After owning several BJT and MOS-FET design amps, I can confidently states I would prefer the latter's when properly designed. Most BJT manage to handle deep, taut and fleshy bass lines and are able to reproduce mids with clarity, however when it comes to midrange ultimate transparence and resolution, mainly regarding reproduction of textures and tone accuray, a well designed MOS-FET amp like Accuphase E-460/470, A-45/A-60/A-65, Gamut Si-100/Di-150 and Gamut's power amps and those budget priced Creek's, like 5350SE and Destiny are unbeatable.

Some low price MOS-FET amps, like Creek 5350 let 3 or 4 times as much expensive amps ashamed in a side by side comparison when reproducing mids and highs. Off Course, BJT handles low frequencies with better grip, but the mentioned MOS-FET models are capable of reproducing bass lines with faster transient response and superior control.

Talking about Si-100, it's a very neutral amplifier that will not sweeten highs by rolling-off sharp edges or will bring more "flesh on the bones" to bass lines. It will simply reproduces recorded files as it is. If you have overbright speakers or other electronics with tonal issues, Si-100 will show those artifacts with no mercy and some may blame the amp.

In summary, if you need a really high fidelity amplifier and are after magical mids and highs, this is your cup of tea. This is certainly the best integrated amplifier I have ever had.

If you have a real high-end performance preamp, I encourage you using it with Si-100 as a pure power. You will be suprised how good amp sections of Si-100 is. Apart from its lower power, the latter is as good as Gamut D200i and may outperform some $10.000 power amps.

For your reference, some of integrated amplifiers and powers I owned:

- Accuphase A-45
- Luxman L85V, Luxman L-540 and Luxman L-505u
- Sansui AU-alpha707KX, Sansui AU-alpha607MOS Premium
- Creek 5250SE, 5350SE and Destiny
- Rega Mira
- Cambridge Audio A5, 640A V2 and 740A
- many NAD and Rotel integrated amps and pre/power combos
- Marantz PM-14SA