Tascam M-3500 refurbishment

As to 3500 schematics, send me your e-mail. I have what you need.

Pulling caps is tricky; be careful. May clean the signal path but may also open the door to spikes to an IC or opamp!

As to fader lube, I'd suggest you contact Viva Nguyen at Caig (viva.nguyen@caig.com )

He will set you straight as to what cleaner is best for what, and you don't have to guess.

Like the stand for the mixer.
 
timkroeger said:
If the faders ain't misbehaving, don't do anything except some cleaning or maybe use the D-100 on them like Miroslav described. They're very good, unless you mess with them like I did. Ahh well... :spank:
Click to expand...

In case you want to try and buy some new ones...Farnell Electronics, UK use to carry them a couple of years back...not sure if they still do.
Here in the USA, Mouser Electronics use to carry them...and of course TASCAM use to...not sure if they even still do???

The other option is to wait for someone to part out a 3500 on eBay. I bought a new stereo fader from Newark/Farnell and a couple of mono faders...but I got a bunch of used ones in great condition (just needed some cleaning, but plenty of life in them) from a guy who parted out his board (along with some channel sections, master section, meters, power supply...).
I can now run for another 20 years with my 3500. :)

There are still 3500 boards being sold on eBay (some real cheap)…so anyone planning to keep theirs going for a long time…grab some parts or a complete spare board while you still can!
 
Funny this thread popped back up. I was just looking into re-capping the M-3700 PSU, but it doesn't look like Mouser has the 35v caps I'd need.


Also I've been curious about playing with opamps a little. I've no intention of re-chipping the whole board due to cost/relative value, but was curious if it would be worth trying some opa2604 in the vicinity of CR monitor/master buss, though not clear on whether it would make sense, where they would go or whether the circuit would need to be modified to prevent oscillation (some say yes, some say no). If it's gonna be complicated, I won't bother; if soldering a few direct replacements in place of certain 4580Ds would open up the stereo L-R summing and monitoring, then swell. My main monitors are Dynaudio BM15As with Zu Birth cords on a Furman power regulator with some further conditioning/PF correction so they would certainly show any improvement...also wondered if re-chipping the first three in the inputs (mic pre/EQ section) would be worth it, even on just 4 or 8 channels. Maybe this kind of thing would sweeten the pot when it's time to sell this console...and maybe not!

After reading Tim's post above, maybe I won't bother though. It seemed that most of the positive rechipping reports cam in conjunction with expensive and complicated re-capping jobs, grounding mods etc so it's not as clear which made the biggest improvement in noise floor and improved fidelity. Tim, can you tell me where in the manual (or in which places on which boards) I can look to see where you put in the BB chips?
 
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briank said:
Also I've been curious about playing with opamps a little. I've no intention of re-chipping the whole board due to cost/relative value, but was curious if it would be worth trying some opa2604 in the vicinity of CR monitor/master buss, though not clear on whether it would make sense, where they would go or whether the circuit would need to be modified to prevent oscillation (some say yes, some say no). If it's gonna be complicated, I won't bother; if soldering a few direct replacements in place of certain 4580Ds would open up the stereo L-R summing and monitoring, then swell.
Click to expand...

Based upon my own findings I'd tend to say it's not worth it. From what I read 2604s are nice chips but they were definitely oscillating in a few positions of the channel modules. They need more power and I didn't hear a difference. Now, that might just be my ears. If you have very good monitoring equipment I'd definitely be interested in hearing if you'd notice a difference. But I'd use OPA2132PAs 'cause you wouldn't have to alter the circuit and you can use sockets and they still don't oscillate.

Regarding "opening up" the summing, I don't really know how that might sound. What would I try to listen for? That's my basic problem with all the articles and posts I've read, I don't really know how to interpret terms like "opening up", clean, clinical, depth, lively and such.

Cheers
Tim
 
It looks like the OEM PSU caps called for in the service manual for the M-3700 are:

4x 22,000uf 35v
2x 18,000uf 35v
1x 1000uf 100v
1x 2200uf 25v
1x 6800uf 35v


The Nichicon PW line recommended in this thread seem to top out at 15000uf...any other suggestions? I can solder just fine but I'm still learning about specs...
 
I believe you are right but you can parallel the caps.

The PW series listing file is too big for this system.

If anyone wants just let me know.
 
timkroeger said:
Regarding "opening up" the summing, I don't really know how that might sound. What would I try to listen for? That's my basic problem with all the articles and posts I've read, I don't really know how to interpret terms like "opening up", clean, clinical, depth, lively and such.

Cheers
Tim
Click to expand...

Mainly I would be after a smoother sound all around, with a bigger, punchier soundstage a little more substance in the midbass and a more dimensional midrange; it seemed from what I read that the opa2604 would possibly offer exactly such attributes but I wouldn't bother if I had to alter the circuit to stop them oscillating as that's too complicated for me. I've read that the opa2132PAs would also be an improvement over the stock opamps although not as "fat" in the midbass or as dimensional a soundstage as the 2604s...but knowing that they're less likely to oscillate, maybe it would be worth playing with a couple of them...certainly my monitors are up to the challenge, though the 2132s are quite expensive.

When I say dimension, I mean literally when sitting behind the monitors, the soundstage, or speaker's envelope, should seem more 3-D, like I can close my eyes and "see" and "feel" the instruments in front of me. When I say punchy, think of the of a very dynamic kick drum and snare "hitting you in the chest" or a "thumping bass guitar."
 
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Put really good caps in the circuit and films for non-polars and the mid and high end will just open up.

You would be amazed as to difference that can make w/existing opamps.
 
Auction: Tascam M3700 full optional but without power supply on ebay

Hi, cause i've urgently need some money i've put a Tascam M3700 32 channel mixer on ebay.

My item is a full optional one ( with meter bridge, jl coopeer midi automatation, balanced board ) but there's NO POWER SUPPLY .... so the start price is very cheap

I can't insert direct link ( cause i don't have al least 10 post here )... but you can easly find on ebay my username is "askmarstar"

Also i've other items on auction too like ada8000 modded and so on...

thanx

Rob
 
Price is cheap, but the mixer is useless without the power supply (except for parts), what happened to it?

Alan.

P.S here is the link. And it's in Italy so factor in freight unless you are nearby.
 
witzendoz said:
Price is cheap, but the mixer is useless without the power supply (except for parts), what happened to it?

Alan.


Hi Alan i've buyed the item as is from a '90 famous italian music tv show called "Roxy Bar", so i've never owned the PS.

And of course You're right about freight factor but i hope some european users can find my m3700 interesting...at least i hope so....but if that's no the case i'll start selling by parts ( but i really disappointed about mixer's disjoint)

best wish

Roberto
Click to expand...
 
Right...i've never turned on and the previous owner didn't have the PS

But please don't forget the starting price very low.....i've set up meaning charge just the value of spare parts like meter bridge, fader and so on
 
Hi there;

I own an M3700 and am looking to sell it as well (USA based on the East Coast).

It seems that the point being made here (from what I can tell) is that if this board has never been turned on (or seen working) by you, then you really do not know for sure if the mixer is "fully operational". Correct?

Is that a proper assessment? (Just trying to get to the point)

Thanks.

AK
 
fonzobrown said:
Right...i've never turned on and the previous owner didn't have the PS

But please don't forget the starting price very low.....i've set up meaning charge just the value of spare parts like meter bridge, fader and so on
Click to expand...

I agree the starting price is low, and if it was in my town I would pick it up, however as it has not been turned on and tested it can only be considered as a parts machine. Unless someone wants to build a power supply. I hope you did not pay much for it? I have seen power supplies sell for as much as some consoles.

Alan.
 
I've payed almost 700 euro...because who sold it to me said that was perfectly funtional ( until the tv show was closed )

But for those that look at my auction please consider UNKNOWN FUNCTIONAL STATUS 'cause having no PS i haven't had the possibility to check it

In the end, from a price range prospettive and as Alan rightly said, consider my 3700 as parts machine...as simple as this!

My plan is to wait next sunday ( auction end ), and if nothing happens i'll start to sell it by parts 'cause i'm little in trouble with money

And if even this will never work ...when will be a better time with money i'll try to buid a PS using JLM Audio's power station or somthing like that

Rob
 
No lucky with Ebay auction...so i'm starting to sell my tascam m3700 by parts!

I don't wanna "spam" this thread with my personal affairs....so this is my last post about auction/selling things

Please feel free to contact me to my personal email for quotation

roberto.fonzo(at)email(dot)it

Next sunday i'll put the avaible items ( m. bridge, jl cooper midi, alps faders ,preamp module, etc. ) on ebay again....but until that i'm open to set the price point on single item with You

Best to all

Roberto
 
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