Strange noise from my Pulse +

gregor z · 22nd May 2009

Hi!

I turned on my Pulse + after long time and I noticed that is emitting a constant low level sound.......and it is different with every preset.....like an oscillator that is on all the time....

It is low....but is annoying on certain sounds......

Did anyone had similar problems or knows anything about this......or this is normal....?

I attached the normalized MP3 of the sound......

Thanks in advance,

Gregor Z

chrisrnps · 22nd May 2009

Sounds like an oscillator that is on all the time and/or a 'stuck' note.

I don't own a Pulse, but...

Does the unit have any sort of auto-calibrate / auto-tune function? Have you tried it?

Or a manual-tuning-reference oscillator like an old Moog? Is it on?

If not, or if that doesn't work, sounds like it's in need of service and a tune-up by a qualified tech.

On some traditional analog synth architectures, the oscillators really are 'on all the time', and if something goes wrong with the filter / amp / envelope sections, it can do that.

If you max out the polyphony (play more notes at the same time in different ranges than the synth has notes of available polyphony) does that 'always on' note change, or is it always at that same frequency?

gregor z · 23rd May 2009

sounds like an oscillator that is on all the time and/or a 'stuck' note. Jkthtyrt

i don't own a pulse, but...

Does the unit have any sort of auto-calibrate / auto-tune function? Have you tried it?

Yes.....it has filter tuning procedure.....it does not solve the problem

or a manual-tuning-reference oscillator like an old moog? Is it on?

Hmmm.....nothing like that in manual......i dont know....

If not, or if that doesn't work, sounds like it's in need of service and a tune-up by a qualified tech.

Definitely......but i wanted to check all other options first.....

On some traditional analog synth architectures, the oscillators really are 'on all the time', and if something goes wrong with the filter / amp / envelope sections, it can do that.

I agree.....

If you max out the polyphony (play more notes at the same time in different ranges than the synth has notes of available polyphony) does that 'always on' note change, or is it always at that same frequency?

it is monophonic synth.......there is one sound which is always present......and the others change with different presets.....

Thanks for reply........still searching for the solution ......any other ideas?

Gregor Z

nofi · 23rd May 2009

is that sound changing all the time like that? or did you step through the presets for that recording?

anyway - easy to test if it's an osc or 2 bleeding through - just go to the settings for each osc in a patch, and change them... if the sound changes when you are working on one (or more!) oscs, then you know what the source of the noise is.

Whatever it is though, it sounds like your synth needs a service.

gregor z · 23rd May 2009

Quote:

QUOTE=nofi;4213628]is that sound changing all the time like that? or did you step through the presets for that recording?

I went through presets...you can hear that the sound changes....but there is one sound which is always present.....

Quote:

anyway - easy to test if it's an osc or 2 bleeding through - just go to the settings for each osc in a patch, and change them... if the sound changes when you are working on one (or more!) oscs, then you know what the source of the noise is.

I tried that first.......it is still present......i suspect a bad VCA or something similar.....

Quote:

Whatever it is though, it sounds like your synth needs a service.

Seems so.....does anyone have a service manual for Pulse?

DSPaudio · 23rd May 2009

Could be the power supply filter caps giving out and polluting the rails.

\just a thought/

chrisrnps · 23rd May 2009

Quote:

Originally Posted by DSPaudio

Could be the power supply filter caps giving out and polluting the rails.

\just a thought/

That 'note' in the audio clip wouldn't happen to be 50 or 60 Hz, by any chance, would it?

submodern · 23rd May 2009

This probably isn't it, but...

I remember when I had a Pulse+ that I had to reset the CV out MIDI channel parameter every time I turned it on, or weird things would happen. I forget exactly what those weird things were, they might have been limited to the CV outs but I kinda remember a low droney noise (might have been on the attached CV synth though).

Anyway, it is worth a try... when you turn the Pulse+ on just go to the parameter that sets the MIDI channel of the CV out and change the value back and forth.

Porque Bronco · 24th May 2009

It's been a long time since I touched a Pulse but I remember this happening. I always thought it was a stuck midi note and a power cycle solved it.

23rd May 2009	#4
nofi Lives for gear Join Date: May 2007 Location: australia Posts: 1,116	is that sound changing all the time like that? or did you step through the presets for that recording? anyway - easy to test if it's an osc or 2 bleeding through - just go to the settings for each osc in a patch, and change them... if the sound changes when you are working on one (or more!) oscs, then you know what the source of the noise is. Whatever it is though, it sounds like your synth needs a service. __________________ http://bleepin.com http://myspace.com/bleepinjsquawkins

23rd May 2009	#6
DSPaudio Gear maniac Join Date: Sep 2008 Posts: 189	Could be the power supply filter caps giving out and polluting the rails. \just a thought/ __________________

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22nd May 2009	#2
chrisrnps Lives for gear Join Date: Feb 2004 Location: Seattle Posts: 977	Sounds like an oscillator that is on all the time and/or a 'stuck' note. I don't own a Pulse, but... Does the unit have any sort of auto-calibrate / auto-tune function? Have you tried it? Or a manual-tuning-reference oscillator like an old Moog? Is it on? If not, or if that doesn't work, sounds like it's in need of service and a tune-up by a qualified tech. On some traditional analog synth architectures, the oscillators really are 'on all the time', and if something goes wrong with the filter / amp / envelope sections, it can do that. If you max out the polyphony (play more notes at the same time in different ranges than the synth has notes of available polyphony) does that 'always on' note change, or is it always at that same frequency?

23rd May 2009	#3
gregor z Gear addict Join Date: Apr 2005 Location: Slovenia Posts: 397 Thread Starter	sounds like an oscillator that is on all the time and/or a 'stuck' note. Jkthtyrt i don't own a pulse, but... Does the unit have any sort of auto-calibrate / auto-tune function? Have you tried it? Yes.....it has filter tuning procedure.....it does not solve the problem or a manual-tuning-reference oscillator like an old moog? Is it on? Hmmm.....nothing like that in manual......i dont know.... If not, or if that doesn't work, sounds like it's in need of service and a tune-up by a qualified tech. Definitely......but i wanted to check all other options first..... On some traditional analog synth architectures, the oscillators really are 'on all the time', and if something goes wrong with the filter / amp / envelope sections, it can do that. I agree..... If you max out the polyphony (play more notes at the same time in different ranges than the synth has notes of available polyphony) does that 'always on' note change, or is it always at that same frequency? it is monophonic synth.......there is one sound which is always present......and the others change with different presets..... Thanks for reply........still searching for the solution ......any other ideas? Gregor Z

23rd May 2009	#8
submodern Gear Head Join Date: Sep 2007 Location: sf, ca, usa Posts: 73	This probably isn't it, but... I remember when I had a Pulse+ that I had to reset the CV out MIDI channel parameter every time I turned it on, or weird things would happen. I forget exactly what those weird things were, they might have been limited to the CV outs but I kinda remember a low droney noise (might have been on the attached CV synth though). Anyway, it is worth a try... when you turn the Pulse+ on just go to the parameter that sets the MIDI channel of the CV out and change the value back and forth.

24th May 2009	#9
Porque Bronco Gear interested Join Date: Nov 2005 Location: Utrecht, The Netherlands/ Philadelphia PA Posts: 2	It's been a long time since I touched a Pulse but I remember this happening. I always thought it was a stuck midi note and a power cycle solved it.