Solar Fusion digital amp available

KevinW · « **on:** 14 Oct 2003, 08:30 am »

Note: This thread has been updated to reflect final pricing. The original intro period has passed, although there is still a special deal available for AC members through the end of the month.

Reviews are starting to come in, and they are glowing. I have worked hard to embody this amp with only the best qualities of tube amps and solid state. It has the emotional connection capability of the finest SET tube amps, while retaining the natural, uncolored sound of the finest SS amps. Detail, imaging, micro and macro dynamics are similarly outstanding. This amp lets you "relax" into the music while at the same time engaging your mind to experience every last detail of the music.

Some initial reviews are:
http://www.audiocircle.com/index.php?topic=6111
http://www.audiocircle.com/index.php?topic=5323

And of course, the homepage for the amp is
http://www.solarhifi.com/fusion.php

It is called the "Fusion", since it merges many different technologies into one product that is greater than the sum of its parts. Fusion is also the power source of the Sun, which fits my Solar theme.

The Fusion comes in three flavors:

Fusion H1 -- aka "Hydrogen"
Straight class D, no vacuum tube input stage
Instantaneous power: 250/500 watts/ch into 8/4 ohms
RMS power: 250 watts/ch into 4 and 8 ohms
Introductory prices are:
$1799 - Stereo power amp ($1999 after Nov 30th)
$2199 - Integrated Stereo amp with three inputs, sub outs, cryo'd Dact attenuator and Elna switch, Jena labs ultrawire ($2499 after Nov 30th)
$1249 ea. - Monoblock power amp (250/500 watts each into 8/4 ohms) ($1399 after Nov 30th)

Dimensions: 17"x13"x4" (stereo), 8"x17"x4" (mono)

Clock upgrade to 750 kHz - $150
Remote control for Dact - $350
Stillpoints ERS cloth - $75
Balanced inputs - $150
Tube preamp circuit upgrade - ~$1200

Fusion H2 - aka "Deuterium"
This is the amp with the tube preamp stage designed by Jena Labs. It will have the exact same power specs as the Hydrogen version. We are in the midst of a slight redesign of the tube circuit to lower the noise floor and improve the sonics. This amp will be released in about a month, and will cost about $3k for a basic stereo amp.

The H1 version will always be upgradeable to the H2 version at a later date. I am designing flexibility into my products, so the customer gets exactly what he wants.

Fusion H3 -- aka "Tritium"
This is the no-holds-barred amp with the absolute best sonics possible with digital technology. It will also feature a one of a kind, work of art chassis created by a local metal worker, glass blower, and stone mason all rolled into one. The chassis will be made entirely of recycled materials and/or sustainably produced materials. This will be a museum quality work of art, as my artist does absolutely incredible work. Release date will be in 4-6 months, and price point will be in the $5-7k range.

There is a new chassis design, that is similar yet much improved over the original. It uses a full-wrap bamboo plywood around all four sides of the amp, and has a stainless steel top plate, and stainless steel rear insert for all input and ouput jacks. Everyone who has seen the bamboo has been very taken with the look. It has class and style.

This photo is of the original design. Photos of the new chassis are coming soon.

audiojerry · « **Reply #1 on:** 14 Oct 2003, 03:59 pm »

Congratulations on a great looking product!

I have a few questions.

If I used my current tube preamp as input to the Fusion, can the input switching and volume control circuitry be bypassed or removed from the signal path?

What is the input impedence?

Does the XLR mod consist of anything other than using a different input connector? Your mod mentions "balanced" inputs.

Do you have a trial period / return policy?

KevinW · « **Reply #2 on:** 14 Oct 2003, 04:36 pm »

Jerry,
The input impedance is 25k ohms. The LC Audio modules have true balanced inputs, so the XLR option is indeed balanced. It is not just an XLR jack with two pins shorted together. However, this option increases the price of the integrated version of the amp because it requires a 4-pole dact.

Regarding bypassing the switch and Dact, the cheapest way to do this of course would be to buy the non-integrated stereo amp.

However, I have not been able to notice any deleterious effects from having the volume control wide open and using an external preamp. In theory, there should be some problems, but with the immersion cryo treated Dact and Elna switch, and Jena Labs Ultrawire in the signal path, there really is no detectable loss in SQ.

I am offering a 21 day trial period. If you don't like them, just pay for return shipping within that period. However, I seriously doubt that anyone will exercise this option. I think this amp is really going to make some lucky people extremely happy.

azryan · « **Reply #3 on:** 15 Oct 2003, 12:12 am »

Oops,

looks like you answered some of my questions here I just posted in a diff. thread. sorry.

Anyway...

"-Straight class D, 250 watts/ch into 4 and 8 ohms"

Is this right? 250W in both 8 Ohms and the same into 4 Ohms?

I'm guessing no 'cuz of this -"Monoblock power amp (250/500 watts each into 8/4 ohms)"?

Are the monoblocks in the same case as the stereo Fusion?

KevinW · « **Reply #4 on:** 15 Oct 2003, 02:34 am »

Quote from: azryan

"-Straight class D, 250 watts/ch into 4 and 8 ohms"

Is this right? 250W in both 8 Ohms and the same into 4 Ohms?

Azryan, good catch. There is a typo... I meant to say 250 watts/ch RMS into 4 and 8 ohms.

I'm not the kind of person that likes to inflate specs just to sell a product. I made a design decision to keep the amp cost effective and still meet the needs of most customers. The transformer used in the stereo amplifier is good for 500 total watts (250/ch). 250 watts/ch is more than sufficient for most people. To make the amp capable of producing 1000 total watts of RMS power, I would have needed to double the size of the transformer. This would incur a significant cost, and also not be useful to the vast majority of the customers. I don't like doing that kind of thing for many reasons, including sustainability theory.

The key difference is RMS wattage outputs vs. instaneous wattage. By law, it is required to report the RMS power output of the amp, with both channels running simultaneously. I have done this.

However, this doesn't mean that you don't get the benefit of the 500 watts that the LC Audio modules can output into 4 ohms. This is because the Fusions' power supply is designed to handle the short duration bursts of the music and can put out 500 watts of instantaneous power as the music demands. For real-world listening, this is all that most people need.

Very few speakers have such a low impedance (eg. <2 ohms) that 500 watts/ch of RMS power would be necessary. The vast majority of people will get the benefit of 500 watts/ch into 4 ohms. If somebody really wants 500 watts/ch RMS, they can buy the monoblock version for a few hundred dollars more. This way only those that need the power have to pay for it.

I should make a distinction between instantaneous power output and RMS power output, and then put it into a FAQ.

guest1632 · « **Reply #5 on:** 15 Oct 2003, 03:13 am »

Quote from: KevinW

The Solar Hifi class D amp is now available for purchase! I have worked very hard to make this dream into a reality, and the sonic quality of this amp has greatly exceeded my own personal expectations. Every detail of this amp has been designed to create emotional involvement into the music. This amp lets you "relax" into the music while at the same time engaging your mind to experience every last detail of the music.

It is called the "Fusion", since it merges many different technologies into one produ ...

Beezer · « **Reply #6 on:** 15 Oct 2003, 12:33 pm »

What is the form factor for the stereo and mono amps (LxWxH, weight)?

Thanks,
Beez

KevinW · « **Reply #7 on:** 15 Oct 2003, 07:45 pm »

Quote from: Ray Bronk

Hi Kevin, Is the steering PS an additional $650--the one that Gina Labs designed does that come with the amp or an additional $650. and for $1900, the preamp, that is passive? the stereo version for $1500, uses one transformer? Sorry, but since I am visua -

The Steering PS uses very expensive blackgates to isolate each channel of the stereo amp. That is why it is so expensive. But it does provide the ultimate in monoblock performance from a stereo amp. It is an add-on to the introductory base price of $1599.

The preamp stage is not active, since an active stage is not needed. It would only get in the way of the sound. Immersion cryo treated Dact and Elna switches, with Jena Labs Ultrawire is the best you can get for sonic purity.

KevinW · « **Reply #8 on:** 15 Oct 2003, 07:47 pm »

Quote from: Beezer

What is the form factor for the stereo and mono amps (LxWxH, weight)?

Thanks,
Beez

Form factors are...
Stereo: 17" wide, 13" deep, 3.5" high
Monoblocks: 8" wide, 17" deep, 3.5" high

Weight is about 30lbs on each.

guest1632 · « **Reply #9 on:** 16 Oct 2003, 07:03 am »

Quote from: KevinW

The Steering PS uses very expensive blackgates to isolate each channel of the stereo amp. That is why it is so expensive. But it does provide the ultimate in monoblock performance from a stereo amp. It is an add-on to the introductory base price of $1599.

The preamp stage is not active, since an active stage is not needed. It would only get in the way of the sound. Immersion cryo treated Dact and Elna switches, with Jena Labs Ultrawire is the best you can get for sonic purity.

KevinW · « **Reply #10 on:** 17 Oct 2003, 01:48 am »

Quote from: Ray Bronk

Hi Kevin, Are you using two transformers, true mono blocks on one chassis, or one transformer with several windings? Also, it would be interesting more for marketing if you built one with average parts. That would show off the basic model's attributes. -

In the stereo amp, there is only one transformer for both models. That is how stereo amps are usually done. Dual-mono wouldn't fit in one chassis, and wouldn't save much $$$ vs. the monoblocks. It's not very practical to do a dual-mono poweramp. Much better to do a dual mono preamp, where the transformers are small.

guest1632 · « **Reply #11 on:** 18 Oct 2003, 08:38 am »

Quote from: KevinW

Quote from: Ray Bronk
Hi Kevin, Are you using two transformers, true mono blocks on one chassis, or one transformer with several windings? Also, it would be interesting more for marketing if you built one with average parts. That would show off the basic model's attributes. -

In the stereo amp, there is only one transformer for both models. That is how stereo amps are usually done. Dual-mono wouldn't fit in one chassis, and wouldn't save much $$$ vs. the monoblocks. It's not very practical to d ...

KevinW · « **Reply #12 on:** 20 Nov 2003, 09:13 pm »

Bumped to the top to represent latest introductory pricing. See the first post in this thread for the info.

audiojerry · « **Reply #13 on:** 20 Nov 2003, 09:38 pm »

Kevin, I probably missed the explanation, but what is the driving force behind the tubed front-end upgrade? No disrespect intended, but is it meant to address any sonic issues that exist without tubes in the signal path?

KevinW · « **Reply #14 on:** 20 Nov 2003, 10:25 pm »

Quote from: audiojerry

Kevin, I probably missed the explanation, but what is the driving force behind the tubed front-end upgrade? No disrespect intended, but is it meant to address any sonic issues that exist without tubes in the signal path?

The H2 amp uses tubes to add a little extra tube warmth. I'm a dedicated tubeophile, and I am addicted to the sound of tubes. The H1 amp already has much of the magic of tubes, but the H2 takes it to a new level. I'm expecting the H2 to compete with the likes of Tenor OTL amps.

I also love the look of tubes glowing in a dark room. The combination of tube glow reflected on the polished stainless steel top plate, smartly finished bamboo, and the yellow LED should be very seductive.

J North · « **Reply #15 on:** 20 Nov 2003, 10:46 pm »

Kevin,

WIll the tube stage change the input impedence of the amp?

Will the tube stage be bypassable (with a switch)?

Thanks!

KevinW · « **Reply #16 on:** 20 Nov 2003, 10:52 pm »

yes, the impedance of the amp will be higher with the tube stage. Approx 50k. A switch is possible... I like having switches that give a different sound. It makes amps more fun.

I'll see how it sounds in comparison during the prototyping phase before I make my final decision whether to include it.

Zero · « **Reply #17 on:** 20 Nov 2003, 11:31 pm »

Sad to see the price will sky rocket upwards after the introductory price. Im sure its one hell of a unit.. I cant see myself earnin the cash to get that anytime soon though. Ah well! Cant wait to hear about others results.