Help with a Tascam 312B please

[GlowPlug]

Well, I finally scored a nice minty Tascam M312B!!!! Its in great shape, and comes with the infamous phantom power! I'm totally siked~ I think that it will go nicely with the TSR-8 that I am hopefully getting soon.

But unfortunately I don't know how the darn thing works!!!! I have always wanted a nice heavy duty analog mixer. I'm new to all this analog stuff, and I'm totally clueless on how to get sound out of this thing. I have ordered the manual but, it wont be here for a week or two, and I would like to check out and see if any of the pots are scratchy, and if all the XLR inputs and VU meters are working.

Duh, I feel like a 'Kentucky Fried idiot', but when I turn it on, and plug a mic into the XLR inputs I cant get any sound through the headphones.

Can someone kinda give me a short checklist on what buttons and knobs need to be pressed to get this thing going, and maybe how to check out some of the inputs to see if they are working?

Sorry for such a brain dead question. I promise once I get the hang of this things, I will come up with much better questions . Many thanks

 

[The Ghost of FM]

Plug Mic into rear channel input.

Ensure rear panel phantom power slide switch, assigning two channels at a time, is on or off depending on microphone's requirement.

On top panel for the Mic's channel, ensure that the Line Button is off in the up position of the push button.

Turn the Mic's trim control to the mid position to ensure modest electrical gain at this first pre stage.

Down close to the channel's 100 mm linear fader, ensure the fader is up to the hash mark area of it's slide range, (7 - 8) and turn the channel on be pressing in on the "ON" button.

In that same vicinity, depress the orange stereo buss button so that the channel's signal feeds the stereo buss.

Slide the master L & R faders to the same hash mark area.

On your headphone pushbutton selector strip, press the orange stereo button in and on, turn up the gain control on the headphones, ( this control is right by the button you just pressed.

Talk in the microphone and if it works, move on to the next channel on the board and repeat the steps above.

.....................................

If you do encounter scratchy pots, try rotating them back and forth several times before you resort to using cleaning chemicals on them...same thing goes for the switches: push them on and off several times to work out the crap.

Cheers!

 

[GlowPlug]

Excellent! Thanks very much Mister Ghost! I appreciate you taking the time to write all that out. It helps a lot.

So, if I don't get any sound from the headphones (cause the guy who sold it to me, did say that the headphone plug might not be working) is there a way to check out the individual channels through a pair of monitors? I have an small pair of powered monitors that I could plug in.

Also, when I test each XLR input channel, is there a way to check the VU meters, or will they automatically work when I plug the mic in. Cheers

 

[The Ghost of FM]

Right below the headphone pushbutton sellect area of the board is the control room mix section with a similar set of selection buttons and it's own level control.

Locate the MON OUT jacks on the rear panel of the mixer in either 1/4" or RCA jack connectors to plug in your powered monitors and perform the same procedure as above.

As for the Vu meters, the main stereo ones will work under our test scenario. If you want to see the other meters work, along with pressing the Stereo assign pushbutton, also press the 1-2-3-4 buttons and bring the buss master faders, 1-2-3-4 to the same levels and ensure the pan control on each channel is at the center position or panned hard left or hard right for the odd and even numbered busses.

Cheers!

 

[GlowPlug]

Ahhhhhh, its so nice when things work. I finally got it to make sound! Thanks Ghost.

Well, it looks like the headset jack is dead, and both the 1/5 & 4/8 VU Meters don't seem to be functioning on any of the channels. . . any ideas on what would make the VU meters not work? Maybe just two bad meters.

But, other than that, the board seems to work great! No scratchy pots, or any intermittent Channels . .so, if it turns out to be tow bad VU's and a bad headphone jack, I'm in good shape!

 

[The Ghost of FM]

The 1-2-3-4 meters have switches near the top right surface of the mixer. Check the positions of those switches to ensure they're not inadvertently set to receive signals from sources which aren't currently present on your set up.

hint;

Those Vu switches are there so that you can monitor 8 channels coming back from an 8 track tape recorder on the tape inputs which you don't have connected at the moment.

Re-check those meter switches.

As for the headphone section not working, it might be the case that the previous owner of the board blew that section by possibly trying to drive speakers directly off of the headphone jack...in a way, TASCAM is kind of guilty of encouraging users to try using it for that purpose in some of their brochures from days gone by, as that headphone amp actually offers 1.5 wpc of power which is about 100 times more then what a Walkman might offer to its headphone output. If that's the case in your mixer, the circuit might require professional service...I don't remember if it's as simple as just changing an internal fuse but somehow, I doubt you'd be that lucky!

As a work-around, there are a number of headphone distribution amps on the market and if you find one that can work from a line level source, you mixer has a multitude of outputs that could feed it.

Cheers!

 

[GlowPlug]

The 1-2-3-4 meters have switches near the top right surface of the mixer. Check the positions of those switches to ensure they're not inadvertently set to receive signals from sources which aren't currently present on your set up.

So, I checked the 1-2-3-4 meter buttons, and they were all IN, and unfortunately still no meter movement. Only the two middle meters seem to function. Are there any other buttons that should be pressed, or switched ON?

hint;
Those Vu switches are there so that you can monitor 8 channels coming back from an 8 track tape recorder on the tape inputs which you don't have connected at the moment.
Re-check those meter switches.

Ahhh, very cool feature. So, do these VU's allow you to directly monitor the VU of an 8 channel recorder without directly having to look at the recorders VUs?

As for the headphone section not working, it might be the case that the previous owner of the board blew that section by possibly trying to drive speakers directly off of the headphone jack...in a way, TASCAM is kind of guilty of encouraging users to try using it for that purpose in some of their brochures from days gone by, as that headphone amp actually offers 1.5 wpc of power which is about 100 times more then what a Walkman might offer to its headphone output. If that's the case in your mixer, the circuit might require professional service...I don't remember if it's as simple as just changing an internal fuse but somehow, I doubt you'd be that lucky!

Speaking of fusses and accessibility! Where are the fuses located on this mixer, are they easily accessible~ and should I even bother checking the fuses for the headphone problem?

and what about the VU bulbs, are they easily accessible to change, or are they difficult to reach?

As a work-around, there are a number of headphone distribution amps on the market and if you find one that can work from a line level source, your mixer has a multitude of outputs that could feed it.

Great idea! Thanks Ghost

 

[The Ghost of FM]

So, I checked the 1-2-3-4 meter buttons, and they were all IN, and unfortunately still no meter movement. Only the two middle meters seem to function. Are there any other buttons that should be pressed, or switched ON?

Those buttons should ordinarily be in the up position...generally, they are only used in the pressed in position to monitor tracks 5 - 8 coming off your tape recorder. You should also double check your pan pot position to ensure that you haven't panned the microphone's mixer channel away from the buss in question. As an example; If you wanted to feed buss one and it's meter but had the pan controlled turned to full right, the buss wouldn't see any signal and the meter wouldn't move to reflect that.

You should verify that the buss itself is working first, regardless of the meter and you can do that by assigning only the 1-2-3-4 buttons alone and turning off the orange L-R assign button on the mixer's Mic channel and also making sure the buss master faders 1-2-3-4 are slid up to the hash mark area.

The 1 through 4 busses automatically feed the main stereo buss provided you turn on the 8 channel sub mixer section above the 4 buss master main faders...each one has an ON button, level and pan pot of its own which must be turned up and panned correctly to feed the stereo buss directly. You only need to turn on the first 4 of these channels to check the recording busses themselves as working or not. So long as they do pass sound, your only problem is the VU meter itself which is a nuisance but not the end of the world.

Sometimes meters that haven't been used in a long time get stuck and if you jolt them carefully with a health signal, enough to near bury the working meters, you might just wake them up out of their coma....maybe.

Ahhh, very cool feature. So, do these VU's allow you to directly monitor the VU of an 8 channel recorder without directly having to look at the recorders VUs?

The idea of that function is to help you more easily see your levels once you have ensured that they are both reading the same values as the recorder and from that point, yes, you can trust what they tell you, going to the recorder and receiving signal from the tape deck. Calibration is a whole other topic that we won't get into in this thread, OK?

Speaking of fusses and accessibility! Where are the fuses located on this mixer, are they easily accessible~ and should I even bother checking the fuses for the headphone problem?

I own two M312B's and I've been lucky enough to never have needed to open them up to check fuses so I don't know directly where they are but I suspect they are close to the power supply which is on the right side of the board, near the top of the master section of the mixer. Whether to bother doing this is up to you and how much time you have to spend on this problem...one way or another, though, the mixer will have to be opened if you're gonna change the burned out bulbs so, sure! Have a look for blown fuses while you're in there.

and what about the VU bulbs, are they easily accessible to change, or are they difficult to reach?

Changing the bulbs is a bit of a job because you have to disassemble the meter bridge section of the mixer to get to the meter assembly and once there, you have to disassemble that to get your hands on the meter casing itself which is scotch taped together...believe it or not...and once that tape is cut, the lens of the meter will pop off and expose the bulb which is soldered into place...make sure you can get the right bulbs first before you go tearing the mixer apart!

I've done this job on my 16 track reel to reel's VU meter assembly and that was an all day job that required my full attention and patience to accomplish successfully. If you're a decent Do it Yourself'er or DIY'er for short, it should be a doable task for you...if not, there's no harm or shame in seeking out a qualified technician to do this kind of work.

Thanks Ghost

You're welcome.

Cheers!

 

[GlowPlug]

You should verify that the buss itself is working first, regardless of the meter~ The 1 through 4 busses automatically feed the main stereo buss provided you turn on the 8 channel sub mixer section above the 4 buss master main faders...each one has an ON button, level and pan pot of its own which must be turned up and panned correctly to feed the stereo buss directly. You only need to turn on the first 4 of these channels to check the recording busses themselves as working or not. So long as they do pass sound, your only problem is the VU meter itself which is a nuisance but not the end of the world.

Well, it sounds like there is some sort of problem with Channel 1, on the Sub mixer-- I'm getting a real weak signal, and the sound is intermittent, and cuts in and out. So, I think this will need to be checked out.

The idea of that function is to help you more easily see your levels once you have ensured that they are both reading the same values as the recorder and from that point, yes, you can trust what they tell you, going to the recorder and receiving signal from the tape deck. Calibration is a whole other topic that we won't get into in this thread, OK?

Yep, I totally agree! I think that it might be a good idea to save that question for a later date, or at least until I have an 8 track to calibrate~ However, without going into too much detail. When you calibrate the VU's on a 312 to your 8 track recorders VU's. Do you adjust the calibration by using a screwdriver or some kinda tool to calibrate the needles, or is it all done by matching sound tones?

Changing the bulbs is a bit of a job because you have to disassemble the meter bridge section of the mixer to get to the meter assembly and once there, you have to disassemble that to get your hands on the meter casing itself which is scotch taped together...believe it or not...and once that tape is cut, the lens of the meter will pop off and expose the bulb which is soldered into place...make sure you can get the right bulbs first before you go tearing the mixer apart!

Ouch! I think that I just might pass on this procedure, . .especially since I might be taking the mixer into the shop to have a tech look at the Channel 1 on the sub mixer section.

Thanks again for all the tips Ghost, I would have never thought about testing the sub mixer section!

 

[The Ghost of FM]

When you calibrate the VU's on a 312 to your 8 track recorders VU's. Do you adjust the calibration by using a screwdriver or some kinda tool to calibrate the needles, or is it all done by matching sound tones?

The meters themselves rarely to never need actual calibration. And no, you are not using a screwdriver on the meter itself.

what I was referring to was more the process of getting a signal on those meters to show 0Vu on the meter and to then have your recorder's meters showing the same level assuming that the recorder was properly calibrated itself.

On playback from a properly calibrated recorder, you will put your master faders into the hash mark area and bring the line input trim controls on each channel up to the point where 0Vu on the recorder's output meters match the mixer's 0Vu meters.

The deck in question also has to have the noise reduction units off and/or bypassed to do these adjustments because noise reduction systems like dbx will mess with the levels that the tape receives and outputs.

As I mentioned before, calibration is a whole other thick book and speaking of books...did you get your manual yet?

Cheers!

 

[Bill Furnett]

Hell yeah!

Congrats Glow

I went from a broke down porta studio to a 312b and let me tell you, it's been Christmas morning ever since.

Had it not been for the dead on advice of the Ghostest with the mostest, i would have ended up buying something new and bunk and that i didn't want.
I said it in another post today, but i'll say it again here, the 312b is everything in a mixer i thought i couldn't afford.


-Happy B-day Glow's 312b-

 

[GlowPlug]

HEY GUYS, Thanks for the input!!! Sorry for the delayed response, I have been away for a few weeks without internet access.

But, Yes!!! I'm definitely lovin' my 312b! Each time I play with it, I learn more and more each time. Its a great board, and perfect for my needs. Maybe slightly advanced for me, but hopefully I will grow into it.

The meters themselves rarely to never need actual calibration. And no, you are not using a screwdriver on the meter itself.

what I was referring to was more the process of getting a signal on those meters to show 0Vu on the meter and to then have your recorder's meters showing the same level assuming that the recorder was properly calibrated itself.

Thanks for the explanation 'Ghost' I'm definitely gonna have to ask more question, when I'm ready to begin to calibrate the VU's.

...did you get your manual yet?

Unfortunately, the manual is on backorder from Tascam, but hopefully I should have it soon. I'm sure it will help quit a bit. But as I mentioned before, I think that I have a problem with Channel 1 on the submixer. The channel is very weak, and intermittent. So, I think I might just bite the bullet, and bring it to a tech, and have him check it out.

 

[Bill Furnett]

Hey Glow,

You want a signal flow chart for your 312?
I have one Ghost sent me a few years ago in jpeg.
I think it's right out of the manual.


-Billy-

 

[GlowPlug]

Thanks Billy!
Yeah, that would help alot, atleast until I receive the manual.
I will PM my email addy.
Bobby--

 

[Bill Furnett]

Yeah man, PM an email and i'll send it.