[Barbarous]

I bought a Hart Chiarra amp on eBay inexpensively. It needs a power supply, not just an IEC, which I hadn't realized. It takes a + or - 15 V supply. Hart sold a kit for the PS too but they seem to be out of business now.

I noticed an APS Headroom wallwart I have is + or - 15 V. I thought I might make an adaptor to power up the amp and see if it works. This raises a bunch of questions, some simpler than others.

1) Does anyone know what this kind of power connector is called? DigiKey and its ilk are so huge I can't always find parts if I don't know their names.

2) According to Wikipedia DIN connectors are numbered like this:

So would this be right, on the Headroom wall wart?

3) Someone with an Astrodyne supply posted a pin-out on Head Fi based on a sticker from the back of it:

PIN 3: +15 == 2A
PIN 1, 2: COMMON
PIN 4: N/C
PIN 5: -15V == 1A
SHELL: GND

I presume the pins are the same in the APS wart since both power the same products. Inside my APS Headroom wart there are only 3 wires going into the cable; I'm guessing +15V, -15V, and Gnd? So what does Common mean here? I realize this may be a bone-headed question. I can read, so even the right phrase to use to search the web, or an index, would send me in the right direction, and be appreciated. Sorry if it is a bad question.

4) The guy who owns the Rock Grotto site liked this amp and posted various pages about it. One is this diagram of the power supply:

Does that "0V" output mean the Headroom wart won't work? It doesn't have a 0V output. I've seen toroids rated -15 / 0 / +15, but again I'm a little lost as to what that 0V output means.

The Rock Grotto guy posted directions for an Easy X PSU; maybe this kind of thing would work with a -15 / 0 / +15 toroid? I'm guessing not.

5) Are there suitable kits for this? Here's what I've found:

Jaycar has a "Headphone Amplifier Power Supply Kit" CAT. NO. KC5418 (no "0V" output); Mouser has something PD-2515 Mean Well (again no "0V"); Hagerman has a half kit as well Bugle (& Power)(again no "0V"). There is also one on eBay Bipolar +/-15V 100mA per side but I don't know if 100mA is adequate.

Thanks for any help you may be able to give.

 

[Menisk]

The connector on the back of you amp looks like an RS-232, but I've never seen one of those used for power before. Interesting...

 

[tomb]

There's no absolute standard for DC power connectors, especially when + or - supplies are involved. For instance, the only thing that makes that 9-pin connector on the amp an "RS-232" connector is common usage. It can be used to connect any circuit, as long as the ratings are sufficient. Several of us around here have used DIN connectors for the SOHA or CKKIII, but of course - we're wiring the connectors on both ends.

Here's some answers to your questions:
1. DIN Audio connectors and their pin designations have no bearing on this discussion.
2. The Headroom connector is easy enough to confirm with a DMM, but the posted photo and key makes sense.
3. "Common" means the "0 Volts" in your Chiarra connections diagram in this instance. Note that if you have a + or - 15VDC power supply, the only way to insure the + or - portion of the supply is to have a "0" reference (common) included, also. This is distinctly different from Ground.
4. Yes, if the diagram you've posted for the Chiarra amp is correct, then you should be able to use the Headroom adapter and re-wire it for 9-pin D-connector (you'd need a male connector). However, you should also measure/inspect these connections yourself to confirm. That would include opening the Chiarra amp to trace which connectors are used on the inside.
5. As for the other supplies you reference, I didn't look at them specifically, but any + or - 15VDC supply is going to have a "0" reference included - by definition.

Note that you may very well find the easier option is to rewire the amp with a female DIN connector to match the Headroom power supply. Another option is to use two 2.1mm sockets and plugs (ground is not necessarily needed - that's why only 3 wires coming from the Headroom walwart: -15VDC, 0, +15VDC).

 

[Barbarous]

Thanks very much for your answers! I found the 9-pin D connector at RadioShack. I am going to do an adaptor first just to confirm the amp is working, then can decide where to go from there, but long term a panel-mounted connector to match the Headroom one makes sense.

I'm going to watch the Tangentsoft video on how to use a DMM again. I'll hold off on further questions as that may answer them all.

I did open the Chiarra amp once, and it matches the photo on the Rock Grotto site of a stock amp. But measuring to be sure makes sense.