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Model 864 & 864SR Power Amps

COMPONENTS
Power Amp  864
DECO Amp  864
Preamplifier  770
Amplifier  Upgrades

Discontinued Amps
Power Amp  860
Power Amp  861
Power Amp  860.1

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73kb photo

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IN-HOME AUDITION

NEW
2012 Model

This amp is all new on the inside. 

At first you might think it looks similar to the Model 861 on the outside.  But, the similarity is only skin deep.  This new model sports a custom granite look 5R4WGB rectifier tube just like the one on our flagship DECO amps.  Then the circuitry inside is so different from the 861 that it demanded a whole new model number. 

The 864 has a dramatically improved signal-to-noise ratio of 102dB at rated output.  This is due to the all new filament, plate, and volume control circuits.  And the THD Total Harmonic Distortion measurement is also improved 50%.  Then the 864SR Silver Reference has its internal signal path wired with our world renowned 470 silver interconnect wire.  This wire is 99.9999% pure silver and double shielded to reject noise and make sure you have the cleanest purist path for your music.  Our customers have been asking us to internally wire our power amps with our 470 silver wire for years.  They've come to appreciate the great sonic benefits of the 470 silver interconnect between their top quality components and it only made sense that we finally carry that same super quality wire to the interior circuits that carry the precious music signal.  Of course we also offer the 864 without the internal silver wire to give you the choice.

We debuted the all new 864SR at CES in Las Vegas.  And everyone was blown away by our sound.  You will be too when you hear the 864SR  Silver Reference.

COMPONENTS
POWER AMPS
PRE-AMPS
CD PLAYERS
GROUND ZERO

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INTERCONNECT
SPEAKER
POWER CORD
DIGITAL
VIDEO

    ACCESSORIES
TEST CDs
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TIGER PAW


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TROPHY FISH STORY

    TRADE  SHOWS
HI-FI  '98
CES  1999
CES  2000
CES  2001
CES  2002
CES  2003
CES  2004
CES  2005
CES  2006

"Most Outstanding
Rooms at the Show."


Stereotimes magazine writer Michael Wright picked the Granite Audio room as one of the "Most Outstanding Rooms" at the 2005 show.

SMALL PHOTO       LARGE PHOTO

Stereotimes CES 2005 show coverage

"Now let's talk about the music rooms. Having been an avid reader of quite a few of the competing periodicals and web-zines I have a pretty good idea of what fellow reviewers like in terms of exhibitor rooms and it's typically the usual stuff, i.e. Jeff Rowland, Krell, Thiel, etc. What I shall do here is give you my picks for the "Most Outstanding Rooms at the Shows." These were the rooms of . . . . companies that I genuinely enjoyed being in and who I feel don't get the amount of recognition they deserve."

"I found myself having a good time listening to music in the
Granite Audio room. Everything in their room, except for the wonderful sounding Von Schweikert Research VR4jr, was made by Granite. The VR4jrs were driven by the Granite 864SR KT-88 monobloc amps, Model 770 tube preamp and Model 657 tube CD player. All interconnects, speaker cables and noise suppression was by Granite as well. The sound here was lively and dynamic with a tonality that gave performers a "you are there" quality that was refreshing."
by Michael Wright

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Click here for details on the
IN-HOME DEMONSTRATION PROGRAM

"Their (Granite Audio) tubed electronics and speakers are encased in the many-hued stuff (acrylic-granite) that's said to offer good inherent damping characteristics.  These are quality tube designs; you'll find Vishay, Holco, Sprague, and other audiophile parts scattered throughout."

"CES Expensive Tubes"
Jonathan Scull, Senior Contributing Editor
Stereophile  May 1999, Page 61.

This amp can run without a preamp!


Simply plug your CD player directly into it.  The 864 has a 100K ohm constant impedance Alps input volume control, (that is improved quality over the #860.1), for just such a simple system!  The CD player "sees" a constant high impedance load at all frequencies.

The Model 864 is the newest 2012 power amp.  It has the same live, dynamic circuit with a few improvements that give an extended bass response that is fuller and richer.

The 864 has zero feedback, and even better frequency response than the earlier #861.  The zero feedback design is much more challenging for the designer, but equally more enjoyable for the listener because of the increased dynamic range and excitement of live present-sounding vocals.  The amp also has a built-in user adjustable contour circuit with three settings for use with other brands of speakers or listener preferences of circuit damping.  When the contour switch is in the "Off" position there is no circuit and even the switch is out of the circuit.

The tube filaments are run on AC voltage which is lifted from ground by 40 volts DC, and wired with shielded twisted pair wires for maximum current handling, minimum noise, and a smooth voltage rail.  Switches and contacts are either gold or silver.  Tube biasing is user adjustable with factory supplied tool and
Vishay trimmers, all easily accessed from the rear of the chassis.  The bias procedure for the 864 is even easier than the earlier Model 860.

The amp is easily switchable from pentode to triode with an 18 amp solid silver contact toggle switch located between the KT88's.  The amp develops a minimum of 60 watts in pentode and 30 watts in triode.  If the user has efficient speakers, the triode mode offers some excellent dynamic sound. The RCA inputs and speaker outputs are hard gold plate over silver over copper for the best in long-life wear and maximum transfer of a clean unaltered signal.

To contact us:
Phone:    480-829-8374
CLICK HERE TO EMAIL GRANITE AUDIO.