Reverse polarity output pre amp

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lightman1
lightman1 Posts: 10,776
in 2 Channel Audio
Why? I have the Rogue 66 Magnum pre that I stole from Sketchy Craig. In my research of this fine piece of this gear, it is noted that it is a reverse signal path to the outputs. Thus requiring you to reverse the polarities of the speaker outputs of the amplifier.....- is +...+ is -.
What is the reason for this in the tube pre circuits to justify this?
Curious minds want to know.
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  • lightman1
    lightman1 Posts: 10,776
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    :D Off to a flying start! I have been known to unknowingly switch polarities at the speakers and curse the audio gods for lacking low end response.
    My terminology was not right.
    It's an inverting pre amp.
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  • kharp1
    kharp1 Posts: 3,453
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    IF what I understand is correct, it's because each step in the circuit inverts it and they leave the last circuit out to improve sonics. Better to have to switch the polarity at the binding posts then an added circuit. At least that's the philosophy according to Joule from what I read.
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  • mhardy6647
    mhardy6647 Posts: 33,046
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    ^^^ I think that's the crux of the biscuit (as Mr. Zappa would've put it).

    I don't know, though.

    It is kind of arbitrary (especially since there's no guarantee that the master recording manifests "correct" polarity).

    Remember, the convention of electricity dates back to Benjamin Franklin, who had a 50/50 chance of guessing correctly the "true nature" of electricity. He guessed wrong, and so we were stuck with electrons being "negative".

    urgent_mission.png

    Little-known-fact.png

    or not :blush:

    http://www.austincc.edu/wkibbe/truth.htm


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  • mhardy6647
    mhardy6647 Posts: 33,046
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    ... and what, I hear you ask, does the nature of electricity have to do with the polarity of a sound wave?

    Well... nothing... but I have a reputation to maintain!

    Back, sort of, on topic. The cool little gizmo I just got (Galaxy Cricket) can, it appears, be used to check the polarity through an active component (e.g., an amplifier) -- although I haven't tried it for that yet.

    It could be a little tricky to use in a typical home hifi, though, as the gizmo's designed primarily for balanced connection to everything except loudspeakers :)

    http://www.galaxyaudio.com/products/cpts

    CPTS.jpg

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  • pkquat
    pkquat Posts: 742
    edited March 2017
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    It's so people have to buy ULTRA expensive polarity reversion cables of course. :p
    Or is it polarity inversion cables. I get them confused. :D

    I'd go with @kharp1 's answer.

    I use Phil Collins synth bass drum on the extended version of "Take Me Home" from 12"ers to verify polarity. The woofer visibly extends out first.
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  • FTGV
    FTGV Posts: 3,649
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    If you are one the "golden ears" that can actually perceive absolute phase then reversing the polarity of the speaker connections will be sonically benificial.
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  • lightman1
    lightman1 Posts: 10,776
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    FTGV wrote: »
    If you are one the "golden ears" that can actually perceive absolute phase then reversing the polarity of the speaker connections will be sonically benificial.

    Thanks, FreddyJimBob. I am not a golden ear. But I know what I like.
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  • lightman1
    lightman1 Posts: 10,776
    edited March 2017
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    Why would the Rouge build this pre?


    And to say this pre doesn't give towards
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  • JuanR
    JuanR Posts: 718
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    I own the 66 and I never reversed it, guess I should try it since it makes a world of difference on my Joule -150... BIG SOUND DIFFERENCE! not just a subtle one...
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  • Dennis Gardner
    Dennis Gardner Posts: 4,860
    edited March 2017
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    You have to think of it as a bass drum facing backwards. You can tell the difference, but you don't know why. I think that a lot of recordings that sound lean are due to absolute phase issues.

    When that kickdrum hits and your woofer is sucked in instead of pushing out on that first attack, there is a difference in how that wave exits the speaker.

    I have always thought that absolute phase was why certain tracks sounded so much better with SDA than others, but who knows.
    HT Optoma HD25 LV on 80" DIY Screen, Anthem MRX 300 Receiver, Pioneer Elite BDP 51FD Polk CS350LS, Polk SDA1C, Polk FX300, Polk RT55, Dual EBS Adire Shiva 320watt tuned to 17hz, ICs-DIY Twisted Prs, Speaker-Raymond Cable

    2 Channel Thorens TD 318 Grado ZF1, SACD/CD Marantz 8260, Soundstream/Krell DAC1, Audio Mirror PP1, Odyssey Stratos, ADS L-1290, ICs-DIY Twisted , Speaker-Raymond Cable
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  • pitdogg2
    pitdogg2 Posts: 24,579
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    Pffft i just push the absolute phase 180* button on my carver c16 .....
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  • [Deleted User]
    [Deleted User] Posts: 7,658
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    And to add even more to worry about some record companies suggest that their records sound better when absolute polarity is reversed at the speakers.
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  • geppy1
    geppy1 Posts: 3,071
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    Is this like the phase invert function on the old NAD 1700 and Yamaha CX 800 preamps?. If it is, I thought things sounded more natural and for sure on the Yamaha.
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  • dhart86
    dhart86 Posts: 1,594
    edited March 2017
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    Russ ..thanks for posting this thread. I got the Joule 150 MK II pre ....oops I meant MII (sorry) and i connected everything the traditional way, forgetting that it was an inverting pre,

    So I just reversed the polarity connections at the binding post and I am pretty sure that I got a better, clearer and cleaner sound stage....or maybe Juan just suggested it?

    Anyway, I'll be leaving it this way!
    Main Rig:
    Antipodes DX > Roon > PS Audio Directstream Jr.>deHavilland Ultraverve 3 >Belles Reference 150a >Harbeth C7 ES3


    Second Rig:
    Roon> PS Audio Directstream Jr Bridge II > EE Minimax pre (Tutay mods) >Belles 150A Ref >Monitor 5 (Westmassguy-modded)


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  • BlueMDPicker
    BlueMDPicker Posts: 7,569
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    KennethSwauger wrote: »
    And to add even more to worry about some record companies suggest that their records sound better when absolute polarity is reversed at the speakers.

    Hi Ken,

    Would there be an issue with reversing polarity at the speakers with SDA's due to the need for a common ground?

    Additionally, I have a Joule Electra LA-100MkIII connected traditionally (+ to +, - to -) as are the rest of that system's components. This thread caused me to question my memory when I setup the turntable so I played by setup LP again yesterday. I have correct phase from turntable to speakers. With the Joule being phase inverting, I'm surprised by my results.

    I use SDA 2B Studio speakers in this system - Music Hall MMF-5, Bottlehead Seduction, Joule LA-100MkIII, DCM 75+75 and SDA's. I'm apprehensive with experimentation at the amp or speaker binding posts due to the SDA cable. Thoughts?
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  • lightman1
    lightman1 Posts: 10,776
    edited March 2017
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    That's part of the reason for my query. If the SDA are a phase sensetive type of crossover, will it have an effect the sound or throw off the crossovers?
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  • Dennis Gardner
    Dennis Gardner Posts: 4,860
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    The answer to the SDA absolute phase issue is to swap the phase between the preamp and amp. This leaves the amp/speaker in good relation to each other with absolute phase in tact. Have a set of ICs inverted and marked just for this purpose.
    HT Optoma HD25 LV on 80" DIY Screen, Anthem MRX 300 Receiver, Pioneer Elite BDP 51FD Polk CS350LS, Polk SDA1C, Polk FX300, Polk RT55, Dual EBS Adire Shiva 320watt tuned to 17hz, ICs-DIY Twisted Prs, Speaker-Raymond Cable

    2 Channel Thorens TD 318 Grado ZF1, SACD/CD Marantz 8260, Soundstream/Krell DAC1, Audio Mirror PP1, Odyssey Stratos, ADS L-1290, ICs-DIY Twisted , Speaker-Raymond Cable
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  • lightman1
    lightman1 Posts: 10,776
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    Now we're cookin'! Thanks Dennis.
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  • pitdogg2
    pitdogg2 Posts: 24,579
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    Yep I'm deaf in both eye's
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  • MrBuhl
    MrBuhl Posts: 2,419
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    My Audible Illusions Modulus is phase inverting. I have used it with SDA's set up both ways, speaker cables reversed, and not. I let my ears be my guide, I liked it best reversed as intended. YMMV.
    VA HT HK AVR20II, Sony S9000ES CD/DVD/SACD, Polk Audio RC80i / Polk Audio CSi3, 60" Panasonic Plasma, Nordost / Signal Cable A2 / Wireworld / Pangea / Magic Power
    VA 2 Channel Focal Electra 926 speakers, Pass Labs X150.5 Amp, Eastern Electric MiniMax Preamp (Tutay mods), Eastern Electric Minimax CDP (Scott Nixon mods), Music Hall mmf 5.1 Turntable, Parks Audio Budgie Phono Pre , Audioengine B1 streamer, MIT S3 IC's / MIT Shotgun S3 Speaker Cables / PS Audio power cables
    Noggin Schiit Valhalla, Pangea, Phillips Fidelio X1, Polk UF8000

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    Soundcraftsmen PCR800
    Audible Illusions L1 Preamp
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    Signal Cable Silver Resolution IC's






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  • lightman1
    lightman1 Posts: 10,776
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    Dig it. IF I ever get home, I'll be setting up the goods and letting it settle in.
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  • [Deleted User]
    [Deleted User] Posts: 7,658
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    I don't believe you can reverse the polarity between the preamp and power amp via the interconnect cable. You have to do that either at a balanced connection (most phono cartridges are balanced, for example) or at the speaker.
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  • lightman1
    lightman1 Posts: 10,776
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    I don't want to cook anything in the tube amps by using SDA 3.1 in reversed polarity. Maybe I'll just buy some better speakers.......... >:)
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  • pitdogg2
    pitdogg2 Posts: 24,579
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    KennethSwauger wrote: »
    I don't believe you can reverse the polarity between the preamp and power amp via the interconnect cable. You have to do that either at a balanced connection (most phono cartridges are balanced, for example) or at the speaker.

    I believe your reversing phase not polarity
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  • lightman1
    lightman1 Posts: 10,776
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    Therein lies the confusion between terminology and topography, Ivan.
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  • [Deleted User]
    [Deleted User] Posts: 7,658
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    "Would there be an issue with reversing polarity at the speakers with SDA's due to the need for a common ground?"

    Yes, the concern is to not short out the amplifier with the SDA connection. If the left and right SDA speaker negative's were connected to the amplifier's positive terminals and this was a pair of twin/blade SDA speakers then the amplifier would be shorted. If it were a pair of pin/blade SDA speakers there wouldn't be any SDA information created but the amp wouldn't be shorted.

    One of the real early audiophile tweaks was to reverse the polarity on one channel of the phono cartridge and reverse the polarity on the speaker connections of the same channel. Supposedly this made life easier for the amplifier's power supply.
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