5U TM3030 output volume.

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eggpie
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5U TM3030 output volume.

Post by eggpie » Mon Nov 11, 2019 3:16 pm

Hi folks.
I've had my TM3030 finished and tested for a while but only recently fitted it to its 5U panel and into my modular alongside two ASVs and a handful of 5U modules. The output of the TM3030 is really quiet, especially compared to the ASV main out. It measures about -0.5 to +0.5v, peaking about +-1v with high res and accent on my ancient scope. Does this sound normal? The actual sound is great, with no obvious noise even though it's in a wooden case (earthed alloy front and rear panels of course).
The user guide says the OP is faithful to an original 303 and that loading the OP with different impedances can alter the sound. How can I do this? Is it possible to alter the OP level by changing resistor values in the OP stage. If so, which ones? Any ideas greatly appreciated of course, it would be convenient to have an OP level similar to the ASVs.
If anyone fancies a 5U TM3030 MOTM panel, I'll try to attach the FPD.
Attachments
TM3030.fpd
Vol, Tune, Wav switch via fly wires.
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Synthbuilder
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Re: 5U TM3030 output volume.

Post by Synthbuilder » Tue Nov 12, 2019 4:39 am

eggpie wrote:The output of the TM3030 is really quiet, especially compared to the ASV main out. It measures about -0.5 to +0.5v, peaking about +-1v with high res and accent on my ancient scope. Does this sound normal?
That sounds about right. The TM3030 produces only standard instrument level signals which are about a tenth of what most 5U modules will produce. It's not really possible to change the output level on the TM3030 to get to the same levels as those on a modular without adding circuitry. A simple op-amp non inverting amplifier with a gain of around five will do the trick but you'll need to access the +/-15V of your modular to power it.
The user guide says the OP is faithful to an original 303 and that loading the OP with different impedances can alter the sound. How can I do this?
You can add to the loading of the output stage by putting an extra resistor in parallel to R108 on the TM3030 PCB. Try playing around with resistors in the region of 4K7 to around 100K - maybe even a variable resistor. The smaller the resistance the more bass cut and rougher sound. It's fairly subtle until the loading gets extreme at the very low resistances. I think there are better ways of getting that sound by using an external distortion unit, like the Oakley Overdrive-II, or deliberately overdriving a pre-amp.

Tony

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eggpie
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Post by eggpie » Tue Nov 12, 2019 4:46 pm

Hi Tony.
Thanks for your reply and insight. I tried the TM3030 thru the overdrive-II and it does give it a great deal of grit. Very easy to overdo it though.
I've never heard a real 303 'in the flesh' but the TM3030 does sound cool. If you ever decide to produce some more, I would definitely build another.
Cheers. :yay:

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tvh
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Post by tvh » Wed Nov 13, 2019 6:41 pm

My standalone TM3030 is pretty quiet, so I agree it's probably par for the course. I run it through a Metal End distortion pedal which increases the output substantially and really makes it scream. I'm not sure I'd build another though because I was hitting analysis paralysis with deciding what parts to source. :hihi:

I preordered the Behringer TD3 so I'm excited to do a comparison. I have been using the TM3030 on every jam session lately - just easy to get great, usable sounds from it.

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