DSI Tetra Annoyance/Possible Issue

[lewdie]

I bought a used Tetra and received it in good working order. However, every patch seems to produce some extremely undesirable noise. This occurs even on an init patch. I am not sure if this is a natural byproduct of this synth or what. I have uploaded a sample of 3 diff patches. Listen particularly to :17. I am manually adjusting LPF throughout the sample. http://chrisandjenna.com/jasiu/tetra_noise.mp3

[lewdie]

I should also mention that I have connected headphones in and am able to reproduce the same results.

[justinvm]

There's an automatic calibration procedure for the tetra. Try that.

[lewdie]

Tried the calibration and it's still the same. Call me crazy but I believe I can detect the artifacts in the Dave Smith demo. You can hear it clearly @ 1:01... Nobody else who owns a Tetra can confirm?

Thanks!

[TrondC]

only noise I can hear in the youtube vid @1:01 is the metallic distortion that occurs on most youtube videos when faced with powerful bass.. as for the audio demo, I have no idea. kinda hard to tell what's the patch and what's the noise tho. could you upload an example using a dead basic square wave?

[masstronaut]

Is that the feedback?

Do you need to check the feedback mix / level?

If you can't get rid of it then maybe something is wrong.

[lewdie]

Here's a square (PW50) sample with everything off, including feedback. The artifacts are more pronounced as the resonance is increased.
http://www.mediafire.com/?jwzwyhziwm0

[masstronaut]

If you still have problems with it, get in touch with Dave Smith Instruments, they are usually very helpful.

One thing, is it the same on all voices?

[masstronaut]

Is it that whole low rumble you are talking about? I mean, that doesn't sound right, but also could be to do with the feedback line. Either that or a filter is faulty, but in that case I'd expect it to be different on other voices.

[lewdie]

This is apparent on all voices, yes. I will give DSI a call. Thanks a lot.

[justinvm]

s**t!

This just happened to my tetra.

After jamming for about 2 hours.

Let me know what Dave Smith says?

I think it overheated.

[justinvm]

By the way this isn't just an annoyance.

It sounds exactly like the filter is being modulated by a high frequency oscillator when the resonance is cranked.
The distortion seems to constantly build and decay at low frequency. Resonance is completely out of whack.

Calibration does not resolve the issue.

It's happening to all 4 voices so it has to have something to do with the final output stage.. or what is driving the filter modulation on all 4 voices. My guess is that it's what is driving the filters. Maybe something wrong in the D/A stage. Good news is it could be a software issue due to the consistency over the 4 voices. I could only hope!

Really bizarre.

Quite annoyed. I live in Australia so if repair is needed ill be shipping this back overseas.

[justinvm]

Ok Weird.

After a couple of hours the problem has corrected itself completely.

Maybe it's a power supply issue?

[lewdie]

I wish I could say mine went away... DSI is asking me to send the samples to them for a listen. Any chance you could upload a square wave sample like the one I put up here (tetra_noise2)? I'd like to hear what a normal Tetra sounds like for reassurance.

[gosh]

just seen this..I've not noticed anything but at work so can't hear your examples. Will check over weekend, and post some examples of mine! Bit worried now!