capacitor question?

[walpurgis]

Hi, yes ground at one end. Is that correct?

That's probably what I'd do. But I'd try it unearthed as well to see if there'd be any discernible difference.

[the_doc735]

That's probably what I'd do. But I'd try it unearthed as well to see if there'd be any discernible difference.

All this opens another 'can of worms': can shielding tape be used without grounding? (anyone). I've only seen grounding on braided earth wire, not tape?

[the_doc735]

...interesting that the best JB JSX caps finish in price is were the Mundorf Mcap MKP starts and goes on to hundreds per cap. Does this show the Mundorf superiority, or are mundorf purely praying on the naive hobbyists?

[walpurgis]

All this opens another 'can of worms': can shielding tape be used without grounding? (anyone). I've only seen grounding on braided earth wire, not tape?

I can't see why it would make any difference. You could earth either.

Should I choose to do this, I personally would put thin teflon sleeving on the capacitor wires and then screen with copper foil or braid. At least that can have wires soldered to it for earthing connections.

Desoldering braid is thin, made of copper and often tubular. I have some that would be ideal as a narrow screening braid.

[RothwellAudio]

OK opinions, not evidence. Do you think the humble report is worthless and why? http://www.humblehomemadehifi.com/Cap.html

No, I don't think it's worthless but it is just more subjective evaluation and probably won't help you unless you are prepared to use something based on a subjective opinion you have read on a website.

That's probably what I'd do. But I'd try it unearthed as well to see if there'd be any discernible difference.

How can a screen work if it isn't earthed?

All this opens another 'can of worms': can shielding tape be used without grounding? (anyone). I've only seen grounding on braided earth wire, not tape?

Same question - how can a screen work if it isn't earthed?

I can't see why it would make any difference. You could earth either.

Should I choose to do this, I personally would put thin teflon sleeving on the capacitor wires and then screen with copper foil or braid. At least that can have wires soldered to it for earthing connections.

Desoldering braid is thin, made of copper and often tubular. I have some that would be ideal as a narrow screening braid.

One possible source of braided copper for shielding is to use the braided screen from co-ax cable. It's possible to remove the outer insulation (though you might be better off not removing it) and pull out the center conductor if the cable isn't very long. Some cable is easier to work with than others.

However, all this talk of messing about with screening mesh etc. is probably getting way off what is actually required and over-complicating something that should be very simple.

[the_doc735]

No, I don't think it's worthless but it is just more subjective evaluation and probably won't help you unless you are prepared to use something based on a subjective opinion you have read on a website.
How can a screen work if it isn't earthed?
Same question - how can a screen work if it isn't earthed?
One possible source of braided copper for shielding is to use the braided screen from co-ax cable. It's possible to remove the outer insulation (though you might be better off not removing it) and pull out the center conductor if the cable isn't very long. Some cable is easier to work with than others.
However, all this talk of messing about with screening mesh etc. is probably getting way off what is actually required and over-complicating something that should be very simple.

Clearly you are something of a guru on the Audio front! My mind is beginning to boggle at all the aspects to take into consideration. My secondhand DAC has clearly had several previous owners who have all swapped out parts: e.g.

1) Input power wiring upgraded to cast copper silver plated with Teflon dielectric.
2) Power board dc filter now a Mundorf Supreme (Panasonic removed).
3) Both transformers placed on Neoprene sheets to remove casework resonance.
4) DC filter cap from power board to output board now a Multicap.
5) Dac board supported with a military foam (as used to remove noise in tanks) to prevent vibration.
6) Output capacitors now TRT Dynamicap 5uf (up from the 3,7uF after direct discussions with Cary Audio). Improves bass response (Panasonics removed).
7) Output bypass caps now Rel-Cap TRT Teflon (were Wima originally I think).
8) Output tubes now NOS Mullard 6922 Pearl Cryo Gold Grade Plus (matched and balanced) – costly upgrade.
9) Herbies tube dampeners.

************************************************** ************************************************** ***************************

1) Internal power cable to the mains board has been upgraded to cast stranded copper with PTFE insulation.
2) Earth cable upgraded to solid core copper PTFE insulated.
3) Transformers dampened with Dynamat Extreme.
4) DC filter cap upgraded from the cheapo Panasonic type to Mundorf Supreme,
5) Power cable from the power board to the output board upgraded to solid core copper PTFE wrapped.
6) Dac board support with an acoustic type from used in military tanks. Same foam used as support stilts for the power and output board.
7) Signal wires from the dac board to output board upgraded to pure cast solid silver, PTFE wrapped and shielded cable.
8) On the output board, 10 electrolytic caps have been upgraded from Panasonic to Elna Silmic.
9) The Wima bypass caps were removed and upgraded to RelCap polystyrene caps.
10) Output capacitors were upgraded from Panasonic types to Modwright Oil capacitors (larger uF as suggested by Cary themselves - better bass!).
11) AMR fuse upgrade.
12) Output tubes upgraded to Reflector Military types with Herbie dampeners.

So, I was wondering if you could possibly 'give it the once over' and see if it is optimal in its current state OR if there are any 'improvements' that can be made that would give more "middle, richer, deeper, 3D, spatial detail"; 'enhancements', OR find that it is already at its optimal specification?

You are clearly an expert in these matters and I would appreciate your hands on help to 'ring every last drop out of this design'. (?)

[RothwellAudio]

Clearly you are something of a guru on the Audio front!

You are clearly an expert in these matters and I would appreciate your hands on help to 'ring every last drop out of this design'. (?)

You're very kind but I don't make any claims to be a guru or expert on anything.
Yes, it sounds like your DAC has had plenty of modifications carried out, most of which seem to be swapping capacitors for more expensive capacitors or wires for more expensive wires. Maybe one more capacitor swap will rescue it from being "all bass and treble" but I honestly don't know what capacitors to recommend that would do that.

[sq225917]

I'd suggest an output buffer stage that is load tolerant would be a start. Swapping caps is just a band aid for the technically insufficient.

[Arkless Electronics]

I'd suggest an output buffer stage that is load tolerant would be a start. Swapping caps is just a band aid for the technically insufficient.

[the_doc735]

You're very kind but I don't make any claims to be a guru or expert on anything.
Yes, it sounds like your DAC has had plenty of modifications carried out, most of which seem to be swapping capacitors for more expensive capacitors or wires for more expensive wires. Maybe one more capacitor swap will rescue it from being "all bass and treble" but I honestly don't know what capacitors to recommend that would do that.

Thanks Andrew, no harm in asking - right? Thanks for being honest with me: "I honestly don't know". I like it when people are straight with me, no bullshit!