Tascam M520 VU Meters

pitol678

New member
Hello everyone, This is my first post here but Ive been reading sweetbeats' epic "Tascam M520 Story" thread and have thoroughly enjoyed it. I picked up my 520 about a month ago and its in great cosmetic condition and sounds great and very 3D compared to what Ive been using which has thus far been a DAW, an interface and/or a Tascam 388. The routing has been a learning experience but its coming along, but one issue Im having is how to use the VU meters for setting levels. For instance, my assumption is that if I connect a Mic, I should be able to monitor the corresponding channel's VU meter to adjust my levels appropriately? I have been able to monitor using the solo buss with Aux 3/4 but the level changes depending on my solo buss pot's position, however at this time Im using each channel's direct out into my DAW (until I possibly get a tape machine later on) and would prefer to use the 520's VUs rather than the one's in my DAW. I do have the manual and have read through a great deal of it but have not found a solution to this yet. Any tips are much appreciated and thanks!
 
For instance, my assumption is that if I connect a Mic, I should be able to monitor the corresponding channel's VU meter to adjust my levels appropriately?

First off, welcome to the nuthouse. Sweetbeats epic thread is what brought me to this place too. He should get sign up bonuses :)

Your individual channels don't have metered monitoring. The channel has to be assigned to a buss (or busses)

The vu meters are monitoring the buss. Run the test tone to the buss and set whatever buss you'll use to unity gain.

The meters are flexible in that you can switch from internal to external sources, but those inputs are on rca jacks. That wouldn't be much good for a mic.

Ps. You will still want to use the meters in the daw. What is coming off of the console may sound great but too hot a level for your daw . Consider that your source.

However, since digital has NO headroom above zero, monitoring and adjusting your daw input levels is crucial. So you're gonna need to rely on daw metering as well.
 
Im using each channel's direct out into my DAW (until I possibly get a tape machine later on) and would prefer to use the 520's VUs rather than the one's in my DAW.

I don't know the M520...so the other guys here will give you more specific info about the mixer itself....but first off, why do you want to use the VU meters to measure/monitor the signal at the DAW...? I mean, why do you think that's of any value instead of just using the DAW meters, because regardless of what the 520 meters tell you, you would still end up at least checking what is happening at your DAW (and I think by "DAW" you really mean the meters at your DAW interface...yes?)

Also...if you are going direct out to the DAW interface...what's the point of even sticking the mic into the 520, since the 520 will have no effect on the signal...?
Why not just stick the mic into the interface...?...and then just bring the interface outs back to the 520 for monitoring/cue mixes.

If you are actually going to run the signal through the 520 before the DAW...then that's a different thing.

All that said...maybe I'm not fully understanding your thoughts/goals with the setup, so a little more info would help, once you have digested some of the manual info and you reevaluate your plans.
 
Thoughts to consider ^^^^.

But regarding metering/level monitoring, like RFR said the VU meters on the M-500 series monitor the PGM groups not the individual channels. Yes, you can, using an RCA cable, patch individual output patch points to the meters using the “EXT” controls on the meter bridge monitor the channel direct out, but the meters are averaging...they have peak LEDs too...but the O/L (overload) peak monitoring LED is what you want to reference for setting the input level to the channel (its source is...let me look at the block diagram again...post TRIM control and pre ACCESS SEND). Set put the channel fader to the shaded area, set your TRIM using your ears and that O/L LED and that should give you good signal to noise at the direct out without overloading the output...but use your ears. Use the PFL control to listen to the input post ACCESS and post EQ but pre fader, and use the SOLO control to listen to the signal post fade and PAN control.

Gain staging and level monitoring is accomplished by using a combo of peak indicators, averaging indicators and your ears. The last one is the most important. And you want to monitor levels at the inputs and the outputs...and ideally, on a channel strip with insert points and EQ, at a point post insert and EQ.
 
But regarding metering/level monitoring, like RFR said the VU meters on the M-500 series monitor the PGM groups not the individual channels.


This is similar to how the VU meters are on my Trident...they don't read the signals from the input channels, but rather from the 24 monitor channels, which would be getting their source from the deck playback. I kinda thought that was weird at first, considering that on my old TASCAM M3500 console, the metering was switchable with a press of the 4 selection buttons...and considering that a deck has its own VU meters, so why would it matter to see the same signal on the Trident VU meters...?...kinda redundant....but that's how they designed it for some reason.

When I first switched to the Trident...it had me all wonky with that, as I was so use to always seeing the input metering on the 3500...but frankly, after using the Trident a bit, I completely forgot about the VU meters, and except for the two main stereo output meters, I don't use at the other 24 VU meters for anything...which is a shame, considering there are 24 damn VU meters.
I don't even pay attention to them when using the 24 channels of the playback monitor section.
Of course...all those meters make the console look really cool. :cool:

When I'm mixing down through the console...I still have no need for the meters...as it's all been "metered" before on other pieces of gear...so I just pay attention to the main stereo bus meters, and use my ears. :D
Not to mention...when initially setting up the individual input channels for a mix, I also use the main stereo meters to calibrate levels per input channel.
After that, metering is really not important for channel inputs.
 
I don't know the M520...so the other guys here will give you more specific info about the mixer itself....but first off, why do you want to use the VU meters to measure/monitor the signal at the DAW...? I mean, why do you think that's of any value instead of just using the DAW meters, because regardless of what the 520 meters tell you, you would still end up at least checking what is happening at your DAW (and I think by "DAW" you really mean the meters at your DAW interface...yes?)

Also...if you are going direct out to the DAW interface...what's the point of even sticking the mic into the 520, since the 520 will have no effect on the signal...?
Why not just stick the mic into the interface...?...and then just bring the interface outs back to the 520 for monitoring/cue mixes.

If you are actually going to run the signal through the 520 before the DAW...then that's a different thing.

All that said...maybe I'm not fully understanding your thoughts/goals with the setup, so a little more info would help, once you have digested some of the manual info and you reevaluate your plans.


Thanks for the reply, lots of good points! In part, the reason I would like to use the VU meters was just trying to be sure they worked since Im just getting used to using a larger mixer with more routing options :) The other reason, is that the VUs are just a little easier to read since they're larger than the DAW meters (inside of Reaper as my interface is a Tascam 1800 and has no meters) and I was expecting to be able to set the preamp level (as I do on my 388). But RFR made a good point too in saying that the signal from the 520 may be too hot so I need to use the DAW meters anyway to set levels.

At this point Im thinking of the DAW as a tape machine and kind of working out how to use the M520's features and incorporating it into outboard gear as well as the best setup in general. So the reason Im not plugging straight into the interface is so that I can use the preamps and the features of the board and generally just learn how to use it. Your idea about using the board for monitoring/cue mixes is something I hadnt considered (or even know how to setup yet :p ) but I'll definitely give that some consideration. Thanks again!
 
Looking at the schematic...it appears the direct out is after the Pre/Inserts/EQ section...so yeah, I guess you can use the mixer to add some flavor to the signal before it hits the DAW.

That said...IMO (and no right/wrong)...during tracking I would go as "direct" as possible to my recording device with the signal, and bypass unnecessary circuits if they are not really needed.
IOW, unless you really want to use the preamp section of the 520, or to use the EQ...you would have a cleaner signal when bypassing the 520 and going straight to the DAW with your mic(s)...and then EQ the recorded tracks later, and/or during mixing.

I only say this based on many years of using a few different mixers, and usually bypassing it when tracking, unless I wanted to use the mixer's preamps for something...and instead, I would run the playback monitoring from the recording device back to the mixer so I can better create my cue/headphone mix.
During mixing, that's a different story...all my recorded tracks come through the console for the final mix. Of course, coming from the DAW, you need as many interface output channels as you plan to run through your mixer.

The mixer may also be good when recording, if say....you only have a 4-channel interface, but you want to record a whole drum kit using 8 mics. Then the 520 would be used to sub-mix the 8 mics down to 4 (or two) tracks that you record through the interface to the DAW.

Not trying to put you off about using the 520 in any way you find helpful...just making the point that especially with a DAW setup, don't feel bad if the mixer lays dormant most of the time.
I can do a lot of tracking, and only use my mixer for the cue/headphone mix....and then spend days in the DAW editing, and the mixer is never even powered up...and then finally when I'm ready to actually mix, and bring all those DAW tracks back out, will my console see some serious use. :)
 
First off, welcome to the nuthouse. Sweetbeats epic thread is what brought me to this place too. He should get sign up bonuses :)

Your individual channels don't have metered monitoring. The channel has to be assigned to a buss (or busses)

The vu meters are monitoring the buss. Run the test tone to the buss and set whatever buss you'll use to unity gain.

The meters are flexible in that you can switch from internal to external sources, but those inputs are on rca jacks. That wouldn't be much good for a mic.

Ps. You will still want to use the meters in the daw. What is coming off of the console may sound great but too hot a level for your daw . Consider that your source.

However, since digital has NO headroom above zero, monitoring and adjusting your daw input levels is crucial. So you're gonna need to rely on daw metering as well.

Thanks for the welcome! Yep totally agree he should get sign on bonuses lol

I wasnt sure about the individual metering, I think I was just expecting it to function like the 388 but how wrong I was :) I'll have to look through the manual some more to learn more about the test tone as thats an entirely new thing to me.
 
Thoughts to consider ^^^^.

But regarding metering/level monitoring, like RFR said the VU meters on the M-500 series monitor the PGM groups not the individual channels. Yes, you can, using an RCA cable, patch individual output patch points to the meters using the “EXT” controls on the meter bridge monitor the channel direct out, but the meters are averaging...they have peak LEDs too...but the O/L (overload) peak monitoring LED is what you want to reference for setting the input level to the channel (its source is...let me look at the block diagram again...post TRIM control and pre ACCESS SEND). Set put the channel fader to the shaded area, set your TRIM using your ears and that O/L LED and that should give you good signal to noise at the direct out without overloading the output...but use your ears. Use the PFL control to listen to the input post ACCESS and post EQ but pre fader, and use the SOLO control to listen to the signal post fade and PAN control.

Gain staging and level monitoring is accomplished by using a combo of peak indicators, averaging indicators and your ears. The last one is the most important. And you want to monitor levels at the inputs and the outputs...and ideally, on a channel strip with insert points and EQ, at a point post insert and EQ.

Sweetbeats Im sure you've heard this a lot, but your threads, especially the "Tascam M520 Story" and "Tascam M_ Story" are very interesting and packed with great info so thanks! Ive been taking off all the knobs and dress panels a section at a time and cleaning it based on your threads and its very satisfying to see how much nicer it looks not to mention that Im cleaning off 30 years of grime. I bought some Deoxit and had aspirations of taking out the cards and shooting it into the pots and switches, but once I tried to imagine disconnecting things I got intimidated pretty quickly and abandoned the idea for the moment. I'll do it eventually but for now I want to focus on learning how to operate her but really want to get into recapping as well. Ive built some mic pres, done some guitar repairs and can use a soldering iron, but the understanding the intricacies of cap values etc eludes me at the moment.

I tracked some vocals for a friend last night using some of the suggestions that were made here as far as gain staging and setting levels. It actually helped out a lot and enabled me to more quickly get levels since I wasn't so concerned as to why the VUs weren't functioning as I assumed they did. I still need to get my head around the PFL vs the Solo buss as far as why/how/what it does. Its a little abstract to me at this point but I'll get my hands on it and look at the diagrams and gain a better understanding Im sure. Thanks again!

---------- Update ----------
 
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Here's some food for thought from a longtime 520 guy,

Here's how my ancient desk fits into the modern world. :)

I'm running 2 interfaces and 16 track tape.

1) One interface is an allen and heath unit set up for stand alone. It has no preamps, just 16 analog in and 16 analog out. I could hook it up the computer as an interface but just use it as a tape machine.
It's hooked up so i can use it as a recorder, and so I can dump 16 tracks of tape to a harddrive which gets proceesed in protools or reaper.

Both can be mixed in the box or on the desk.


2) I have a focusrite interface hooked to the computer into protools.
This as well I can put back into the console for mixing.

3) My trusty MSR 16 tape machine is hooked up to the desk and the interface which is really acting as just an analog to digital converter.

So, as you can see, got lots of options.

The M 520 despite being an rca unbalanced -10db mixer has an 8 channel balanced amp option so you could hook up via xlr cables to an 8 channel interface. You would feed this via the 8 buss faders.

I haven't used this and wonder if the signal coming off the board into the interface would be too hot. Dunno, will have to experiment at some point.

I do know that the -10 db going into an interface works just fine. When it gets into the daw the signal is low but in digital that works out just fine. You can always bring it up with clip gain.

So in closing, I'm using my mixer as part of the "instrument into daw" signal chain. And often I'm using it as part of the mixdown.

But for recording, basically I get the sounds i want with the analog gear then send it into the digital world.


You brought up pfl and solo fuctions.
Solo takes what you have on the channel including any effects you have on the insert and you hear only that channel in its pan position.

Pfl brings that channel up in mono and before the fader.

I like to think if pfl being for tracking and solo for mixing.

One word of caution. Watch out when using headphones!!!!!

Whenever you push pfl or solo and that red light comes on, the orange solo volume controls the level. The green headpine volume does nothing! You can turn it down in a panic and still blow your ears and/or headphones out !

I make it a habit to keep both volume knobs turned down untill I'm actually using them.

You also mentioned cleaning and becoming overwhelmed.

You don't have to take it all apart to clean up the switches and pots. You can spray the deoxit through the top. Then with a shoelace or some string wrapped around the shaft 'massage' the pot.

It's very effective.

Hope some of this helps.

Read your manual, study it and watch some of sweetbeats videos. I think the yt channel is called sweetbeats tech stop.
 
Hi Pitol678 and yes, welcome!

Now, I am not in nearly the same league as Sweetbeats and the other guys here ref these old tape machines, just a 72yrd old tech' who has poked about in most things electronics, especially audio. I would like therefore to give my view on 're-capping'?

Can be a bit of a 'fashion' in many areas but I suspect these machines are mostly old enough to warrant it?
Before you get stuck in however do some homework and gather some test gear or software to 'spec out' the kit. Aged capacitor can cause the following problems..

1) loss of low frequency response. This is because as the cap falls in value its impedance rises and attenuates LF.
2) As well as LOSS of LF, a drop in value can cause an increase in harmonic distortion, this is due to two possible effects. Electrolytic caps ALL cause slight distortion but the higher the value, the lower it is at any given frequency but since the distortion in a tape path is many times that of say digital recording, the effect is likely never noticed. However, a reduced cap value CAN reduce Negative Feedback and that will increase distortion.
3) Failing caps can cause increased power supply noise or even in some cases instability. The latter can be hard to spot without an oscilloscope.

So, bottom line. You need to run a frequency response and distortion test to check that these parameters are up to specification. If they are 'good' there is little point IMHO in the protracted, possible damaging process of re- capping.

Note, if you DO replace any electrolytics, fit 105C types if you can. Likely bigger than MODERN 85C caps but probably about the same size as the originals?

Dave.
 
Dave, what the hell is the matter with you? :D
While you're very knowledgeable in all things electronic, you're just going to scare the shit out of him! :D

Let the boy get his feet wet, and learn how to swim out of the wading pool first. :D

Besides, mine has never yet been recapped and sounds great still.

They seem to suffer more from neglect and non- use. I can't prove or back this up, but i think one well maintained and in use, does better than one stored away.
They like juice flowing through them. :D
 
Dave, what the hell is the matter with you? :D
While you're very knowledgeable in all things electronic, you're just going to scare the shit out of him! :D

Let the boy get his feet wet, and learn how to swim out of the wading pool first. :D

Besides, mine has never yet been recapped and sounds great still.

They seem to suffer more from neglect and non- use. I can't prove or back this up, but i think one well maintained and in use, does better than one stored away.
They like juice flowing through them. :D

I think you have missed my point R'? I am saying DON'T re-cap just because people tell you you should. (in the same vein, with the possible exception of the 741, most modern op amps have easily good enough noise and slew rate performance for tape. The venerable NE5532 might be over 30yrs old but is still used in much high end gear) .

If you mean I have scared him about measuring FR and THD? These are THE defining parameters of the tape recording system. Performance is largely tied to a tape flux at 1,2, or 3%THD.

But! IF I have caused the chap pain and doubt? SORRY! NOT my intention at all!

Dave.
 
Hahaha :)
I get you, Dave. ... but

He's talking about figuring out routing and metering......in short, just learning 'how' to use this mixer. You're talking him into getting test equipment.
:D
Nothing wrong with that, I just prefer concentrating on the basics first.

:D
 
Hahaha :)
I get you, Dave. ... but

He's talking about figuring out routing and metering......in short, just learning 'how' to use this mixer. You're talking him into getting test equipment.
:D
Nothing wrong with that, I just prefer concentrating on the basics first.

:D

Well, (don't want to go on here but!) he DID mention 'servicing'? Getting in there, pulling boards, spraying pots? And HE did mention 'caps'.

To me that means he could be thinking/persuaded into re-capping and I wanted to forestall that process.
"Measure twice, cut (or in this case, solder) once!

Dave.
 
Lets see what the op has to say.:D
Right now it's just you and I dominating his thread. Lol :D

Eh. Slow morning for me. Only reason I'm on the net this early, is I'm tracking a pkg.

New mic....oh the anticipation.
 
Seeing how you guys are already heading the OP into techno-madness.... :D ...I'll just say that most people who don't want to recap a 20+ year old piece of gear, are usually convinced it sounds the same as it did 20 years ago. :p

Seriously though...it is certainly a PITA doing a recap on a larger mixing console, and while the differences may be subtle, they may also be obvious too.
When you use the same piece of gear over a 20 year period (or longer)...the degradation slow and your ears adjust with it, but there may also be a point where you "suddenly" realize that the sound coming through it seems duller and not as transparent.

Considering that even some od today's high quality caps only have a 15 year shelf life before they start to drift off spec...when you get something that is 20-30 years old, you can be sure the caps have drifted, and the bigger issues with a console is that they may not all have drifted equally....so the channels all sound a little different.

I know with my old TASCAM M3500...I was starting to hear the age of the mixer about 3-4 years before I swapped it out, and had I kept it, I would have done the recap on it...which on that console was a real PITA considering how the channels cards were all grouped I fours. Instead, I did the recap and rechip on my :new" console, where it was a lot "easier", and certainly well worth it.

Still...I would start by using the gear, and doing some tests and comparisons before rushing to any mods and such.
 
...I'm tracking a pkg.

New mic....oh the anticipation.


What did you get?

I'm also tracking a package from your side of the country...a couple of NOS Quantegy 499, 2" tapes....but it looks like they get here tomorrow. :)
 
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