Club Polk Perception

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  • DarqueKnight
    DarqueKnight Posts: 6,760
    DSkip wrote: »
    John, when would one need 700 watts of tube power?

    I'm not being argumentative there - I really would like to know where you think this application is needed.

    That isn't to say its a bad design or Bob doesn't know what he is doing (obviously he does), but when I see that kind of number I think its more to do with sticker-shock as opposed to ingenuity in design.

    Bob Carver is a firm believer in the concept that clean reproduction of some transient sounds requires huge reserves of instantaneous power. I agree. The more dynamics, particularly bass dynamics, you are trying to reproduce, the more power required.

    The quote below is from page 5 of the 1982 Carver catalog:

    "Once, Bob Carver visited a famous sound researcher who was attempting to recreate the "snip" of an ordinary pair of scissors. Between the microphone and the speakers he had installed TWENTY-FOUR 200-watt amplifiers. Yet when viewed on an oscilloscope it was apparent that the final tip of that instantaneous transient was being distorted. Believe it or not, he needed more power!"

    The "famous sound researcher" was Dick Burwen. You can read about his home audio system, which uses 17 200-watt solid state QSC SRA 1222 studio amplifiers, here:

    http://www.burwenaudio.com/Sound_System.html

    and here:

    http://www.burwenaudio.com/images/Audio_April_1995.pdf

    From page 30 of the Audio April 1995 article:

    "Why all that power? Because it takes most of the power available for any one horn to reproduce drums at live levels, leaving only 3 to 6 dB of headroom for the contributions of other orchestral instruments."

    But...but...but...aren't tube watts louder than transistor watts and can't a lower powered tube amp produce the same sound level as a much higher powered transistor amp?

    No. Watts are watts. The noise products of tubes are primarily even order harmonics, which are even multiples of the music frequencies. Therefore, when tubes are driven hard, such as in high volume and high transient demand situations, the noise present is mostly exact overtones of the music frequencies and the music sounds apparently louder due to the harmonic reinforcement. When you multiply a music note frequency by an even number, you get the exact same note, just at a higher octave. The effect is similar to adding tenor and soprano (higher octave) voices to a choir consisting of baritone voices. Even though the added voices may not sing loud enough to increase the actual sound level, since the added voices are singing the same words and notes, the result is fuller, richer, and apparently louder, sound.

    The noise products of most transistors (except FETs) are odd order harmonics, which are odd multiples of the music frequencies and have no relationship to the music. Odd order harmonics are heard as discordant noise and the audible effect is to make the music sound apparently lower. This situation would be similar to some higher octave voices in a choir whispering a different song from the main baritone singers.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • txcoastal1
    txcoastal1 Posts: 13,124
    ^^^^Agree but only a hand full of speakers are capable of 500watts needing amps with that reserve headroom

    But it was nice providing my Dyn C4's the power and headroom the Thresholds provided :)
    2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures
    Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
    Gear on standby: Melody 101 tube pre, Unison Research Simply Italy Integrated
    Gone to new homes: (Matt Polk's)Threshold Stasis SA12e monoblocks, Pass XA30.5 amp, Usher MD2 speakers, Dynaudio C4 platinum speakers, Modwright LS100 (voltz), Simaudio 780D DAC

    erat interfectorem cesar et **** dictatorem dicere a
  • BlueFox
    BlueFox Posts: 15,251
    I can live with my 1200 watts. Sounds good to me.
    Lumin X1 file player, Westminster Labs interconnect cable
    Sony XA-5400ES SACD; Pass XP-22 pre; X600.5 amps
    Magico S5 MKII Mcast Rose speakers; SPOD spikes

    Shunyata Triton v3/Typhon QR on source, Denali 2000 (2) on amps
    Shunyata Sigma XLR analog ICs, Sigma speaker cables
    Shunyata Sigma HC (2), Sigma Analog, Sigma Digital, Z Anaconda (3) power cables

    Mapleshade Samson V.3 four shelf solid maple rack, Micropoint brass footers
    Three 20 amp circuits.
  • megasat16
    megasat16 Posts: 3,521
    edited August 2017
    Like Mr. Bob Carver; VTL, Manley, and probably a small handful others have made tubes power amps that are over 500W output.

    Unlike Bob Carver; these amps usually weight a good fraction of a TON and requires 2-3 guys to lift and place them.

    What I am saying is that VTL, Manley amps above 500W weights about 200-300lbs per channel while Bob amps weight about 100lb combined (55lb for Power Amp Chassis and 45lbs for the Power Supply Chassis) per channel. Bob claims his amp can do 700W RMS at 8 ohms and 900W music and speech.

    When it comes to tube amps, the quality (primary inductance really) of output iron determines the lower end frequency response. In Universal terms, it usually requires heavier and chunkier output transformers for better low frequency response even in push pull circuits. Bob claims his amps can do 2Hz-85KHz with -3dB bandwidth. It's rather interesting because the output iron once again needs lots of inductance (Bigger and Heavier iron) even for the 20Hz response for a mere 35W PushPull amps if you are referencing to the United Transformer Corp Linear Standard transformers.

    I don't know how Bob end up with his transformer design but I don't see any real changes in Transformer designs or efficiency in the last 60 years. They all use the same formulae, and the same kind of core (EI, C or Double C or Toroid) structure and same kind of lamination types and sizes. There are now better core materials for better frequency response and tonal quality but none of that makes any considerable increase in the low end response or power handling efficiency. Enameled wires and sizes for winding transformers are the same as well.

    Referencing to UTC Linear Standard design, 20W P-P iron weights about 7lbs and 35W P-P iron weights about 15lbs. The power transformer for continuous duty to supply a 150W amp could weights in at 30lbs or more. Heck, it will even weight about 20-30lbs filament transformer to light up the 20 KT88 bottles because each KT-88 filament consumes 1.6amp at 6.3V. It takes about 10W for each KT88 bottle to light up so it takes about 200W alone to light up the 20 x KT88/6550 tubes. Unless bob decides to wire the 6550 tubes in series and plug them straight into a wall socket, a 200W (6.3V x 40amp) transformer probably weights about 20-30lbs on it's own. Well, there needs to have a plate transformer to supply B+ and bias and various transformers to power the input and driver tubes.

    Unless Bob decides to use switching type transformers, I don't see how a 45lb power supply chassis to supply 700W RMS out of 20 x 6550/KT88.

    I know all these questions are better addressed with Bob but I also know I will just get some smart answers that is beyond a comprehension for the like of me. I am still a fan and had probably about tens of Bob's amps at one time. And I still owe two pairs of Carver ALS so just saying out loud for what's in my mind with silver seven 700.

    My 8Watts 845/211 SET amp in three chassis weights nearly 150lbs. It sucks about 250W from the wall output to pump 2 x 8W RMS to the 100dB+ speakers. It's not very pleasing to the wife when the electric bill is coming due every month. I don't want to think about the electricity draw from a pair of Silver 7 700s.

    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
  • treitz3
    treitz3 Posts: 18,230
    Bob uses math and ingenuity to design his transformers and winds them himself.

    Tom
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
  • mhardy6647
    mhardy6647 Posts: 32,926
    DSkip wrote: »
    John, when would one need 700 watts of tube power?

    I'm not being argumentative there - I really would like to know where you think this application is needed.

    That isn't to say its a bad design or Bob doesn't know what he is doing (obviously he does), but when I see that kind of number I think its more to do with sticker-shock as opposed to ingenuity in design.

    Bob Carver is a firm believer in the concept that clean reproduction of some transient sounds requires huge reserves of instantaneous power. I agree. The more dynamics, particularly bass dynamics, you are trying to reproduce, the more power required.

    The quote below is from page 5 of the 1982 Carver catalog:

    "Once, Bob Carver visited a famous sound researcher who was attempting to recreate the "snip" of an ordinary pair of scissors. Between the microphone and the speakers he had installed TWENTY-FOUR 200-watt amplifiers. Yet when viewed on an oscilloscope it was apparent that the final tip of that instantaneous transient was being distorted. Believe it or not, he needed more power!"

    The "famous sound researcher" was Dick Burwen. You can read about his home audio system, which uses 17 200-watt solid state QSC SRA 1222 studio amplifiers, here:

    http://www.burwenaudio.com/Sound_System.html

    and here:

    http://www.burwenaudio.com/images/Audio_April_1995.pdf
    ...

    Yup, you beat me to it. Mr. Burwen, last I knew, is still at it, too.
    Admirable man.

    (He's on LinkedIn, too! -- apropos of nothing)

    Still rockin' 3-ish wpc here. Fortunately, I listen to very few scissors recordings.
    But Patty Larkin's in the room with me this morning as I sip my third (ahem) coffee of the day.

    Don't tell Mrs. H ;)


  • pitdogg2
    pitdogg2 Posts: 24,477
    treitz3 wrote: »
    Bob uses math and ingenuity to design his transformers and winds them himself.

    Tom

    That and iirc made of different steel that others. I've seen pictures of him in heavy duty gloves winding them up one at a time.
  • megasat16
    megasat16 Posts: 3,521
    edited August 2017
    I am pretty sure everyone winding transformers needs to use a precise number of core lams and wire size and turns ratio to end up with the desire transformer. The formulae for transformer winder has been around before my time and will probably the same for the next few generations. If Bob were to come up with a new transformer winding scheme, a noble prize wouldn't be that far fetched at all.

    I became interested in the transformers since I started building SET amps and they requires 2x - 3x the size of the push-pull type transformers for a good frequency response. The guys who can wind a good Single Ended output transformers are far few and less than that of the counterparts (i.e. Push-Pull output transformers winders).

    Anyway, I think Bob should publish the spec on the power draw for these Silver 7 700s and the -1dB bandwidth.

    3dB down at 20Hz in 700W means the output power is actually only 350W at 20Hz but could be 700W at 40Hz. But if it's 1dB down at 20Hz at 700W RMS, the silver seven 700s could well be the end game amp.
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
  • The audio rags might be more interested in "Quantity" (of advertisers) over "Quality" (of gear).
    Not true in all cases, to be sure, but it's there.
    Sal Palooza
  • megasat16
    megasat16 Posts: 3,521
    Bob and audio rags has a little history. Carver fans knew it well.
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
  • megasat16
    megasat16 Posts: 3,521
    edited August 2017
    Yep2 wrote: »
    megasat16 wrote: »
    Bob and audio rags has a little history. Carver fans knew it well.

    Unreal specs.
    Distortion & driver control could be a contributing factor?
    Im just guessing here?

    Nothing like that at all. Stereophile lost a bet with Bob. Bob knows his stuff and the guy is a Genius! And it's worth noting carver gears are decent for the price it commends at one time. Now, I think he is just getting the best of his fame.

    I saw how Bob's winding his own transformers and all. He had it all figured out from unwinding the old trafo from the 40s and 50s and come up with his own design.
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone. :redface::biggrin:
  • BlueFox
    BlueFox Posts: 15,251
    I remember seeing ads for his amps in Sterophile or Absolute Sound a few years back. That was before he went with Emotiva.
    Lumin X1 file player, Westminster Labs interconnect cable
    Sony XA-5400ES SACD; Pass XP-22 pre; X600.5 amps
    Magico S5 MKII Mcast Rose speakers; SPOD spikes

    Shunyata Triton v3/Typhon QR on source, Denali 2000 (2) on amps
    Shunyata Sigma XLR analog ICs, Sigma speaker cables
    Shunyata Sigma HC (2), Sigma Analog, Sigma Digital, Z Anaconda (3) power cables

    Mapleshade Samson V.3 four shelf solid maple rack, Micropoint brass footers
    Three 20 amp circuits.
  • pitdogg2
    pitdogg2 Posts: 24,477
    Bob and Stu did come up with something new in his transformers. I just do not recall what it was.
  • lightman1
    lightman1 Posts: 10,776
    Shut up, Ken....
  • pitdogg2
    pitdogg2 Posts: 24,477
    Fargin canuck....


    B)
  • treitz3
    treitz3 Posts: 18,230
    edited August 2017
    Humor is good but don't temp him. He'll even proceed it by a , "Hey y'all, watch this!".

    We did an interview with Bob years ago where he had touched on all of the information you would ever want to know about why he winded his own transformers, what the mathmatical difference was with his winding and how he winded them. It's out there in internet land somewhere if you are really that interested.

    Bob didn't do jack for Emotiva BF. Emotiva basically wanted Sunfire's rights and Bob got paid royally for them, they split quickly and Bob started his 5th audio company, Bob Carver Corp. Bob Carver, LLC is what Emotiva owns IIRC.

    Tom
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
  • pitdogg2
    pitdogg2 Posts: 24,477
    edited August 2017
    treitz3 wrote: »
    Humor is good.

    We did an interview with Bob years ago where he had touched on all of the information you would ever want to know about why he winded his own transformers, what the mathmatical difference was with his winding and how he winded them. It's out there in internet land somewhere if you are really that interested.

    Bob didn't do jack for Emotiva BF. Emotiva basically wanted Sunfire's rights and Bob got paid royally for them, they split quickly and Bob started his 5th audio company, Bob Carver Corp. Bob Carver, LLC is what Emotiva owns IIRC.

    Tom

    Believe they also wanted him to build some tube stuff for them also...yes he showed them the bird and split
  • EndersShadow
    EndersShadow Posts: 17,517
    edited August 2017
    @treitz3

    Isn't this when you guys asked him about his thoughts on Emotiva :wink:

    ndy6xk541t3b.jpg


    RIP TNRABBIT! I miss seeing you post and chatting about going active every once in a while

    Here is also a pic of bob doing his thang! I'm a big fan

    s-l1600.jpg
    "....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)
  • pitdogg2
    pitdogg2 Posts: 24,477
    @treitz3

    Isn't this when you guys asked him about his thoughts on Emotiva :wink:

    ndy6xk541t3b.jpg


    RIP TNRABBIT! I miss seeing you post and chatting about going active every once in a while

    Agree gone too soon
    RIP
  • treitz3
    treitz3 Posts: 18,230
    edited August 2017
    That was about the same time frame, yes. That photo was taken at Carverfest and who you see there is Robert R. and Bob Carver with a PS unit for one of DaveS's Silver 7's.

    Agreed with Gary. The photo you provided with the knife has actually been made into a "cartoon" T-shirt of Bob, the knife and the amp in Gary's (TNRabbit) honor. For those of you who don't know, he was the one who had the avatar of the bunny with the pancake on his head and was taken from this world way to soon in an unexpected motorcycle accident. He was a dedicated Bob Carver fan and well regarded by any and all who knew him. A true friend to all, enemy to none.

    Back to Bob, he told me at the time that he was done with board rooms and corporate shenanigan's. He wanted to go back to doing what he truly enjoyed. Going back to his roots building tube amps. That's where he stated his true passion lay.

    Tom
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
  • pitdogg2
    pitdogg2 Posts: 24,477
    edited August 2017
    Yep2 wrote: »
    pitdogg2 wrote: »
    treitz3 wrote: »
    Humor is good.

    We did an interview with Bob years ago where he had touched on all of the information you would ever want to know about why he winded his own transformers, what the mathmatical difference was with his winding and how he winded them. It's out there in internet land somewhere if you are really that interested.

    Bob didn't do jack for Emotiva BF. Emotiva basically wanted Sunfire's rights and Bob got paid royally for them, they split quickly and Bob started his 5th audio company, Bob Carver Corp. Bob Carver, LLC is what Emotiva owns IIRC.

    Tom
    yep he showed them the bird and split

    Please dont mention my name Ivan!
    Bwaha! :D

    My bad Paul ...

    Fixed it B)
  • kharp1
    kharp1 Posts: 3,453
    treitz3 wrote: »
    Humor is good but don't temp him. He'll even proceed it by a , "Hey y'all, watch this!".

    We did an interview with Bob years ago where he had touched on all of the information you would ever want to know about why he winded his own transformers, what the mathmatical difference was with his winding and how he winded them. It's out there in internet land somewhere if you are really that interested.

    Bob didn't do jack for Emotiva BF. Emotiva basically wanted Sunfire's rights and Bob got paid royally for them, they split quickly and Bob started his 5th audio company, Bob Carver Corp. Bob Carver, LLC is what Emotiva owns IIRC.

    Tom

    And "here, hold my beer."
  • pitdogg2
    pitdogg2 Posts: 24,477
    kharp1 wrote: »
    treitz3 wrote: »
    Humor is good but don't temp him. He'll even proceed it by a , "Hey y'all, watch this!".

    We did an interview with Bob years ago where he had touched on all of the information you would ever want to know about why he winded his own transformers, what the mathmatical difference was with his winding and how he winded them. It's out there in internet land somewhere if you are really that interested.

    Bob didn't do jack for Emotiva BF. Emotiva basically wanted Sunfire's rights and Bob got paid royally for them, they split quickly and Bob started his 5th audio company, Bob Carver Corp. Bob Carver, LLC is what Emotiva owns IIRC.

    Tom

    And "here, hold my beer."

    And that is when all the fun begins....

    Stand back