XLR or RCA -> CD and Pre

thsmith
thsmith Posts: 6,082
edited June 2009 in Electronics
I should receive my Adcom GFP-750 tomorrow. My CDP and DAC both can use XLR or RCAs and the GFP can support RCA or XLR for CD input.

Any advise or recommendations on would XLR be a benefit over RCA with say a $150 budget?

TIA
Speakers: SDA-1C (most all the goodies)
Preamp: Joule Electra LA-150 MKII SE
Amp: Wright WPA 50-50 EAT KT88s
Analog: Marantz TT-15S1 MBS Glider SL| Wright WPP100C Amperex BB 6er5 and 7316 & WPM-100 SUT
Digital: Mac mini 2.3GHz dual-core i5 8g RAM 1.5 TB HDD Music Server Amarra (memory play) - USB - W4S DAC 2
Cables: Mits S3 IC and Spk cables| PS Audio PCs
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  • ShinAce
    ShinAce Posts: 1,194
    edited June 2009
    Doesn't that pre-amp use Pass's design using a differential pair?

    If yes, XLR is the best way to go, assuming your CDP is giving out a 'balanced' XLR signal.
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  • thuffman03
    thuffman03 Posts: 1,325
    edited June 2009
    The only reason I can think of for using XLR over RCA is if you are running long distances or going through walls and around equipment that gives off some electronic interference.

    That of course IMO.
    Sunfire TGP, Sunfire Cinema Grand, Sunfire 300~2 (2), Sunfire True Sub (2),Carver ALS Platinum, Carver AL III, TFM-55, C-19, C-9, TX-8, SDA-490t, SDA-390t
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  • ShinAce
    ShinAce Posts: 1,194
    edited June 2009
    Not true. If everything is balanced and differential, it changes the way the 'signal' is 'amplified'.

    I'm not saying the RCA connection will be bad, but the XLR is better, even for a short run. Again, assuming your CDP has balanced outputs.
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  • LessisNevermore
    LessisNevermore Posts: 1,519
    edited June 2009
    ShinAce wrote: »
    Not true. If everything is balanced and differential, it changes the way the 'signal' is 'amplified'.

    I'm not saying the RCA connection will be bad, but the XLR is better, even for a short run. Again, assuming your CDP has balanced outputs.

    In what specific way does an XLR connection change the way a signal is amplified?
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  • tcrossma
    tcrossma Posts: 1,301
    edited June 2009
    LessisNevermore wrote: »
    In what specific way does an XLR connection change the way a signal is amplified?

    I don't pretend to know what it means, but this is what Nelson Pass has to say about the GFP-750:
    Says Pass, "It's a differential pair—the end. A single gain stage, balanced input, balanced output, no feedback....We took a pair of MOSFETs, and the inputs go to the gates of the MOSFETs. The MOSFET sources are tied together and biased with a current source, with the signal taken off the drains. [The circuit] can run unbalanced on either side, although the performance is best when it's run balanced."
    Speakers: Polk LSi15
    Pre: Adcom GFP-750 with HT Bypass
    Amp: Pass Labs X-150
    CD/DVD Player: Classe CDP-10
    Interconnects: MIT Shortgun S3 Pro XLR
    Speaker cables: MIT MH-750 bi-wire
    TT:Micro Seiki DD-35
    Cartridge:Denon DL-160
    Phono Pre:PS Audio GCPH
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  • heiney9
    heiney9 Posts: 25,497
    edited June 2009
    thsmith wrote: »
    I should receive my Adcom GFP-750 tomorrow. My CDP and DAC both can use XLR or RCAs and the GFP can support RCA or XLR for CD input.

    Any advise or recommendations on would XLR be a benefit over RCA with say a $150 budget?

    TIA

    I went balanced the whole way and found I had too much gain to my liking so I went back to single ended. It's really a judgment call, try it both ways because everyone's system is different. In both cases (RCA or XLR) I used MIT's of comparable lines.

    Some will say "go balanced no matter what", but I find single ended to work better for me and since I have no noise issues (which balanced can help) I am doing just fine. Using the balanced connection cancels out 2nd order harmonics..........which is a more pleasant type of harmonic compared to 3rd order. 2nd order are the same types of harmonics that give tubes their sweetness.

    I suspect ultimately the GFP 750 performs best in balanced mode (whatever "best" means according to NP in the Stereophile review) but I notice no degredation at all running single ended.

    Good luck and enjoy that pre-amp. Be sure to post your impressions.

    H9

    P.s. I've e-mailed Nelson about balanced connections and he states many audiophiles prefer them because it cancels 2nd order harmonics. Reading between the lines of the e-mail he prefers single ended connections.
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Puritan Audio PSM136 Pwr Condtioner & Classic PC's | Legend L600 | Roon Nucleus 1 w/LPS - Tubes add soul!
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  • heiney9
    heiney9 Posts: 25,497
    edited June 2009
    LessisNevermore wrote: »
    In what specific way does an XLR connection change the way a signal is amplified?

    See above 2nd paragraph.
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Puritan Audio PSM136 Pwr Condtioner & Classic PC's | Legend L600 | Roon Nucleus 1 w/LPS - Tubes add soul!
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  • thsmith
    thsmith Posts: 6,082
    edited June 2009
    Thanks all. Since I do not have any XLRs (yet) I will wait for a good deal. The Signal Cable reference are in my price range unless someone can recommend a better one for near the same price.

    Thanks again !
    Speakers: SDA-1C (most all the goodies)
    Preamp: Joule Electra LA-150 MKII SE
    Amp: Wright WPA 50-50 EAT KT88s
    Analog: Marantz TT-15S1 MBS Glider SL| Wright WPP100C Amperex BB 6er5 and 7316 & WPM-100 SUT
    Digital: Mac mini 2.3GHz dual-core i5 8g RAM 1.5 TB HDD Music Server Amarra (memory play) - USB - W4S DAC 2
    Cables: Mits S3 IC and Spk cables| PS Audio PCs
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  • Systems
    Systems Posts: 14,872
    edited June 2009
    thuffman03 wrote: »
    The only reason I can think of for using XLR over RCA is if you are running long distances or going through walls and around equipment that gives off some electronic interference.
    Correct ,true balanced cables are less suseptable to noise pickup and ground loops etc.Aswell the balanced connection in most cases will provide an additional gain of about 6db.This because there are two separate amplified signals (+ and-) on each channel.

    The cancelation of the low even order harmonic distortion when operating the 750 balanced is because of it's single ended nature( as in it's gain stage not connection.)
    Testing
    Testing
    Testing
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