Cps1.x Multi Audio Merge Discussion

Derick2k sent me a prototype of the audio merge kit and I installed it over the weekend. Install requires one to remove the two rca jacks off of the multi and install a pcb in their place. This pcb is powered via a 3 pin connector. You must tap 5v, ground, and the Dash signal from the multi to plug onto this connector. There is a cable used to tap line-level from the cps1 A board via the CN5 connector. This cable plugs directly from CN5 to a connector on the audio mod pcb.

The other part of making this work requires modding the A-board by removing the sound pot. CN5 does not output actual line-level unless the volume pot is removed. So to remedy this we remove the volume pot and install a small pcb that adds back the volume pot but with a bypass switch so we can choose whether we want jamma audio (bypassing the pot mutes jamma audio) or proper line-level. Note that doing the A-board mod is not required but I'd you don't you will have uneven channel volume and bad sound mixing.

One thing we may add is a volume control between CN5 and the audio pcb. Currently you can't control the volume from CN5 unless your cab has a volume pot. So some cabinets, such as q25, have super loud music because you can't lower it via the pcb.

Comments are appreciated. Pics below:

What does this do? I read it a few times, and am not sure what audio its merging.

I know stock, both qsound and CPS1 games output via JAMMA just fine - I haven't checked but assume they output via the RCA jacks just fine as well?

Matt

mathewbeall said:

What does this do? I read it a few times, and am not sure what audio its merging.

I know stock, both qsound and CPS1 games output via JAMMA just fine - I haven't checked but assume they output via the RCA jacks just fine as well?

Matt

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Normal CPS1 games only output sound over Jamma.

This solution is to allow people to use a single set of RCAs and both CPS1 and 1.5 will output over that.

Cabinets with Q sound amps (Gen 2 big blue for example) aren’t wired for jamma sound by default, so this mod “fixes” the issue of how to get sound for normal CPS1 games

This puts line-level audio at the RCA jacks on the multi as well as auto-switch the audio between CPS1 and CPS1.5 games based on the game loaded. Basically will work with any cab that has its own amp for audio.

Got it - I only ever used JAMMA out - so didn't realize that CPS1 didn't also go out the RCA jacks.

Thanks!

Nice. Looking forward to this. It's the only reason my cabinet has been gutted and not put back together for the past four or five years. (Now I'm just hoping that my A-Board works. If it doesn't, I'll likely have to end up selling my multi-board since I can't just go out and get replacement A-Boards willy-nilly to try. Unlike many, I don't have a closet full of spare, confirmed working A-Boards I can use).

Looks great, very nice work. Love the bypass switch so you can still use JAMMA audio if/when needed too.

My prayers have been answered! Can’t wait to install this and have some proper cps1 audio in my big blue

Looking forward to this! Would favor inclusion of the on-board volume pot mentioned.

Thanks for the interest and feedback guys. I will do a few minor improvements and get it sent over to @Mitsurugi-w. Will probably do a small/limited run of these.

Slight update:



So I added an optional thumbwheel volume pot and an extension header.
Both are optional and can be used as follows:
1. If you dont need them, you can just bridge the pad and pass the audio straight through.
2. You can use just the thumbwheel pot to control CPS1 volume internally, I would use it as a set it and forget it and adjust the volume level to your liking for your setup
3. Use the extension header to route the audio lines and mount a volume pot of your choice somewhere on your case or outside of it.

So per my usual manner, asking a few questions.

CPS1 Multi currently has the audio adjustment for CPS1.5 sound via either the Jamma Mono, or the RCA Stereo
CPS1 "A" board has the audio adjustment for the CPS1 games via the Jamma Mono

This new pcb will combine CPS1 sound and CPS1.5 sound, both in stereo, and output both through the RCA jacks.
The kit will contain two pcbs, one to attach to the DS Multi itself, and one to attach to the "A" board, to bypass the new mod, and output CPS1 and CPS1.5 via Mono on the Jamma edge.



If all this is true, then my questions begin below.

Was there a reason this wasn't addressed in the development of the multi, so that the filter board could have contained this circuitry, including the volume pot and a bypass, and cases could have been made to accommodate?

Is there any way to tie this new volume control, back to the volume adjust that already exists on the DS Multi, in order to limit the now 3 volume pots this multi is using?

The CN5/Jamma Volume PCB will be installing a new pot, apparently, in order to connect the mod and the main pcb together. Is it possible to source a pot that is shaped the same as the existing CPS1 volume pot, so that those of us with LIONS3 cases do not need to 3dprint/order a new adjusment extension for our cases?

The statment that this will "Auto-switch" the stereo output source based on the Multi game that is run....will this require new Multi firmware updates, or does it work similar to the crystal mod?

Is it safe to assume all of the "auto-switch" functionality is bypassed, if the CN5 PCB has it's bypass set to "ON", and CPS1 and CPS1.5 will continue to output via the Jamma edge in that case, or once the QSound and voltage lines have been run to this new mod, that CPS1.5 will ONLY work via the RCA Jacks?

This is the 4th modification PCB for this multi (Spinner, Crystal, Kick/3p/4p combiner), how much is the cost estimate for this mod, and will it be the last mod PCB needed to finally have a "Complete" multi-kit, or are there other mods still in the works?



Please understand that with the above questions, I am not knocking the current mod design, or the improvements it offers, or being ungrateful for all the work that has been put into the DS Multi, but merely trying to ensure I have everything correct, that all concerns have been checked, and hopefully encourage more thought into any future multi's so that situations like this can be tackled at the multi-development stage, and not afterwards.

I can only respond to why a few of these weren't considered during multi production. For the audio and for the extra buttons the multi was designed to work exactly like the originals. It was my idea to add connectors to the filterboard so the original cps1 kicks could be extended to there. The audio for the multi also works exactly like the originals. It was simply never considered to change it. The extension cables for kicks was a simple cheap way to add them to the filterboard.

Originally the multi did not support spinners at all. The first protos did not have the connectors to plug spinner pcb into. After people started complaining they couldn't play Forgotten Worlds we decided to try to find a way. Adding the circuitry to every multi would have required a huge redesign and would have made an expensive multi even more expensive. We were able to add a connector with some difficulty. Most people who bought a multi haven't bought a spinner pcb. I think what we did was the right choice here.

Dual-crystal was never once considered by Darksoft and couldn't have been done by the multi regardless.

The audio mod and dual crystal mods are not official releases endorsed by Darksoft. It's more like Game Shark territory. All of these are also NOT required. They are just optional things to add options that people have requested.

Mitsurugi-w said:

I can only respond to why a few of these weren't considered during multi production. For the audio and for the extra buttons the multi was designed to work exactly like the originals. It was my idea to add connectors to the filterboard so the original cps1 kicks could be extended to there. The audio for the multi also works exactly like the originals. It was simply never considered to change it. The extension cables for kicks was a simple cheap way to add them to the filterboard.

Originally the multi did not support spinners at all. The first protos did not have the connectors to plug spinner pcb into. After people started complaining they couldn't play Forgotten Worlds we decided to try to find a way. Adding the circuitry to every multi would have required a huge redesign and would have made an expensive multi even more expensive. We were able to add a connector with some difficulty. Most people who bought a multi haven't bought a spinner pcb. I think what we did was the right choice here.

Dual-crystal was never once considered by Darksoft and couldn't have been done by the multi regardless.

The audio mod and dual crystal mods are not official releases endorsed by Darksoft. It's more like Game Shark territory. All of these are also NOT required. They are just optional things to add options that people have requested.

Click to expand...

I will echo that the Multi really is feature complete - what we are seeing now are "quality of life" upgrades. You certainly don't need them, and fit certain use cases that might matter to some folks, and not to others.

bagheera369 said:

This new pcb will combine CPS1 sound and CPS1.5 sound, both in stereo, and output both through the RCA jacks.

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Correct, with the exception that the line level output from the CPS1 A board is not true stereo, I don't think any of the CPS1 games have stereo.

bagheera369 said:

The kit will contain two pcbs, one to attach to the DS Multi itself, and one to attach to the "A" board, to bypass the new mod

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Yes to having 2 pcbs, the bypass on the A board is there to bypass the volume pot on the A board only, it disconnects it from the circuit. If it were to remain as is it causes audio issues with the line-level output on the CN5 header

bagheera369 said:

Was there a reason this wasn't addressed in the development of the multi, so that the filter board could have contained this circuitry, including the volume pot and a bypass, and cases could have been made to accommodate?

Click to expand...

See Mitsu's response above.

bagheera369 said:

Is there any way to tie this new volume control, back to the volume adjust that already exists on the DS Multi, in order to limit the now 3 volume pots this multi is using?

Click to expand...

No. There would have to be some modifying, trace cutting, etc. I don't like doing things like that if it can be avoided. I like it when things are more plug-n-play and reversible. The extra volume pot is being added to support the cabs that have amps without volume control. And it's completely optional to have it installed at all.

bagheera369 said:

The CN5/Jamma Volume PCB will be installing a new pot, apparently, in order to connect the mod and the main pcb together. Is it possible to source a pot that is shaped the same as the existing CPS1 volume pot, so that those of us with LIONS3 cases do not need to 3dprint/order a new adjusment extension for our cases?

Click to expand...

You can reuse the old pot that's already there, but you will still need a new extension or cut down the one you have since the volume pot will now sit higher by a few mm

bagheera369 said:

The statment that this will "Auto-switch" the stereo output source based on the Multi game that is run....will this require new Multi firmware updates, or does it work similar to the crystal mod?

Click to expand...

It will work similarly to the crystal mod, no updates are needed, this works off of the qsound setting

bagheera369 said:

Is it safe to assume all of the "auto-switch" functionality is bypassed, if the CN5 PCB has it's bypass set to "ON", and CPS1 and CPS1.5 will continue to output via the Jamma edge in that case, or once the QSound and voltage lines have been run to this new mod, that CPS1.5 will ONLY work via the RCA Jacks?

Click to expand...

If there is no power applied to the mod, it will still output CPS1.5 audio through the RCA jacks as the multi does just like the original boarset would running those games. The bypass is not for the mod but for the volume pot on the A board.

bagheera369 said:

This is the 4th modification PCB for this multi (Spinner, Crystal, Kick/3p/4p combiner), how much is the cost estimate for this mod, and will it be the last mod PCB needed to finally have a "Complete" multi-kit, or are there other mods still in the works?

Click to expand...

I can really answer this. I don't know if anyone is working on anything else. The dual crystal and this mod are my own design for the convenience of it all. Darksot was nice enough to have/add support for these, but they are not "official" Darksoft products/add-ons. I am not selling these or making any profits, but will have Mitsu offer these if anyone is interested in getting them since he can also offer to install them. I dont have a price on how much these will cost, Mitsu will be better at pricing these once he has a chance to look at whats involved.

bagheera369 said:

Please understand that with the above questions, I am not knocking the current mod design, or the improvements it offers, or being ungrateful for all the work that has been put into the DS Multi, but merely trying to ensure I have everything correct, that all concerns have been checked, and hopefully encourage more thought into any future multi's so that situations like this can be tackled at the multi-development stage, and not afterwards.

Click to expand...

Please ask all the questions you want, its the reason for this thread, it can only help make a better mod.

I am interested. This would make it a lot easier to switch games without having to switch how the audio is connected.

I agree it would have been nice if the multi handled this (and also if it had red and white rcas instead of yellow, and supported 3p/4p button 3, and spinners through the filter board) but also not a big deal.

As long as this would be fully functional in a Lions 3 case without having to cut holes, I'm all for it. It seems like the bypass switch might be either in the way or inaccessible. In the way is more of a problem than inaccessible imo.

@Mitsurugi-w and @Derick2k - Thank you both for the replies!!

"If there is no power applied to the mod, it will still output CPS1.5 audio through the RCA jacks as the multi does just like the original boarset would running those games. The bypass is not for the mod but for the volume pot on the A board."

I'm sorry, my question was, once this mod is in place, will the CPS1.5 audio, still output on RCA AND Jamma, as it does currently, or ONLY via RCA Jacks, due to the voltage/Qsound wiring that's being done.

bagheera369 said:

@Mitsurugi-w and @Derick2k - Thank you both for the replies!!

"If there is no power applied to the mod, it will still output CPS1.5 audio through the RCA jacks as the multi does just like the original boarset would running those games. The bypass is not for the mod but for the volume pot on the A board."

I'm sorry, my question was, once this mod is in place, will the CPS1.5 audio, still output on RCA AND Jamma, as it does currently, or ONLY via RCA Jacks, due to the voltage/Qsound wiring that's being done.

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No, because we are cutting the line level audio being fed to the amp on the A board.

While what you are asking can be done it would involve more components and more modding. My design behind this is directed towards my use case, which is a cab with an amp, where I can feed it line level audio and not have to switch cables etc. to reroute audio between cps1 and cps1.5 games.

Yeah the audio mod is only designed for people who want all sound through rca. If you are happy with jamma audio this isn't intended for you.

I thought the bypass switch would re-enable CPS 1.5 audio through the JAMMA edge?