I want one of these...like rillyrilly bad...>>PS520<<

[sweetbeats]

Sent a well-written (IMHO) email to the radio station that originally owned the $50 M520 I pick up on Wednesday with a plea to assist in locating the power supply that allegedly never left the station with the console...sent it from two email addresses in case it was getting caught in their spam filter. Not too hopeful though.

Please keep this in your memory in case you hear of one for sale.

Those that are into prayer, please lift one up occasionally about this.

I've been reading up on the M520...mixed reviews...this is my favorite statement from a critic:

"summing busses with no headroom. Try 5532 chips in every channel that sound like ass. Try no way to directly assign an input channel to the master output; must pass through a superfluous gain stage/summing amp. Try pcb-mounted RCA connectors for all gozintas & gozouttas.

One of the worst-sounding boards I have ever had the displeasure of working with...and unfortunately I got stuck working at three different studios that all had M-520's during the mid-1980's."

Don't really care too much about that opinion...I figure its got to sound better than my ART Phantom 1608 board ever did, or than my Yamaha 01X does now (not that I'm not happy with it).

I tried to find the pics with the worst presentation of the M520 to out up on the What would you pay... thread. I was looking over all the pics today and it really is a nice looking board...will need cleaning and who knows what actually works, but HELP ME FIND ONE OF THESE.

 

[cjacek]

Cory, what you are hearing, for the most part, are the so called 'pros' who thumb their noses at most of the gear we own and discuss on this board. You have no idea how many people think Tascam and FOSTEX is junk and that anything below a 2" 24 track and a $100,000 console, is useless. We know better, don't we? My best advice is to not listen to 'em. If I went by their recommendations, I'd never have what I currently own. The M520 is a fine, fine board.

I will keep a close lookout for the power supply. That I can promise. BTW, I sent you a PM.

-----

 

[sweetbeats]

Thanks, Daniel.

I appreciate that very much.

Yeah, there was a review or something I read somewhere where the M520 was regarded as one of the best "budget" boards of its day...I compare what would be in the same relative cost-basis in today's dollars and I'm realizing that what the reviewer was considering non-budget would be the $100K+ consoles, and budget would be in the $10K range...okay..that's certainly good enough for me. More pro than I can handle.

I'll probably start a thread with the details and progress of the M520...probably call it "Tascam M520 Story..."

 

[Dr ZEE]

heh heh

If I went by their recommendations, I'd never have what I currently own.

Incorrect.
If you went by their "recommendations", then you would never need to have what you currently own. Instead all you'd need to do is to submit to their services.
And the best part of it is that you could "free yourself" completely and to dedicate all your time and "creative" energy to "actually" "music" and actually "performance", and "your" recordings would sound absolutely "amazing". Hey! you even could become No More Lonely - that is on a Big Screen TV!!!!!! Imagine That!
And then at the end you could "own" anything you wish to own.

 

[evm1024]

want one

If you think about it you will realize that the Mona Lisa has a crooked smile.....





I do look for a M520 to replace my 312b once in a while. Nice score.

 

[mshilarious]

"summing busses with no headroom. Try 5532 chips in every channel that sound like ass. Try no way to directly assign an input channel to the master output; must pass through a superfluous gain stage/summing amp. Try pcb-mounted RCA connectors for all gozintas & gozouttas.

Why does everybody hate on 5532 so bad? Yeah, it's an old design, but it still specs pretty well up against modern chips, certainly at the price. I rate it as very useable. Back in the day, they would have certainly picked it cause it kicked the ass of many/most of the alternatives.

Heck I bought some 553 (2 or 4, I can't remember) SIPs to upgrade my 424mkII . . . then after I disassembled it, I haven't got around to it

PCB-mount connectors aren't a big favorite, but if you don't patch constantly, they should hold up.

 

[dementedchord]

those power one modules i told you about used to be available from digikey... should still be there... look at the manual for current draw... bump it up 25-50 % for better headroom... and build a box to hold them.... you may need to devise your own cableing and connectors...

 

[sweetbeats]

mshilarious,

Why does everybody hate on 5532 so bad? Yeah, it's an old design, but it still specs pretty well up against modern chips, certainly at the price. I rate it as very useable. Back in the day, they would have certainly picked it cause it kicked the ass of many/most of the alternatives.

Heck I bought some 553 (2 or 4, I can't remember) SIPs to upgrade my 424mkII . . . then after I disassembled it, I haven't got around to it

PCB-mount connectors aren't a big favorite, but if you don't patch constantly, they should hold up.

Thanks for the info. Helps to put things into perspective.

And I definitely don't plan on doing any frequent patching/repatching those RCA connectors...I'm using patchbays for that, and even at that if there is a problem with a jack (cold joint and such) that's what the soldering iron is for.

dementedchord, are you talking about these?

I would definitely need some help...never built a power supply and this would be a big project. I don't know what half those terms mean (as far as supply type...) I'll play around with the page, and maybe it will make more sense when I have the manual for the M520. I was thinking I could even use an ELCO 20-pin connector to connect a fabricated power supply if need be, but selecting the components is definitely over my head...I do have a nice beige rack-mount enclosure though...hmm...I do know enough to be dangerous...that would really stink to try and build a supply, get something wrong and then cook part of the board or worse.

 

[mshilarious]

dementedchord, are you talking about these?

I have bought a switching supply from Digi before, there are some nice units there, just make sure it fits in your rack box and vent it. You will want a linear regulated supply though. You can probably build a linear supply for cheaper than buying, but I bought the switching supply because I needed lots of current and they are way more efficient (also it wasn't an audio application).

Anyway. Did I miss the PSU requirements? Do you need a 20 pin connector? I like to use Speakon connectors for power, if 4 pins is good. Or there is 5, 7 pin XLR.

 

[sweetbeats]

The M500-series consoles use a rare 20-pin connector. Not sure if it uses all or even most of the conductors, but I do know it has been impossible to find spares, so if I fab a PS I figure I'm going to need to change out the male PS connector that is on the console. Its on the left side of the back of the console (as you look at the back).

There's a picture in post #28 of this thread.

 

[themaddog]

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

 

[dementedchord]

mshilarious,

Thanks for the info. Helps to put things into perspective.

And I definitely don't plan on doing any frequent patching/repatching those RCA connectors...I'm using patchbays for that, and even at that if there is a problem with a jack (cold joint and such) that's what the soldering iron is for.

dementedchord, are you talking about these?

I would definitely need some help...never built a power supply and this would be a big project. I don't know what half those terms mean (as far as supply type...) I'll play around with the page, and maybe it will make more sense when I have the manual for the M520. I was thinking I could even use an ELCO 20-pin connector to connect a fabricated power supply if need be, but selecting the components is definitely over my head...I do have a nice beige rack-mount enclosure though...hmm...I do know enough to be dangerous...that would really stink to try and build a supply, get something wrong and then cook part of the board or worse.

yep that's the guys i meant... at one time you had to buysingle supplies of the rating you needed and put insame box... where now it seems they have multi-voltage so cool... the schemo should tellus how many of those pins are really used... i suspect only 5-10 are used.... you'll need +/- 15/18V for audio rails and 48V for phantom... so even if there's separate grnds and double wirring it still would only be 12 pins... cant remember does this have any mute or memory functions like subgroups??? ya may need 5V for that... read the spec page carefully it should tell us what the requirements are.... or maybe someone here can read it off of theirs???

 

[SteveM]

Incorrect.
If you went by their "recommendations", then you would never need to have what you currently own. Instead all you'd need to do is to submit to their services.
And the best part of it is that you could "free yourself" completely and to dedicate all your time and "creative" energy to "actually" "music" and actually "performance", and "your" recordings would sound absolutely "amazing". Hey! you even could become No More Lonely - that is on a Big Screen TV!!!!!! Imagine That!
And then at the end you could "own" anything you wish to own.

They might even give you healthcare, long term financial stability and feed you too!

 

[A Reel Person]

My friends, you sent me to the M520 manual for this one!...

The M520 manual on p. 178 has the circuit diagram of the PSU and the pinouts of the connector. It is an 80's style latching 20 pin connector, but by the diagram several pins are shorted together, and some are not.

However, the diagram reads:
-15V (Pins 14, 15)
0V (C) (Pins 8, 9)
+15V (Pins 1, 2)
GND (Pins 12, 13, chassis)
+48V (Pin 16)
0V (D) (Pins 10, 11)
+6V (Pins 3, 4)
11V AC (Pin 17)
11V AC (Pin 18)
-18V (Pins 19, 20)
GND (same as above)
+18V (Pins 6, 7)
[Current ratings are not specified].

All you design guys with PSU recommendations might have gotten more than you bargained for with this one!
/edit/
Never mind, dementedchord seems to have nailed it above, tho' it seems like a lot of hassle to patch this crap together, and no doubt the 11V AC seems off the wall or at least unexpected.

 

[mshilarious]

However, the diagram reads:
-15V (Pins 14, 15)
0V (C) (Pins 8, 9)
+15V (Pins 1, 2)
GND (Pins 12, 13, chassis)
+48V (Pin 16)
0V (D) (Pins 10, 11)
+6V (Pins 3, 4)
11V AC (Pin 17)
11V AC (Pin 18)
-18V (Pins 19, 20)
GND (same as above)
+18V (Pins 6, 7)
[Current ratings are not specified].

It's that last comment that's a bitch. Without knowing current, you're shooting in the dark.

I don't get the need for +/-15 and 18V. Pick one!!!! If you can figure out where the 15V goes, 18V might be fine there as long as you're not exceeding ratings.

+48V isn't hard for a phantom supply, allow for 10mA per mic, and build a voltage tripler off the 18V rail and regulate. There are plenty of schemos out there that show you how to do that. If +6V is a logic rail, it probably doesn't need much current and can be divided off +18V. Or they could use it to drive LEDs.

11VAC, that is a doozy. VU meter backlights, maybe? That would require a multitap tranny, because those backlights probably use as much current as the rest of the board!

 

[A Reel Person]

Thanx MsH...

IIRC the Tascam VU backlight is an 8V DC tube or fuse type bulb.

I think perhaps the 11V AC may be used in the talkback section or maybe to feed the test oscillator section.

That's an assumption that would have to be verified in the manual, maybe later/TBD.

Yeah, I knew that the "current rating not specified" was a show stopper.

 

[A Reel Person]

If...

If I get a chance, I might try to scan the entire PSU circuit diagram to post it. However, that's just one page and it only specifies where on the 20-pin connector the voltages terminate. It's many, many more manual pages of schematics to determine exactly where every voltage goes to. Even if I scan one diagram, I'll probably not have the opportunity to scan the entire manual. These schematics are oversized foldouts, BTW.

SwBeatz might be better off to order the entire M512/520 manual reprint from Tascam. That way you would at least have a book and you could use the M520/less-PSU as a bookend!!!

Sorry dude, I couldn't help myself from making another M520 joke.

 

[dementedchord]

I don't get the need for +/-15 and 18V. Pick one!!!! If you can figure out where the 15V goes, 18V might be fine there as long as you're not exceeding ratings.

11VAC, that is a doozy. VU meter backlights, maybe? That would require a multitap tranny, because those backlights probably use as much current as the rest of the board!

yeah the 15 and 18 sounds kinda weird to me as well... i suspect your right about the 11Vac is for the metering lights...

but we're screwed without some idea on the current consumption...
is it listed on anyones supply??? how about fuses for the individual rails what are they rated at???? the 48V mostlikely is'nt much... the audio ralis are what worries me... anybody know of a pdf for the manual???

 

[A Reel Person]

...

Search on this site for all posts by user name: "kiira".

I believe she posted the M512/520 manual up once about 2 years ago, but I couldn't get the D/L to open properly. Despite that, it may be worth searching out.

Tascam still sells reprints of the manual, and I think that's advised in this case.

 

[dementedchord]

that thread was feb '06... and apparently she took down the pdf.... too bad...