Announcing the Ultra Double 550 Amplifier

avahifi · « **on:** 7 Jan 2009, 06:27 pm »

We now have a new option available for the Fet Valve Ultra 550 amplifier; the Ultra Double 550 option. The price for this option is $250 during the original build process, or $500 as a retrofit to existing Ultra 550 amplifiers.

The option consists of building the amplifier with twelve "double die" Exicon mos-fets. Each is a 250 volt, 16 amp, 250 watt rated device, equivalent to building the amplifier with twenty four standard production devices.

The result is increased load driving capability, markedly increased "balls" and dynamics, and even more overall power.

It is for those of you that just can't get enough power or want to drive your speakers effortlessly to their absolute limits. Or for those that just want an even closer approach to live dynamic range and musicality.

The Double 550 upgrade is also available for older version of the Fet Valve 550 amplifiers, including major power supply and circuit upgrades. We will quote these prices on an individual basis depending upon the current status of the amplifier in question.

An Ultra Double 550 is shipping today to one of our clients. I bet there will be some comments made herein shortly about his evaluation.

Call us at 651-330-9871 for more information.

Best regards,

Frank Van Alstine

clipped · « **Reply #1 on:** 7 Jan 2009, 06:49 pm »

Hi Frank,

Will there be a 350 version??

TomW16 · « **Reply #2 on:** 7 Jan 2009, 06:54 pm »

Hi Frank,

It sounds as if the double 550 is simply a doubling of power from the original 550. I was happy with the 350 so I can't imagine needing more power than my current 550. Are there any plans to produce a 550 amp that would work with a full differential system that was previously planned but postponed until the DAC chip is available?

Thanks and good luck with the more powerful amp.

Tom

ricmon · « **Reply #3 on:** 7 Jan 2009, 07:01 pm »

I wish this was availble before I got rid of the my 550 Ultra. It sounds like it would have been just what the Dr. (me) ordered.

avahifi · « **Reply #4 on:** 7 Jan 2009, 09:09 pm »

No, it is not a doubling of the rated power. Power is higher because the output impedance of the mos-fet output device arrays are cut in half, so less voltage drop from the same source supply voltage and thus higher power. This is different than the normal output impedance value, which already was very very low. The advantages are that the power is shared by twice as much die area so that current, and power handling ratings go way up. The result is a more "effortless" amplifier.

It could be done with a 350, but since the power there is lower, the benefits would not be as marked.

Regards,

Frank Van Alstine

oneinthepipe · « **Reply #5 on:** 7 Jan 2009, 09:29 pm »

Frank:

Is this similar to the H rated amps in the Insight series?

mark funk · « **Reply #6 on:** 7 Jan 2009, 10:32 pm »

Frank, while we are talking about Double amps could you help Martyo and I out? Back in the days of the Double 400 and the Dyna ST-400 was there any amp called the Double Dyna 400? I am thinking when HP and PHD in the TAS 1977 looked at your Double 400 built in a Dyna chesse they started calling it a Double Dyna 400?

tonyptony · « **Reply #7 on:** 8 Jan 2009, 12:35 am »

Frank, will this have any effect on the ability of the design to drive low impedance loads? You may recall in my case, my speakers are nominally 4 Ohms but go down to a little under 2 Ohms at some points.

Does it change the overall gain at all?

I've found over the years that some high power amps are not as good as lower power jobs in the areas of delicacy, microdynamics, and timbre. Not the Ultra 550, but I'm wondering if you've been able to evaluate the Double in these areas as well.

Any change to the effective bandwidth?

sueata1 · « **Reply #8 on:** 8 Jan 2009, 01:39 am »

Frank,,,
I use 2 Ultra 550's bridged mono,,,
Any advantage to going with the 1 Double version instead of the 2 bridged amps in this case??

Happy listening,,,
Mel

JerryM · « **Reply #9 on:** 8 Jan 2009, 03:45 am »

Dammit. So much for the '09 New Year's resolution...

Talk with you soon, Frank,
Jerry

cdorval1 · « **Reply #10 on:** 8 Jan 2009, 08:02 pm »

Hi Frank,

This is intriguing. Is this similar to the step-up from the Insight 240 to the 260?

Craig

Wayner · « **Reply #11 on:** 8 Jan 2009, 09:19 pm »

Frank,

Would you expect the RMS power rating to be around 330-350 per channel?

Wayner

avahifi · « **Reply #12 on:** 8 Jan 2009, 10:17 pm »

The first one out the door made a bit more than plus and minus 70V peak, both channels driven into 8 ohms. That works out to about 307 watts per channel RMS.

Regards,

Frank

Wayner · « **Reply #13 on:** 8 Jan 2009, 10:40 pm »

So, If you had 2 of these amplifiers and used the phase inverter bridge to make them mono-blocks, they would roughly be capable of 900 watts RMS, each or 1,800 watts RMS for the stereo system?

If so, I couldn't imagine the Dynamic capabilities for this amplifier pair on any loudspeaker system in the world. It's dynamics and speed would be absolutely crushing....mind blowing, if you will.

Wayner aa

Tom Alverson · « **Reply #14 on:** 9 Jan 2009, 02:12 pm »

Quote from: Wayner on 8 Jan 2009, 10:40 pm

So, If you had 2 of these amplifiers and used the phase inverter bridge to make them mono-blocks, they would roughly be capable of 900 watts RMS, each or 1,800 watts RMS for the stereo system?

Wayner aa

Two of those bridged would give you 280Volts Peak-Peak output. That would be enough to shock your monkey.

Big Red Machine · « **Reply #15 on:** 9 Jan 2009, 02:46 pm »

Quote from: avahifi on 8 Jan 2009, 10:17 pm

The first one out the door made a bit more than plus and minus 70V peak, both channels driven into 8 ohms. That works out to about 307 watts per channel RMS.

Regards,

Frank

Frank, how about a demo unit to travel around? We'll double box it for extra care site-to-site.

rlee8394 · « **Reply #16 on:** 10 Jan 2009, 07:08 pm »

Quote

Two of those bridged would give you 280Volts Peak-Peak output. That would be enough to shock your monkey.

Umm...no. Each bridged unit would yield 140 volts peak-peak. In theory that would equate to roughly 1225 watts RMS into an eight ohm load provided the current can keep up. Still enough to shock your monkey,or any other primate for that matter.

Ron

Philistine · « **Reply #17 on:** 10 Jan 2009, 07:13 pm »

Quote from: Big Red Machine on 9 Jan 2009, 02:46 pm

Quote from: avahifi on 8 Jan 2009, 10:17 pm
The first one out the door made a bit more than plus and minus 70V peak, both channels driven into 8 ohms. That works out to about 307 watts per channel RMS.

Regards,

Frank

Frank, how about a demo unit to travel around? We'll double box it for extra care site-to-site.

I'm curious to Pete - having heard the Frank/Jim combo at Jim's house. What about a HT3 owners tour?

carusoracer · « **Reply #18 on:** 10 Jan 2009, 07:36 pm »

I talked Frank about one and it does seem very promising!

I would like to Audition one first, but I'm sure it would help the thirsty HT3's appetite for current and power

martyo · « **Reply #19 on:** 10 Jan 2009, 08:22 pm »

It arrived yesterday in perfect condition.

We got in 3-4 hours listening last night. aa
Frank had generously "loaned" me an AVA 440H and that is what I had been listening to for the past 3 weeks, so we started with the 440 and Diana Krall Live at the Montreal Jazz Festival cuts 1-2-3 and then switched to the "Double". Really enjoyed my time with the 440, a very fine amp, but the Ultra is fuller/richer, more powerful/authorative, and last night, more transparent, and of course, more $.

I've been moving snow all day, going down for some Keith Jarrett.
I'll post listening impressions tomorrow or Monday morning.