Outputs - L(Mono), R ....Something Doesn't Seem Right

Started playing around with some OPB songs and different drumkits with bass. All that I did played fine in BBM, but when transfered to the SD card and loaded into the BB, some drumkits which were supposed to have bass didn’t play the bass part through an amp from the ‘L/Mono’ output jack on the BB. The drumkit that didn’t play is ‘NP Standard Pro with Bass’. The drumkit that worked OK is ‘SuperBassG’
Looked at all the MIDI note assignments in the drumkits, etc and all that seemed OK. Finally plugged headphones into the BB. The non-playing bass was in the right side can on the headphones. Then swapped the amp cable to the ‘R’ jack on the BB. The bass came through the amp along with the drums.

Most all my other gear that has an output jack marked ‘L/Mono’, outputs a mix of left summed with the right by means of a contact that is closed in the right jack that connects over to the left jack when no plug is in the right jack. The BB isn’t not working this way and oddly testing a bit further it seems the right output jack is the mix of left and right if I plug a source into the ‘L/Mono’ or ‘R’ Input jack. I think the stereo drumkits are also mixed to the ‘R’ output jack also. If I plugged a source into both left and right inputs the output is then on the respective left and right output jacks, but not mixed on the right as when only one jack of the inputs is used.

Is the labeling on the output jacks reversed as to the intended electrical design of the BB or an error in the electrical design that didn’t match the labeling?
In the PDF manuals I have I don’t think I found mention of the input or output jacks and how they they may configure/route themselves depending on what is plugged in. Are the output jacks dependent on what is plugged into the input jacks as well? It seems so as the outputs split out to stereo when two jacks were plugged into the inputs, rather that mix it to a single mono output.

If anyone else would try different input and output combinations your results would be welcomed.

I’ve always known that the left did not perform as a summer mono. I assumed that both outputs were just one side of the stereo channel. I always advised folks to use both outputs for my kits that had a panned instrument. If, in fact, the right acts as a summed mono, that’s good news.

I’ve noticed it too – although, as I’ve only really seen it recently, I assumed it was only with the latest firmware. I’d say that’s a bug. And a big one at that.

Is it possible that the right channel is actually the summed-mono one and not the left?

For the outputs it’s likely hardware in the way its PCB wiring is layed out. Not sure how the inputs get through to the outputs, such as some sort of buffer amp, but those seem affected somehow in the scheme.
It does seem as if the right output is the summed mono.

Below is a screenshot of a Yamaha keyboard showing how L/R is summed at the jacks. One plug into L/R is summed. A plug in the R jack breaks the connection over to the L.

Is that the actual schematic, or is that a generic schematic?

Which output gets the summed mono is often decided by a combination of hardware and software/firmware, so it’s possible for it to be affected by firmware changes. But (as I think you’re implying, albeit indirectly :slight_smile: ) it’s more likely I’ve just seldom used the BB in mono mode so I’ve just never noticed.

PS: Maybe I’ll try using the Right-Out for the first set tonight to see what happens.

Schematic is from a Yamaha keyboard service manual (PSR S910) to show a typical output summing circuit as I’m familiar with. Most any other gear I’ve come across is about the same.

Well I just tried something and it seems neither the ‘L/Mono’ or the ‘R’ output jacks on my BB provide a left/right mono mix of a stereo WAV file with a single cable connected to an amp. I created a test drum file with a kick drum, a closed hi hat, and metronome. The kick drum I hard panned to the right, the closed hi hat hard panned left, and the metronome to the center. I then created a MIDI pattern with the BBM editor which alternates the kick and the closed high hat and saved as a song. Loaded this into the BeatBuddy on a card and played it.
The kick only plays out of the ‘R’ output jack and the closed hi hat only from the ‘L/Mono’. There is no summed mix of the sound, which is what I expected the ‘L/Mono’ out jack should provide. The ‘R’ out jack is not summed mono either as I originally had thought. The metronome being centered is heard equally from both output jacks. Unless my BeatBuddy has a problem with the output jacks, this may mean that if stereo WAV files are used that have a mix of instruments that are panned significantly left or right, they may not sound correctly as intended with a single connecting cable application to an amp

The drum and song files are attached that I used to test with if anyone should want give this a try, which I would appreciate so I would know if my BeatBuddy has a problem or this is inherent in the design of the pedal. This was a first on exporting both a drm and sng file, so hopefully I did it correctly.

I would hope SingularSound might step into this thread and offer some enlightenment as to how the ‘L/Mono’ jacks on both the outputs and inputs are supposed to work, both with onboard playback of audio, as well as a source into the input jacks. I again searched the PDF manuals I had and could find no reference to input/output jack usage in a mono or stereo configuration.

New_Drumset.drm (407.3 KB) Right_Left_Test.sng (1.4 KB)


Hi guys, thanks for bringing this to our attention. The way this is supposed to work is, if only the left output is plugged in, both R and L output is sent out the left output. If both are plugged in, the stereo output should work as normal. If both inputs are used, then the R and L should be kept seperate if both outputs are used, or combined if just the L is plugged in.

We are investigating whether this is a software or a hardware issue and will keep you guys informed.

Thanks again for posting your findings!


I can confirm that from day 1, when I developed the Hammond and Bass kit, the BB always kept the right and left side unsummed. I have 2 BB pedals, one with the old printing and one with the new, and it is the same on both pedals. I had believed that since the Singular kits were center panned, that the non-summing was a decision on your part that summing was unnecessary. But, if you are certain that summing was intended, then that would appear to be a flaw in all units.


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The drums aren’t panned center – I don’t think…

That could be. That was my impression owing to way the left and right outs worked. I only got pan when I programmed in it, by panning drums in varying degrees, and using both outputs.

A post was split to a new topic: How to use BASS/drums

Was this issue resolved in FW? Does L/Mono out now contain the entire stereo image in mono? Thanks

I believe it has not been resolved.

We have changed the behavior of stereo and mono in the firmware, it really depends what you mean by contain the entire stereo image in mono, do you mean recording and stereo by writing the recording to the Aeros in mono? Could you be more specific what you’re trying to achieve?

Thank you


The original question was regarding the BB handling of the L/R into a summed mono, not the Aeros. I do not believe you have made any improvements to the BB in this regard. Although given the topic, @KevinT may have been referring to the abilities of the Aeros.

Oh you’re right, I think someone made a mistake when placing it, I’ll put it in the correct place. To your point, I know that this is something we have already fixed in a tested version of the BB.

…that will be available, when?


And thanks!


Yes my question on L/mono having the stereo image was for BB. Good to know its coming.

I just wrote to Santa and said all I want for xmas is BB AP and a stereo image from L/mono.

Please make my wishes come true.