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+/- 16 transformer

PostPosted: Wed Sep 12, 2018 9:00 pm
by arjepsen
Hey.
I bought a +/-15vdc power supply, in my quest to get rid of the big bulky cpu unit.
However, I'm suspecting that it is giving me trouble.
I can adjust the positive side to provide 16vcd, but unfortunately the negative side stays at around -15,3 volts.
Generally the desk seems to work fine, but there are small problems, like: I can't load plugins to my ufx cards.
(have tried moving the fx cards around with no change).
Now I'm trying to make a +/- 16v power supply myself, but I'm having trouble figuring out the specifics of the transformer that I need. Anyone know the specifics of the transformer that powers the +/- circuit? can't seem to find specifics in the service manuals.

Re: +/- 16 transformer

PostPosted: Thu Sep 13, 2018 1:19 am
by FrankH
Can't help you with the supply. Sorry.

I just wanted to ask, to be clear: are you planning an attempt to move a smaller CPU with its associated cards, power supplies and cooling into the d8B desk itself?

If so, I should back up Crash's response to that in the other thread. The original design of the D8B was actually planned to do just that. (I actually have a proto D8B with a floppy disk slot built into the armrest that was part of this plan).

The reason they gave up on this plan was basically two reasons:

1. It became impossible to control the heat inside. Fans didn't help and introduced a ton of totally unacceptable noise radiating from the desk.

2. (and this was the killer) the CPU radiated uncontrollable EMI and some RFI into the rest of the desk's circuitry, making the audio pathways pretty much unusable. Just a shit-ton of "click-click-click" clocking noise everywhere.

Just thought I'd point this out.

Re: +/- 16 transformer

PostPosted: Thu Sep 13, 2018 6:51 am
by arjepsen
Thanks for the reply. Sounds interesting with the old prototype :-)
I am thinking about putting power supplies in there, though not the entire cpu unit. My idea was to still keep the pc parts outside - it's not too difficult to have a much smaller pc on the outside, but I want to get rid of the BFC and umbilical cord.

I have a 5V supply, 12v supply, and the +/- 15v as mentioned. Also a small 48v for the phantom power.
They can fit inside, no problem, but I haven't check it out regarding noise - at the moment they are lying just outside, with wires going in - for testing.
The 5V and +/15V do get quite hot - not sure if it's too much though I might be able to attach them to an external heatsink with some hacking, but would prefer not to. More testing has to be done for this issue.

Anyways, it seems to work so far - except I can't load plugins to the UFX cards. (seems to work fine for the MFX)
I get an error # 74, just saying it can't load the plugins. I'm wondering if it's because of the slightly "low" negative side of the +/- supply as mentioned.

Re: +/- 16 transformer

PostPosted: Thu Sep 20, 2018 4:34 pm
by the boss
Hi

1. unload fx in d8b menu .
2. reset ufx in d8b menu.
3. Reboot.
4. Try load your fx again

Hope it helps (;

Re: +/- 16 transformer

PostPosted: Thu Sep 20, 2018 8:39 pm
by arjepsen
Hey again.
I think the problem was my soldering being done too fast.
I resoldered some wires, and now the desk works.
Some times it takes me a couple of starts to get it working, but I think that's a problem with the pc parts.