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.
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.
@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.
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.
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.
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.
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?
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.
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?
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?
I generally use something like this site (link below) as a rough guide to size for signal conductors to ensure that I'm not using a solid core cable where you shouldn't.
American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies
For signal wire I normally use 24gauge of reasonable quality copper. Conductor material and insulation is a funny thing and you'll get a different answer from anyone you ask, qusp might not be the guy to ask for economical options though
American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies
For signal wire I normally use 24gauge of reasonable quality copper. Conductor material and insulation is a funny thing and you'll get a different answer from anyone you ask, qusp might not be the guy to ask for economical options though
Quisp (and others) will probably disagree, but, this is where I buy my hookup wire:
New Arrivals, 24 AWG items in John's Silver Teflon Wire Shop store on eBay!
Great service, great prices.
24 AWG for most all purposes at this voltage/current level. Single stranded for most all work, however, I do prefer twisted pair for input/output wires.
New Arrivals, 24 AWG items in John's Silver Teflon Wire Shop store on eBay!
Great service, great prices.
24 AWG for most all purposes at this voltage/current level. Single stranded for most all work, however, I do prefer twisted pair for input/output wires.
If you buy from that ebay mob just be sure to read the description along with the ad heading. Heading says silver, description is more accurate in describing the wire though, it is silver plated copper with teflon insulator. Certainly not bad, but its also not pure silver. I've used it on my build with the wire bal-se headphone amp and qusp still talks to me 
I've actually used 22awg on mine but I'd use 24awg if I had it on hand. I'm certainly not losing sleep over that difference.
Belden plenum rated CAT5/CAT6 is nice wire also for use as signal conductor.
For power supply wire, just use something that is appropriately sized for current carrying capacity and copper conductor since it is small you can afford it.
If you're buying big cables (see attached pic for an idea of BIG cables that get used at my work) then maybe you'd consider a cheaper conductor! Since I know someone will ask - that is one phase of a 110kV copper conductor, lead sheath, oil impregnated paper in the insulator. The other cables edge of pic are alu 33kV.
I've actually used 22awg on mine but I'd use 24awg if I had it on hand. I'm certainly not losing sleep over that difference.
Belden plenum rated CAT5/CAT6 is nice wire also for use as signal conductor.
For power supply wire, just use something that is appropriately sized for current carrying capacity and copper conductor since it is small you can afford it.
If you're buying big cables (see attached pic for an idea of BIG cables that get used at my work) then maybe you'd consider a cheaper conductor! Since I know someone will ask - that is one phase of a 110kV copper conductor, lead sheath, oil impregnated paper in the insulator. The other cables edge of pic are alu 33kV.
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Me, I would still use 4 conductors as it means each signal wire can be twisted with a ground/return. any currents in this build whether signal or power 24-22awg is fine. I prefer properly pure UPOCC copper over SPC, but yeah you probably dont want to be taking my wiring advice for high quality stuff
I cant stand that johns 'silver' wiring. thick 'teflon' pita to strip and the number of times I see someone recommending it for headphone cables, even IEM cables i've seen, is hilarious. you could be standing in the next room when someone farts and it would be transmitted up the cable to your ears, the microphonics are that bad. I bought some 28awg SPC from him nearly 3 years ago, used it twice and still have the rest, the stuff is stiffer than some 20awg solid core I have as it has such thick 'teflon'
I would buy PTFE SPC from Apex Jr well before that stuff. strips properly, milspec wire with easily workable/strippable PTFE, good range of colours and excellent prices. I use it sometimes for internal power wiring, got heaps of it, decent range of colours, sizes etc. hes also a forum sponsor and I think we should support them when we can. hes got some decent quality milspec coax too, as well as shielded SPC etc etc. cheap NOS power supply caps etc. also a good person to deal with, no affilliation
I cant stand that johns 'silver' wiring. thick 'teflon' pita to strip and the number of times I see someone recommending it for headphone cables, even IEM cables i've seen, is hilarious. you could be standing in the next room when someone farts and it would be transmitted up the cable to your ears, the microphonics are that bad. I bought some 28awg SPC from him nearly 3 years ago, used it twice and still have the rest, the stuff is stiffer than some 20awg solid core I have as it has such thick 'teflon'
I would buy PTFE SPC from Apex Jr well before that stuff. strips properly, milspec wire with easily workable/strippable PTFE, good range of colours and excellent prices. I use it sometimes for internal power wiring, got heaps of it, decent range of colours, sizes etc. hes also a forum sponsor and I think we should support them when we can. hes got some decent quality milspec coax too, as well as shielded SPC etc etc. cheap NOS power supply caps etc. also a good person to deal with, no affilliation
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I agree, the stuff from Apex Jr is much better than the johns 'silver' wiring. I still have a bunch of that ebay stuff. Never again, I say!
As for power cables...how about a CERN power cable? Actually, it's probably not "audiophile" quality
As for power cables...how about a CERN power cable? Actually, it's probably not "audiophile" quality
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yes, or belden 1583A cat 5 24awg solid core PTFE/copper, multicore network cable. already twisted for you 100ohms impedance so works well for digital too. not easy to find in small amounts though
most people I see recommending that ebay SPC for headphone cables, or IEM cables in particular simply cannot have ever seen it, or ever made an IEM cable and just recommend it because it gets recommended (not saying thats you Jake) .
the 'teflon' on the thinner stuff I got is so tightly molded that stripping it invariably scores or cuts some of the wire and does not pull off easily. thats what makes me sus of it, its like its been cast/moulded onto the wire rather than extruded like most PTFE. I dont know how hot teflon has to be to be actually molten, but I would think the wire would not be in great shape by that point.
basically given Apex's wire is at least as cheap, I cannot think of a single reason to buy the ebay stuff and given he still calls his ebay shop 'J----s silver wire shop' and he doesnt carry a single silver wire, that doesnt really sit well with me.
/rant
most people I see recommending that ebay SPC for headphone cables, or IEM cables in particular simply cannot have ever seen it, or ever made an IEM cable and just recommend it because it gets recommended (not saying thats you Jake) .
the 'teflon' on the thinner stuff I got is so tightly molded that stripping it invariably scores or cuts some of the wire and does not pull off easily. thats what makes me sus of it, its like its been cast/moulded onto the wire rather than extruded like most PTFE. I dont know how hot teflon has to be to be actually molten, but I would think the wire would not be in great shape by that point.
basically given Apex's wire is at least as cheap, I cannot think of a single reason to buy the ebay stuff and given he still calls his ebay shop 'J----s silver wire shop' and he doesnt carry a single silver wire, that doesnt really sit well with me.
/rant
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