Granite Audio 860 Amplifiers

5/5 (2 Reviews) MSRP : $8400.00


Product Description

KT-88 Tube Monoblock Power Amps - 30 Watt Triode / 60 Watt Pentode


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Reviews 1 - 2 (2 Reviews Total)

User Reviews

Overall Rating:5
Submitted by Zenith a an Audiophile

Date Reviewed: September 13, 1999

Bottom Line:   
MODEL #860 MONOBLOCK AMP.GRANITE AUDIO – ROCK SOLID MUSIC SYSTEMS:

This is a review of the Granite Audio Model 860 Power Amp.

It took me several months to save up for the amps. But, I finally saved enough money and got a bargain on one of Granite Audio’s promotional ads. They asked if I would write a review and then left it up to me.

The other equipment in my system is:
Speakers – ProAc 3.8
Preamplifier – Cary SLP98
Cables – Kimber

I don’t know anything about writing reviews. I just know how much I like these amps. I liked the sound of them at CES and they sound as good in my home with my components. My only problem is the other Granite Audio components sound better to me more of the time than the Kimber, ProAc, and Cary. These other brands are great to say the least. But, they lack the synergy that the Granite Audio System has. All the components sound good some of the time. But, the Granite Audio System sounded good all the time and it sounded GREAT much of the time. I believe the synergy of the system helped it adapt to, and perform more kinds of program material with quite stunning sound reproduction. I listened to all sorts of music at their CES exhibit and it all sounded very live and dynamic. Even the crappy recordings were full of life and emotion. I found myself wanting to listen to everything for extended listening sessions. I don’t have to hunt for something “good” to listen to anymore. I can enjoy all my music now. And I can be thoroughly moved to tears by the awesome sound of my great audiophile quality CDs.

The 860 uses KT-88 power tubes in a push-pull arrangement and can be operated in a pentode or triode situation. The triode setting gives more air, dynamics, and a better soundstage than the pentode setting, but at one half the power output. The amp gives 60 watts in pentode and a strong 30 watts in triode. I say it’s a strong 30 watts because it drives the speakers so well and at high listening levels. I was measuring 96 decibels and it sounded superb.

The amp is completely enclosed and isolated with the half inch thick granite that covers everything except the back which is open. I auditioned this amp with and without the granite box. The granite definitely does its job. I didn’t think power amps were sensitive to microphonic vibrations, but they are. The Granite Audio 860 uses 6SN7 driver tubes, as does my Cary. I like the open sound of the 6SN7 and it’s not at all microphonic, unless you get a defective one. However, things were cleaner sounding and the sound stage was fuller and more detailed with the granite enclosure in place. I don’t know what’s in this stuff and the Granite Audio guys won’t say anything more than “It’s an acrylic based artificial granite,” but, it works!

I first heard these awesome amps at the Consumer Electronics Show in Las Vegas. I might not have paid much attention to the Granite Audio room except their poster outside their exhibit room caught my attention. It showed a whole system in a unique granite material. I don’t know any other companies that are doing systems or granite. The whole concept was so new I had to go in and see what they were doing.

I was impressed by their casual personal approach to me and to specialty audio. Those guys do not dish out any hype. I felt comfortable so I stayed for a demo in the back room. Wow! Jim, the long-haired guy with the boots played some really interesting demo tunes. He played some of the standard audiophile type recordings, but he also played music that he liked personally. He played stuff like Blood Sweat & Tears, Dire Straights, and the sound track from the movie Braveheart. The battle drums on Braveheart were awesome! The drums sounded so deep and dynamic that I could feel the fear that the warriors must have felt when they heard them coming at them in the battles.

Jim’s demonstration was important to me because I don’t just play audiophile recordings all the time. There is a ton of music that I love that is recorded in, um, non-audiophile quality. When I spend that much money for stereo equipment, I want to know what all my music will sound like; not just some of it.

I would give these amps a strong 5 star rating, even at full list price.

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Overall Rating:5
Submitted by Burt Rollins a an Audiophile

Date Reviewed: September 7, 1999

Bottom Line:   




























GRANITE AUDIO Model #860 Tube MonoblockThe first thing I have to say about this great amp is how good it sounds.  It sounds not only live and dynamic, but better than anything else I've heard.  Originally I wanted to bi-amp my JM-Lab speakers using the Granite Audio 860's for the midrange and tweeters, while using my solid state amp for the woofers.  I've heard how great tubes are on the high end and how great SS is on the bottom end.  So, I bought a pair and hooked them up that way.  Yep, it sounded better with the 860's on the top.  Lots better.  Then I tried reversing the amps.  I put the SS on top with the 860's on the woofers.  It still sounded better than all solid state amplification did.  The bass and midbass were much more dynamic and live sounding with the tube amps.  I was surprised.  I didn't expect the 860's to handle the bass so well.  And, I really didn't expect them to outperform my SS amps.This got me thinking.  So, I hooked up the 860's to drive both the top and bottom.  WOW!  Did that ever sound great!  I put on a CD with a bass fiddle solo.  It sounded so real.  I swear I could actually see strings vibrating.  The audio illusion was that realistic.  Solo singers sounded natural and real just like they were there in front of me.  The sound stage of the voice was big and full and very present.  I admit I was expecting this after reading the press reviews on these amps.  I was expecting them to shine on vocals and they did.  I have a decent size room for my stereo.  I have my JM-Lab speakers set out 5 feet from the back wall.  I didn't use to set them out so far but I wanted to take advantage of the deep soundstage that these 860 amps can project.  I was hearing horns on a jazz CD that sounded like they were 16 to 18 feet behind the speakers.  Listening to these amps with my eyes closed created an illusion that my listening room is much larger than it really is.  (PS.  I am selling the solid state amps and using the money to buy more CDs.)An amazing part of these amps performance was their ability to articulate the details in the music.  I think this is called micro-dynamics.  The amps were quick enough to articulate these details while letting other ambient and echo sounds drift and decay naturally.  Regardless of the playback  room acoustics, the amps had a live sound to them.  Even studio recordings had an air of life to them.  The recordings I've played had an exciting quality about them.  There was an immediacy to the performances that I've not heard in other amps.  Granite Audio President, Don Hoglund, attributed much of this to the zero feedback design.  He says it lets the circuit do what the music is trying to make it do.  Music starts out live and the zero feedback doesn't put any restrictions on it playing back with it's original life.  Don also said that having monoblocks lets you put the amps closer to the speakers and take advantage of the tremendous listening improvements derived from getting the speaker cables as short as possible.  I don't know if all that is true, but I do know what I heard was awesome,  quick, and extremely accurately detailed.The amp itself is intriguing.  The simple design and high gloss finish are quite elegant.  The Granite Audio logo barely shows when the amp is in the off position.  It is impressively subtle.  But, when you hit the on button the logo leaps out of the granite in a stunning ruby red glow.  Trust me, it makes a statement.  The back of the enclosure is fully open for cooling the big power tubes.  I've left the amps on for days on end and the top of the granite gets warm but not hot.  Those granite guys know what they're doing with the heat.  Don said the logo and word "POWER" are engraved into the granite and epoxy filled before being polished flush.  He said the enclosure can be buffed for decades without fear of rubbing the letters or logo off.  Well, I should hope so.  I would expect to be able to keep this high polish finish looking good at this price point.The feature I like best is the input volume control.  This allows me to connect my CD player directly to the amps without a preamp.  Martin DeWulf of Bound For Sound wrote a review of these amps that clued me in to this innovative feature.  The other plus for the input control is the convenience of being able to change speaker cables, interconnect cables, speakers, and other components without shutting the amps down.  I like to do lots of comparisons and equipment swapping and I get tired of shutting down the amps to protect the speakers and then waiting for them to heat up again.  This way, once I get them hot they stay hot and ready for instant listening tests.The owner's manual is very easy to understand.  The tube biasing is simple and the adjustments are amazingly stable.  The tubes are adjusted separately so you don't have to buy matched tubes or hope the tubes age at the same rate.  The bias trimmer is a super accurate 15 turn Vishay pot that can set the bias exactly with a digital volt meter.  The designer is obviously an exacting tweak like myself.I would describe these amps as very involving and enjoyable to listen to.  I don't get tired of listening after an hour.  I find myself listening for many more hours than I used to.  I'm looking forward to buying more CDs.  These amps worked superb on jazz, rock, folk, classical, and even reggae.  I love them.




















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Reviews 1 - 2 (2 Reviews Total)

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