Mother-32 drone mode in VCA Mode "ON" / Sine wave issue

[manick]

Hi there,

I noticed that my Mother-32 sounds permanently if VCA Mode is set to "ON" (of course the Cutoff needs to be opened to a certain amount as well to hear it).
If I hit a note, the VCO pitch follows, and the signal remains steady at that pitch until playing another note and so on. So, kind of an "allways on" oscillator.
As soon as the VCA Mode is set to "EG", it behaves as usual, it is quiet until a note is played.
Since I expected it to be quiet in Mode "ON" as well until a note is played, I'm wondering if this is by design, of if there is a setting I might have changed accidentally (though I couldn't find any in the manual)?

Another strange thing I noticed by trying the Sine wave sound as described in the manual on page 12: when I patch the VCF output to the EXT.AUDIO input, then nothing is audible, there is only a tiny signal level present at the audio output. My unit only plays the Sine wave when I disconnect the patch cable from the VCF output, but it must remain connected to the EXT.AUDIO input, so it needs a patch cable there without the other end being connected to an output, then it works.

I already tried more than once to "reboot" by disconnecting the power supply for a while, but it remains the same.

Did anybody encounter the same behaviour? Maybe I'm just missing something, or is my unit faulty at the end?

Any answer is welcome, thanks!

[mmarsh100]

Your first issue is not an issue that behavior is as designed. With the switch in the ON position, Mom bypasses the envelope and sends the signal to the amplifier directly. Think of it as "drone mode" - very useful.

As to your second issue, again I think your unit is fine. My guess is that you patched the other end of the cable to the wrong output - I've done this many times the labels for the jacks are on top, and I sometimes think they are on the bottom. The reason you still get sine wave is because you likely have the MIX knob at full clockwise, effectively muting the oscillator (with a cable patched into EXT.AUDIO, the internal connection to the noise source is broken and nothing is heard). Since the filter is setup to oscillate anyway, that's what you are hearing. Just a guess, but that's what it sounds like to me.

[manick]

Thank you for your answer mmarsh100!

I'm more than happy to hear that the first issue is as designed. You are right, it can be very useful as a "drone mode", but still I wanted to be sure it behaves as intended
And thinking and trying again, I see now that the playable "ON" sound is achievable by turning on the EG sustain and setting the Attack and Decay to minimum.
So they really made both the "playable" and the "always on" features possible, that's great!

To the second issue, well it wasn't because I mixed up the labels - I did read through most other posts here and had seen you posting this, which was very good because it made me attentive to this, so I double checked to be sure the cables were patched as described - which is indeed always a good starting point to "troubleshoot"
But now, after reading your explanation, it became so clear to me why this can not work as it is described in the manual (unless I might have been too stupid to get it right, see attached pics).

The manual says on page 12:

The key thing I missed here and hope I got it now thanks to your explanation: if the MIX control is at maximum, the VCF output will only be fed with NOISE, however NOISE is muted if a cable is plugged into EXT.AUDIO, no matter if that cable receives any signal or not. But if the other end of that cable is plugged in an OUTPUT where no signal is, it will in fact mute the EXT.AUDIO, and that is the case here because of the NOISE being muted by the EXT.AUDIO and thus no signal at VCF output.

Here is how I patched it according to the manual, resulting in silence as just described:

And here is how the Sine wave plays as it was probably intended (and works also without the KB to VCF Cutoff, then the pitch is only controlled by the cutoff itself without keyboard follow):

So, that's all about the "magic" that I didn't seem to catch yesterday... at least I hope I got it right now
If so, it would be good if somebody of the Moog staff would be around here, as that part on page 12 should be corrected, and maybe it would also be good to mention the "drone mode"

[jido-genshi]

Thank you for your answer mmarsh100!

I'm more than happy to hear that the first issue is as designed. You are right, it can be very useful as a "drone mode", but still I wanted to be sure it behaves as intended
And thinking and trying again, I see now that the playable "ON" sound is achievable by turning on the EG sustain and setting the Attack and Decay to minimum.
So they really made both the "playable" and the "always on" features possible, that's great!

To the second issue, well it wasn't because I mixed up the labels - I did read through most other posts here and had seen you posting this, which was very good because it made me attentive to this, so I double checked to be sure the cables were patched as described - which is indeed always a good starting point to "troubleshoot"
But now, after reading your explanation, it became so clear to me why this can not work as it is described in the manual (unless I might have been too stupid to get it right, see attached pics).

The manual says on page 12:

Mother-32_Sine_Manual.jpg

The key thing I missed here and hope I got it now thanks to your explanation: if the MIX control is at maximum, the VCF output will only be fed with NOISE, however NOISE is muted if a cable is plugged into EXT.AUDIO, no matter if that cable receives any signal or not. But if the other end of that cable is plugged in an OUTPUT where no signal is, it will in fact mute the EXT.AUDIO, and that is the case here because of the NOISE being muted by the EXT.AUDIO and thus no signal at VCF output.

Here is how I patched it according to the manual, resulting in silence as just described:

Mother-32_Sine_01.jpg

And here is how the Sine wave plays as it was probably intended (and works also without the KB to VCF Cutoff, then the pitch is only controlled by the cutoff itself without keyboard follow):

Mother-32_Sine_02.jpg

So, that's all about the "magic" that I didn't seem to catch yesterday... at least I hope I got it right now
If so, it would be good if somebody of the Moog staff would be around here, as that part on page 12 should be corrected, and maybe it would also be good to mention the "drone mode"

Plug that cable back in and turn down the Filter's Cutoff knob. And to be safe/to start at the basics, also turn down the LFO Rate and VCO MOD AMT knobs. Also, turn up the Decay knob and turn down that VC Mix knob. Now do you hear the sine wave from the Filter's Resonance?

[mmarsh100]

Well, two things:

• Check page 14 of the manual: it discusses drone mode pretty clearly
• Looking at your sine wave patch, the filter cutoff is way too high. Turn it down and you will be able to hear it.

Hope that helps,

Mike

*EDIT* I see jidogenshi has mentioned turning down the filter, so sorry about the cross-post.

m

[red]

Very interesting...
I have the triple Mother (currently only a dual because one of them DOA...)

So I tested also the sine patch as described in the manual:
a) one of the Mothers sounds as expected
b) the other one only produces a sine if the cable is removed from VCF out (2nd case as described by manick)

Removing the cable also in a) results in a slightly deeper sine and with more power...

In both a) and b) there is a signal direct out of VCF - so I don't understand why I can't hear the sine if VCF is connected to EXT. AUDIO

... And switching the filter to HIGH PASS both working the same with connected VCF---EXT. AUDIO

[manick]

Well, two things:

• Check page 14 of the manual: it discusses drone mode pretty clearly
• Looking at your sine wave patch, the filter cutoff is way too high. Turn it down and you will be able to hear it.

Hope that helps,

Mike

*EDIT* I see jidogenshi has mentioned turning down the filter, so sorry about the cross-post.

m

Thank you Mike! ...Gosh how could I overlook that section on page 14 where the ON state is described clearly... I guess I was already too tired when reading page 14 and didn't catch it anymore, sorry
At least the VCA "ON" drone mode is clear now, phew!

Plug that cable back in and turn down the Filter's Cutoff knob. And to be safe/to start at the basics, also turn down the LFO Rate and VCO MOD AMT knobs. Also, turn up the Decay knob and turn down that VC Mix knob. Now do you hear the sine wave from the Filter's Resonance?

Thank you jido-genshi! I Actually I had turned the Cutoff to this position because the sine wave was clearly audible WITHOUT the cable plugged in. Now today I tried it again with the settings you advised, and for a moment I really thought I got it, there was some weak signal audible. So I thought it must be something else... however the more I tried, the more the signal seemed to disappear. Disconnecting the one end of the patch cable from the VCF out again, and the Sine was clearly here.

So let me show this to you in a video, I guess this way it will be clearer what's going on. I'll upload the video as soon as it is ready in a follow-up post (hope this is okay).

So I tested also the sine patch as described in the manual:
a) one of the Mothers sounds as expected
b) the other one only produces a sine if the cable is removed from VCF out (2nd case as described by manick)

Removing the cable also in a) results in a slightly deeper sine and with more power...

In both a) and b) there is a signal direct out of VCF - so I don't understand why I can't hear the sine if VCF is connected to EXT. AUDIO

... And switching the filter to HIGH PASS both working the same with connected VCF---EXT. AUDIO

And thanks also to you red! This is really interesting, that you've got two units with different behaviours. What you're experiencing with b) seems to be exactly the same. I can confirm that there is a signal direct out of VCF, I can see it coming in at the equalizer, however it is so tiny that it is almost not or not at all audible.
I'll show that on my video, stay tuned...

[manick]

So here's the Video... Moog Mother-32 Sine Wave Issue

//EDIT: ...but one thing I need to say now: Actually I really like the Mother-32 so far - I just want to be sure to completely understand it before expanding to a 2nd or 3rd one...

BTW: sorry for double-posting, I wasn't sure how long it would take me with the vid and if I'd still be able to edit my previous post by then.

[red]

Confirmed, exactly the same as with one of the Mothers

[jido-genshi]

So here's the Video... Moog Mother-32 Sine Wave Issue

//EDIT: ...but one thing I need to say now: Actually I really like the Mother-32 so far - I just want to be sure to completely understand it before expanding to a 2nd or 3rd one...

BTW: sorry for double-posting, I wasn't sure how long it would take me with the vid and if I'd still be able to edit my previous post by then.

Very strange! After seeing the video, I had to test this on my three Mother-32s... they all work as the manual says (in fact, I got such interesting tones from this, especially after mixing in the Pulse Wave, that I'll have to explore this further!) The only thought I had is maybe you had the VCF Mod Amount down too low (that's sort of your tuning in this mode) or the Polarity switch on Negative instead of Positive, but looking at your video again, all your settings seem fine... which means it may be time to contact Moog Support directly. Hope you get it sorted out!

Here's the video of my test - https://www.youtube.com/watch?v=JgOUkyNcWYA

EDIT: Just to try again, play around with the VCF MOD AMOUNT again; there is a sweet spot for the tuning, too high and you may not hear it, too low and you may not hear it either.

[manick]

Very strange! After seeing the video, I had to test this on my three Mother-32s... they all work as the manual says (in fact, I got such interesting tones from this, especially after mixing in the Pulse Wave, that I'll have to explore this further!) The only thought I had is maybe you had the VCF Mod Amount down too low (that's sort of your tuning in this mode) or the Polarity switch on Negative instead of Positive, but looking at your video again, all your settings seem fine... which means it may be time to contact Moog Support directly. Hope you get it sorted out!

EDIT: Just to try again, play around with the VCF MOD AMOUNT again; there is a sweet spot for the tuning, too high and you may not hear it, too low and you may not hear it either.

Thanks! Yes I kept the VCF Mod Amount rather low (but also tried to turn it up) because the filter Cutoff gives the fine-tuning of the pitch, so no modulation should be necessary to hear it. And as you could see, with the VCF out plugged off, it always worked with and without modulation, so that doesn't seem to be the reason.

And believe me, I'm eager to get that sound to work with the VCF OUT plugged in, because thanks to you guys I understood by now that the VCF OUT should be driven by self-oscillation of the filter, creating that nice Sine wave sound, and it must be connected to be able to mix it back with the Pulse (or Saw) Wave as you do... interesting Video by the way, sure this has to be explored further

However, right now I can play around with any knob or switch as I want, the result is always as shown in the video.
So I need to find out why it is that silent and even disappearing on my (and obviously also others) Mother-32

[jido-genshi]

Very strange! After seeing the video, I had to test this on my three Mother-32s... they all work as the manual says (in fact, I got such interesting tones from this, especially after mixing in the Pulse Wave, that I'll have to explore this further!) The only thought I had is maybe you had the VCF Mod Amount down too low (that's sort of your tuning in this mode) or the Polarity switch on Negative instead of Positive, but looking at your video again, all your settings seem fine... which means it may be time to contact Moog Support directly. Hope you get it sorted out!

EDIT: Just to try again, play around with the VCF MOD AMOUNT again; there is a sweet spot for the tuning, too high and you may not hear it, too low and you may not hear it either.

Thanks! Yes I kept the VCF Mod Amount rather low (but also tried to turn it up) because the filter Cutoff gives the fine-tuning of the pitch, so no modulation should be necessary to hear it. And as you could see, with the VCF out plugged off, it always worked with and without modulation, so that doesn't seem to be the reason.

And believe me, I'm eager to get that sound to work with the VCF OUT plugged in, because thanks to you guys I understood by now that the VCF OUT should be driven by self-oscillation of the filter, creating that nice Sine wave sound, and it must be connected to be able to mix it back with the Pulse (or Saw) Wave as you do.

However, right now I can play around with any knob or switch as I want, the result is always as shown in the video.
So I need to find out why it is that silent and even disappearing on my (and obviously also others) Mother-32

You must have quoted me a moment before I Edited my post to add a video of my test... here it is again - https://www.youtube.com/watch?v=JgOUkyNcWYA

[manick]

You must have quoted me a moment before I Edited my post to add a video of my test... here it is again - https://www.youtube.com/watch?v=JgOUkyNcWYA

Haha ...yes and while you wrote this I watched your video and edited my previous post ...

... interesting Video by the way, sure this has to be explored further

It's really an interesting sound, I definitely need to be able to achieve it with mine too

[Vsyevolod]

Thanks for bringing up this issue gang. It's great feedback for Moog as they will have to track down what's going on... which will only give us a more finely tuned machine.

I tried this patch out on my two Mother's today and it works well, just as Craig found. Truly nice sounds coming from this patch.

Stephen




.

[manick]

Thanks Stephen for trying and feedback! On Tuesday, I contacted the local service center and got feedback from the technician there that he was able to reproduce the issue.
He forwarded it to Moog and now we're awaiting their answer. I'll follow up here as soon as there are any news.