Recently, my boss discovered an Orban/Parasound 621b Parametric EQ in storage that slipped through the cracks in bookeeping (we didn't know we had it, and there was no record that we did other than the unit itself).
We'd like to check it out and see how it sounds, except we can't locate a power supply anywhere.
Additionally, there are a few things about the unit that we find confusing...
1) There is a sticker on the back that states "Factory wired for +- 16 VDC regulated." However, the info tag on the back (with model number, serial number, etc.) states that the unit uses +- 22 VDC. While the extra voltage probably just means more headroom, the discrepancy doesn't help us in our search for a power supply.
2) We did find something on the web that looks like it's the right thing to buy, assuming that 22 VDC is acceptable to use. However, the online supply web page states that it generates 125mA of current, whereas once again this figure disagrees with the info tag on the back (the tag says the unit takes 100mA). This seems like more of a problem than the voltage difference, because putting an extra resistor in series won't drop the current source in a way that is definitely predictable.
I've already contacted the vendor about the supply, and we're waiting for a response.
Anybody have any advice? Or does anybody have/use this unit and can give insight about where to purchase a power supply?
Maybe this link will help.
The last page of this manual shows a +/- 22VDC supply. From looking at the schematic of the EQ, I would estimate that a 1 amp DC supply would be fine.
The schematic on page 14 shows an internal regulator circuit (RC4195T) that can be bypassed (hence the dashed lines). Maybe your unit has the regulator bypassed. That would explain the +/- 16 VDC requirements.
The link to this supply should be more than adequate to power the 621B
A little DIY will be required. You'll need to add a chassis, power cord, fuse, and DC cable. This supply can be adjusted to +/- 16 VDC.
That manual answered a lot of questions.