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Unofficial Mackie User Forums => Analog Mixers => Topic started by: plz on August 18, 2013, 06:07:27 PM

Title: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: plz on August 18, 2013, 06:07:27 PM
Has anyone actually checked this? According to the manual (pg10) & every review I've seen, all outputs are said to be balanced... but I was checking my new studio wiring with a scope and found nothing was coming out of any of the TRS cold (ring) connections except for the Main outputs, i.e. the direct outs, aux sends, subs and the control room outputs all appeared to be unbalanced.
I checked the circuit diagram in the user manual and sure enough, all outputs apart from the main outs only feed the hot output; the cold appears to be connected to earth via a resistor.
Am I missing something or is there some deception going on?  ???
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: RoadRanger on August 18, 2013, 08:00:07 PM
No deception - just confusion. Those outputs are "impedance balanced" - the theory is that the resistor matches the impedance of the cold output pin to the impedance of the hot output pin, hence a balanced input will work almost as well with it as a true balanced output :).
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: plz on August 19, 2013, 07:09:26 AM
Many thanks RoadRanger - it's all becoming clear now. Have heard the term before but never understood how it worked. So the fact that the cold wire can now 'float' means interference noise on the cable will still cancel out at the balanced input end... but you sacrifice the signal-to-noise benefits of the larger voltage swing from two out of phase signals. It's a nice simple trick with one resistor - seems the Allen & Heath mixer does the same thing but the manual uses the terms 'differentially' and 'impedance balanced' so is a lot clearer (although not as humorous as the Mackie :) ).

This has scuppered my idea of verifying the new wiring by checking the hot & cold levels at the patch panel end - if there's no signal on the cold when it's behaving normally, how can you check it's wired ok? The non-pedants might say who cares; you wouldn't hear any difference and it's only the noise immunity which would suffer, but that's just me :facepalm:
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: Greg C. on August 19, 2013, 10:19:34 PM
So the fact that the cold wire can now 'float' means interference noise on the cable will still cancel out at the balanced input end... but you sacrifice the signal-to-noise benefits of the larger voltage swing from two out of phase signals. It's a nice simple trick with one resistor - seems the Allen & Heath mixer does the same thing but the manual uses the terms 'differentially' and 'impedance balanced' so is a lot clearer (although not as humorous as the Mackie :) ).

Impedance balanced outputs have been used for decades now to save money and provide comparable CMRR of active balanced outputs. balanced lines are not about having both hot and cold be active, they're about having matched impedance relative to ground. Most people don't need the extra 6dB of gain that active balanced outputs provide. As for degraded S/N, that may not be true. In theory you would lower the noise floor by 6dB with double the voltage swing. However, the active output circuit on the cold line adds some noise, so it's probably a wash.

This has scuppered my idea of verifying the new wiring by checking the hot & cold levels at the patch panel end - if there's no signal on the cold when it's behaving normally, how can you check it's wired ok?

You can measure the resistance from the hot and cold lines relative to ground if you want to make sure your line is balanced. If you want to make sure your point to point polarity and lines are correct, get something like a Rat Sniffer/Sender pack (http://soundtools.com/xlrsnifsend.html) with the appropriate adapters in and out of your patch bays to make sure your wiring is good.
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: plz on August 20, 2013, 04:47:21 PM
Impedance balanced outputs have been used for decades now... ...balanced lines are not about having both hot and cold be active, they're about having matched impedance relative to ground.
Thanks for the clarification Greg. I've used them for years but never fully appreciated them - it was only this recent re-wiring exercise which showed up my lack of knowledge. When the previous layout was wired, a cold connection was missing on an active balanced output - the signal was still there but the level had dropped and I spent ages tracking it down; it was then that I incorrectly presumed all balanced outputs were differential. This time round I tried to be clever by checking all hot & colds first - that'll teach me :-[

You can measure the resistance from the hot and cold lines relative to ground... ...get something like a Rat Sniffer/Sender pack to make sure your wiring is good.
These sound good ideas so I'll get on with the testing.
Thanks to all for your quick help on this - the Mackie is exonerated.
Phil
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: WK154 on February 16, 2014, 05:25:16 AM
In case anyone ever cares I was looking at the CR1604 VLZ schematics and found that mains L&R and Mono out are in fact active balanced outputs the rest are impedance matched in the days where the magic # was 120ohms. Cheers.
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: Kev tyler on December 26, 2014, 11:48:23 AM









Does the onyx pre amp in the cheapest mackie  mixer sound the same as the most expensive?
Kev
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: Kev tyler on December 27, 2014, 10:20:54 AM
I think what I am saying is this, I regularly use the 1640i, thought of purchasing the 820i but have now noticed they are flogging the onyx preamp in the guise of vlz, without parametric eq, it's not really the same channel is it?


Sent from my iPad using Tapatalk
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: WK154 on December 27, 2014, 04:58:42 PM
The difference is that the 1640i has a 4 band eq vs the 806 3 band Perkins. The older VLZ has fixed Q (3 band) as opposed to the variable Q in the Perkins. The difference on vocals is not that much unless your into distortion and effects so money is better spend on a better mic match to vox than mixer.
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: Kev tyler on December 27, 2014, 05:01:13 PM
Thansk

:)
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: Kev tyler on December 28, 2014, 09:49:51 AM
Sorry

Thanks wk, I have nice mics, I have always been a bit against mic  channels without parametrics as I seem to find these on cheap thin sounding desks, and to be honest I have often ruled out the purchase of more up market desks equally without sweeps due to the often lack of built in fx, which ultimately forces you in to lugging a 2ft and over square case everywhere you go in order to contain the separate 19 inch reverb unit you have to buy.

So I am in a bit of dilemma right now, when I work with my band I use either the large onyx or a midas desk, and the stage is ours, supporting acts have to fit in around us, and that's great, the problem is when I am the solo support act and I roll up with gear that does not either fit in my allocated space or impose a health and safety risk. Hence the constant craving for the non existent products I keep hinting about.

As I said a while back, I think the dl with its secure home for a pad is my best option, despite the bells and whistles of the new x range, only the largest mixer in the  x range is going to offer a safe place to leave a 500 dollar euro pound ipad, and some amount of diy tinkering will be required to ensure the pad is still there when you come back from the toilet etc.

Thanks

Kev

Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: RoadRanger on December 28, 2014, 03:52:38 PM
[...] often lack of built in fx, which ultimately forces you in to lugging a 2ft and over square case everywhere you go in order to contain the separate 19 inch reverb unit you have to buy
That's not true - I used a Alesis Picoverb with my 1604. It's tiny and sounds better than the DL's FX IMO.
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: WK154 on December 28, 2014, 06:22:04 PM
I'd recommend the Nanoverb 2 since it also has the much desired foot-switch and a ton more effects.
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: RoadRanger on December 28, 2014, 06:56:27 PM
I'd recommend the Nanoverb 2 since it also has the much desired foot-switch and a ton more effects.
Yup - but the Picoverb sounds better (24 bit vs 16 bit) and most just want a simple chorus/reverb.
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: WK154 on December 28, 2014, 07:14:11 PM
I'd recommend the Nanoverb 2 since it also has the much desired foot-switch and a ton more effects.
Yup - but the Picoverb sounds better (24 bit vs 16 bit) and most just want a simple chorus/reverb.
Actually it's a 18 bit system and of course the rest is individual opinion and there are lots.
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: RoadRanger on December 28, 2014, 08:01:30 PM
Actually it's a 18 bit system and of course the rest is individual opinion and there are lots.
Picoverb is actually 28 bits internally with 24 bit converters, Nanoverb 18. I've never compared the two but many say the Pico sounds better. I do know it sounds better than the FX in a MixWiz, I assume it is convolution based. Dunno if the DL has enough processing power left to run that?

Nanoverb 2 looks to be better than both :) .

EDIT> Or not :( : http://www.mattborghi.com/2014/08/06/alesis-nanoverb-2-review
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: WK154 on December 28, 2014, 09:39:14 PM
Actually it's a 18 bit system and of course the rest is individual opinion and there are lots.
Picoverb is actually 28 bits internally with 24 bit converters, Nanoverb 18. I've never compared the two but many say the Pico sounds better. I do know it sounds better than the FX in a MixWiz, I assume it is convolution based. Dunno if the DL has enough processing power left to run that?

Nanoverb 2 looks to be better than both :) .

EDIT> Or not :( : http://www.mattborghi.com/2014/08/06/alesis-nanoverb-2-review
It's always good to put it into perspective and live sound applications are certainly different from studio apps. The Nano has a 52bit DSP for internal processing and 18 out is more than you need for live sound. Matt is just one of many opinions or sour grapes. From what I understand the DL has 70-75% power in reserve. Most of the recent changes fell on the Blackfin not the DSP.
Title: Re: Mackie 1604VLZ-Pro - are balanced outputs really balanced?
Post by: Kev tyler on December 29, 2014, 12:33:33 PM
Hi guys

I have a quadraverb here, the audience didn't complain about the reverb 20 years ago when I bought it, I doubt they will now, much of my work is outside and prone to odd reflections anyway, the boards are all separate and I might just try disconnecting the edit boards and hoping the main module will still function and  fit in a smaller case, and house it under my next mixer purchase if it's small enough to warrant that,

Thanks for the suggestions

Kev