"The Wire" Ultra-High Performance Headphone Amplifier - PCB's

[jdkJake]

So, as far as the rk27, the body (the screw on the back) should be tied to the chassis. So should the earth ground of the IEC socket. This can be done independently or with a single connection. Just be sure to scrap any anodize and use a good star or lock washer to insure a good connection to the chassis. Especially with the earth ground.

Wire the power supply up to the amp. Isolate the RCA jacks from the chassis. Wire the signal and ground of each RCA jack through the RK27 and into the +/gnd inputs to the amp. Wire the output connection of the amp to the headphone jack and bring the headphone jack ground back to the power supply (ground connection between + and - 15). There really is no need for a star ground as the power supply ground can serve this purpose.

You can of course tie the power supply ground to the chassis (either directly or through a ground breaker) at the same point. Some folks float, some folks don't. If you decide to tie to the chassis (and by default, the earth ground as it is connected to the chassis as well, see above) and get a ground loop (hum), then a ground loop breaker can be deployed. I would only use one if you need to.

As for left/right, well, you choose! Just be sure to follow through the circuit from RCA to headphone jack. The wire is two identical amps on one board. You can decide which side is left and which side is right.

[Mull3t]

@jdkJake -- Thanks for the clarification. The star ground method of grounding seemed to clutter up this build.

With regard to tying the 1/4" ground to the power supply ground, I'm assuming I'm going to hook up two wires to the terminal and one goes to PS gnd and the other to output gnd of the amp. Is this assumption correct?

Thanks again for your guidance and help.

[jdkJake]

You know, I just took another look and forthe first time noticed the amp board does indeed have output ground pads. Not sure how I missed those prior.

In this case, just wire the 1/4 inch jack tip and ring to the appropriate output pad and the sleeve to one of the output grounds on the amp. Not sure I would wire to both, but, I suppose it would be okay if you did. BTW, something in the back of my head tells me one of these output ground pads is not wired correctly on the rework boards. So, I would buzz them out to be sure they are both indeed ground (or go back through this thread a few dozen pages or so).

In the absence of a dedicated ground on the amp board, I would have brought the sleeve back to the power supply ground that goes to the amp board with a single wire. You can still do this, but, the dedicated pad(s) is probably more convenient.

[hochopeper]

The problem with output ground pads is only on bal-se boards from memory though I'm not sure about rework boards.

I think Owen has flagged the bal-se floating pad in the build wiki.

[jdkJake]

Thanks hochopeper, you are right, it is just the BAL-SE boards and is documented as such on the wiki.

Thanks!

[Mull3t]

Well that's good news. Glad I'm not in for some trouble.

All of the ground pads "buzz out" so I don't think having two wires coming from the amp to 1/4" sleeve is necessary. Do you think I should still wire up two wires to the sleeve and one goes to an output pad and the other goes to power supply ground? Or was this just necessary if there wasn't an output gnd pad on the amp pcb?

[qusp]

you should have a dedicated return connection for every output connection IMO. just connect it to the output ground, this was just to bring ground in from the star as the pad wasnt connected

[jdkJake]

Originally Posted by Mull3t

Well that's good news. Glad I'm not in for some trouble.

All of the ground pads "buzz out" so I don't think having two wires coming from the amp to 1/4" sleeve is necessary. Do you think I should still wire up two wires to the sleeve and one goes to an output pad and the other goes to power supply ground? Or was this just necessary if there wasn't an output gnd pad on the amp pcb?

What are you using as a jack? Does it bring out separate grounds for each output? If so, use both of the ground pads on the amp. A common connection point is the goal and these will suffice.

[qusp]

even for phono, I think 2 wires, or one that is double the gauge of the signal wires; should be used. if at all possible use a 4 pin connector even for single ended output

[Mull3t]

I'm using a neutrik 1/4" jack... NMJ6HCD2 Neutrik | Mouser

So I'll just use one of the two out ground pads as it only has three terminals.

qusp -- you bring up something I was wondering about... what gauges to use for wiring things up...

In the past, I've used a mix of 20 gauge hookup wire from rat shack for both electrical and audio output signals. Then I would grab some belden 9452 24 gauge single pair cable from work for use between RCA in and my Pot. So far so good. For AC wiring should I use a higher gauge wire? What's a good decent economical audio signal wire as a new option to the ratshack stuff?