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This is a very uncommon combination. It makes part of the music sound better than with the other amplifiers and even nicer (although a step away from neutrality but acceptable) than the reference set. Although their resolution may be better, the timbre and mentioned midrange/treble traits of the American amplifier allowed rock and electronic music to sound very good. It is not that Jazz sounded bad or that Classical suffered but that those characteristics promoted less well recorded discs without warming and dulling. I started the listening session with the Dire Straits disc but Maria Peszek playing just after confirmed my observations. Similar to Porcupine Tree's On the Sunday of Life and Genesis' Calling All Stations, each disc retained its own character and the poor recorded quality of Ray Wilson's vocals on my otherwise beloved disc was laid bare with scrutiny. But the Belles did not kill any of those recordings, did not shred them to pieces even if like the Genesis disc, they deserved it. In absolute terms this departs from neutrality because more expensive systems show this more precisely and reach deeper but considering the pros and cons, one can easily agree to such a voicing.

I mentioned resolution. This amplifier can do much and even the equally convincing but completely different Accuphase E-450 is not able to show so many coincident things so clearly. The emphasis of the Japanese competitor is on a kind of sweetness or slight warmth, which -- of course in absolute terms we are very high on that axis -- reflects on the background, second plane elements and other low signals, which are handled very nicely by the Belles. Of the mentioned amplifiers, only the Aaron No.1 was a bit better in that regard. Anyway, the American amplifier shows a recording's character in a completely satisfying way and without making a massacre out of it. I recently bought a new version of the Harbie Mann & The Bill Evans Trio Nirvana disc. This is a beautiful, almost contemplative recording I've never owned before but knew partially from many different listening sessions.

After receiving the Internet shipment, I was enchanted by the way the disc was issued - a beautiful reproduction of the cover, new material for the disc itself (SHM-CD), only advantages. The sound was not as good as remembered but I got accustomed to it and just listened to the music - until I heard the ordinary version from a German 1996 Rhino pressing. This is much better than the Japanese in terms of sound. The mix is different as though it was a monophonic recording yet it has much better dynamics and is far less muffled than the Japanese re-master. The latter shows certain things clearer like the slight hum accompanying the double bass but this can be heard better because the bass is not center stage with the other instruments but placed far into one channel. In general, the German version is much more pleasing to listen to and the Belles tracked these differences very well. The resolution of the amplifier, its ability to differentiate recordings wass good enough for me to know which version (these are two different versions, not just different pressings) of the album I wanted for me. This is not the final word in resolution as my reference gear differentiates timbres better but it did show that the Japanese version is muffled without a trace of doubt - not that it has less treble energy per se but that the individual instruments are 'damped'. No other amplifier in this price range can reach as deeply into a recording.

I would like to summarize this elegantly to show how the Belles IA-01 sounds in one single sentence but it's not that easy. On one hand the American plays with a smooth non-bright sound that flatters inferior recordings like rock and electronics more than others in this range. The whole is coherent and has very good tone. On the other hand, the resolution at the extremes could be better as shown by Aaron and Accuphase. The Pass meanwhile presents a fleshy, full, dynamic bass which the others can only observe from a distance. In defense of the IA-01, let's admit that the Accuphase E-450 also is not very resolving and that the Aaron is an exception but we do need to emphasize what we just said. The lower bass here is more indicated than fully developed when compared to my reference system and the Pass. Vividness is top notch and discs like Mulligan Meets Monk are very expressive. There is no talk of hyper holography within the boundaries of a given sound source. That's why the music played from the best re-edition I know, Analogue Productions 45rpm vinyl, was not as superior over the XRCD version as the reference system shows it to be. Again, even the Aaron showed this better but it did not have the Belles' smooth saturated midrange. The latter comes always handy and for example on one of my late purchases Feel Like Making Love from Korean jazz vocalist Woong San, sounded incredibly sensuous and intimate. As always not without shortcomings and with a clearly voiced sound (we should add a slight depression of dynamics), the Belles reveals the nicer side of the discs without overt warming up or grossly emphasizing any of the frequency ranges. Splendidly built, nicely styled, this amplifier from the USA is environmentally friendly (it does not heat up at idle to run a low bias of the output transistors) and worthy an audition.

Description
The Belles IA-01 is an integrated amplifier manufactured by Power Modules Inc.owned by David Belles. This is a heavy but rather small device (much smaller than the Accuphase E-450 and Luxman L-550A II). Its front cover is a variation on what Nelson Pass proposed some time ago. This is no simple carbon copy but an 'inspired by' modification of somebody else's original idea. The front panel is 15mm thick aluminum with strongly beveled edges and a vertical recess which splits the front in half. This looks very attractive, clean and fresh. At the same time, it's not too technical or impersonal. To the right we have a small volume knob. To the left there are four blue LEDs showing chosen input and a red one for mute. Below those we have three small switches for power, mute and inputs. Although all of them have a center detent and can be switched in two directions, the source selector sadly is one-directional and proceeds 1-2-3-4-1-2-3-4. The back panel too is aluminum, not very thick but still aluminum where most manufacturers just bend the bottom plate. Here it is a separate rigid element.
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We get four pairs of nice RCA inputs and one preamplifier output (suggesting an active preamplifier section), an IEC power inlet and single loudspeaker terminals. The latter are gold-plated but rather small and too close to each other. With bigger spades we must be careful not to create a short circuit. The terminals are conveniently placed at the sides of the back however, making for easy reach of the speaker cables. Those will not mix with power or signal cables (assuming placement on a rack). The top plate is also aluminum but with ventilation holes. The bottom plate is 6mm thick and ventilated as well. The outside heat sinks are large elements with many small fins whose edges are quite sharp so be careful to not cut yourself. The amp does not run hot so it can be placed in small openings without worries.
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We get inside by removing 12 Allen bolts on top and three at the back. We see a quite typical but clean layout. In the middle and close to the front we have a big toroidal transformer whose center is filled with resin. Almost the entire circuit including the main power supply (we have one secondary winding for both channels, pre- and power sections) sits on a large PCB. The only exception is a slave PCB with the potentiometer, logic ICs and stand-by circuitry. From nut tightened RCA input sockets, we go to a small PCB with relays.
From here the signal goes via long Alpha Wire leads to a Blue Velvet Alps potentiometer mounted in front and back again with another long lead. This is similar to the Anthem Integra 275 where I also criticized it. It would have been far better to place the potentiometer in the back and elongate the shaft as the Aaron No.1.a. does it. Here the signal is amplified only by transistors. The power transistors (four pairs of very nice Exicon Mosfet 10P20+10N20 units) are screwed tight to the heat sink. Special attention was given to the connecting leads. AC power is led from the input socket by van den Hul silver-coated cable and the ground
within the star topology is taken from many places by very thick cables from a different brand. In the power supply we have one rectifying bridge and two quality Panasonic filtering capacitors bypassed with polypropylene capacitors for increased linearity. It seems there is no protection circuitry on the loudspeaker outputs so we must be very careful to avoid shorts. The amplifier is placed on very good Stillpoint feet made from two elements, the lower being actuated so we can level the amplifier. The remote is small and plastic but the buttons are very logically placed.
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