GCalo
Member
Just make sure he's wearing his cap!!!
Just make sure he's wearing his cap!!!
RICK FITZPATRICK
New member
Arn't friends wonderful! Especially if they're a tech!
I have a friend who is a WONDERFUL friend and TECH. Last year he moved from Arizona to my state, and to ease the transition, he lived in my home for 4 months. First thing he did was read the M3700 manual start to finish. Then he moved all his tech gear in his bedroom and set up a "tech station". For 4 months he tore into all my gear from monitors to my MSR's and tweaked everything! Here's a few pics of his tech station setup.
He even tried to fix the ole TDM 1000...but it was hopeless.
Never worked from the time I bought it on ebay. 
Here he's testing my old Studiomaster board so I could sell it.
He never needed to open the 3700. And btw, when I bought mine, the guy I bought it from called it a M3600.
It had a meterbridge from a M3500, but had the automation stuff. He said that Tascam only had one meterbridge left when he bought it, and they used it on the M3700. Anyway, hope you get the PSU thing straightened out. I hate the thought of that thing just collecting dust.
GCalo
Member
Now that he is done with your items send him over here!
S
sr71rules
Member
Interesting about your meter bridge, mine also says M3500. In all of my googling, whenever I found a picture of an M3700 large enough to read the text on the bridge...it says M3500. Easy to tell from looking at the boards though that they are M3700s.. hard to miss the extra section filled, with a little screen and floppy disk drive poking out!
miroslav
Cosmic Cowboy
sr71rules...the pictures you put up with the ground wires...are you referring to the two black wires?
I can't see in the first picture where/how they are connected....?
There was a lot of "grounding mod" talk going back 10-15 years, when it came to the 3500 and especially the 3700.
Can you tell if the wires/connections look like a factory soldering job/hook-up...or something done by hand, after the fact?
Maybe the previous owner tried to mod the grounding to improve it?
Post up a few more pictures...I'm curious to see how it all runs and where it connects...etc.
I can't see in the first picture where/how they are connected....?
There was a lot of "grounding mod" talk going back 10-15 years, when it came to the 3500 and especially the 3700.
Can you tell if the wires/connections look like a factory soldering job/hook-up...or something done by hand, after the fact?
Maybe the previous owner tried to mod the grounding to improve it?
Post up a few more pictures...I'm curious to see how it all runs and where it connects...etc.
RICK FITZPATRICK
New member
Yea, that's how I knew mine was a 3700!
BTW, one of the reasons my friend didn't open the M3700 is because its in my DIY console. The support bars in the frame prevent pulling the belly pans. I spent a long time working out all the details to mod my old console for the M3700 in Sketchup. Had to re weld the bridge support frame, make new "interface hinges" because the mixer was much deeper than my old one, and modify lots of other things too. Like a new wrist pad, and make new rack bays, and modify the linear motion track to fit between the mixer and the pad.
Here is some pics and Sketchups with the M3700 in it. Just thought you might like to see one in a custom console.
Here is one of the two interface locks/hinges. What a bitch. They have to support the complete bridge with THREE computer monitors and two sets of audio monitors, not to mention the bridge it self which weighs in about 80lbs.
Worked great though. They are adjustable in 3 axis'. 
S
sr71rules
Member
Nice looking place Rick. Looks comfortable and that hinge certainly looks well engineered! 
Miroslav: I believe it is a grounding mod. I'll try and get some better shots tonight. The wires are hand soldered to the underside of the PCB that has the master busses on it. It's the module that has the FX returns/talkback/studio and CR monitor options on it, directly above the 8 Group Out faders. The wires are massive and the soldering job doesn't look especially good to me.
I'm going to try and take all the modules out of the console tonight and get some more shots of the wires to see where they go. I would guess it was done when they modded 1-16. It certainly didn't come from the factory like that...
Miroslav: I believe it is a grounding mod. I'll try and get some better shots tonight. The wires are hand soldered to the underside of the PCB that has the master busses on it. It's the module that has the FX returns/talkback/studio and CR monitor options on it, directly above the 8 Group Out faders. The wires are massive and the soldering job doesn't look especially good to me.
I'm going to try and take all the modules out of the console tonight and get some more shots of the wires to see where they go. I would guess it was done when they modded 1-16. It certainly didn't come from the factory like that...
miroslav
Cosmic Cowboy
If you could...I would very intersted to see exactly how the grounding mod was done...what points were soldered and how/what was conencted to the grounding mod...and where the the wires finally terminate (in the PS I would imagine?).
Thanks
Thanks
S
sr71rules
Member
Extra Wires...
It looks like the extra wires are indeed for grounding. I posted a couple pictures in post #11 and I've finally had a chance to strip the board of all it's modules and get a better look.
For frame a reference, the extra wires come out on the left of this shot and go under a bar of metal that runs just above the faders. This is a picture taken from behind the console:
Here you can see some wires that look professionally installed by Tascam that ground the PCBs for the master buss that run along the belly of the console under the channel strips. The metal channel runs along at an angle at the bottom left of the image.
This last shot shows the end point of the two wires soldered to the Buss PCB under the master module section of the board. The wire is thicker and the ends are different from those that connect to other places on the board. The really curious part though is that the extra wires travel all the way from the Master Module on the far right of the board, under the metal channel and then screw to that same metal channel on the far end, fully on the right side, under module group 1-4. In the top image you can see them run out from the Master section and then dip into the channel and back out again.
A single wire connects from the channel to a wire that runs to the back of the board and connects, presumably, to the power connector. Once it leaves the cavity left by the modules I'm not sure where it goes and I don't have the time this evening to really disassemble the console to find out. Some hunting with a flash light and some gentle tugging on the wire though does tell me it gets very close to the power connector, if it's not attached directly to it.
I'll be curious Miroslav to hear how this differs from your board. My M3500 however appears to lack completely the metal grounding channel in front of the faders. My thought is that because of the computer on board they added the grounding channel to help get rid of any noise it causes. Considering the extra capacitors in the M3700's power supply versus the M3500 PSU I'm beginning to wonder if computer noise was a major concern/problem during development. My M3500, in my admittedly limited testing, always proved quiet.
I'm sorry the shots are so hard to read.. I need work out a better way of shooting the board. Being so pressed for time this week isn't helping either...
Robert
It looks like the extra wires are indeed for grounding. I posted a couple pictures in post #11 and I've finally had a chance to strip the board of all it's modules and get a better look.
For frame a reference, the extra wires come out on the left of this shot and go under a bar of metal that runs just above the faders. This is a picture taken from behind the console:
Here you can see some wires that look professionally installed by Tascam that ground the PCBs for the master buss that run along the belly of the console under the channel strips. The metal channel runs along at an angle at the bottom left of the image.
This last shot shows the end point of the two wires soldered to the Buss PCB under the master module section of the board. The wire is thicker and the ends are different from those that connect to other places on the board. The really curious part though is that the extra wires travel all the way from the Master Module on the far right of the board, under the metal channel and then screw to that same metal channel on the far end, fully on the right side, under module group 1-4. In the top image you can see them run out from the Master section and then dip into the channel and back out again.
A single wire connects from the channel to a wire that runs to the back of the board and connects, presumably, to the power connector. Once it leaves the cavity left by the modules I'm not sure where it goes and I don't have the time this evening to really disassemble the console to find out. Some hunting with a flash light and some gentle tugging on the wire though does tell me it gets very close to the power connector, if it's not attached directly to it.
I'll be curious Miroslav to hear how this differs from your board. My M3500 however appears to lack completely the metal grounding channel in front of the faders. My thought is that because of the computer on board they added the grounding channel to help get rid of any noise it causes. Considering the extra capacitors in the M3700's power supply versus the M3500 PSU I'm beginning to wonder if computer noise was a major concern/problem during development. My M3500, in my admittedly limited testing, always proved quiet.
I'm sorry the shots are so hard to read.. I need work out a better way of shooting the board. Being so pressed for time this week isn't helping either...
Robert
miroslav
Cosmic Cowboy
My 3500 is stock AFA grounding....I never did anything to beef it up, but have been curious how others did it.
Just running a bunch of additional wires and connecting them here-n-there would not necessarily do much...so if you are going to do it, it has to make some grounding sense, and then end up somewhere where it will actually go to ground...which I'm guessing should/would be in the PS...???
If you don't feel like posting addition pictures for the grounding in this thread...I'll be happy to give you my email...I am very curious, because who ever did that, looks like they at least tried to do a good job, it looks very neat and clean. Now, how much it improved the grounding to actually lessen any noise in the system...that might only be discoverable if/when you get it all running...and then simply A/B with and without the extra ground connected/disconnected (where ever it all terminates).
It should follow a basic star scheme...all kinda coming together at one, final point from several various points...and it looks like it does in that one picture, but I would still like to know if there is any wire taking the grounding mod out of the console, or is it all just connected internally...???
I've thought about doing something like that, as it doesn't (shouldn't) mess with the rest of the board's electronics, so you're not going to hurt anything...though of course, it still needs to be done right so as not to add more noise instead of taking it away!
I don't think the 3500/3700 are THAT noisy...but even if you drop the existing noise floor by another 25% or so...it's a decent and worthwhile thing to do.
Maybe on my next rainy day.
Thanks for the effort posting pictures!
When you get a chance to trace the rest of it out...I would love to see those results too, as that will be the key as to what/here the grounding mod does/goes.
Just running a bunch of additional wires and connecting them here-n-there would not necessarily do much...so if you are going to do it, it has to make some grounding sense, and then end up somewhere where it will actually go to ground...which I'm guessing should/would be in the PS...???
If you don't feel like posting addition pictures for the grounding in this thread...I'll be happy to give you my email...I am very curious, because who ever did that, looks like they at least tried to do a good job, it looks very neat and clean. Now, how much it improved the grounding to actually lessen any noise in the system...that might only be discoverable if/when you get it all running...and then simply A/B with and without the extra ground connected/disconnected (where ever it all terminates).
It should follow a basic star scheme...all kinda coming together at one, final point from several various points...and it looks like it does in that one picture, but I would still like to know if there is any wire taking the grounding mod out of the console, or is it all just connected internally...???
I've thought about doing something like that, as it doesn't (shouldn't) mess with the rest of the board's electronics, so you're not going to hurt anything...though of course, it still needs to be done right so as not to add more noise instead of taking it away!
I don't think the 3500/3700 are THAT noisy...but even if you drop the existing noise floor by another 25% or so...it's a decent and worthwhile thing to do.
Maybe on my next rainy day.
Thanks for the effort posting pictures!
When you get a chance to trace the rest of it out...I would love to see those results too, as that will be the key as to what/here the grounding mod does/goes.
S
sr71rules
Member
Microslav - I can confirm the grounding wire does in fact connect back to the umbilical power cord. The M3700's PSU, different from the M3500, has a 3 pin power connector and it's getting to it's final ground through there.
I spent several hours with a friend today going over the console and testing everything imaginable. What is happening, we believe, is that (as Sweetbeats prediected) the voltage regulator controller chip is failing. The chip is in place to setup the +15 and a -15 voltage rail. Under no load the chip does a wonderful job and puts out +/- 15.09V. With up to 12 channel modules, meters, master section, and faders, things are fine. As we added channels back though beyond 12 it would start to falter and when the M3700 was fully loaded the 15V rails were putting out under 13.5V. As we added more and more load, and with the regulator chip unable to handle it, it would pull more and more power. We found, with the M3700 fully loaded it was pulling 6.56A across the 5A fuse.
I'm sure that the regulator chip is faulty but I'm not sure it's the only fault. I've ordered the new part, at rather steep $8.50 and will attempt to patiently wait for it's arrival. Once installed, testing resumes again and hopefully we'll find everything else is good order. It's possible this issue is one of many and it's also possible that this issue and the other guys testing (with overrated fuses) has created other problems. I'll think about that later...
Robert
I spent several hours with a friend today going over the console and testing everything imaginable. What is happening, we believe, is that (as Sweetbeats prediected) the voltage regulator controller chip is failing. The chip is in place to setup the +15 and a -15 voltage rail. Under no load the chip does a wonderful job and puts out +/- 15.09V. With up to 12 channel modules, meters, master section, and faders, things are fine. As we added channels back though beyond 12 it would start to falter and when the M3700 was fully loaded the 15V rails were putting out under 13.5V. As we added more and more load, and with the regulator chip unable to handle it, it would pull more and more power. We found, with the M3700 fully loaded it was pulling 6.56A across the 5A fuse.
I'm sure that the regulator chip is faulty but I'm not sure it's the only fault. I've ordered the new part, at rather steep $8.50 and will attempt to patiently wait for it's arrival. Once installed, testing resumes again and hopefully we'll find everything else is good order. It's possible this issue is one of many and it's also possible that this issue and the other guys testing (with overrated fuses) has created other problems. I'll think about that later...
Robert
sweetbeats
Reel deep thoughts...
Don't rule out that there could still be something faulty downstream in the mixer...on one or more of those strips, so make sure you add them back in just one at a time and measure each time...any loading should be consistent. Any rapid changes means something ain't right.
Also, if it were me, I'd take this opportunity to:
Replace all the electrolytic capacitors in that supply rail and
pull one leg of all the resistors in that rail and measure their resistance to see if they are on-spec...this isn't an absolute since things can change under load, but after another quick look some of the resistors most likely work in concert is the IC to form the regulator loop.
Also, if it were me, I'd take this opportunity to:
Replace all the electrolytic capacitors in that supply rail and
pull one leg of all the resistors in that rail and measure their resistance to see if they are on-spec...this isn't an absolute since things can change under load, but after another quick look some of the resistors most likely work in concert is the IC to form the regulator loop.
S
sr71rules
Member
Good advice Sweetbeats! We did test all the resistors this past weekend and didn't see any trouble. I'm cautiously optimistic about the part on order. The caps are so big... they make me nervous. I know how to drain them but I may need to work up some confidence before replacing them. I plan to re-cap at least one of my M-1bs and if that goes well I can't imagine the M3700 PSU is far behind. Maybe I'll do a dry run on the M3500 PSU
In our testing we meticulously tested each bank of channels, faders, meters, ect looking for anomalies and once the new part is installed it will all be done again. Interesting to find out where the power for each piece is coming from and how much power each section pulled. My feeling is we've done the first round of testing and the second round will turn up more issues.
So far I know the headphone jack doesn't work. I've yet to figure of if it's the jack, the interconnects inside the board, or the source PCB that's the issue...
My 'new' 20 year old network card arrives today and the 20 year old 'Macintosh LC' tomorrow. Should give me something to keep me occupied while I wait for the part to arrive. Fingers crossed I can get things up and running.
Robert
In our testing we meticulously tested each bank of channels, faders, meters, ect looking for anomalies and once the new part is installed it will all be done again. Interesting to find out where the power for each piece is coming from and how much power each section pulled. My feeling is we've done the first round of testing and the second round will turn up more issues.
So far I know the headphone jack doesn't work. I've yet to figure of if it's the jack, the interconnects inside the board, or the source PCB that's the issue...
My 'new' 20 year old network card arrives today and the 20 year old 'Macintosh LC' tomorrow. Should give me something to keep me occupied while I wait for the part to arrive. Fingers crossed I can get things up and running.
Robert
S
sr71rules
Member
Quick update:
Macintosh LC arrived today and is able to load the JL Cooper software. I'm going to rebuild the OS on the machine tomorrow but so far so good. I even found a NIC for it. Cool thing is the machine boots in about 5 seconds. Once the OS install is clean and things are working well with the board I'll try to start building up some spares...
Macintosh LC arrived today and is able to load the JL Cooper software. I'm going to rebuild the OS on the machine tomorrow but so far so good. I even found a NIC for it. Cool thing is the machine boots in about 5 seconds. Once the OS install is clean and things are working well with the board I'll try to start building up some spares...
K
Kittelsen
New member
Hi,
just a short question to the Tascam m3700 Topic...has anybody an idea how to install the
balancing boards (got two ins an one out without cables, just the pcbs)??
Thanx
just a short question to the Tascam m3700 Topic...has anybody an idea how to install the
balancing boards (got two ins an one out without cables, just the pcbs)??
Thanx
S
sr71rules
Member
I suspect they go under the meter bridge.. I'll take a look around on mine to see if I can be any help.
Honestly though, I wouldn't bother. Even if you use the balanced I/O the whole board internally is unbalanced so unless you have to run really long cables for some reason it's probably not work the trouble.
Honestly though, I wouldn't bother. Even if you use the balanced I/O the whole board internally is unbalanced so unless you have to run really long cables for some reason it's probably not work the trouble.
K
Kittelsen
New member
Ok, thanks.
The main problem is to wire the pcbs right.
Perhaps you can find something...
Greetings
The main problem is to wire the pcbs right.
Perhaps you can find something...
Greetings
S
sr71rules
Member
I have the Macintosh LC wired up to the board with MIDI via an Opcode Midi-to-Serial interface and I can see fader moves happen in real time on the screen. Pretty cool! Happens a lot faster than I expected. I have the board short loaded with only 8 channels strips but the Mutes and EQ buttons work like a charm and show up on the screen.
I'll try and post a video showing it's function this weekend.
Couple of small issues I'm seeing:
1.) Faders 23 and 24 don't register on the computer. A quick visual inspection doesn't show any thing unpluged or damaged but I'll dig a little deeper when I have time.
2.) Many of the faders are a bit jumpy as you move them up and down their throw. I expect this is dust or grit in the fader. The fader package is considerably more complex than those on the M3500, obviously, but I imagine I can still get inside for a good cleaning. Am I safe to do as Tim Kroger did with his M3500 and give them a once over with Dexoit D100?
The amazing mass of cables below the master section of the board with the automation system is incredible and it's not something I look forward to disassembling again... Tascam did do a nice job with color coding though so it's not too hard to reattached the 50 or so connectors.
Robert
I'll try and post a video showing it's function this weekend.
Couple of small issues I'm seeing:
1.) Faders 23 and 24 don't register on the computer. A quick visual inspection doesn't show any thing unpluged or damaged but I'll dig a little deeper when I have time.
2.) Many of the faders are a bit jumpy as you move them up and down their throw. I expect this is dust or grit in the fader. The fader package is considerably more complex than those on the M3500, obviously, but I imagine I can still get inside for a good cleaning. Am I safe to do as Tim Kroger did with his M3500 and give them a once over with Dexoit D100?
The amazing mass of cables below the master section of the board with the automation system is incredible and it's not something I look forward to disassembling again... Tascam did do a nice job with color coding though so it's not too hard to reattached the 50 or so connectors.
Robert
miroslav
Cosmic Cowboy
I'll have to look for them...but I have the original Balancing Kit installation instructions from TASCAM.
If I find them, I will scan them and post them up.
(Is that you on Gearslutz asking the same question?)
K
Kittelsen
New member
Wow, that would be great!!
Yes I think its me on gearslutz...
Yes I think its me on gearslutz...