My new Preamplifier

[kawo]

My new Preamplifier

Introduction


HPA-1 uses Dual FET input, Dual transistor and Class A transistor. It has one balance and one unbalance input. The 4 layers circuit board is sandwiched between two copper templates. External power supply is convenient to choose any kinds of power supply.
Material


Circuit board 4 Layers plating
Transistor
Linear Systems LS843 (Dual FET)
Toshiba 2SA1349 (Dual transistor)
Toshiba 2SC3381 (Dual transistor)
Toshiba 2SA970
Toshiba 2SC2240
Toshiba 2SA1930
Toshiba 2SC5171
Resistance
Vishay UXB 0207 0.1% 10ppm (Instrumentation)
Vishay MMB 0207 0.1% 25ppm (Instrumentation)
Vishay RN55D 1% 100ppm
Precision Rssistive GP1/4 0.1% 50ppm
Capacitor
Philips 116 Aluminium electrolytic
Nippon Chemi-Con Aluminium electrolytic
Sanyo Aluminium electrolytic
Wima MKP2
Evox Rifa MMK
AVX Kyocera Ceramic
Johanson Dielectrics Ceramic
Integrated circuit
Texas Instruments LM317
Texas Instruments LM337
Texas Instruments NE5534P
Analog Devices AD847AQ (Ceramic PGA)
Potentiometer
Alps RK097
Selector
Alps
On/Off
Matsushita
Wiring
Quirkwire M16878 silver plated (Signal wiring)
Connector
Neutrik NC3FD-LX-HE (Top XLR connector)
Fischer connector S103 / Neutrik RCA
Neutrik NRJ6HM-1-AU (Top 1/4’’stereo jack)
Neutrik NAC3MPA (Power socket)

(Above components are subjects to change without prior notice)
Specifications

Level
10Hz → 100kHz ±0.5dbm (0dbm@XLR)
20Hz → 50kHz ±0.1dbm (0dbm@XLR)
THD+N
10Hz → 40kHz ±0.05% (0dbm@XLR)
Phase
1kHz < 0.03℃ 100kHz < 9℃(0dbm@XLR)
Gain
6.2dbm (0dbm@XLR)
Noise
10Hz -110dbm 1K -130dbm 10K -135dbm
(Neutrik A2D-Audio Measurement System)
Headphone


16Ω → 600Ω
Power Supply

DC ± 20V
(Internal regulator circuit, suitable for DC ± 20V→ 24V)

[kawo]

The noise level

[Eric Juaneda]

Hi kawo,

Originally Posted by kawo

My new Preamplifier
...It has one balance and one unbalance input...

Nice realization. I don't see any output on the picture except headphone on front panel! Is it only a headphone amplifier.

[lineup]

HPA-1
... means usually Head Phone Amplifier, HPA
A good headphone amp can of course be used as a preamplifier, too.
Can it drive headphone, it can drive most other low level loads.

[kawo]

Hi: Eric

Yes,both headphone amplifier,Preamplifier.

replacement the RCA to Fischer connector S103 -3way,than have one output and two intput.

[kawo]

Power on

[kawo]

balance to unbalance

[kawo]

main circuit (R-CH)

[Joachim Gerhard]

That looks pretty but are you also willing to post the citcuit diagram ?

[kawo]

Hi: Joachim
I am sorry.HPA-1 for sale in Hong Kong.I can't post the circuit.