This project
was initiated by a gentle man who charllenged us to propose "one
of a kind solution" amplifier which could merit his uncompromise
demands:
1) Pure class A power amplifier that can deliver full drive force to
any ineffcient loudspeaker
2) Fully Balanced circuitry from input to out (but must be able to play
RCA with no loss of performance)
3) Very wide bandwidth, 100KHz is the minimum acceptable power bandwidth
(-3.0dB)
4) Lowest harmonic and intermodulation distortion, since he owns very
critical ears especially at high tone.
5) Must implement "Simple" approach as much as possible.
300B tubes are among the best direct heated triode that we select. We
know that when employ in push-pull Class A, 300Bs blend sweet refine
sensation, triode sound with precision in bass control, impace and full
body sound. (whereas when employ in most SE class-A, 300B can easily
have bass boom since THD at low frequency is very high) We developed
fully balance input circuit, driving circuit, and output circuit to
meet the customer's request; however, we also experienced that the whole
combination would generate just a little bit more extending in details,
pace, and soundstage of conventional push-pull class-A circuit (with
ordinary RCA input) if the new fully balanced output transformers were
not created.
As of many prototypes we were finally address the major issue of unbalance
leakage inductance and parasitic capacitance of conventional output
transformer that caused performance bottleneck in the full balance topology
circuit. To solve this issue, we have created new SILK balanced winding
technique that allow all new SILK balanced output transformers to fully
realize the benefit of balanced circuit topology. This new balance output
transformer is so good that allow us to minimise the use of negative
feedback while maintain the frequecy response beyond 100KHz at -3dB
full power.
With many new techniques to combine into one amplifier project, we're
not only meet but also exceed customer and ourself expectation.
The sound characteristic of this combination is very accurate and powerful
while capture all details with great refinement.
Therefore, these new techniques of fully balanced circuitry & new
SILK balanced output transformer will be incorporated into our upcoming
SILK amplifier products in near future.
