Amp/Preamp Asylum: REVIEW: Bent Audio 102s Passive Components by Tuckers

Model:	102s
Category:	Passive Components
Suggested Retail Price:	$950
Description:	2 input transformer passive Preamp
Manufacturer URL:	Bent Audio
Model Picture:	View

Review by Tuckers ( A ) on December 21, 2002 at 02:08:16
IP Address: 66.167.201.13

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for the 102s

I received this unit for evaluation from John Chapman of Bent Audio. It is a simple device that uses a transformer to control volume in 35 stepped increments. I was interested to hear this, as it is an exceptionally minimal piece with only a few parts of very high quality. I have a Spectral DMC 30 that has held me in good stead for three years (a long time in my neurotic audiophile world). The Spectral is a very good preamp with a lot of dynamics, neutrality, and very clean sound. The Spectral is anything but minimal in it's design.
The unit was an evaluation copy that has made it around to many users, and was a bit beat-up, but fully broken in. Since it was passive, it only needed a day or two to sound it's best. Fit and finish of the unit is OK, not to my preference, if you want a sexy Pre, look at Bent Audio's TAP which is as design forward a piece as there is in hi-end gear. The first time I turned it on I heard something special. It sounded really laid-back, relaxed, and very clear.
With use of about a week, the unit grew on me. With it my system sounds more laid-back, real, detailed, solid, tonally balanced and tonally richer. Bass is deeper and tighter, macro dynamics increased, micro dynamics became more apparent. Everything sounds more relaxed and flowing, the soundstage was wider and more natural. The highs are a bit recessed, but there is significantly more detail and shimmer. My system sounded much more 'analog' with the tx102 in place, and that was a good thing. It lost an edge to the sound, and had less spotlighting or instruments. At the same time pinpoint imaging seemed a little more diffuse, but in a way more like an instrument in the room.
In all, the sound was less like hifi and more like music.
I listened for the tell-tale signs of a passive pre in my system, and apart from the imaging thing, found none. The unit has no resistors or capacitors in the circuit path, the transformers are supposed to work much better as a passive. It sounded so in my system.
Reservations
I have been looking for reservations about this pre. First, it may not play well with every setup, I have been lucky that there has been no hum or impedance problems for me. I understand this is a common problem with these. I brought it over to a friends, and we did have some hum problems and 'popping' problems with their amps, but we didn't have much time to work with it. My dealer has told me that the Spectral DMC 150s Universal is designed for pro use, and has been made to be immune to most hum and impedance mismatch problems, this could be the partial reason I have had good luck.
I suspect that this type of product would have problems in the retail marketplace, as it needs proper setup, attention to hum, and component matching to work at an acceptable level.
You need to use short cable runs, the sound dulls out with longer runs.
The 35 step attenuation turned out to be fine for me, but I would like it to have a bit more finesse. I understand you can add a motorized element control the volume control.
Most people build Bent Audio products from the kits, but I will have one assembled to my specs. The TX102 offers a lot of nice options and inputs if configured right, including motorized remote volume. They have a high-end product, the TAP for those who wish to have a statement product with more remote capabilities. I am stuck between a tweaked out tx102 or a full TAP system. It's not a question of money, but sound and features. The TAP is not currently very flexible.
The unit I tried does not have the latest silver-wound transformers, and word is those are better. I'm very curious to hear them.
The case is decent, but I have a couple of theories about how good casing can enhance the sound. I may look into building my own later that uses an extreme case and mounting material. Maybe I'll get a single billet of aluminum carved to house it, and see if that improves things still further!
Conclusion
Wow! a pre that mightily outperforms my Spectral DMC30 at 25% of the cost, is quite a pre. So what it's finicky and a bit hair shirt, . . . I can live with that while I have beautiful sound pouring forth from my system. All of the best hi-end products are fairly finicky pieces. But the TX102 will either not work for you, or it will. if it works, I suspect it's about as pure as you can get in a preamp.

Product Weakness: Sensitive to hum, limited functionality.
Product Strengths: Natural laid-back unhifi sound that just lets the music through. Hard to describe in audiophile perms as it does seem to disappear in the audio chain.

Associated Equipment for this Review:
Amplifier:	Spectral DMA 150 II Universal
Preamplifier (or None if Integrated):	Spectral DMC 30
Sources (CDP/Turntable):	Spectral Ref. transport/Audio Aero Prima DAC
Speakers:	Vandersteen 5s
Cables/Interconnects:	Synergistic Research Designers active
Music Used (Genre/Selections):	Jazz Classical Rock
Room Size (LxWxH):	30 x 25 x 8
Time Period/Length of Audition:	1 week
Other (Power Conditioner etc.):	Sound Applications latest gizmos, Elrod EPS power cables
Type of Audition/Review:	Home Audition

Product Weakness:	Sensitive to hum, limited functionality.
Product Strengths:	Natural laid-back unhifi sound that just lets the music through. Hard to describe in audiophile perms as it does seem to disappear in the audio chain.