Audio Database

The

Technics EAA-2010/SU-2010/SU-50A/Technics 50A 95,000yen(June, 1969 release)
95,000 yen(around the 1970 time)

Description
 
The solid-state Integrated Amplifier which compiled into one book and completed a series of tube amplifier development technologies of Technics 10A, 20A, 30A, and 40A.
The model number is changed 3 times with EAA-2010, SU-2010, and SU-50A.

The differential-amplification circuitry of a two-step stream composition and the OCL circuitry by 2 power-source schemes are used for a main-amplifier part, and it constitutes the whole page hardwired-connection circuitry. By circuitry without an output capacitor, the low-pass property is improving and the stability and the linearity are also improving.

The equalizer stage of a preamplifier part is constituted from a three-step hardwired-connection NF type which used the low noise PNP transistor, and high S/N has been obtained while canceling the shortage of a dynamic range.

The scheme original with technics which used the special Dual-unit volume is adopted as a tone control circuit.
This scheme has a special structure which combined the silver conductor and the resistor, in order that both of brushes may touch a silver conductor, all the capacitors separate from a circuitry, it becomes a circuitry of only a resistor, and a flat property is acquired at the middle point.

The protection network using four transistors and two diodes is carried.
In this circuitry, the automatic-control protective device which detects the operating point of a power transistor and maintains a safe operation, and the automatic revise circuitry by a temperature change are carried. Furthermore, even if an excessive electric current flows by considering it as a returned type at the moment, an operation is not interrupted only by a signal clipping.

The front panel adopts push-button-type an input selection button, a large-sized sound-volume thumb, etc., and is improving facility.
Moreover, if a switchpoint is turned on, the design from which the values of the front panel rises will be adopted.

The pre-out termination carries two lines, the Low termination of Output power 1V, and the High termination of 5V.

Four AC outlets are carried.

Two speaker contact buttons are carried.

Internal


Rating of a mode
Form Solid-state Integrated Amplifier
Circuit system Whole page hardwired-connection differential amplification
SEPP OTL-OCL circuitry
<Power amplifier part>
Music power (IHF) 120W (4ohms)
80W (8ohms)
50W (16ohms)
Output power (IHF) 40W/40W (4ohms)
30W/30W (8ohms)
20W/20W (16ohms)
Frequency characteristic (at the time of an Output power) 5Hz - 150kHz
S/N ratio 95dB or more (IHF, A network, input short-circuit)
Input sensitivity/impedance 1V/50kohm
Dumping factor 150 (8ohms)
Conformity load impedance 4ohm-16ohm
Transistor protection network It is a returned type at the ASO detection scheme moment.
<Preamplifier part>
Input sensitivity/impedance
(1kHz, Volume max)
Phono1, 2:1mV / 47kohm
Tuner: 100mV / 70kohm
Aux1, 2:100mV / 70kohm
Maximum permissible input
(1kHz, 0.1% of distortion)
Phono1, 2:140mV
Tuner:10V
Aux1, 2:10V
An Output voltage/impedance
Output power : 1V / 3kohm (Low)
5V/200 ohm (High)
Maximum output (1kHz, 0.1% of distortion) : 1.8V(Low)
9V(High)
Tapes monitor Rec out: 100mV/200 ohms
Playback: 100mV / 70kohm
Rec/Play(DIN): 30mV / 60kohm (IN)
100mV / 70kohm (OUT)
SN ratio (IHF, A network)
Input short-circuit
Phono1, 2:70dB or more
Tuner: 90dB or more
Aux1, 2:90dB or more
THD 0.1% or less
Frequency characteristic
High, VR max, TCflat : Deflection of less than ±0.5dB from a Phono1 and 2:RIAA standard curve
Tuner: 5Hz - 200kHz, and +0 -3dB
Aux1, 2:5Hz - 200kHz, and +0 -3 dB
Low, VR max, TCflat : Deflection of less than ±0.5dB from a Phono1 and 2:RIAA standard curve
Tuner: 5Hz - 150kHz, and +0 -3dB
AUX1, 2:5Hz - 150kHz, and +0 -3 dB
Tone control Bass: +15dB--15dB
Turnover frequency: 250Hz, 500Hz
Treble: +15dB--15dB
Turnover frequency: 2.5kHz, 5kHz
Filter Low-pass: 30Hz-12dB / oct
High region: 8kHz-12dB / oct
Muting -20dB
<Synthesis>
The semiconductor used
Transistor (43 pieces) : 2SA564A: 20 pieces
564:2 2SAs
828:4 2SCs
171:4 2SB
2SC696A: Four pieces
2SA547A: Two pieces
2SC697A: Two pieces
189:4 2subset dependencies
473:1 2SB
Diode (17 pieces) : 242:2 MA(s)
MA242R: Two pieces
subset-dependency-1Y: One piece
SV-02: 2 piece
SM-150-005:8 piece
OA-70:2 piece
Power source AC100V/117V/220V/240V, 50/60Hz
AC outlet Switched: Three lines
Unswitched: One line
Power consumption At the time of an Output power: 175VA
At the time of a non-signal: 37VA
Dimensions Width 420x height 147x depth of 325mm
Weight 13.5kg