Mixers/Consoles Yamaha 01V Omni Out Noise Floor?

[simoneves]

First time poster... be nice to me...

I am the sound engineer for a small community theatre group which operates at two different theatres. In one, we use the house system, which is based on a fairly recent Mackie 24-channel analog board.

For the other, we use our own original Yamaha 01V feeding the house Meyer Sound powered speakers, three across the front, from main L and R, and from a Bus mix routed to one of the Omni outs. I use other Bus and Aux mixes to the other Omni outs to drive stage and band monitors, and very recently for recording to a Zoom H4n digital recorder (XLR in as well as on-board stereo condenser mics).

The problem I have is excess digital noise on the Omni outputs. I have often noticed noise on the stage monitors but put it down to dodgy house cabling or some other analog problem. However, this past time I ran my own known-good cables and the noise was still there.

Worse, when I tried to run a mono wireless-mic-only mix to the Zoom in order to get a third clean vocals channel to mix into the on-board stereo, the recording as unusably noisy, even though the level coming out of the 01V seemed to be plenty hot enough. This mix was to "Bus 1" internally, which I'm guessing meant that it got the L part of each mono wireless channel (all of which were panned centre so that they came out of Main L & R).

I messed around with the routing and found that the noise was present even if all the input channels were muted (which I'm assuming is a digital mute), but went away if I de-routed the channels from the Bus in question.

The Main L & R outputs, on the other hand, are dead quiet.

Does anyone have any experience with 01Vs behaving like this? I'm familiar with digital audio processing and the need to keep levels up to avoid quantisation problems, and the limitations of older DACs, but the noise I'm hearing is at a much higher floor than I'd expect. I have no idea what the internal architecture of the 01V is, but surely digital is digital and there's no real way for anything to go wrong with the summing mechanism such that some parts would be noisier than others, and my original assumption was the the Omni outs were dying in an analog manner (or just that they had crappy DACs) but the fact that the noise goes away when I de-route channels from the Bus seems to go against this.

I completely love the mixer in every other way (it's 15 years old and has needed nothing more than one replacement fader motor a few years ago) so I'm hesitant to scrap it in favour of something newer and (maybe) quieter.

I have a Behringer ADA8000 box which can hook up with ADAT to get extra/alternative/quieter outputs, but that would be a P.I.T.A. for general use.

Thoughts? I'll keep playing with it, but any input is welcome...

Simon Eves
Stapleton Theatre Company
San Anselmo, CA

 

[Footer]

The original 01V (the white one) had pretty horrible head amps... and that is what you are expereincing. As they age, they get nosier. That console is not worth doing any type of repair on. You got your money out of it, time to get a new console.

 

[simoneves]

The original 01V (the white one) had pretty horrible head amps... and that is what you are expereincing. As they age, they get nosier. That console is not worth doing any type of repair on. You got your money out of it, time to get a new console.

Sorry to be dumb, but what specifically do you mean by "head amps", please? Do you mean the channel 1-12 mic/line ins?

What I don't get is how I can get a perfectly clean and quiet mix out of the mains at roughly the same mix levels from the same channels routed...

 

[Aman121]

Sorry to be dumb, but what specifically do you mean by "head amps", please? Do you mean the channel 1-12 mic/line ins?

What I don't get is how I can get a perfectly clean and quiet mix out of the mains at roughly the same mix levels from the same channels routed...

Head amp is another term for mic preamp. I never really was a fan of yamaha boards, way to sterile sounding for my taste. As for your noise issue, I really don't have an idea, other than your oldish console may be reaching the end of its life. Perhaps the aux out line amps are going bad? That might explain why the problem isn't present on the main outs.

 

[simoneves]

Head amp is another term for mic preamp. I never really was a fan of yamaha boards, way to sterile sounding for my taste. As for your noise issue, I really don't have an idea, other than your oldish console may be reaching the end of its life. Perhaps the aux out line amps are going bad? That might explain why the problem isn't present on the main outs.

Could be, but it's not an analog noise. It's a digital quantisation thing, like a bad cellphone connection, and it's only there with a signal present. There's no white noise analog hiss. With a quiet (not that quiet) signal, there's twangy digital distortion. With a loud signal, it sounds OK. It's like there's not enough resolution (bit-depth) in the digital signal. Maybe one of the lines of the data bus into that DAC chip is stuck or something...

Granted, I'm not certain. I could also be some strange non-linear failure mode of the analog line amps on those outputs, but all four sound exactly the same, and I would still expect to hear analog noise all the time, not just when there's a quiet signal.

But OK, whatever it is, it's probably age-related. Like I said, it's a first-gen from 1998-1999. Hell, I've owned it eight years myself, and rented it regularly from its previous owner for two years before that. Maybe a dying capacitor on the DAC power feed, like all those problems with PC motherboards a few years ago. Not a bad run for the $400 it cost me to buy, I suppose. I'd just hate to have to scrap it...

Shame I would have no idea what to replace it with... I like the look of the Presonus StudioLives, but I'd miss the powered faders. What does Yamaha make at that price point these days? I can't afford an LS9, that's for sure.

 

[Aman121]

Could be, but it's not an analog noise. It's a digital quantisation thing, like a bad cellphone connection, and it's only there with a signal present. There's no white noise analog hiss. With a quiet (not that quiet) signal, there's twangy digital distortion. With a loud signal, it sounds OK. It's like there's not enough resolution (bit-depth) in the digital signal. Maybe one of the lines of the data bus into that DAC chip is stuck or something...

Granted, I'm not certain. I could also be some strange non-linear failure mode of the analog line amps on those outputs, but all four sound exactly the same, and I would still expect to hear analog noise all the time, not just when there's a quiet signal.

But OK, whatever it is, it's probably age-related. Like I said, it's a first-gen from 1998-1999. Hell, I've owned it eight years myself, and rented it regularly from its previous owner for two years before that. Maybe a dying capacitor on the DAC power feed, like all those problems with PC motherboards a few years ago. Not a bad run for the $400 it cost me to buy, I suppose. I'd just hate to have to scrap it...

Shame I would have no idea what to replace it with... I like the look of the Presonus StudioLives, but I'd miss the powered faders. What does Yamaha make at that price point these days? I can't afford an LS9, that's for sure.

Studio lives are a bit overrated IMO. Not bad boards, but id rather have a true digital with motorized faders instead of something pretending to be digital. I'm really not a digital guy at all but many companies are working to bring digital consoles to the masses. Maybe take a look at the behringer x32. Despite behringers rep it actually appears to be a solid piece of gear. It may also be worth it to have your old yammie board looked at, perhaps it just needs a firmware re install?

 

[simoneves]

The X32 looks amazing. I too, am wary of Behringer's rep, although nothing of theirs that I own has failed me yet, but it reviews well and maybe there's enough Midas DNA in there to make it a safe bet. I just don't have $3000 to spend right now, unfortunately. I shall play with the faithful 01V a little more before giving up...

 

[FMEng]

This is only a guess on my part...

In that era, digital summing may have been limited by the processing capabilities of the DSP chips of the day. On secondary busses, they may have simply truncated less significant bits to reduce the computational horsepower required, or they may not have added proper dithering, which affects the detail of the audio as levels near the digital noise floor. Those consoles were really pushing the limits of the technology for the time.

 

[simoneves]

This is only a guess on my part...

In that era, digital summing may have been limited by the processing capabilities of the DSP chips of the day. On secondary busses, they may have simply truncated less significant bits to reduce the computational horsepower required, or they may not have added proper dithering, which affects the detail of the audio as levels near the digital noise floor. Those consoles were really pushing the limits of the technology for the time.

I thought that too, but I'm sure I have got a clean signal out of those outputs in the past, although I don't think I've tried to record from it before (and therefore heard the actual output on headphones, as opposed to a stage monitor speaker which was pretty buzzy anyway). Also, like I said, the level to those outputs was way up beyond where you'd normally expect quantisation or the lack of dithering to be audible.

I'm going to drag it out of storage at the weekend and play with it some more. Thanks, all, for your input.

 

[TimmyP1955]

Sounds like you need to run your bus level higher, and reduce the master. Or maybe even run the bus levels higher and passively attenuate the signal before it hits the recorder.

 

[simoneves]

Sounds like you need to run your bus level higher, and reduce the master. Or maybe even run the bus levels higher and passively attenuate the signal before it hits the recorder.

I tried that at the time. The Omni Out meters were showing peaks up to the -6 line. I figured that was plenty. The same levels were going to the Main, and that was dead quiet.

This is all speculation, though, as I still haven't had time to dig it out of storage and play with it again to try to recreate the problem.

Meanwhile, an X32 or a 24.4.2 is looking mighty appealing...

 

[avkid]

A used 01V96 V2 can be had for around $1200 lately.
The updated version of your console and you can still use your ADA8000.

 

[DSPROD]

I know this an old thread but it helped me so I thought I would share what I found with the same issue. I am getting noise across all my quarter-inch outputs and my two-track RCA jacks. As I tested further I am not having noise out of the XLR or the SPDIF COAX outputs. So my guess without getting any deeper into it is that the quarter-inch outputs are tarnished or rusted so the contact is not very good. In my case, I can use the SPDIF but your post helped my troubleshooting thanks.