ER-301 power concerns

hey all. i just put all the mannequins set with teletype, ansible, and er301 in my move 104. i set the er301 5v to BUS, as well as split my usb cable to the monome to external power. hence i should be close to being ok with power. supposedly i’d be at 1023 mA +12V which would be over for the move 104 (850-900mA on the +12V). but brian has said here that the er301 set to BUS would be 120mA +12V, and according to brian from monome, the ansible draws only 40mA +12V when not powering the monome, which i’m not cuz of my mod. so, according to these two workarounds, instead of the 1023 mA +12V, i should be actually at around 683 mA +12V, 321 mA -12V, and 0 mA 5V. the specs on the move104 should be +12V @ 900mA, -12V @ 700mA, and 500mA @ +5V. well within means it would seem.

here’s the issue: my er301 visibly pulses when placed in the move104 with mannequins modules. when the mannequins modules (all) are unplugged, it stops pulsing. when i plug it into another case, it stops pulsing as well. but i’m pretty sure i’m within my power range, yet who knows. here’s a video or what the display is doing. it’s fully functional, btw, as far as i can tell. i noodled two hours with no issues (i thinks!?)

thanks. just wanna know if i’m risking any problems with breaking anything. i’m not concerned about my case. it’s cheap. i’ll prolly just get another case. anyways, thanks in advance.


keep in mind if you’re set to bus, then the 301 will need 320ma from the 5V rail, not 0ma. Are you sure nothing else is using 5v and pushing you near the edge?

haha i’m watching your new videos right now!!! kick ass. glad you’re doing them again. missed em!

the only thing using 5V is the er301.

ps. i’m way over the 900mA on the move 104’s power, but see caveats above. *


hmm… i wonder if the 5v feed on that psu… is just… dirty?

upon further inspection, it would seem i have an older move 104 under these specs.

hence my overhead is 850mA +12V and 300mA +5V.

i’m cutting it so close it’s dumb. i’m dumb haha.

Yeah, I was going to say that a. it looks like ripple and I wonder if the voltage from that rail is well regulated and b. I’ve seen lots of reports of power difficulties with various modules with users using Pittsburgh cases.

I had a Pittsburgh move 208 and the power supply was terrible… noise, grounding issues, crosstalk… and that was the last version before they were discontinued so if this is an even earlier revision you probably have a dirty 5v supply

yeah you’re going to blow that PSU or hurt the 301 or both. You’re 20ma short, AND switching power supplies don’t like operating at 100% capacity, let alone going OVER (ER301 needs 320ma on 5V if the row switch is on bus mode). This is also an indication of the PSU quality as there appears to be no overload protection (most switching supplies kick on and off on overload or shut off). So if it’s straining it may even be dropping the voltage on the rail… essentially giving the 301 a brownout of power. :open_mouth:

I’d sub out the Power or find a new case… in the mean time I’d remove enough modules to properly run this on the +/- 12 rails to avoid any damage.

The 301 isn’t a module I’d want to damage., a) because it’s awesome b) it wouldn’t be a cheap fix if there was damage outside the CPU pop-in board (guessing) c) Brian is away for a month! :open_mouth:

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Hi all! First post here : - )
Hopefully this question belongs in this topic.

Just received my ER-301 yesterday, and I’m super excited to dig in!
However, the ribbon cable it shipped with with isn’t very long and doesn’t reach the bottom of my (admittedly very deep) case.

I have a longer 16-to-16 ribbon cable that I use with my O’Tool scope…but for some reason, that cable, which I bought used, has a blue stripe, and a small portion of the other side of the cable is colored in red with a Sharpie…The blue side slots in with the -12 marked on the pcb (which has a keyed connector like the 301), and has worked fine, but I’m still worried it’s somehow mis-marked.

Which is all a long way to say I don’t want to accidentally fry this beautiful sound computer with my crappy second-hand ribbon cable. Hopefully someone wiser than me can help me out. If it has keyed in and worked fine with the O’Tool, is there any reason why it wouldn’t work with the 301? Sorry if this is the dumbest question ever.

Here’s a picture of the second-hand cable in question:

I would just ignore the red marking on that cable and use the blue line as your reference. So basically treat the blue line like it is the “red line”.

All that matters is that -12 on the module is matched with -12 on the psu.

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Thank you, took the plunge and tried it out and it’s all working fine! Now to practice!

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