Tascam M-308B Story...

Hey, Christian,

Thanks for joining and posting. Welcome!

The disadvantage to using the direct outs is patching and submixing. This doesn't matter to you if you always run one source to each track and you don't change your setup (i.e. so you don't have to repatch sources to different channels to get them on different tracks), or if you don't mind repatching. Like if I had drums mic'ed with three mics, bass in another channel, guitar in another, keys in another and two mics for vocals, that would use up 8 mixer channels and 8 tracks. If that is the way I run recordings all the time, like in a rehearsal space or tracking that lineup live consistently, then using the direct outs is the way to go.

Now, what if the setup/lineup changed all the time, like if you were running an 8-track project studio with that M-308B and had different instrumentation day in and day out? What would you do if you had 5 mics on a drumkit and only wanted to use 3 tracks on a multitrack recorder? You'd submix them right? And the submixer would let that happen and better yet you'd be able to put those 5 mics into any three tracks you want thanks to the fact that the M-300 mixers have two outputs for each PGM group...and you'd be able to do it with the press of a few switches and the twist of a few knobs on the control surface. Fast, convenient...I come to think of the submixer (the PGM groups) as a infinitely variable summing patchbay (that is 8 in and 4 out on the M-308).

The other thing to think about is this: in an age when so many are trying so hard to get the cleanest signal to the recorder possible, it is totaly possible to bypass something in the signal chain that might add something nice. I've spent a lot of time avoiding the submixer to stay away from added noise and distortion...nothing wrong with that but you might be surprised at how things sound when they go through that "unnecessary extra" circuitry, and the added headroom might be just the ticket. Something to think about. If you typically track no more than 4 tracks at a time, you've got options. Try them out and see what sounds more appealing to your ears...plus you might like punching more buttons and twisting more knobs to get your routing setup instead of repatching.

Hope that helps...at least you've got one opinion. :D

What do you track with?
Thanks for clearing that up.

I haven't gotten too adventurous with tracking so many instruments at a time, or done many recordings that required more than 8 tracks with the 1/2" deck (which I just realised is actually the 38...which will likely point me in the direction of some other threads since I'll be needing to tinker with it soon) yet.

Next time I want a dedicated mix to hit the tape, I'll definitely try out the submixer.

Recently I've done a few practice space recordings using the 408 for a drum/bass submix, but since that was tracking to the 488 (I find the odd/even, 1/5, 2/4 etc. patching on the 488 seems like sort of a crippled version of the submixer in the 408), I just used the stereo outs feeding 2 passive channels on the portastudio. Maybe there's a better way of doing this?
By "408" you mean "308" right?

The 488 submixer is still indeed 4 channels. Crippled? Yeah, I guess that's one way to put it...I'd say it is functionally focused. You are limited to recording 4 independent tracks at once when using the submixer on the 488 just like using the PGM groups on the M-300 mixers. The 488 will only do 4 tracks simultaneously though whereas you have the option with an 8-track deck paired with the M-308 of using the direct outs like we discussed to do up to 8 tracks at once...no "direct outs" from the mixer to the recorder section on the 488 so everything gets routed to any combination of GROUP 1L/2R and/or GROUP 3/4. And then you have to be mindful of the fact that the groups are routed to each of the 8 tracks in 4 pairs of two tracks (i.e. GROUP 1L can only be assigned to tracks 1 and 5, GROUP 2R to tracks 2 and 6, GROUP 3 to tracks 3 and 7, etc. like you noted). So you use the 4 groups for routing and "patching" during tracking, and then when you are mixing down you route the tape tracks to GROUP 1L/2R to the LINE OUTPUT jacks to your mixdown unit...that's why they have them labeled like that (where GROUPS 1 and 2 also have the L and R designators). When mixing down GROUPS 3 and 4 can be used for monitoring and a variety of other things. It is actually a very nice mixer for an 8-track PortaStudio. Tascam really did a nice job of incorporating some key features from a more full-function mixer into that dedicated unit (i.e. even having the 4 groups at all)...they didn't have to but they did and made decisions that kept the features up and the cost managed. So a 488 "system" is similar to using a "system" like the M-308 with a dedicated 8-track deck when using the PGM groups...the 488 is just not as flexible and does not have as many control elements on the control surface...and naturally since the 488's mixer is internally patched to the recorder lacks flexibility to interface with external gear. Again, that was a good price-point decision. Teac put a more full-function mixer on the 388 open-reel all-in-one solution...that is an 8-buss (8 PGM groups) mixer that does have individual group outs so the mixer can actually be interfaced with external gear if one chooses to not use the built-in 8 track recorder. Still not up to par with the M-300 mixers feature-wise, but aptly fills a gap in between the M-300 mixers and the mixing section on the 488 and is in a different class component and engineering-wise as compared to the 488 mixer...the 388 mixer is sort of like a baby M-300 mixer whereas the 488 mixer is a glorified 424 mixer.

So, wait...you are tracking to the 488...that's your tracking deck? Why are you using the M-308?? Why not just use the mixer on the 488?
Yeah, 308 sorry...:o

I'd love a chance to try out a 388 some time.

I normally track to the 38, but now and again to the 488 for demos, and because I enjoy using it.
The portastudio I have doesn't have phantom or XLR ins though, so if either of those is a problem, I'll use the 308 on the way in. But I was under the impression that the preamps in the 308 were superior anyway, and the sweepable mids and more versatile eq in general are often handy.
Yes. That makes sense. So you are using a 488 mkI. I was assuming (duh) you wree using a 488 mkII with the 3-band swept-mid eq and phantom power on inputs 1&2. I understand now why you are using the M-308B when you are tracking to the 488 now. The M-308 preamps are superior IMO as well as the eq. You probably know this already but to take best advantage of the preamps and line amps in that configuration (i.e. using the M-308 in front of the 488) make sure you have the levels hot enough coming out of the M-308 so you can leave the trims fully counter-clockwise on the 488.

BTW, Portastudios are indeed fun aren't they? :)
Definitely, I can't even count the number of projects I've done with the 488 alone. I love this one although sounds like having an MKII would have solved a lot of the earlier problems I had with it. I own a lot of XLR to 1/4" transformers now, anyway...

I generally use a pretty hot signal out of the board, and go into the non pre-amp channels.

I generally use a pretty hot signal out of the board, and go into the non pre-amp channels.
Yeah,... it's a smart fit & perfect application for those pesky "Line" input channels!:eek:;) You, sir, have done your homework!:eek:;)

This setup, (M308>488), would point to the salient positive effect of a "PGM-Buss" output vs. a Direct-Out hookup. "Buss-Assign" mode gets my vote.

When using a mixer, I'll typically go thru the Assign (PGM) busses, and virtually never DI. HINT: I do subgrouping of channels pre-recorder/inputs for virtually every track & at every step of the way. More on that later, maybe.:eek:;)

I'm...parting it out folks. :eek:

With now two 388's (primary and parts systems), and the prototype M-___ mixer (as well as my Yamaha 24 x 2 x 2 digital mixer) I need to clear some room.

The M-308B that is the subject of this thread has a rough exterior, but the insides are clean.

I'm giving the AO forum family first crack at anything y'all need. All offers considered so PM me if you have an M-308/312/320 or a 388 and you are looking for something. After that it will be completely torn down and sold off. I feel yucky saying that. M-300 mixers rock but this one is cosmetically rough, and I need space and $$$.

I have owned the M308b for a long time but not used it.

I was told I could use it like I do my mackie board for live sound.

I have amplified speakers. I have plugged my guitar into this thing, and no sound. It is clearly plugged into the speakers and I can tell if an instrument actually "worked", it would be loud.

I can't find a manual.

I am not savvy on soundsystems. All the terms and abbreviations you guys use just makes my head spin.

So can I plug in instruments and use this mixer for live sound, or is this mixer for something else? I would like to use it at a small church for the keyboard, guitsr, bass and some mics.

Any help is appreciated. God bless you all.
Kjs, are you trying to plug your guitar straight into it? If so, that won't work. You need a thing called a direct box. Its a box that takes the kind of signal that comes out of a guiatar and converts it to the kind of signal the mixer can use. The M-300 series mixers are perfect for small venue live sound.

To see if the mixer works, plug a microphone into a mic input. Then make sure the red MIC/LINE switch at the top of the channel strip is in the up position, turn the MIC TRIM knob (the top one of the stacked knob with the red color cap on it) to about 12:00. Raise the channel fader up to the shaded area that is about 3/4 of the way up and push in the orange L/R button that is right above the PAN knob on that channel strip. Now you should be able to slowly raise the red STEREO MASTER faders up and hear you talking into the mic. Be careful of feedback. Make sure you have your speakers connected to the STEREO OUT L/R jacks.

That's just a test to make sure things are working and then we can take it deeper from there.
Thanks for the reply. I once plugged a mic into it--the input that has the three holes--whatever thats called, and it worked. But it also has 1/4" inputs, but no sound for the guitar. That is what I don't understand. This seems like a mixer like my Mackie. I plug the mics in the 3 prong thingies, and any guitars or keyboard into the 1/4 jack inputs,and it works. I expected this to be the same.

Is this a mixer that just doesn't do what my more modern mackie does, and if not, why not? Thanks for your time.
The input with the three little holes is just called the MIC INPUT, like its labeled. That kind of jack is an XLR jack.

Okay. So we know your mixer is working because the mic works when routed through the mixer.

So make sure that the guitar is plugged into the LINE INPUT, not the DIRECT OUT or INSERT, and then make sure that the red MIC/LINE push switch is in the down position. That tells that channel strip to listen to whatever is plugged into the LINE input jack on the back, not the XLR MIC input. They can't be listened to at the same time. Your Mackie may be able to listen to both at the same and/or it switches automatically depending on what you have plugged in. It is actually a nice feature to be able to switch it manually. So push in that red button, and now turn the lower section of the MIC/LINE TRIM knob (the one with the red cap). The top section controls the boost of the signal connected to the XLR MIC jack, and the lower section controls the boost of the signal coming into 1/4" LINE jack. On the M-300 mixers you can have things plugged into the MIC jack and the LINE jack at the same time, set the signal boost for them independently via the two sections on the red TRIM knob, and then switch between them with the red MIC/LINE button.

So if you still can't hear the guitar when leaving the rest of the mixer the way it was when you could hear the mic, then answer this:

Can you tell me about the guitar you are trying to hear? Is it an electric guitar or an acoustic guitar? Does it have its own battery in it?

It is possible that the Tascam doesn't have enough boost to hear the guitar depending on the kind of pickup that is in it, but the Mackie might. More boost doesn't necessarily mean its a better or worse mixer. Just different.

Try the above steps and let us know about the guitar.
Thanks for the advice and info. I figured it HAD TO BE a button that needed to be hit, so I started pressing buttons. There are A LOT MORE on this mixer than the Mackie! Well, I was testing it with one speaker connected, and when I hit the little button that says L-R, the sound came on for my guitar. I guess that button allows you to turn off a speaker.

This is clearly a very cool mixing board. I sure do need to learn how to use its capabilities. I have a video that teaches basic sound-system info, so i should watch it.

I found the manual available for $25.oo online, so that would be logical to purchase.

I do appreciate your help. The Lord bless you.
A manual for $25 - do tell!

Greetings, folks!

Well, I got back to my church this week and lo and behold: someone had given them an M308B board. I've been told it works (and I did check for phantom power - it's there at 48 V) though they seem to have a hard time getting the condenser mics working on it. KJS: you mentioned finding a manual online for $25 - what is the source? (it's been about 20 years since I last touched a tascam mixer, so I'm a tad rusty...)

sorry for the year + bump, but did you cheat us on telling the story on the mystery jacks & knobs? - I would have guessed they were just an extra monitor mix to the mystery jacks, no? (i'm pretty sure i read through the whole thread....)

what was the eventual fate of this desk, did you get rid of it whole, finish parting it out - or are you still in process?

What extra stuff did those knobs & jacks have inside? do you think that's a mod someone could get away with doing without having specialized tascam parts?
in the final analysis, d'you think it was a factory mod or a homebrew?


Yeah...the blue mystery knobs on mine are definitely non-stock, but whoever added them did a nice job on drilling the holes, and the pots were soldered into the group channel PCB's where the AUX 3 & 4 pots would be on a 312 or 320...dunno yet what they feed...I'll find out though. ;) I'm wondering if the feed the mystery jacks...maybe those jacks are AUX 3 & 4 outs sans master, but that wouldn't make sense bacause they'd be lacking the amp stages of those masters...anyway, to be determined...
Well my goodness!

Thanks fer askin'!

First of all, the M-308B was parted out. I have most of the buss section still, the power supply and a couple channel cards and some knob and switch caps, but the rest is gone.

Ahhh yes...the blue mystery knobs...It was aftermarket, but used OEM pots and knobs. The buss master cards are the same PCB for all the M-300 versions (8, 12 and 20 channels), and the 12 and 20 channel models have more stuff populated on the board. I figure somebody with enough savvy took the schematic and modded that M-308B to have AUX 3&4 like the 12 and 20 channel models, and the jacks in the back were fed by those busses. A hack using parts ordered from Tascam.

Mystery solved?