-play.
Actually it was developed before the advent of an international standard
and the Bachmann K27 has a reversed chuff logic (stock)
so you can blame Aristo, Bachmann and whatever else.
Your main issue was the Bachmann logic, which is NOT Aristo's fault... if you want to say:
"Pity the Revolution isn't completely plug-n-play."
then you are blaming Aristo... in this specific case, you need to blame Bachmann...
Although in this case, it seems that Bachmann has a solution that would have made it plug and play.
Quote from: Greg Elmassian on August 16, 2025, 05:33:25 PMYour main issue was the Bachmann logic,
How do you figure that? The Bachmann motherboard seeems to be set up for a proper p-n-p board. My problem was/is that the Revo doesn't have it's speaker output on the correct pins, nor does it use the J1-5 chuff sensor pin. If they had done that, I wouldn't have had all this trial-and-error.
Huh? Oh, you want the Aristo product invented and designed before ANY socket other than Aristo existed... that socket to be updated to current sockets?
Yeah, I get that, it would be nice... but the Revolution is no longer supported by Aristo, because they went out of business, and believe me, no one is getting rich on ANY G scale only electronic product.
Phoenix sound - gone
Soundtraxx Sierra - gone
Aristo - gone
Locolinc - tragically small market share
Piko - they oem from major DCC manufactures.
But, why not? Why not contact the Revolution people and ask for a new board layout... (of course what NMRA standard? 21MTC? now that would make sense, but too much work)
What is the suggestion? Surely not the non-standard Bachmann socket? (no offense Bachmann, you need to embrace a standard socket NMRA and MOROP/NEM)