#11
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I read somewhere that the 12AX7s in V1, V2, & V5 are the ones to change for improved performance on a Mc275 MKV. I am using Mullard reissued in those positions. Did I waste my money?
What about the Mc2000? Which ones are more bang for the buck?
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Mike ~Your pet is your best investment~ Preamps/tuners:McIntosh C50, C46, MR88, MR73, C2200, C22ce, Cary SPL-98L Integrate amps:McIntosh MA6100, Denon PMA2000ivr Amps: McIntosh Mc602, Mc2000, Mc275 MK-V, Cary 805ae mono blocks. Speakers: JMLab Mezzo Utopia, Focal Twin6 BE, Tannoy Mini Autograph Headphones: Sennheiser HD800, Beyer T1, Denon D7000, Grado RS1i, Sony MDR-SA5000, MDR-Z1000, AKG K701, and many many more Digital Sources:Sony SCD-1 & SCD777es, CDP-XA7es, 2010 Mac Mini Music Server, Amarra Mini player, Musical Fidelity V-Link & M1 DAC, Apogee Mini-DAC & Duet 2 |
#12
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Quote:
Another tidbit I'd like to correct: if by significant were talking sonically significant, then clearly the two 12AX7 gain stage tubes (V-2,5) have the most affect on sonics in a 275, as I'm sure anyone who has rolled the three different kinds of tubes in a 275 will attest. Sounds to me like maybe lunch involved a little too much alcohol Last edited by nsgarch; 04-18-2010 at 02:46 AM. |
#13
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My 12AT7s in V3 & V6 are stock Mcintosh USA tubes. When I bought the Mullard 12AX7s I did not compare the sound against the stock tubes so I can't say if they sound better. Perhaps I should.
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Mike ~Your pet is your best investment~ Preamps/tuners:McIntosh C50, C46, MR88, MR73, C2200, C22ce, Cary SPL-98L Integrate amps:McIntosh MA6100, Denon PMA2000ivr Amps: McIntosh Mc602, Mc2000, Mc275 MK-V, Cary 805ae mono blocks. Speakers: JMLab Mezzo Utopia, Focal Twin6 BE, Tannoy Mini Autograph Headphones: Sennheiser HD800, Beyer T1, Denon D7000, Grado RS1i, Sony MDR-SA5000, MDR-Z1000, AKG K701, and many many more Digital Sources:Sony SCD-1 & SCD777es, CDP-XA7es, 2010 Mac Mini Music Server, Amarra Mini player, Musical Fidelity V-Link & M1 DAC, Apogee Mini-DAC & Duet 2 |
#14
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Hi Neil, As we've communicated several times in the past concerning tubes for MC275's I appreciated every tidbit you were willing to share and took many of your recommendations to heart. I valued and respected your input (and still do, by the way). However, in this case you are absolutely off the pentode beam concerning the information in bold. V3 and V4 (and V6/V7) do not drive the plates & cathodes of the KT88's which you purport in posts. Infact, there isn't a McIntosh amp that was designed, nor developed, nor in use in which any 12v tube is used to drive the cathodes. If you look at a schematic, it's easy to see how one could come to that conclusion that you do. The cathode to driver tube connection is actually performed using what McIntosh refers to as a bootstrap -- a form of cathode feedback to resistors in the path. Secondly, to clarify a larger misnomer, McIntosh is able to squeeze 100 watts, or near that amount of wattage out of a pair of KT88's is because the output is taken from the plates and cathode and then applied in the unity coupling. The driver tubes only drive the plates as noted above. So, I'll stand by what I reported as obtained from Ron Evans --a person who knows more about the MC275 than anyone on this forum will ever be able to comprehend. In summary, V3 and V6 are significant and I'll concede with stating from Mr. Evans that V2 and V5 follow those in importance. So, in closing, I didn't appreciate the lunch and alcohol comment -- next time -- just tell me I'm full of shi+. I appreciate frankness more so than bullshit. I'll take my First Sergeant hat off now and get back to music. Bob
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Amps:VAC 450iQ Monos in Silver Flake on HRS M3X2-1921's, HRS G7 Footers/G-Links & Sound Anchor Conecoasters. Preamp:VAC Statement (on order) (Silver Flake) Digital Source: dCS Rossini CD/SACD Transport, Vivaldi APEX DAC, Upsampler Plus & matching Clock (Silver) Analogue Preamp:VAC Renaissance SE Phono stage in Silver Flake with XLR Output Option & with Nordost Valhalla XLR's. Analogue Sources:SME 20/2 w/SME V arm & Nordost Odin 2 Tone Arm Cable, Palo Santos Presentation Cartridge & Akai GX-400D Reel-to-Reel w/relapped heads by JRF Magnetic Sciences. Akai RC-17 cabled remote (original owner since 1974). Vibration Control:TT on HRS M3X2-1921 shelf. Speakers:Wilson Audio Alexia V (on order in Ferrari Argento Silver/Parchment grills sitting on Acoustic Diode Kit). Power Cables:4 Nordost Odin Supreme Reference on amps, preamp & DAC. Ansuz Acoustics C2 on Transport & Clock. Power Distribution:Ansuz Mainz D3 Distributor & Ansuz Mainz C2 1M Power Cable Power Outlets:Furutech GTX-D NCF (R) duplex outlet, GTX Wall Plate & Duplex Cover (x2) on dedicated, same panel phase, 20A breakers. Speaker Cables:2M Nordost Odin 2 Supreme Reference on Nordost Sort Lifts. Signal Cables:Nordost Odin XLR's on dCS DAC & Amps. Digital Cables: Nordost Odin 2's, 110-ohm AES/EBU on dCS Transport to DAC. Clock Cables:5 each 75 ohm 1.25M Nordost Valhalla BNC/BNC Digital Ethernet Cable: WireWorld Platinum 1M Starlight® 8 Twinax Headphones:Vintage Koss Pro IV AA. RCM: Audio Desk PRO Tube Test Gear:Mint late '60's/calibrated Heathkit TT-1A, MaxiMatcher Power Amp & Preamp & Space Tech Labs ATT-3.02 tube test sets. Last edited by vintage_tube; 04-20-2010 at 12:18 AM. |
#15
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Wind-bag. For some reason that sobriquet comes to mind when reading the preceding post (not you, Bob).
And, I'll be putting my triode matched 12AT7s in V3 & V6 this weekend.
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Glenn... Canton Reference 9 Clearaudio SM Pro Focal Bathys JLA 10" Dominion Kuzma Stabi S w/MC & MM Magnepan 1,7i McIntosh MA8950 & MR88 Oppo 203 Roon Nucleus Rose Hifi RS150B Shunyata Gemini-4 Sony ST-A6B, TA-F6B, ST-J75 & PS-X75 Sorane SA1.2 & TA-1L Stillpoints LP1v2 WW Pt, Au & Ag Last edited by Formerly YB-2; 04-19-2010 at 07:32 PM. |
#16
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Bob,
Thanks for the info - very helpful. I've been experimenting with 12AT7's because I can actually hear a difference when I change them out, and they don't break the bank, only 4 of them are needed. I'm now running NOS Mullards. Much better to my ears than the stock tubes. So your post clarified that for me. Awesome. Did Ron Evans comment about trying to find high transconductance examples, or was he just focused on matching?
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Main System: Amati Futura Mains Amati Homage VOX Center, Proac Response 1sc Rears, Three MC2301's for L,C,R MC 602 for the rears C 1100, MX 151, MCD 1100, MR 80 Nottingham Dais with Wave Mechanic Sumiko Palo Santos Presentation SurfacePro 3, RPi 4, ROON, WW Starlight Platinum USB, Schiit Yggdrasil, Benchmark DAC3 HGC MX 151, OppO BDP-95, JVC RS-500 DILA projector, 106" diagonal Stewart Luxus Screenwall Deluxe with Studiotek 130 G3 material. Lake House: Ohm F, MC 275V, C2300, MR 77, Rega P3 OnDeck: McIntosh MAC 4300v |
#17
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Hi
If one does not have a tube tester, how will I now that the two tube is matched even if I buy matched pairs. One can never be certain that it is correct. How will I know or find these parameters? What is the tolerance? **What's critical for amplifier performance is based on two designs of the unity coupled output: a. How well matched the idle current is on the right and left power tube banks. b. The maximum cathode and plate current capabilities. Thanks |
#18
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Neil |
#19
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WOOOOOH....................
I read all theses posts and now I need an Aspirin ! Thinking about all these tubes in the 2301, it would surely have been less trouble to buy a pair of 1.2KWs, but I would get Maybe a less charming sound..... ( Jim, don't jump on this one, I said MAYBE ! ) Jerome
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There are two means of refuge from the miseries of life: music and cats Albert Schweitzer |
#20
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Jerome, Hey, I am just lurking here. This thread is way over my head. Jim |
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