Building balanced headphone cables? - Page 4

Sheldon · 23rd October 2011, 03:15 PM

Lots of choices here (available through Digikey): http://www.switchcraft.com/Documents...og.pdf#page=12

I've used them for balanced connection with phono cartridge, also for power connectors between supply and amp chassis.

Sheldon

Wolfsin · 23rd October 2011, 03:39 PM

Thanks, Sheldon, but not sure whether you are recommending one of them over TA4M & TA4F connectors available on eBay for about $2 each?

Actually, in my recent tests I soldered directly to the PCB to eliminate the connector as a vaariable. It does make A-B even harder :-(

Sheldon · 23rd October 2011, 04:07 PM

Quote:

Originally Posted by Wolfsin

Thanks, Sheldon, but not sure whether you are recommending one of them over TA4M & TA4F connectors available on eBay for about $2 each?
(

Haven't compared them with anything. Lots of choices and they work well. Just offered them as an option.

Sheldon

Wolfsin · 23rd October 2011, 05:48 PM

Even more thanks, then, Sheldon. I am still waiting for a suggestion of what cable to use. I agree that the shield is not needed, that the cables must be sufficiently rugged to handle some abuse, that low resistance is a virtue (though solid silver izExcessive IMO), and that a pair of single conductor coax is the work of the devil himself. You know what I have tried. You know I am unwilling to pay boutique prices.

To limit my exposure, and to suppress foolish suggestions, I have put a few conditions on the following offer, which is one time only. Here is the offer. If you have a cable you believe will sound superior AND you have HD6x0 Cardas compatible cans AND you will wire a bridged TA4M connector to your gear, suggest that cable in this thread. If selected you agree to send me six feet of that cable. I will supply another pair of Cardas connectors and a TA4F, build the cable, listen to it and then ship it back to you for your opinion.

If there is more than one suggestion, I will break all ties with considerations of group feedback. The cable will then be shipped from one to another of all those who suggest a cable type not chosen, each paying the postage to the next within one week of receipt. Anyone breaking this chain will . . . If this needs modification, please let ne know.

Keep in mind that qusp lives on the other side of this planet so whoever listenz just before him might go broke :-)

rsdio · 24th October 2011, 09:52 AM

Quote:

Originally Posted by Wolfsin

My conclusion was that bridging made a big difference but was it the additional drive capability across each can or severing of the common conductor? I tried using ever higher driving capability -- a pair of LME49600s on each side in push-pull mode (won't call it balanced) -- and that made it marginally better.

The terms balanced, bridged, and differential are all causing a great deal of pain, I agree. The near impossibility of performing A-B when headphone cable is involved had not occurred to me until faced squarely.

As soon as I can build 'the wire' (bal-bal) I will carefully relisten. I genuinely hope to hear a difference.

What you've documented so far makes sense. Separating the wire for left and right probably makes more of an improvement than changing the wire to more expensive types.

I agree that balanced, bridged, and differential can be confusing. Sometimes they are equivalent. I would be tempted to design a hand-made headphone amp using Nelson Pass' super-symmetry, because that performs better than simple bridged amplifiers. That's because noise on one channel is inverted on the other and canceled out on the speaker, and this sort of thing cannot happen with two independent amplifiers that are bridged. But, I suppose it's a lot of trouble to build your own headphone amplifier just to get a fully balanced circuit from DAC to headphones. I suppose there are headphone amps out there which are about as good, but I also imagine that Nelson's patent is stopping anyone from building a super-symmetric or "X" headphone amp.

In any event, please continue to report your findings. Now you've inspired me to replace these noisy (default) headphone output circuits that I have, even though I rarely use them...

Wolfsin · 24th October 2011, 01:28 PM

Great thought, rsdio. It turns out Russ White has done the heavy lifting for us right here on DIYaudio when he proto'ed the TP IVY. Nelson Pass agreed it was SuSy and it is only $79 as a kit. The best part is that its balanced outputs are sufficiently powerful to drive most cans directly. I have not yet assembled the kit but will before EOY.

rsdio · 24th October 2011, 04:11 PM

Quote:

Originally Posted by Wolfsin

It turns out Russ White has done the heavy lifting for us right here on DIYaudio when he proto'ed the TP IVY. Nelson Pass agreed it was SuSy and it is only $79 as a kit. The best part is that its balanced outputs are sufficiently powerful to drive most cans directly.

Nice! Can you provide a link to that, or the title of the thread? I tried searching for Nelson Pass, Russ White, TP IVY and SUSY headphone but couldn't find any headphone amplifiers after a couple of pages of search results.

I would be very interested in looking over a SUSY headphone amp circuit!

Wolfsin · 25th October 2011, 12:00 AM

Hi rsdio. For a couple of minutes, before Google rescued me, I thought I might have dreamed that one up! First, NP re SuSy.

Discrete Super Symmetric(I think) Opamp for I/V Etc...

Then from the IVY III manual (IVY III being the current rev of the proto being discussed in the link above):

The IVY-III can easily drive most headphones (even down to 16Ω) when used as a balanced headphone driver along with the Volumite or similar digital volume control. The SE outputs are not capable of as much power, but can still be used for most headphones. It is recommended that if you wish to drive headphones you use jumpers for R25/R26 and/or R27-R30, which will allow for better damping factor. The OPA1632 can drive up to 150mA, giving you plenty of power for almost any headphone listening situation. It is recommended when driving power amps to always use the output resistors, especially with very capacitive cables.

Note that this is a non-IV (since the WM874x DAC has voltage outputs) but also a real-IV since the ESS DAC has current outputs that just happens to be capable of driving cans :-) A quick read of tthe entire manual will either cause palpitations or gastric distress!

The IVY Balanced Line Stage

Twisted Pear has a twisted naming scheme for its kits. The proto got called Ballsie but, frankly I think NashvilleNavyNife would have caused less confusion.

rsdio · 25th October 2011, 05:18 AM

Wow! 37 discrete transistors in a single channel? Is all of that really necessary? I guess I've been spoiled by the Zen articles which might have only 6 or 7 transistors per channel in the most complex designs. This also appears to be a current input preamp, so you may need to adjust. But, don't take my comments too seriously, as I haven't spent much time analyzing this. If I look at it longer, I may see that he's combined a preamp stage and amplifier stage together, but I had a hard time reading the schematic with the disjointed pieces.

If you want to start small, maybe try one of the Zen amps, but dial down the output current from the typical 2 A or 6 A to 150 mA or less. Then, if you like where things are heading, maybe you could try Russ White's circuit.

Wolfsin · 25th October 2011, 08:28 AM

If TP had called it SuSyPre, the headamp with BOTH voltage and current inputs it might have been more descriptive. Part of the complexity is the analog filters. I think 'the wire' by opc may be just the ticket but diverged because of your SuSy thought. I am attempting to simplify from quad BB1704s to quad WM874x DACs but that is really off in the weedz.

I want to create bits to cans balanced/bridged pipelines so I can mix and match to see what is important and what is not. The topic of this thread treads periously close to religion and politics but my goal is not controversy but lowcost simplicity. If, in the end I find an SE solution, that wood be even better. For now however I need to keep left and right channels entirely separate so I can play with wave shaping immediately following the DAC.

As regards my headphone cabling offer, the silence is deafening!

Quote:

Originally Posted by rsdio

Wow! 37 discrete transistors in a single channel? Is all of that really necessary? I guess I've been spoiled by the Zen articles which might have only 6 or 7 transistors per channel in the most complex designs. This also appears to be a current input preamp, so you may need to adjust. But, don't take my comments too seriously, as I haven't spent much time analyzing this. If I look at it longer, I may see that he's combined a preamp stage and amplifier stage together, but I had a hard time reading the schematic with the disjointed pieces.

If you want to start small, maybe try one of the Zen amps, but dial down the output current from the typical 2 A or 6 A to 150 mA or less. Then, if you like where things are heading, maybe you could try Russ White's circuit.

25th October 2011, 12:00 AM	#38
Wolfsin diyAudio Member Join Date: Aug 2009 Blog Entries: 2	Hi rsdio. For a couple of minutes, before Google rescued me, I thought I might have dreamed that one up! First, NP re SuSy. Discrete Super Symmetric(I think) Opamp for I/V Etc... Then from the IVY III manual (IVY III being the current rev of the proto being discussed in the link above): The IVY-III can easily drive most headphones (even down to 16Ω) when used as a balanced headphone driver along with the Volumite or similar digital volume control. The SE outputs are not capable of as much power, but can still be used for most headphones. It is recommended that if you wish to drive headphones you use jumpers for R25/R26 and/or R27-R30, which will allow for better damping factor. The OPA1632 can drive up to 150mA, giving you plenty of power for almost any headphone listening situation. It is recommended when driving power amps to always use the output resistors, especially with very capacitive cables. Note that this is a non-IV (since the WM874x DAC has voltage outputs) but also a real-IV since the ESS DAC has current outputs that just happens to be capable of driving cans :-) A quick read of tthe entire manual will either cause palpitations or gastric distress! The IVY Balanced Line Stage Twisted Pear has a twisted naming scheme for its kits. The proto got called Ballsie but, frankly I think NashvilleNavyNife would have caused less confusion. __________________ 'gardz, Dick

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23rd October 2011, 03:15 PM	#31
Sheldon diyAudio Member Join Date: Dec 2003 Location: San Diego	Lots of choices here (available through Digikey): http://www.switchcraft.com/Documents...og.pdf#page=12 I've used them for balanced connection with phono cartridge, also for power connectors between supply and amp chassis. Sheldon

23rd October 2011, 03:39 PM	#32
Wolfsin diyAudio Member Join Date: Aug 2009 Blog Entries: 2	Thanks, Sheldon, but not sure whether you are recommending one of them over TA4M & TA4F connectors available on eBay for about $2 each? Actually, in my recent tests I soldered directly to the PCB to eliminate the connector as a vaariable. It does make A-B even harder :-(

23rd October 2011, 05:48 PM	#34
Wolfsin diyAudio Member Join Date: Aug 2009 Blog Entries: 2	Even more thanks, then, Sheldon. I am still waiting for a suggestion of what cable to use. I agree that the shield is not needed, that the cables must be sufficiently rugged to handle some abuse, that low resistance is a virtue (though solid silver izExcessive IMO), and that a pair of single conductor coax is the work of the devil himself. You know what I have tried. You know I am unwilling to pay boutique prices. To limit my exposure, and to suppress foolish suggestions, I have put a few conditions on the following offer, which is one time only. Here is the offer. If you have a cable you believe will sound superior AND you have HD6x0 Cardas compatible cans AND you will wire a bridged TA4M connector to your gear, suggest that cable in this thread. If selected you agree to send me six feet of that cable. I will supply another pair of Cardas connectors and a TA4F, build the cable, listen to it and then ship it back to you for your opinion. If there is more than one suggestion, I will break all ties with considerations of group feedback. The cable will then be shipped from one to another of all those who suggest a cable type not chosen, each paying the postage to the next within one week of receipt. Anyone breaking this chain will . . . If this needs modification, please let ne know. Keep in mind that qusp lives on the other side of this planet so whoever listenz just before him might go broke :-)

24th October 2011, 01:28 PM	#36
Wolfsin diyAudio Member Join Date: Aug 2009 Blog Entries: 2	Great thought, rsdio. It turns out Russ White has done the heavy lifting for us right here on DIYaudio when he proto'ed the TP IVY. Nelson Pass agreed it was SuSy and it is only $79 as a kit. The best part is that its balanced outputs are sufficiently powerful to drive most cans directly. I have not yet assembled the kit but will before EOY.

25th October 2011, 05:18 AM	#39
rsdio diyAudio Member Join Date: Feb 2008 Location: Seattle	Wow! 37 discrete transistors in a single channel? Is all of that really necessary? I guess I've been spoiled by the Zen articles which might have only 6 or 7 transistors per channel in the most complex designs. This also appears to be a current input preamp, so you may need to adjust. But, don't take my comments too seriously, as I haven't spent much time analyzing this. If I look at it longer, I may see that he's combined a preamp stage and amplifier stage together, but I had a hard time reading the schematic with the disjointed pieces. If you want to start small, maybe try one of the Zen amps, but dial down the output current from the typical 2 A or 6 A to 150 mA or less. Then, if you like where things are heading, maybe you could try Russ White's circuit.