Little Phatty distorted / wheezy OSC

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art507
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Little Phatty distorted / wheezy OSC

Post by art507 » Tue Nov 14, 2017 6:55 pm

Hi !

I have a second hand Moog Little Phatty and just noticed that the pure Sawtooth wave ( 1 OSC only, Resonance=0, Cutoff = open ) sounds a little wheezy and distorted in the middle and high range. There is the same effect with both of oscillators, the effect is similar also if I use different waveforms . I can hear it very well using the monitors (speakers). Its difficult to hear the distorted sound using headphones.

I compared it with a filter open sawtooth wave on my Minitaur and Nord Stage 2 that sound very clean in comparison with the LP.
I have used also different audio and electric cables. LP has the same problem.

What could it be ?

Thank you!
Last edited by art507 on Wed Nov 22, 2017 4:21 pm, edited 2 times in total.

art507
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Re: Little Phatty OSC wheeze

Post by art507 » Mon Nov 20, 2017 8:37 pm

Anybody has the same problem? :shock:

art507
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Re: Little Phatty OSC wheeze

Post by art507 » Wed Nov 22, 2017 3:39 pm

I made a short audio of the problem .
The first instrument on the audio is LP, and another one is Nord Stage 2.

https://www.dropbox.com/s/fvdpql7q2s1m8 ... d.wav?dl=0

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hieronymous
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Re: Little Phatty distorted / wheezy OSC

Post by hieronymous » Tue Nov 28, 2017 10:02 pm

I noticed the filter cutoff on my LP Tribute was scratchy and jumpy - it was kind of sticking and then jumping instead of being smooth and continuous.

I ended up "exercising" the knob, turning it back and forth like 40-50 times. Seems to have done the trick! Not sure if this is related to your problem but figured I should mention it. My LP is probably around 10 years old, and sits around a fair amount without being used. I have no actual knowledge that this is a legitimate fix for the problem I had, but I do know that it works for Alembic equipment that I own and is one of the first things to try when diagnosing the problem.

If I'm totally off-base, hopefully someone will come along and set me straight! :mrgreen: I have a track that I used a slow, long filter sweep on - when it gets posted I'll post it here for proof!

Ledbetter
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Re: Little Phatty distorted / wheezy OSC

Post by Ledbetter » Wed Nov 29, 2017 1:04 am

Overload at zero and no modulation of osc or filter?
Former owner of Prodigy #2845 (purchased new, long ago), Animoog, Voyager Select (Fire & Maple), Little and Slim Phatties, Nord Electro 4D, 5D and Lead 2X, Roland AX-9.

art507
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Re: Little Phatty distorted / wheezy OSC

Post by art507 » Wed Nov 29, 2017 1:30 pm

hieronymous wrote:!
Thank you !

art507
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Re: Little Phatty distorted / wheezy OSC

Post by art507 » Wed Nov 29, 2017 2:51 pm

Ledbetter wrote:Overload at zero and no modulation of osc or filter?
There is no modulation and overload is 0.
I understood what was the problem .I think is a grounding issue. When I plug LP and a Minitaur that I have in the same soundcard, I receive that wheezy/ buzzy sound . Also and that case I have a "Dancing Light " issue , that was observed at this forum.

The problem of grounding appears also when I put my LP to the MXR M222 talk box. The synth works fine with other pedals that I have. It Is a really strange thing :shock:

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stiiiiiiive
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Re: Little Phatty distorted / wheezy OSC

Post by stiiiiiiive » Wed Nov 29, 2017 5:24 pm

I had listened to your extract (on my laptop speakers ahem...) and did not noticed anything weird.

Now, about the dancing quee... huh lights problem, try to supply power to your LP and pedal (and sound card, maybe) from the same outlet.

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