Balanced to single-ended converter (XLR to RCA / BAL to SE)

Discussion in 'DIY' started by purr1n, Jun 27, 2020.

  1. Baten

    Baten Friend

    Pyrate
    Joined:
    Mar 18, 2018
    Likes Received:
    1,133
    Trophy Points:
    93
    Location:
    EU
    Link? Because I remember in the Topping A50s thread Amir posited you could just use an XLR>RCA cable to feed the amp 'more voltage' which is just laughably incorrect. He was corrected inside the thread but just radio silence and left the original post/review as it was.

    No, an XLR>RCA cable will not get >2 Vrms in your single ended amp. That's just an arrogantly bad proposition. XLR is 2-pin and ground, RCA is 1 pin, I don't get he can even misunderstand this if he ever made his own cables...
     
  2. internethandle

    internethandle Almost "Made"

    Contributor
    Joined:
    Sep 23, 2017
    Likes Received:
    871
    Trophy Points:
    93
    Location:
    long beach, ca
    Last edited: Jan 8, 2023
  3. rhythmdevils

    rhythmdevils MOT: rhythmdevils audio

    Pyrate
    Joined:
    Apr 15, 2020
    Likes Received:
    12,503
    Trophy Points:
    113
    Location:
    Bay Area, CA
    Home Page:
    @schiit

    Hey all,
    I'm wondering if I can use the CMLI-600/600C cinemag transformers with the Gungnir A1, or if I have to use the CMLI-15/15B transformers. I have a unit with each.

    I’d rather use the CMLI-600/600C because they aren’t as sensitive to cable capacitance or distance but I know a lot of DAC’s can’t drive them. I know the Yggdrasil can, but I just don’t know about the Gungnir A1.

    Thanks! Whitney
     
    • Agreed, ditto, +1 Agreed, ditto, +1 x 2
    • List
  4. internethandle

    internethandle Almost "Made"

    Contributor
    Joined:
    Sep 23, 2017
    Likes Received:
    871
    Trophy Points:
    93
    Location:
    long beach, ca
    Apropos timing because I’m ordering some Cinemags to build a converter and was trying to parse the differences between those two models. Would be into Studio B. @rhythmdevils already providing useful info since I wasn’t aware of the cable capacitance issue.

    I was also going to bump the thread with some more data points against using XLR->RCA cables or adapters, at least with Yggdrasil, and instead going the converter route as suggested:

    (TL;DR: I played with fire and possibly got burned by using pin 3 float XLR to RCA adapters. Yggdrasil’s trafos, at least as much as I’ve noticed, never buzzed for me prior to doing this, but now buzz even after ditching the adapters and connecting with RCA outs. It’s relatively quiet, and I do have a lot of buzzing transformers from other components in my chain from either DC offset or overvoltage, unsure (usually toroidals, more susceptible), but not a good feeling to think I may have borked the Yggdrasil in some way. I also have developed a weird issue with something in my network chain - a switch, my router, or my network card - that conspicuously started showing up the moment I connected the adapters)

    I got a pair of used Cardas FXLR-FRCA (pin 3 float) adapters, and while I enjoyed what felt like a bit more plankton (which I whore over like some other members), it shifted the overall tonality toward too thin and unnatural. I also just plain did not like the idea of using only one chip/phase per Yggdrasil board. Felt like using a gimped DAC to overcome a “gimped” output. I had tried a Radial Twin ISO but didn’t like the coloration and sold it.

    I read a lot prior to doing this to try and assure myself nothing would blow up. I found enough Yggdrasil use cases on forums, including here, with pin 3 float, plus an old 2015 reply from Schiit support and Jason chiming in confirming Schiit didn’t feel too worried (short of outright recommendation) about such a scenario, that I thought, at least, the risk would be low. Still, other reports bothered me, including an old post here reporting an adapter made Yggdrasil produce transformer hum. And then the TL;DR portion of my post above happened.

    Anyway, stick to the converters if you’re gonna play with BAL to SE and don’t be like me with epic fail nervosa idiocy. Bob et. al know what they’re talking about. In fact, one of the things that struck me about this experience is SBAF really seems to be the only place advocating for these kinds of 1:1 converters. You certainly can find folks on other forums warning about hotter pro audio XLR outs and using converters in that kind of application, and sometimes people warning to check an amp manual or not short pin 3, but if anyone even makes a peep about conversion it’s usually someone linking this thread at this point. The Amirites are almost uniformly dismissive of any risk (see here if you want to subject yourself). This point is just another reason of many why Bob and Marv and co. provide a real value to this community that you seriously can’t find elsewhere. It’s all noise elsewhere on this topic, at least, with tons of conflicting info. Stick to the converters.
     
    Last edited: Jan 26, 2023
  5. rhythmdevils

    rhythmdevils MOT: rhythmdevils audio

    Pyrate
    Joined:
    Apr 15, 2020
    Likes Received:
    12,503
    Trophy Points:
    113
    Location:
    Bay Area, CA
    Home Page:
    From Dave at Cinemag:

    RCA cable length after (2) CMLI-600/600C VS (2) CMLI-15/15B

    Q:
    Can you tell me the max RCA cable length after the CMLI-600/600C before I start loosing sound quality in this chain?

    Yggdrasil DAC -> 2 CMLI-600/600C -> 1 amplifier

    A:
    The acceptable length depends upon the total capacitance of the cable. For this application, I would keep it to less than 1000pF. Cables are rated at capacitance per foot.

    Q:
    What about the CMLI-15/15B?

    A:
    I would keep cable length to under 1 meter. Even shorter is better. This is to keep the total capacitance at a minimum. Low capacitance cable is good to have. Place the transformer at the input of the device that is being driven. This is because of the high impedance.

    Thread listing all low capacitance cables I could find
     
    • Like Like x 1
    • Epic Epic x 1
    • List
  6. Cspirou

    Cspirou They call me Sparky

    Pyrate
    Joined:
    Sep 27, 2015
    Likes Received:
    8,319
    Trophy Points:
    113
    Location:
    Northwest France
    RCA -> XLR is generally fine and even has an advantage over RCA input if that’s an option

    The opposite is terrible practice. Any conversion should be done at the preamp stage. Either through an active circuit like a THAT chip. Or something like a TVC
     
  7. rhythmdevils

    rhythmdevils MOT: rhythmdevils audio

    Pyrate
    Joined:
    Apr 15, 2020
    Likes Received:
    12,503
    Trophy Points:
    113
    Location:
    Bay Area, CA
    Home Page:
    More good info from David at Cinemag. The Gungnir cannot drive the Cinemag CMLI-600/600C, you need to use the CMLI-15/15B and then keep cable distance very short with low capacitance cables, as seen in my above post.

    OR

    From David at Cinemag on using the CMLI-600/600C with the Gungnir

    "I would prefer a buffer amplifier to drive the CMLI-600/600C's. The output amps of the Schiit [Gungnir] apparently have series resistors to protect th0se ICs from being shorted out to ground. You will get more punch on big transients with a more capable line amplifier stage to drive the transformers."​
     
  8. Azimuth

    Azimuth FKA rtaylor76, Friend

    Pyrate
    Joined:
    Nov 9, 2015
    Likes Received:
    6,999
    Trophy Points:
    113
    Location:
    Nashville, TN
    Home Page:
    I thought Gungnir had a discrete output and not IC’s.

    I don’t disagree with him though on the other stuff. But this is also why I use Freya N out of my Yggdrasil A1 to feed my balanced and unbalanced amps.
     
  9. rhythmdevils

    rhythmdevils MOT: rhythmdevils audio

    Pyrate
    Joined:
    Apr 15, 2020
    Likes Received:
    12,503
    Trophy Points:
    113
    Location:
    Bay Area, CA
    Home Page:
    You don’t think you loose something compared to using Cinemag transformers? The Freya wasn’t designed to convert balanced to SE it’s just a preamp.
     
  10. Pancakes

    Pancakes Friend

    Pyrate Contributor
    Joined:
    Aug 13, 2020
    Likes Received:
    1,445
    Trophy Points:
    93
    Location:
    Atl
    Actually it is. The Saga is "just a preamp" ;)
     
  11. Paul Scandal

    Paul Scandal New

    Joined:
    Sep 2, 2021
    Likes Received:
    9
    Trophy Points:
    8
    Location:
    Florida
    Is Yggdrasil > Lokius different than Yggdrasil > CineMag transformer vis a vis the balanced signal it accepts and transfers?

    I mean, is the transformer box more transparent somehow? I'm thinking with stepped attenuator from Justin.
     
  12. bobboxbody

    bobboxbody Friend

    Pyrate BWC Contributor
    Joined:
    Sep 6, 2016
    Likes Received:
    1,474
    Trophy Points:
    93
    Location:
    GR, MI
    Sorry to grave dig this, but I've been reading about simple XLR to SE rca cables and saw a suggestion to bridge pins 1 and 3 with a resistor equal to the input impedance of the intended destination component. In my case it would be Gungnir XLR out to Scott 222C rca in, with an input impedance of 500k ohms. It seems like that would help with the current imbalance, but I may be wrong. Would this be a relatively safe option to try, despite not being the ultimate in SQ or best practices?
     
  13. Wobbletits

    Wobbletits Facebook Friend

    Joined:
    Feb 9, 2022
    Likes Received:
    125
    Trophy Points:
    43
    Location:
    Maryland
    I think that tying cold to g through a 500k resistor is probably "safe" though no coment on what you are trying to fix/accomplish by using this vs the se outputs. You might get some cmrr, maybe.
     
  14. bobboxbody

    bobboxbody Friend

    Pyrate BWC Contributor
    Joined:
    Sep 6, 2016
    Likes Received:
    1,474
    Trophy Points:
    93
    Location:
    GR, MI
    Thanks, I preferred the balanced outputs back when I had a balanced amp, hoping to get a little more oomph with the SE amp without adding any more transformers or active devices into the chain.
     
  15. Armaegis

    Armaegis Friend

    Pyrate BWC
    Joined:
    Sep 27, 2015
    Likes Received:
    7,685
    Trophy Points:
    113
    Location:
    Winnipeg
    Even if you believe that the Gungnir SE output is gimped compared to the XLR, I'd bet dollars to doughnuts that rawdogging the SE is still gonna be better than a hacking the XLR with an adapter or cable.
     
  16. bobboxbody

    bobboxbody Friend

    Pyrate BWC Contributor
    Joined:
    Sep 6, 2016
    Likes Received:
    1,474
    Trophy Points:
    93
    Location:
    GR, MI
    I will better direct my urge to tinker by building a nicer set of SE cables. It really never bothered me before, but vinyl playback upgrades and the addition of more revealing speakers has made my digital chain sound noticeably worse than the analog side. The Gungnir is still a good value, but hard to compete with an analog chain at 6x the cost. Thanks for the perspective.
     
  17. Garns

    Garns Friend

    Pyrate
    Joined:
    Jul 9, 2016
    Likes Received:
    2,486
    Trophy Points:
    93
    Location:
    Sydney, AUS
    Dave at Zenwave cables did make the same suggestion to me (tie pin 1 to pin 3 through a resistor) when I described how the yggdrasil worked, and thought it would likely yield the best SQ. Didn't try it because I figured it was more productive just to change DACs but I think if you are tinkering it's reasonable to try out.

    Leaving pin 1 fully unconnected made the trafos hum when I tried it on a gungnir a few years back, so I guess this would work around that.
     
  18. Abhishek Chowdhary

    Abhishek Chowdhary Friend

    Pyrate
    Joined:
    Sep 27, 2015
    Likes Received:
    420
    Trophy Points:
    63
    Location:
    India
    Has anybody made use of Lundahl LL1588 for Bal -- SE conversion?
    I have a pair with me but can't figure out how to do it
    [​IMG]
     
  19. purr1n

    purr1n Desire for betterer is endless.

    Staff Member Pyrate BWC
    Joined:
    Sep 24, 2015
    Likes Received:
    90,494
    Trophy Points:
    113
    Location:
    Padre Island CC TX
    upload_2023-11-11_12-37-54.png
    Consider a switch to tie 8 to 9 (signal ground to chassis ground - I misdrew 8 as earth ground - meant chassis ground)

    NOTE: SCHEMATIC IS DIFFERENT FROM PHYSICAL LAYOUT. NOTE PINS NUMBERS.
     
    • heart heart x 2
    • Like Like x 1
    • List
    Last edited: Nov 11, 2023
  20. Cspirou

    Cspirou They call me Sparky

    Pyrate
    Joined:
    Sep 27, 2015
    Likes Received:
    8,319
    Trophy Points:
    113
    Location:
    Northwest France

Share This Page