Howdy Cap'n Witzendoz.
Any chance u got a copy of PSM3700 schemo/pinout.Im trying to find the rail output specs (amperage wise) of both rails and wondering if both rails have individual trimmers or are they fixed ?
Am toying with the idea of using this supply rewired to pump juice into a soundcraft spirit in place of its woefully underpowered cps 150 psu.
That thing has 1.5 amp rails so im hoping the 3700 matches or exceeds that...
You won’t find any relevant or helpful output current specs in the M-3700 service manual for the PS-3700 power supply. But I did some load testing once on its nominally less robust PS-3500 cousin. It’s not bad. I don’t remember what the voltage was at the main transformer taps that power the +/-15V rails when it was unloaded, but I started my load tests with a 90R load and the voltage across the taps was 38.3VAC. That’s 0.43A. That’s where I started. I progressed to a 9.6R load, and the voltage only dropped to 36.75VAC. The line voltage at the time of the test was 119.4VAC. That’s 3.83A, so I think the PS-3500 is conservatively good for at least 2A per side on the +/-15V rails, and that seems about right because my experience is Tascam PSUs like this seem to be built to handle about double the theoretical maximum current of all the active devices...with some margin beyond that. I stopped at 9.6R load because that’s as far as I needed to go…that informed me it was plenty burly for what I needed. Anyway, that theoretical maximum in the M-3500 is just over 2A total for all the active devices powered by the +/-15V rails, and my load testing suggests the transformer could go at least 2x that, depending on main line voltage conditions. And the rest of the components in the supply, IIRC, were good for that. The PS-3700 supply would be good for something marginally greater than that because of the additional circuitry onboard the console which would increase the supply demand. The PS-3500 and PS-3700 do not share the same transformer…the PS-3500 weighs about 30lbs, the PS-3700 weighs about 44lbs…most of that differential is probably in the main transformer.
Regarding adjustable voltage, I don’t have the service manual for the M-3700, just the M-3500, but the output voltage can be adjusted, but not all simple like adjusting a potentiometer. The +/-15V supplies utilize a single Mitsubishi M5230L dual-tracking regulator…it will regulate between +/-3V to +/-30V. Now, of course, you can’t take it up to +/-30V in the PS-3500 because you’re limited by the voltage at the main transformer taps under load, which I included above…you’ve got to take the voltage at the output of the transformer under load and then include a margin for low line voltage conditions, voltage drop across the bridge rectifier and main filter caps and then consider the minimum Vin - Vout specs of the M5230L itself. But that tells you under load what the transformer can do with the regulated supply it powers. In the PS-3500 I think I figured the main transformer was *conservatively* good for at least 1.5A per side (3A total) at +/-16V. You adjust the voltage by changing the value of specific components hanging off the adjust pins of the M5230L. You can read the gory details in the datasheet here:
http://pdf.datasheetcatalog.com/datasheets/270/220427_DS.pdf
Again, the PS-3700 I believe can go beyond what I determined the PS-3500 is good for, but I don’t have any details.
You want to run it at +/-17V. You quoted 1.5A for the CPS 150. It looks to me like it’s actually 1.25A per side? But here’s the rub…you can tell something about a linear supply generally by how burly the main transformer is…how much the thing weighs. Again, PS-3700 = 44lbs…CPS 150? About 9lbs. I’m thinking that’s why the CPS 150 does not have a lot of fans. I bet the main transformer is saturated at 1.25A per side where the PS-3500 I tested was pushing 2A per side and still going. The voltage drop was not suggesting at all the main transformer was crapping out. And the PS-3700 is beefier.
Short answer: I’m reasonably certain PS-3700 would grind CPS 150’s bones to make its bread, and then make CPS 150 eat its own bone-bread…while powering the M-3700…with one hand tied behind its back.
Then there’s the power supplies for my Studer console. They are loaded with modular Lambda switching power supplies. The +/-15V supply is rated at 10A…*per side*…and…my console uses three of them. So I’ve got 60A total on tap across the +/-15V supplies. Now we’re talking.
But Teac did a reasonably good job in this era with over-engineering their outboard linear console supplies. Seriously I don’t think the PS-3700 would have ANY trouble getting the job done.
Which console are you powering with the CPS 150?
then I realize what happened! 
