I swapped the clipping diodes in my DS-1 to LEDs and holy fuck it sounds amazing now.

Anyone ever prototype for 500 series? A guy dropped off a Yamaha M916 Console at my house a few years ago and I'm thinking about parting it for Preamp and EQ's. Wondering if doing it with some sort of 500 Series prototype boards would be a good solution. Seems like maybe an idea.

Kniferide wrote: Tue Aug 26, 2025 5:24 pm Anyone ever prototype for 500 series? A guy dropped off a Yamaha M916 Console at my house a few years ago and I'm thinking about parting it for Preamp and EQ's. Wondering if doing it with some sort of 500 Series prototype boards would be a good solution. Seems like maybe an idea.

wouldn't those channel strips be more suitable for 19" racking or even make a wooden box with a front panel to mount the channels and then use a power supply from fivefish audio or JLM? not even sure if you could regulate a 500 series rack to the needed +24/-24 volts.

bassdriver wrote: Sat Aug 30, 2025 3:06 am

Kniferide wrote: Tue Aug 26, 2025 5:24 pm Anyone ever prototype for 500 series? A guy dropped off a Yamaha M916 Console at my house a few years ago and I'm thinking about parting it for Preamp and EQ's. Wondering if doing it with some sort of 500 Series prototype boards would be a good solution. Seems like maybe an idea.

wouldn't those channel strips be more suitable for 19" racking or even make a wooden box with a front panel to mount the channels and then use a power supply from fivefish audio or JLM? not even sure if you could regulate a 500 series rack to the needed +24/-24 volts.

I wasn't sure of the spec of 500 series, but the one place I found 500 series proto boards had +/- 24v on the blade connector, so I assumed the did it. I have none and have been avoiding 500 series for the same reason I avoid Eurorack modular... Money pit swapsplosion disorder. I was just thinking it might be a fast good way to get a few channels affordably that doesn't take up much space. I have very little space. Still looking at options. I have only looked inside for about 5 min, I think there was a mouse in there! Wiring is in a way.

I have done some 500 protoboard/shoehornin’
10 or more years back you could get the card edge, and blank ‘sleds’ from CAPI

I had a metal shop make a bunch of sleds and I drilled as needed…I will go dig through some abandoned projects and take pics

500-series is a money pit but that stuff sells so fast on resale it almost makes up for it.

might be easier to just get a proper power supply and build a adequate case to put them in. I have zero room for any more 19" racks in my room so table top was the plan and small was the hope. I kind of want to see if I can slice up the channel strip to make the EQ and Preamp sections side by side as opposed to in a line to save space. I'm going to poke around and see what can be done. I got the mixer for free so it isn't costing me a single thing. I've considered just trying to revamp the whole mixer but I'm not sure I have the time/skills to do it.

We picked up an Acoustic bass 410 in the practice space a while back with a 'free' sticker. Sat it under the main cabinet and forgot about it .

Got around to plugging it in- nothing. Pulled the box out of the back with the circuit board for the tweeter, speakon etc etc stuff in there. A capacitor has come loose and looks busted. I think it's just a replacement and we're good to go. Took it home to investigate further. Will report back.

I’ve got a gain issue on a little Spectra STX complimiter preamp 500 unit. I thought it was a phantom power thing, but its not so simple

These are some of my favorite pres, even over the big 610s since the STX600 has a more limited range and is easier to setup, at least until I get a rolling rack setup that I can use away from the little ‘control room” area.

Basically, its got an input and output gain. You turn up the input until the threshold light blinks sometimes, then leave it - that’s peak limiting mode. Turn up more if you want compression regular compression w/o peak limiting - that’s where the threshold light blinks pretty much any time there’s signal.

So anyways, I have two, and one felt like it needed more juice than the other, but its hard to tell. Of course an acoustic instrument is going to require a different gain structure than a condenser in front of an amp, and while I would use them together in a pair, they would have diff mics or different positions.

Last night it starting hissing quite badly out of nowhere to where it was unusable. I was using my KU5A on a nylok string acoustic and thought it was a phantom issue. The outboard phantom seemed to work at first, but then the hiss returned.

Anyways, while troubleshooting I started to heat rain very clearly from outside and realized that I wasn’t just getting hiss, I was getting a shitload of gain from the complimiter pre start to roll in out of nowhere. I’m glad this didnt happen in the middle of a take on an amp.

At this point, I don’t know what to do other than swap out other mics and cables and 500 series slots. I bought this one used, so not looking forward to sending this back to Spectra, but at least they’re there to fix this stuff. I just get nervous about pro audio repair bills.

I have a fancy Emo (?!) mic splitter with Carnhill transformers, so when I next record an amp I’ll send a 57 to both Spectra complimiter pres and just see what happens with the initial setup and intermittent issue.

Kniferide wrote: Sat Aug 30, 2025 1:14 pm
I wasn't sure of the spec of 500 series, but the one place I found 500 series proto boards had +/- 24v on the blade connector, so I assumed the did it. I have none and have been avoiding 500 series for the same reason I avoid Eurorack modular... Money pit swapsplosion disorder. I was just thinking it might be a fast good way to get a few channels affordably that doesn't take up much space. I have very little space. Still looking at options. I have only looked inside for about 5 min, I think there was a mouse in there! Wiring is in a way.

500-series is an API standard and only has +/-16; there's a different, very rarely used system called 51X that adds +/- 24 to the edge connector. 500-series modules will fit in a 51X rack, but the reverse is not true. You might've found a 51X protoboard.

I think other 500-series projects running on +/- 24 are probably using charge pumps?