[rockadanny]

First, let me say that I am very happy with my new Fet Valve Ultra 550.

My gear is in a cabinet (and will never be in an open rack, so please don't go there). I have removed the glass door and cut large slots in the back. I have also drilled two rows of holes in the top of the cabinet (I painted the inside wood of the holes black to conceal my furniture butchery from my spouse). I have 3-4 inches of space above each component. So it's in-between an open rack and a cabinet as far as air flow. But the 550 gets pretty warm.

At what temperature inside its cavity should I be concerned?

I do not want my electronics to suffer from over heating, even if they sound fine while playing. I have since ordered a couple of low-noise fans to place inside for better air flow. But would like to know what the operating environment "danger zone" is for the 550.

Thank you.

[avahifi]

The Fet Valve amps do run warm, they are running Class A up to about 20 watts per channel.  Put a normal household temp gauge in the cabinet on top of the amp and see hot hot things really are.  Note that we have never had a thermal failure of one of our power amplifiers.  The heat sinks are really pulling the heat out of the output devices, there is a very low thermal gradiant between the actual devices and the ends of the heat sinks, which of course is very good for durability and long service life.

I suspect you do not have a problem.

Frank Van Alstine

[rockadanny]

Whew! Thank you Frank.

[tonyptony]

Danny, after my small contribution to your decision to get an Ultra I'm hoping you'll be giving us all a nice post on your impressions!  

[Soundbitten]

First, let me say that I am very happy with my new Fet Valve Ultra 550.

My gear is in a cabinet (and will never be in an open rack, so please don't go there). I have removed the glass door and cut large slots in the back. I have also drilled two rows of holes in the top of the cabinet (I painted the inside wood of the holes black to conceal my furniture butchery from my spouse). I have 3-4 inches of space above each component. So it's in-between an open rack and a cabinet as far as air flow. But the 550  ...

I have a cabinet somewhat like that but with a solid cherry door . My solution was to position it kitty corner and in the space behind it place my amp on an amp stand ( unseen from the front ) .

[rockadanny]

Yes, Tonyptony, I will post a review in a bit. I did not want to do that quite yet, as I am swapping out my current preamp stand-in (which is really an integrated amp, but using its preouts) for an actual real preamp. Even though I like my integrated really well, using just its preouts I suspect it is lacking in some way, adversely affecting the sound. This was kind of confirmed by Frank too. My new preamp is under construction. As soon as it is delivered and I burn it in a bit, I will be able to give a more fair evaluation of my Ultra 550. (However, from what I have already experienced, I suspect it will be an extremely positive one.)

And Tonyptony, I want to thank you for helping me decide on getting the Ultra 550.

[tonyptony]

My pleasure, Danny. Hope it turns out to be all you expect. Take your time with the review; after reading where you'll be going it sounds like it will be worth the wait!  

[rockadanny]

TonyP: Still no system to review 550 yet. Preamp still not built (argh!), though next in the queue. While waiting I sent in my CD player for mods. Now all I have left is the 550. If it weren't built so damned well I could at least plug it in and listen to some hum. But I got NOTHIN'! ARRRGGGHHH!!!!

Last night I was sitting in my driveway, in the dark, in my truck with a cold beer and two cds (Robert Nighthawk, "Live on Maxwell Street - 1964" and Buddy Guy, "Damn Right, I've Got the Blues"). My wife comes out and asks me, "what the hell are you doing out here?" Just then, "Mustang Sally" came on so I did not respond immediately. I just slowly smiled and raised my beer. She rolled her eyes, gave the choir an, "Oh Jesus", and turned on a dime. I think she was saying something to/at me as she was shaking her head, marching back to the house, but all I heard was, "... guess I'll have to put your flat feet on the ground."

For gosh sakes Dr. Lloyd, puleeeeze hurry up and build me my preamp!

[tonyptony]

Danny, great selection of music! Right down my alley.

With you in mind I'll play B.B.'s "Blue Boys Tune" when I get home tonight.  

[rockadanny]

Review of the Ultra 550 (and Salk Veracity HT3 speakers) is at:
http://www.audiocircle.com/index.php?topic=29112.0