no comments .. if you were searching for a S.S that can be in measures bettere than a DHT tube amp.. here are the measures..


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dal 12-1-2005

The BLU EYES AMP features a S.S. SINGLE ENDED Full CLASS "A" Dynamic Regulation output stage. COMPLETELY  NO FEED BACK EVEN LOCALLY - What does it mean Class "A" with Dynamic Regulation?: the end of Tonns of cooling stuff !!! 70% efficiency against 20% of  a normal CLASS A amp when only powered on.


Which one of these 3 figures showing a transistor (BJT) biasing connected in Common Emitter mode is in CLASS A? Any of the above is in FULL Class A biasing. The BLU EYES amp features two COMMON EMITTER OUTPUT TRANSISTORS biased in DYNAMIC CLASS A. BIAS varies from fig 1 (on the left - standby) to Fig 3 (on the right - max power output), depending on the amplitude input signal (positive feed-forward) without the use of any type of negative Feed Back.  The BIAS varies together from min to max  on both the output transistors. Maybe the first time in the AUDIO field applied to DUAL Common Emitter OUTPUT stage.

BLU EYES AMP FREQUENCY RESPONSE and THD  @ 2,83 Vrms / 7,9 ohm (1 Watt/8ohm)

DISTORTION CURVES are risen by 20dB. In the band 20-20 KHz the THD is less than 0,2 %


BLU EYES AMP FREQUENCY RESPONSE and THD  @ 11,8 Vrms su 7,9 ohm (17,6 Watt)

DISTORTION CURVES are risen by 20dB. In the band 20-20 KHz the THD is less than 2 %

FFT - frequency 1 KHz 2,83 Veff/7,9 ohm


BLU EYES 30  Frequency response on DYNAMIC LOAD - LAURA MKII speaker connected instead of dummy load 

(in the band 50 Hz - 20.000 Hz the max peak  is  +/- 1,17 dB, more than nothing compared to the high quality sound reproduced, same as per the -1,96dB @ 32 Hz, where normally the room resonances are the more important matter in this range.

BLU EYES 30 schematic diagram

Notes on the amplfier

The amplifier is made by SOLE 2 transistors in a COUNTERPHASE Single Ended configuration  (NOT MOSFET that are by themselves internally feedback). This last version is for BALANCED INPUT with RD transformere and INDUCTIVE POWER SUPPLY. 1,2 Volts input for 75 Watts Output. A second version use a third transistor as an input adapter (S.E. CLass A completely NO F.B. even locally) for 10 Kohm input Impedance.

Even if the load seems to be connected to the output device emitters, the output is a  COMMON EMITTER STAGE. This is due to the fact that the input signal is in common with the EMITTER and the BASE of the transistor by means of the INTER-STAGE TRANSFORMER and not fed to the BASE in respect to GROUND as normally done on any PUSH PULL amp.  Moreover ONLY a common Emitter stage can amplify either in voltage and current modes as a S.E. TRIODE OUTPUT does. Emitter follower does supply ONLY current amplification. The Voltage stage amplification here is roughly 10 (as TRIODE S.E. output stages). The LOAD has to be seen to be connected to the COLLECTOR (see equivalent circuit here after). Common Emitter mode can only be biased in CLASS A if used as linear device in Audio systems. The  CLASS A BIAS dynamic regulation is a DECOUPLED FEED FORWARD, not a NEGATIVE FEED BACK.



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