Amp/Preamp Asylum: REVIEW: Sonic Frontiers Power 3 Amplifier (Tube) by kwlam

Model:	Power 3
Category:	Amplifier (Tube)
Suggested Retail Price:	$12,000
Description:	Sonic Frontiers Power 3 Mono Amp
Manufacturer URL:	Sonic Frontiers
Manufacturer URL:	Sonic Frontiers

Review by kwlam ( A ) on May 17, 2003 at 18:14:39
IP Address: 24.100.237.229

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Review of Sonic Frontiers Power 3 (with modification by Partsconnexion)
Introduction
This review is for the modification done by Partsconnexion on my Sonic Frontiers Power 3. It is not exactly the same as the stock Power 3 SE (Special Edition). For ease of reference, I'll call it Power 3 SSE (Super Special Edition) in this review. I have the original Power 3 for more than six years, these are excellent amps but they are not perfect. I always wanted the amps to have better treble extension, better resolution, midrange liquidity ... etc. My other concern with the Power 3 is on reliability; my Power 3s were made in 1995, one amp was a little bit noisy and both amps had problem in the biasing circuitry. I wanted to get rid of them but it wasn't easy to find a suitable replacement knowing how good the amps can sound. I used to have a pair of Bryston 7B-ST to bi-amp with the Power 3; I had removed the Power 3s from my reference system early last year because of the biasing circuitry problem. At the end of 2002, I purchased an amazing Pass Aleph 30. It worked very well with the Brystons in a bi-amp setup driving my big Dunlavy Millennium. Then I learnt that Chris Johnson was back in business with his new company, Partsconnexion, and they had started their modification business. I asked Chris if he could upgrade my Power 3 to the Special Edition version plus the repair. I bet you know what's his reply, he offered to upgrade my amps beyond the Special Edition. The modification included replacing all the capacitors, resistors in the signal path plus replacement of critical diodes, internal wiring, power bypass with capacitors and new KT88 EH tubes. I don't have a detailed list of what parts are replaced, I know there are Auricaps, Audio Notes paper-in-oil copper foil caps, Kimber Kables... etc. The mod was done by the co-designer of the Power 3, Glenn Dolick. Glenn is a very nice guy, he knows the stuff very well, I'm glad that I have the chance to meet with him in person. He makes his own cables too! I tried his wonderful power cords in my own system; it beats most of the cords I have at home. After the modification and repair, my Power 3s are like new and sounds like totally different amps. I also replaced the small tubes with the Russian 6H23 and the Tung Sol 5687 that further improved the overall performance of the amps.
The Sound
It is hard to describe the sound of the Power 3 SSE. It is so neutral that it has no sound of its own. The major weaknesses of the original Power 3 is that it lacks treble extension which make the overall presentation 'boring'; the sound is also a little bit cool and dry. The Power 3 SSE has managed to improve upon the original in every performance category. It has extended treble, palpable mid-range, deep and tuneful bass. Its bass performance beats the Bryston 7B-ST, I used to have a bi-amp setup with the Brystons driving the woofers, the Bryston has better bass than the original Power 3. With the Power 3 SSE, there is no need to bi-amp, the SSE has much better bass than the 7B-ST. The bass produced by the 7B-ST seems to be 'tighter', but I found it is a kind of distortion. The 7B-ST (and most other amps) tends to squeeze the bass notes into a single pitch that gives an illusion of 'tightness'. There is no music, no details in the bass region. The Power 3 SSE does that with ease and finesses, I can hear all the color and details in the bass region, I never thought there are so many details in the bass region with most CDs that I'm familiar with.
Another amazing aspect of the Power 3 SSE is the realness it presented at a wide range of volume level. The music at the softest to the loudest volume are so convincing that it's like listening to live performance by siting at different rows in the same concert hall; with other amps, you get the 'rightness' at certain volume level only. I went to a concert in a small Korean church a few months ago; hearing the chorus sang various songs from Bach, Vivaldi and other composers, some songs were accompanied by a 9ft concert grand piano. The acoustics of the church was exceptionally good, I was sitting at about 150 ft away from the stage and the sound of the piano and vocal were most impressive. It reminded me of listening to the same kind of CD at home with the volume set at medium-low level. This kind of realness, especially the depth of the soundstage (more than 100 ft) is not possible with most of other amps. Of course it requires both up stream and down stream components to be of the same caliber, my Boulder 1012 and Dunlavy Millennium are definitely no slouch.

The other improvements of the SSE that are immediately noticeable are the overall clarity and cleanliness of the sound, the highest resolution of details without graininess, top to bottom coherence. All these can be heard easily, even my non-audiophile wife can point these out immediately. My description of the Power 3 SSE has been focused on the most noticeable improvement of the SSE over the original Power 3, it doesn't mean it fall short in other areas. I have both Bryston 7B-ST and Pass Aleph 30 at home as a reference; both amps were reviewed by reviewers at enjoythemusic.com. Basically, I agree with most of their assessments of the 7B-ST and the Aleph 30 and the relative rating of the amps (except a few for the 7B-ST). Let me summarize the performance of the Power 3 and Power 3 SSE in the following table using the rating for the Aleph 30 (and the 7B-ST with few changes) as a comparison.
________________________7B-ST______Aleph 30_____Power 3_____Power 3 SSE
Tonality____________________91__________95__________92__________97
Sub-bass (10-60Hz)__________92__________95__________92__________95
Mid-bass (60-200Hz)_________92_________100__________92__________98
Midrange (200-3000Hz)_______90__________90__________92__________96
High frequencies_____________92__________95__________90__________97
Attack_____________________92__________95__________92__________97
Decay______________________87__________95__________90__________97
Inner Resolution______________88__________90__________92__________98
Soundscape width front________89__________85__________91__________99
Soundscape width rear_________87__________85__________90__________99
Soundscape depth_____________86__________80__________90__________99
Soundscape into the room______88__________80__________91__________97
Imaging____________________94__________85__________94__________98
Fit and finish________________95__________95__________96__________96
Self noise__________________99_________100__________92__________94
Conclusion
I have heard a lot of amps and there is only one that really impressed me: the Lamm ML 2, but its prices is out of reach for me. I don't have the ML 2 to compare side by side with my Power 3 SSE; from my memory, my Power 3 SSE is very close to the ML 2, if not better, with much better bass. So the Power 3 SSE is almost perfect. The weaknesses of the Power 3 SSE are common with any other high power tube amps: it generates lots of heat that could be problematic in hot summer, I have the listening room at the loft with very poor air conditioning. In the winter, the warmth (temperature and the sound) of the amps is a joy to use.

I don't like to change equipment very often, so I buy stuff that could provide 'life long' enjoyment. Over the past 4 years, I have replaced everything in my system except the Power 3 and the cables. I'm quite sure that I'll keep the Boulder 1012 and the Dunlavy Millennium 'forever'. Will I keep the Power 3 SSE for the rest of my life? I probably won't, given the reliability problem I had but I'll keep them as long as they are working; I hope this will be at least another 10 years. If you own Sonic Frontiers Power 2 or Power 3, you owe it yourself to check out this awesome modification from Partsconnexion.

Product Weakness: Generate lots of heat, slight transformer hum.
Product Strengths: Neutral and natural sounding, top to bottom coherency, clarity and extremely detailed, wonderful bass...etc.

Associated Equipment for this Review:
Amplifier:	Bryston 7B-ST; Pass Aleph 30
Preamplifier (or None if Integrated):	Boulder 1012; Krell KRC-HR
Sources (CDP/Turntable):	Sony SCD-1; Apogee DA-2000
Speakers:	Dunlavy Millennium
Cables/Interconnects:	Kimber Monocle; Aural Symphonic AS 1 Vi; TaraLabs Decade IC; BMI Whales; XLO 10A .... etc.
Music Used (Genre/Selections):	Classical; Jazz; Rock
Room Size (LxWxH):	21 x 28 x 9
Room Comments/Treatments:	ASC Tube Trap; ASC Sound Panel; TACT RCS 2.0
Time Period/Length of Audition:	3 months
Other (Power Conditioner etc.):	PS Audio P300; Chang 9900
Type of Audition/Review:	Product Owner

Product Weakness:	Generate lots of heat, slight transformer hum.
Product Strengths:	Neutral and natural sounding, top to bottom coherency, clarity and extremely detailed, wonderful bass...etc.