Tascam M224 Mods

  • Thread starter Thread starter Cynosure
  • Start date Start date
C

Cynosure

New member
I am picking up a Tascam M224 for a really good price because the seller took into consideration that I plan to service it to get it in good working order again. Can anyone help with a service manual or mods?

I read a post by the user Beck about replacing some of the opamps with OPA2604's. Can anyone point out which opamps I should replace? Or do I just replace every single JRC4560?

Also, I read about some issues with the power supply. That doesn't really make sense to me because the power supply either has enough current or it doesn't. Could it need larger filter caps? Would that help?

Beck also mentioned replacing the resistors. Does that really make much of a difference? My previous DIY experience is with synthesizers. With those, it is common to replace the caps but I have never heard of replacing the resistors before.

A service manual or schematic would really help a lot. Does anyone have a pdf that they can share?

Thanks for the help!
 
Cynosure said:
I am picking up a Tascam M224 for a really good price because the seller took into consideration that I plan to service it to get it in good working order again. Can anyone help with a service manual or mods?

I read a post by the user Beck about replacing some of the opamps with OPA2604's. Can anyone point out which opamps I should replace? Or do I just replace every single JRC4560?

Also, I read about some issues with the power supply. That doesn't really make sense to me because the power supply either has enough current or it doesn't. Could it need larger filter caps? Would that help?

Beck also mentioned replacing the resistors. Does that really make much of a difference? My previous DIY experience is with synthesizers. With those, it is common to replace the caps but I have never heard of replacing the resistors before.

A service manual or schematic would really help a lot. Does anyone have a pdf that they can share?

Thanks for the help!
Click to expand...

I don't have a manual but if you want to do any mods you will have to take a few things into consideration......first and foremost, if the unit needs to be repaired you probably should do that first...

you mentioned the power supply....there might be issues there if the replacement op-amps will draw more current than the original ones.... also, the specs on the op-amps will probably be different and might not work to your expected satisfaction....could cause problems....electrolytic capacitors tend to lose their capacitance and develop ESR over time....and if they are bad should be replaced....resistors.....well metal film resistors are less noisy than carbon comp ones......but changing every single resistor with be very time consuming and expensive...but then again, it all depends what you are after....

and after completing a mod it might be best to then check the operation of the unit just in case you ended up making a mistake....not saying that you will but if you do a ton of part replacements and then something does not work right, you will have to back-track everything that you did....which could be very time consuming and fustrating to say the least.....
I just re-read your post....you work on synths so you should not have any problems modding this unit....if I find a schematic I'll let you know....
 
Thanks for the response. The seller says that the mixer works fine, but I assume there will at least be some noisy pots.

The power supply is something I read about in another thread. A user named Beck mentioned it. He did replace the opamps, so maybe that was why he had a problem with the power. He used OPA2604's, and the datasheet does say that they use a bit more current than the 4560's that come in the mixer.

I plan to replace all the caps. I am not sure about the resistors - lots of work. A schematic might help me locate only the ones that the sound actually passes through. I think that they would be the most important ones, and not pull-down resistors or dividers.

Whatever I do end up doing, I will do it one channel at a time. Then I can check for errors and do a/b comparisons between the channels.
 
Ok I have the mixer now. It seems to work pretty well. There are some noisy pots and some of the input jacks wiggle around too much. I will reflow the solder on all of the jacks.

The only thing I am having difficulty with is listening to channels 1/2 or the main mix with headphones. For some reason I can only hear 3/4 or PFL in the headphones. Any suggestions?
 
Cynosure said:
Ok I have the mixer now. It seems to work pretty well. There are some noisy pots and some of the input jacks wiggle around too much. I will reflow the solder on all of the jacks.

The only thing I am having difficulty with is listening to channels 1/2 or the main mix with headphones. For some reason I can only hear 3/4 or PFL in the headphones. Any suggestions?
Click to expand...

Do you get any sound from channels one and 2 through headphones??......and you can't hear the main mix on headphones......but the main mix is at the mains output jacks.......

If you are getting sound from the main output jacks from channels 1 and 2 but not in the headphones, then there could be a connection problem.....is there a switch that routes channels 1 and 2 to the headphones??
If there are any routing switches there then you might try a shot of Deoxit......I would rule out the simple and easy stuff first before I tear too deep into it.....FWIW...I would get these issues fixed up first before upgrading with new parts....I haven't seen a schematic.....did you try to contact Tascam?? if you google them the company website will come up........contact info should be there......
Cheers
 
I don't see a button for 1/2. There is only one for 3/4. So I don't know if the headphones is only for previewing. But that doesn't really makes sense. That is why I was asking - I was hoping someone with the mixer could confirm.

The main output works fine though. It is just getting the 1/2 sub channels to the headphones. I think that it is the switch. They seem a little weird and stick sometimes. I haven't opened it up yet. I am going to do that today. I expect to have to do a lot of cleaning before I even look at the electronics.

I did find a manual and service manual (I think). I found a generic one for the M-200 series. It doesn't mention the M-224 specifically, but what it shows looks identical per channel. I think that will help me out a lot :)
 
Cynosure said:
I don't see a button for 1/2. There is only one for 3/4. So I don't know if the headphones is only for previewing. But that doesn't really makes sense. That is why I was asking - I was hoping someone with the mixer could confirm.

The main output works fine though. It is just getting the 1/2 sub channels to the headphones. I think that it is the switch. They seem a little weird and stick sometimes. I haven't opened it up yet. I am going to do that today. I expect to have to do a lot of cleaning before I even look at the electronics.

I did find a manual and service manual (I think). I found a generic one for the M-200 series. It doesn't mention the M-224 specifically, but what it shows looks identical per channel. I think that will help me out a lot :)
Click to expand...

I took a look at some pics on google......but couldn't see much.....You were lucky to find a manual......if it is for that series of mixers, then the channel and routing sections should be the same......the power supplies might be different as in the particular ratings of components.....such as transformer, diodes, capacitors, and resistor wattages......but the basic design would still probably be the same......

I had originally thought you were referring to channels 1 and 2.......but it is the subgroups 1 and 2.....can you send me a link to the manual......

please note.......I am by no means an expert....I do repair most of the gear for the local music store....and for pretty much most of the musicians and schools in the area.......if I can be of any help I will be happy to do so.......many people in the past have helped me so it is only right that I try to do the same....


you mentioned switches for the sub-groups?? give then a few squirts of Deoxit.....that might be all that is wrong especially if this board has been in storage for some time.....you no doubt have noisy pots and faders....give it a very good cleaning first and then see where you sit....
Cheers
 
It's a nice mixer as it is stock. I still have the M-216 and M-208. If you want to mod the op-amps first thing to do is desolder the original op-amps and solder in high quality 8-pin machined DIP sockets. Machined sockets are far Superior to the standard. Once those are in you can try different op-amps. The early M-224 were a bit underpowered because they added 8 channels, but used the power supply circuit from the M-216. It's fine with the original JRC4560 op-amps, put the BB OPA2604 draw significantly more current, so when you fill a board with them the PS in the M-224 will struggle to keep up. The JRC4580 is the newest and best of the 45xx series and beats the socks off the 4560. You can try those, and of course the venerable NE5532, which is still one of my fav op-amps.

Pulling carbon film resistors in the signal path and replacing them with metal film types is one of the best things you can do to cut down on thermal background noise/hiss. You don't need to replace every resistor in the board; just those in the signal path
 
Thanks for the info Beck. I might give those mods a try in the future. Right now though, everything is working well enough to keep me happy.
 
I have a Tascam M-224 i bought from the band I worked with, they retired it for a newer digital version. Everything works electronically as far as I can tell but the controls area is dirty and the sides pretty scratched and bottom edges full of dings and gouges. Looking for a manual for it but doesn't seem to be available which I need because I don't have much of a clue about how everything works so I'm reaching out here in the hopes I find a someone to at least get me started. If anyone is here to help me I'll have many questions I'd bet but to start I'm mic'ing a 16 piece drum set, each piece including individual cymbals have their own mic, you might think this is over kill and you'd probably be right but I have it my mind how I want this all to go. My first question is regarding the 4 busses and how to understand what that might mean for Toms, Floor toms, Cymbal, rotos and other percussion pieces. Would I assign all cymbals to a buss for example?
 
Are you mic’ing the kit for live sound or recording? Tell us a little more about how you’re using the console.
 
sweetbeats said:
Are you mic’ing the kit for live sound or recording? Tell us a little more about how you’re using the console.
Click to expand...
Mic'ing it for recording. I'm probably way over doing it but it is currently the thing I want to use it for and want to maximize any effect i can use. I'm not a professional drummer nor am I a really good one so I'm sure I'll want to smooth out the volume between toms and floor toms, dampen the snare or add effects to certain drums and not others.

I do have a Scarlett 18i20 I'm sure all of this will have to go through but i want to work in the analog world before i do anything that might offer.

I have a cement floor, cinder block wall in my basement (where my drums are) I will be applying foam pad sound proofing to the walls and a commercial grade carpet throughout my basement.

And thank you for replying
 
So you’re wanting to get each drum mic on its own track in your DAW via the Scarlett?
 
sweetbeats said:
So you’re wanting to get each drum mic on its own track in your DAW via the Scarlett?
Click to expand...
Yes, I know Scarlett has a lot of inputs and can likely handle the job on its own but I want to use the mixer for all of the mics, do what I can with the mixer before sending it to the Scarlett. I guess I want to go to the extreme with it before being more realistic, for example panning or rather partially panning the left side of a large kit on the left channel likewise with the right. I see looking down the controls things I’m not familiar with like “FLB”, TRIM, EFF. EQ I’m partial with but they also seem to have specific uses.
So the first question I have is regarding the 4 busses, would it be Cymbals, toms, snare, kick or keep them on their own channels?
Second is this a 4 Channel board (L,R, front and L,R, rear)?
 
The M-224 is not a 4-channel console. It is a 24 channel console. We usually describe a console by the number of input channels, and often the number of summing or output busses. The M-224 has 4 mono summing busses or groups. So it is a 24x4 console. There is also a stereo master buss, so sometimes you might see it designated as a 24x4x2 console. Sure you could use the 4 groups in a quad setup if you wanted, but it’s not specifically a “quad console”.

Here’s the thing and I’ll now get to my point with the information you’ve provided…if you want to use the analog console as a front end to your computer-based DAW, but you want each drum kit mic to still be on its own track in the DAW, the M-224 is not going to work very well for you because there are no direct outputs to each input channel, and there are only 8 other outputs…the 4 summing groups, the fold-back or “monitor” buss out, the effect buss, and the stereo out. And it’s really only 6 in the case of using it for recording because the stereo buss is fed by the 4 summing groups. And the FLB buss is fixed pre-fade so it is not really practically possible, if you have more than 4 mics, to really use the M-200 consoles for multitrack work if you are wanting to record more than 4 tracks at once and still be able to use the effect and fold back busses as intended. The M-200 consoles are fine for live FOH applications and, again, multitracking where you don’t need to record more than 4 tracks at once. Yes you can use the insert send as a direct out of sorts, but it is pre-EQ and pre-fade…you’d basically only be using the trim controls for all your mixing and not be able to take advantage of the rest of the signal path up front of the DAW when tracking. And you need to make special cables or adapters in order to “sniff” the signal from the insert jacks without interrupting the signal to the rest of the channel if you wanted to at least monitor your inputs using the console. It’s really not an ideal setup. If you sum your cymbals to one group, tons to another, etc, those signals are summed. You can’t split them up later.
 
sweetbeats said:
The M-224 is not a 4-channel console. It is a 24 channel console. We usually describe a console by the number of input channels, and often the number of summing or output busses. The M-224 has 4 mono summing busses or groups. So it is a 24x4 console. There is also a stereo master buss, so sometimes you might see it designated as a 24x4x2 console. Sure you could use the 4 groups in a quad setup if you wanted, but it’s not specifically a “quad console”.

Here’s the thing and I’ll now get to my point with the information you’ve provided…if you want to use the analog console as a front end to your computer-based DAW, but you want each drum kit mic to still be on its own track in the DAW, the M-224 is not going to work very well for you because there are no direct outputs to each input channel, and there are only 8 other outputs…the 4 summing groups, the fold-back or “monitor” buss out, the effect buss, and the stereo out. And it’s really only 6 in the case of using it for recording because the stereo buss is fed by the 4 summing groups. And the FLB buss is fixed pre-fade so it is not really practically possible, if you have more than 4 mics, to really use the M-200 consoles for multitrack work if you are wanting to record more than 4 tracks at once and still be able to use the effect and fold back busses as intended. The M-200 consoles are fine for live FOH applications and, again, multitracking where you don’t need to record more than 4 tracks at once. Yes you can use the insert send as a direct out of sorts, but it is pre-EQ and pre-fade…you’d basically only be using the trim controls for all your mixing and not be able to take advantage of the rest of the signal path up front of the DAW when tracking. And you need to make special cables or adapters in order to “sniff” the signal from the insert jacks without interrupting the signal to the rest of the channel if you wanted to at least monitor your inputs using the console. It’s really not an ideal setup. If you sum your cymbals to one group, tons to another, etc, those signals are summed. You can’t split them up later.
Click to expand...
Ok I get it, thank you.
Then onto a more realistic plan. I can send Stereo L & R out to my Scarlett after making some adjustments to each mic.

I have only seen this console send the left and right stereo outs to a PA amp which powered the PA speakers, I never seen anything summed or if anything was I didn't didn't know it. I just walked to the far wall adjusted the Bass, Kick drum and vocal mics and so on, everything was labelled so even I could handle the job lol
 

Attachments

  • IMG_3246.webp
    IMG_3246.webp
    65.4 KB · Views: 9
  • IMG_3247.webp
    IMG_3247.webp
    71.1 KB · Views: 7
Last edited:
So if you do it that way what you’ll have recorded is a stereo mix of all the mics. There will be no way to individually adjust levels or tweak EQ or panning or apply any dynamics processing. Like if it was me and I was stuck with the M-224 and had no other option, and I wanted to record a drum kit all mic’ed up, I’d probably at least send the kick to PGM 1, snare to PGM 2, and then use PGM 3 & 4 for a stereo mix of the Tom’s and cymbals, or even use the insert jacks of the cymbal channels to feed the overheads to the interface and have a stereo sum of the tom mics on PGM 3 & 4…but now I’m looking at your pic of the kit…do you have internal mics on the toms and snare?
 
You must log in or register to reply here.
Back
Top