Model 12 Distortion

[kwest]

Hi-

I'm having this weird phenomenon, where suddenly (as of last week), my model 12 (had since october) sounds likely distorted via speakers and headphones. I've checked gain and input levels to confirm the signal is not coming in too hot, but to no avail. Everything plays back with low-level distortion that I cannot figure out. I initially thought it was my speakers, so I listened through headphones and hear the same thing. This happens regardless of the channel.

Could my Model 12 be blown out?

I saw someone else mention distortion at certain frequencies in this forum, but their issue seemed a little different. Any insight?

 

[madem]

Have you tried the latest firmware. As you say, my distortion doesnt sound like yours, but the latest firmware update has almost completely got rid of all my issues.

Worth a try.

 

[madem]

From TASCAM regarding this issue...

"We are sorry, but still are unable able to reproduce this issue, although we and R&D tried to reproduce it on all available PC's available.
We would therefore like to ask if you would instruct all the users on the Tascam forum who are reporting the same phenomenon to send a post to: audio-support@teac.de
providing all the relevant details about how and when this issue occurs, what Apps are running in parallel, what hardware is used, what CPU, what mainboard (if known) what USB Chipset, is there anything else connected via USB,…
We will then study all the collated information with our R&D team,"

 

[AltTuning]

The closest thing I'm experiencing to what you're describing is as follows (this sounds different than the digital "glitch" sound I'm having):

When mastering a track in Reaper, I have Youlean Loudness Meter on the output after Ozone. I work in Ozone to set a -1.0 true peak maximum and work with the compressor and limiter in Ozone so that I see -1.0 dBFS true peak max in Ozone, Youlean and the Master bus -- LUFS integrated for a loud passage is -12.3, -8.5 momentary max so I'm confident I'm not clipping in Reaper. The Reaper Master bus, channels 1 & 2 and the Main fader are all set to unity so theoretically it should pass through at the same level, but I hear distortion in my headphones that sounds like clipping. Unlike what you describe however, dropping the faders on 1 & 2 down to -5db and compensating with the headphone output fixes the distortion for me, so I suspect the faders aren't calibrated at unity quite right.

Any chance you have something along the signal path that's clipping the signal? In my example, with Reaper sending via the ASIO driver I know levels should not be touched, but in contrast if I use another Windows application like the default Groove music player I have no idea what 100% on the volume translates to (VLC actually shows you 100% vs boosting on the volume slider so that might be a good test app), so that's a nice one to use), plus if it's going out the Windows audio driver, it's going through the level settings in the Sound Control Panel where 100 is not unity. I'm guessing unity is closer to 80 or so and anything above that is boosting, so if I mess with that setting and play music it'll clip before it even hits the Model 12's channel strip.

Good luck, I hope this helps.

 

[-mjk-]

@AltTuning after reading about your Reaper processing chain, I'm also confident that you're not clipping inside of Reaper.

 

[AltTuning]

I don't think this is kwest's issue, but I think I figured out what may be happening in my case.

With audio from Reaper going to channels 1 & 2 I have to pan them respectively to left and right -- instead I just changed Reaper's main output to 9/10 and the overall level on the MAIN meter is lower and doesn't clip. Also, on 9/10, pan centered and fader at unity nothing changes when I solo that channel.

I remembered the following in the manual: "When PAN knobs are centered (C), signals are reduced by 3dB and sent to both left and right MAIN MIX L/R buses."

Based on comparing the levels of 1/2 panned L/R vs. using stereo track 9/10 I suspect that 3dB of gain is added when panned hard left or right as opposed to 3dB of gain being reduced at center -- a subtle, but important clarification to the wording in the manual. I can also not peak by leaving them centered and only listening to channel 1 or channel 2, but they peak if listening to both as they add up without proper panning applied.

Now if only there was a way to send all Windows audio to either 9/10 or 7/8 easily instead of 1 & 2... =D

 

[Mark Richards]

...I remembered the following in the manual: "When PAN knobs are centered (C), signals are reduced by 3dB and sent to both left and right MAIN MIX L/R buses."...Based on comparing the levels of 1/2 panned L/R vs. using stereo track 9/10 I suspect that 3dB of gain is added when panned hard left or right as opposed to 3dB of gain being reduced at center ...

The OM is stated correctly. The voltage/digital equivalent is 3 dB below unity gain when the pan control of a mono channel is centered. That's how pan circuitry on a mono circuit is designed to function. The mono track pan circuit reaches unity gain when panned full left or full right.

The "pan" control on a stereo circuit is a balance control. A balance control has unity gain when centered, and attenuates the signal on one side as the balance changes in favor of the other side. There's no increase over unity gain as balance changes, only a decrease from unity gain as the signal is attenuated.

 

[-mjk-]

That characteristic prevents center-channel build up.

 

[AltTuning]

I just experienced what sounds similar to the original poster's symptom:

I went to use my Model 12 today and despite seeing signals coming through to the M12 at regular levels (around the line on the meter screen and zero on the main meter) I didn't seem to be getting audio out of the the headphones or speakers hooked up to the sub out. Turning up the volume all the way on the headphone output I could start to hear audio, but before it got to anywhere near regular output it started sounding distorted. I tried both audio from the computer (Windows apps as well as Reaper projects I was just working on last night with no problems) and also playing a song I recorded on the MTR -- same symptoms, very, very quiet in level but distorted when turned up all the way.

Fortunately this fixed the issue for me -- I powered the M12 down, unplugged everything connected to it including the power and also disconnected the cord from the power supply. I then reconnected the power and my headphones and tested MTR output and all was fine so I hooked everything back up and it seems normal.

Hopefully this is not a normal behavior...

 

[AltTuning]

Mark -- Thanks for the info -- that makes sense, but I'm still a little stumped as to how a signal that shouldn't be clipping, like output from a Reaper project I'm measuring on 3 different true peak meters or a professionally-mastered track played on an ASIO-capable player like RX, clips when output 1 is sent to track 1 panned hard left and output 2 is sent to track 2 panned hard right with everything set to unity.

Fortunately the fix is relatively-simple by sending the output to tracks 7/8 or 9/10 instead as that does not clip so I'll stick to that method when doing anything where I need to check levels closely.

 

[Vinibc]

Guys, I have a Model 12 I use it as a recording interface in a daw. I wanted to know if it is possible to record through the model 12 on the daw using its equalizer, effects, compressor. I couldn't do that, I can write flat only. Does anyone know if this option exists? Sorry for my English, I'm using a translator, I'm Brazilian. Thank you very much.

 

[AltTuning]

Vinibc,

Have you tried recording channels 11 and 12? Those would be the default output of the master mix -- send everything you want to the master bus how you want it to sound and record that output. Alternately, if you have the USB mode set to send the master mix to channels 1 and 2, those would be where you want to record in your DAW.

If I want the master mix in my DAW I do it a different way, which isn't actually recording in the DAW -- not sure if you know that if you record with no tracks armed the M12 records the master mix to channels 11 and 12 WAV files, which you can then import into your DAW for additional processing like limiting, fades, etc. You can also export the master mix to a stereo file, which will be in your music folder on the M12's storage instead of in the song folder itself.

Hopefully one of those options gets you pointed in the right direction.