I think that's not going to do anything unless your chassis is made of metal. And even with an aluminium chassis grounding the chassis entirely can be difficult when the parts are properly anodized.
Grounding or double insulated is the requirement for any appliance.
OK, back...
to legato 3 common mode DC discussion. I built up my new B-IIIse and Legato 3 combo on some MDF for testing/tweaking purposes.
With the nCore 400 stereo amp, the Legato 3 needs caps: it will not work with either no pin 1 connection to G, or with pin 1 connected to G. Popped some 2.7 uF Mundorf zns in series with the output, and it plays fine with this amp. Too bad, I was really hoping the differential input of this amp woudl work without caps.
Pass Labs confirmed that my Pass X150.5 should be fine with the common mode offset, so I will give that a go next.
to legato 3 common mode DC discussion. I built up my new B-IIIse and Legato 3 combo on some MDF for testing/tweaking purposes.
With the nCore 400 stereo amp, the Legato 3 needs caps: it will not work with either no pin 1 connection to G, or with pin 1 connected to G. Popped some 2.7 uF Mundorf zns in series with the output, and it plays fine with this amp. Too bad, I was really hoping the differential input of this amp woudl work without caps.
Pass Labs confirmed that my Pass X150.5 should be fine with the common mode offset, so I will give that a go next.
OK, back...
to legato 3 common mode DC discussion. I built up my new B-IIIse and Legato 3 combo on some MDF for testing/tweaking purposes.
With the nCore 400 stereo amp, the Legato 3 needs caps: it will not work with either no pin 1 connection to G, or with pin 1 connected to G. Popped some 2.7 uF Mundorf zns in series with the output, and it plays fine with this amp. Too bad, I was really hoping the differential input of this amp woudl work without caps.
Pass Labs confirmed that my Pass X150.5 should be fine with the common mode offset, so I will give that a go next.
to legato 3 common mode DC discussion. I built up my new B-IIIse and Legato 3 combo on some MDF for testing/tweaking purposes.
With the nCore 400 stereo amp, the Legato 3 needs caps: it will not work with either no pin 1 connection to G, or with pin 1 connected to G. Popped some 2.7 uF Mundorf zns in series with the output, and it plays fine with this amp. Too bad, I was really hoping the differential input of this amp woudl work without caps.
Pass Labs confirmed that my Pass X150.5 should be fine with the common mode offset, so I will give that a go next.
Sorry...
for the double post, I had an internet glitch on my end.
Another data point: The Legato 3 works fine with the Pass Labs X150.5 with no coupling caps and the ground connected to pin 1. I suspect it will work fine with all the Pass Labs X and XA amps then, as they all seem to use the same input (voltage gain) stage.
for the double post, I had an internet glitch on my end.
Another data point: The Legato 3 works fine with the Pass Labs X150.5 with no coupling caps and the ground connected to pin 1. I suspect it will work fine with all the Pass Labs X and XA amps then, as they all seem to use the same input (voltage gain) stage.
I have a dual mono BIII/single Legato build. Balanced out with ground disconnected would work fine with a Krell KSL pre amp, but not with the Krell KRC-HR. With the KSL I also had to turn volume down before changing source on pre amp or I'd get nasty pops through the speakers. I ended up reconnecting ground and using coupling caps. No more pops changing sources now.
After...
listening to the DAC with no coupling caps into the Pass, and then with some caps in place… I sure would like to avoid them.
Or… anyone have a recommended coupling cap which will not break the bank, I have used Mundorf Supreme, and it is good, but what is closest to no cap, still affordable (ie not Duelund VSF Copper) and reasonably sized...
listening to the DAC with no coupling caps into the Pass, and then with some caps in place… I sure would like to avoid them.
Or… anyone have a recommended coupling cap which will not break the bank, I have used Mundorf Supreme, and it is good, but what is closest to no cap, still affordable (ie not Duelund VSF Copper) and reasonably sized...
Hi Barrows
I once used 4.7uF Auricaps at the input to my Class A amplifier. They were markedly more transparent that ordinary 4.7uF polyprops that I bought from Jaycar, which appeared to give a false kind of soundstage.
The attached link will give you a general idea of their size and pricing .
They are also polarity conscious for best results.Something to do with the start and finish of the winding of the foil internally.
Kind Regards
Alex
Auricap
I once used 4.7uF Auricaps at the input to my Class A amplifier. They were markedly more transparent that ordinary 4.7uF polyprops that I bought from Jaycar, which appeared to give a false kind of soundstage.
The attached link will give you a general idea of their size and pricing .
They are also polarity conscious for best results.Something to do with the start and finish of the winding of the foil internally.
Kind Regards
Alex
Auricap
Thanks...
Alex and Roll...
I see that Audience has the new version "XO" of the auracap, which is supposed to be improve on transparency. A nice thing about these is that they are available in a 200V model, which is quite compact as well.
I am considering the Clarity MR as well, so far everyone seems to like these for a transparent, "no cap" sound. It is not too big in 1 uF, about 25mmx40mm or so.
One "sonic signature" I would like to avoid is anything which enmphasizes high frequencies, or has a tendency to harshness or grain. I am not looking for added warmth, but I really do not want added coolness. This is a highly resolving solid state DAC after all.
It also appears that much of the "problems" associated with coupling caps may be caused by vibration. Since this is DIY, taking a little effort to make the caps more immune to vibrations might be a good step. I know the Clarity MRs address this through heroic construction details. Perhaps the Aura XO caps could be made into two cap modules, potted in a block of epoxy, and then mounted via sorbothane damping layers...
Alex and Roll...
I see that Audience has the new version "XO" of the auracap, which is supposed to be improve on transparency. A nice thing about these is that they are available in a 200V model, which is quite compact as well.
I am considering the Clarity MR as well, so far everyone seems to like these for a transparent, "no cap" sound. It is not too big in 1 uF, about 25mmx40mm or so.
One "sonic signature" I would like to avoid is anything which enmphasizes high frequencies, or has a tendency to harshness or grain. I am not looking for added warmth, but I really do not want added coolness. This is a highly resolving solid state DAC after all.
It also appears that much of the "problems" associated with coupling caps may be caused by vibration. Since this is DIY, taking a little effort to make the caps more immune to vibrations might be a good step. I know the Clarity MRs address this through heroic construction details. Perhaps the Aura XO caps could be made into two cap modules, potted in a block of epoxy, and then mounted via sorbothane damping layers...
OK...
Happy to oblige, and thanks for reminding me. Keep in mind this DAC is not yet finished, not in a chassis (it is mocked up on mdf), and I am still waiting for Russ to release his USB solution, as I expect it will address the shortcomings in the different options I have available right now (such as I prefer synchronous clocking of the B-IIIse, but one really needs 45.1584/49.152 master clocks from the USB interface to do this right up to 192 kHz, and having dedicated micro BNCs for really good connections on the I2S lines).
To the MRs. Previously I have used Mundorf Zn, which are tin foil and PP film, and Mundorf Supreme, which are metalized PP film. The Supremes were quite good, and I lived with them for some time with my Legato 2. Now, for my system, the MRs are better. My system is all solid state, and right now I am using the nCore amplifier. The Supremes, in comparison to the MRs, seem to have a little extra emphasis in the high frequencies, and the MRs are a better match with my system. Perhaps the MRs are a little smoother as well, with less grain, but I am cannot be sure (no way to easily A/B this). In any case I am enjoying music more with the MRs. Additionally, I did do some listening with another amp which does not require the caps at all, so I listened with the MRs vs no caps: I am not sure at all if I could hear any difference, again I could not A/B quickly, but this experience did allow me to accept the MRs as being quite transparent, I am happy.
Of course, if someone ever wants to gift me 4 1uF Duelund VSF copper foil caps I would be happy to try them!
Happy to oblige, and thanks for reminding me. Keep in mind this DAC is not yet finished, not in a chassis (it is mocked up on mdf), and I am still waiting for Russ to release his USB solution, as I expect it will address the shortcomings in the different options I have available right now (such as I prefer synchronous clocking of the B-IIIse, but one really needs 45.1584/49.152 master clocks from the USB interface to do this right up to 192 kHz, and having dedicated micro BNCs for really good connections on the I2S lines).
To the MRs. Previously I have used Mundorf Zn, which are tin foil and PP film, and Mundorf Supreme, which are metalized PP film. The Supremes were quite good, and I lived with them for some time with my Legato 2. Now, for my system, the MRs are better. My system is all solid state, and right now I am using the nCore amplifier. The Supremes, in comparison to the MRs, seem to have a little extra emphasis in the high frequencies, and the MRs are a better match with my system. Perhaps the MRs are a little smoother as well, with less grain, but I am cannot be sure (no way to easily A/B this). In any case I am enjoying music more with the MRs. Additionally, I did do some listening with another amp which does not require the caps at all, so I listened with the MRs vs no caps: I am not sure at all if I could hear any difference, again I could not A/B quickly, but this experience did allow me to accept the MRs as being quite transparent, I am happy.
Of course, if someone ever wants to gift me 4 1uF Duelund VSF copper foil caps I would be happy to try them!
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Wow
The approach you describe did not work for me with nCore, weird that it works for you? Wonder why. My amp is stereo, maybe that is a factor. I got lost of hum, and weird sounds with pin 1 not connected. Do you connect pin 1 of the XLR jack in the DAC to chassis, and the chassis to AC ground?
The approach you describe did not work for me with nCore, weird that it works for you? Wonder why. My amp is stereo, maybe that is a factor. I got lost of hum, and weird sounds with pin 1 not connected. Do you connect pin 1 of the XLR jack in the DAC to chassis, and the chassis to AC ground?
Yes, I connected pin 1 of the XLR jack to the chassis and the AC ground to the chassis. I removed the coating with some fine sand paper so that it was a good ground.
I should mention though that at one time did not have the AC ground connected when I was trying to chase a ground loop. And with the AC ground disconnected it did not add any additional hum.
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Well,
Now I am a little perplexed. I tried with Pin 1 left floating at the DAC end, and that did not work for me with nCore, and when connected it to chassis, but without the AC ground connected to chassis, that shoudl have the same outcome.
Guess I'll try again when I get a chassis going...
Now I am a little perplexed. I tried with Pin 1 left floating at the DAC end, and that did not work for me with nCore, and when connected it to chassis, but without the AC ground connected to chassis, that shoudl have the same outcome.
Guess I'll try again when I get a chassis going...
Dear Russ,
in the schematic of the type below (principle) referring to LC Audio Millennium XP (found on the net, www.lcaudio.com):
1. is it possible to link Legato 3.1 Balanced without coupling capacitor?
2. in case it is, floating (2 poles + - ) or with ground (3 poles)?
Thank you in advance!
GM
in the schematic of the type below (principle) referring to LC Audio Millennium XP (found on the net, www.lcaudio.com):
1. is it possible to link Legato 3.1 Balanced without coupling capacitor?
2. in case it is, floating (2 poles + - ) or with ground (3 poles)?
Thank you in advance!
GM
Attachments
You should have no problems using Legato w/o caps with that design. Simply connect + and -, but leave GND floating.
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