After a wait of just over four months, my M1 RIAA has arrived, along with another set of 1m AN UK Lexus interconnects!

a new endeavor for me and a new level of build quality. I'm calling it 'Sercona Audio' (Sercona for 'Serial Controlled Audio'). the box is the 'Audio Controller 3' and its website (once fully constructed) will be www.sercona.net

it runs the Volu-Master arduino code base (along with the LCDuino style backpack CPU system) and acts as a line-level audio preamplifier, input selector and remote system controller (infrared learning remote, usb for pc/web control). of special note is the fact that switching can be done at both analog and digital (spdif) domains.

we plan to do a local manufacturing run to test the concept, with build, assembly and test all done locally to ensure the highest quality.

more info to come. questions and feedback welcome, too!

(work-in-progress) company website: www.sercona.net

After a wait of just over four months, my M1 RIAA has arrived, along with another set of 1m AN UK Lexus interconnects!

Finished dynamic microphone preamplifier prototype.

Electronics hobby

Designing and building a high power amplifier capable of driving low impedance (as low as 2 Ohm’s @ 50 Vpp) loads.

www.diyaudio.com/ see alias FdW

History of DIY audio

Audio DIY came to prominence in the 50s to 60s, as audio reproduction was relatively new and the technology "complex," audio reproduction equipment, and in particular high performance equipment, was not offered at the retail level. Kits and designs were available for consumers to build their own equipment. Famous vacuum tube kits from Dynaco, Heathkit, and McIntosh, as well as solid state (transistor) kits from Hafler allowed for consumers to build their own hi fidelity systems. Books and magazines were published which explained new concepts regarding the design and operation of vacuum tube and (later) transistor circuits.

While audio equipment has become easily accessible in the current day and age, there still exists an interest in building one's own equipment, including amplifiers, speakers, preamplifiers, and even CD players and turntables. Today, a network of companies, parts vendors, and on-line communities exist to foster this interest. DIY is especially active in loudspeaker and in tube amplification. Both are relatively simple to design and fabricate without access to sophisticated industrial equipment. Both enable the builder to pick and choose between various available parts, on matters of price as well as quality, allow for extensive experimentation, and offer the chance to use exotic or highly labor-intensive solutions, which would be expensive for a manufacturer to implement, but only require personal labor by the DIYer, which is a source of satisfaction to them.

en.wikipedia.org/wiki/DIY_audio

Here is my "new" Revox A720 Tuner pre-amplifier. Actually it is older than me :)

Thank you Bernd for repairing this to me. Sound is perfect with 2 x Genelec 8020 and 7050B active loudspeaker set.

Sutherland Engineering Ph3D phono stage arrives.

please visit

sakamatra.blogspot.com

for more details

Pioneer SA 810 (SA 81 for Japan domestic market) the last integrated tube amplifier from Pioneer

www.youtube.com/user/sakamatra1

Year 1966 − 1969

Specifications

Amplifier parts

Tubes

4x 12 AX7

4x 7868

2x 6AN8

Frequency response 20 to 26,000 Hz

+/- 1 dB

Total Harmonic Distortion less than 0,5% (continuos power output)

Spurious Response rejection

better than 70 dB

Power output 66 Watts

Rated power output 30 Watts x 2

Speakers impedance 8 ohms, 16 ohms (switchable)

Preamplifier parts

Input Sensitivity/Impedance (1KHz for rated output)

TAPE HEAD 2.3 mV

PHONO (MAG / CERAMIC) 5.2 mV

MIC 1.3 mV

AUX 1.7 mV

MONITOR 170 mV

REC 170 mV

TAPE REC / PB 170 mV

Miscellaneous

Power Requirements 110v, 120v, 130v, 220v, 240v

Dimensions

390 x 147 x 327 mm / 15.4 x 5.8 x 12.9 inch

Weight 15 kg

please visit

sakamatra.blogspot.com

for more details

Sansui solid state stereophonic amplifier AU 777 A

www.youtube.com/user/sakamatra1

Specifications

Year 1969

Output power

Music power (IHF): 70W±1dB (8ohm)

Effective output: 30W/30W±1dB (8ohm)

THD 0.5% or less

Cross modulation distortion (60Hz:7kHz=4:1) 0.8% or less

Power Band Width (IHF) 20Hz - 50000Hz (0.5% of distortion)

Frequency characteristic 20Hz - 100,000Hz, ±1dB

Channel separation 20dB or more (1000Hz)

A hum and a noise (IHF) 100dB or more (closed circuit)

Input sensitivity/impedance 1V / 300kohm (an Output power, 1kHz)

Dumping factor 15 (8ohms)

Load impedance 4ohm-16ohm

Center channel Output voltage Flat output: 10V (1kHz)

High cut output (fo = 159Hz): 10V (50Hz)

Preamplifier parts

Output voltage Maximum output voltage: 4V

Output-power voltage: 1V

THD 0.1% (Output-power voltage)

Frequency characteristic 20Hz - 70,000Hz, and +0.5 -1.5 dB

A hum and a noise (IHF, maximum output voltage) Phono1, 2:80dB or more (closed circuit)

MIC: 85dB or more (closed circuit)

Tuner: 85dB or more (open circuit)

AUX: 85dB or more (open circuit)

Input sensitivity/impedance

(An Output-power voltage, 1kHz) Phono1:2mV±3dB /, 50kohm

Phono2:2mV±3dB /, 30kohm, 50kohm, 100kohm

MIC: 3.5mV±3dB /, 50kohm

Tuner: 140mV±3dB /, 100kohm

AUX: 140mV±3dB /, 100kohm

Tape Mon(Pin): 140mV±3dB /, 100kohm

Tape Recorder(Din): 140mV±3dB /, 100kohm

Sound-recording output Tape Rec(Pin): 150mV±3dB

Tape Recorder(Din): 30mV±3dB

Control Bass: 20Hz±15dB (3dB step)

Midrange: 1,500Hz±5dB (1dB step)

Treble: 20,000Hz±15dB (3dB step)

Loudness (volume 30dB): 50Hz+8dB, 10,000Hz+2.5dB

Switchpoint A high filter: 20,000Hz-18dB (12 dB/oct)

A low filter: 20Hz-26dB (12 dB/oct)

Muting: -20dB

Synthesis

Stream composition 31Tr, 5Di

Miscellaneous

Supply voltage 220V, 50Hz/60Hz

Dimensions

Width 435x height 155x depth of 334mm

Weight 12.5kg

Option The wood case made from a walnut

A tube preamplifier project with ECC82 / 83 tubes and equivalent.

Wilson Audio Watt Puppy, Spectral DMA 250 with preamplifier,

Wadia 581iSE

Electronics hobby

Designing and building a high power amplifier capable of driving low impedance (as low as 2 Ohm’s @ 50 Vpp) loads.

www.diyaudio.com/ see alias FdW

History of DIY audio

Audio DIY came to prominence in the 50s to 60s, as audio reproduction was relatively new and the technology "complex," audio reproduction equipment, and in particular high performance equipment, was not offered at the retail level. Kits and designs were available for consumers to build their own equipment. Famous vacuum tube kits from Dynaco, Heathkit, and McIntosh, as well as solid state (transistor) kits from Hafler allowed for consumers to build their own hi fidelity systems. Books and magazines were published which explained new concepts regarding the design and operation of vacuum tube and (later) transistor circuits.

While audio equipment has become easily accessible in the current day and age, there still exists an interest in building one's own equipment, including amplifiers, speakers, preamplifiers, and even CD players and turntables. Today, a network of companies, parts vendors, and on-line communities exist to foster this interest. DIY is especially active in loudspeaker and in tube amplification. Both are relatively simple to design and fabricate without access to sophisticated industrial equipment. Both enable the builder to pick and choose between various available parts, on matters of price as well as quality, allow for extensive experimentation, and offer the chance to use exotic or highly labor-intensive solutions, which would be expensive for a manufacturer to implement, but only require personal labor by the DIYer, which is a source of satisfaction to them.

en.wikipedia.org/wiki/DIY_audio

Sutherland Engineering Ph3D phono stage arrives. Time to set up!

EP-10 package of the SL414 audio power amplifier IC. This is combined audio preamplifier and power amplifier IC manufactured by National semiconductors in early days. Related schematics and more details are available at elect.wikispaces.com/SL414+Vintage+power+amplifier+IC.

The insides.I read somewhere that there are some mods you can do to make it better,the problem is I couldn't find these mods anywhere.Anyone got an idea?

please visit

sakamatra.blogspot.com

for more details

Pioneer QA 800 A 4 channel amplifier

www.youtube.com/user/sakamatra1

Specifications

Year 1973

Semiconductors

FETs : 2

Transistors : 65

Diodes : 15

Preamplifier

Output voltage : 500 mV (rated output)

Harmonic Distortion less than 0.08%

Frequency Response 20 to 40.000 Hz, +/- 1 dB

Input Sensitivity/Impedance (1KHz, for rated output)

PHONO 1 MAG ; 2.5 mV/50 Kohms

PHONO 2 MM ; 2.5 mV/50 Kohms

TUNER ; 200 mV/100 Kohms (4 CH)

AUX 1,2 ; 200 mV/100 Kohms (4 CH)

TAPE MONITOR 1, 2 ; 200 mV/100 Kohms (4 CH)

Recording Output

TAPE REC 1,2 (pin jack) ; 200 mV (4CH)

BASS control ; - 10 dB, + 10 dB/100 Hz

TRABLE control ; −10 dB, + 10 dB/10 Hz

LOW Filter ; - 10 dB/50 HZ (6 dB/oct)

HIGH Filter ; - 10 dB/10 KHz

Equalization Curve ; PHONO ; RIAA S.T.D

Loudness Contour ; + 11 dB/100 Hz, +7 dB/10 KHz with volume control set at - 40 dB position

Muting ; - 20 dB

Hum and Noise (IHF)

PHONO ; more than 80 dB

TUNER, AUX ; more than 90 dB

Power Amplifier Section

Music Power Output (IHF) ; 204 watts (4 0hms), 144 watts (8 0hms)

Continuos Power Output ( 1 KHz, 2 channels driven)

34 watts + 34 watts / 34 watts + 34 watts (4 ohms)

27 watts + 27 watts / 27 watts + 27 watts (4 ohms)

Continuos Power Output ( 1 KHz, 4 channels driven)

24 watts x 4 (4 ohms), 20 watts x 4 (8 ohms)

Power in the range of 20 to 20.000 Hz (2 channels driven)

23 watts + 23 watts / 23 watts + 23 watts (8 ohms), harmonic distortion less than 0.5 %

Harmonic Distortion ; Less than 0.5 % (continuos power output)

Intermodulation Distortion ; Less than 0.8 % (continuos power output)

Power Bandwidth (IHF) (4 channels driven) ;

15 to 50.000 Hz (8 ohm), harmonic distortion less than 0.5 %

Frequency Response ; 8 to 70.000 Hz +/- 1 dB

Input Sensitivity/Impedance ; 500 mV/50 Kohms (1 KHz, continuos power output)

Speaker ; 4 to 16 ohms

Dumping factor ; 40 ( 8 ohms, 1 KHz)

Headphone Jacks ; Front and Rear

Miscellaneous

Power Requirements ; 110v, 120v, 130v, 220v, 240v (switchable) 50 − 60 Hz

Power Consumption ; 290 watts (max)

AC Outlets ; Switched 1, Unswitched 1

Dimensions (overall) ; 430 (w) x 138 (h) x 337 (d) mm

Weight ; without package 10.9 kg / 24 lb

please visit

sakamatra.blogspot.com

for more details

Pioneer QA 800 A 4 channel amplifier

www.youtube.com/user/sakamatra1

Specifications

Year 1973

Semiconductors

FETs : 2

Transistors : 65

Diodes : 15

Preamplifier

Output voltage : 500 mV (rated output)

Harmonic Distortion less than 0.08%

Frequency Response 20 to 40.000 Hz, +/- 1 dB

Input Sensitivity/Impedance (1KHz, for rated output)

PHONO 1 MAG ; 2.5 mV/50 Kohms

PHONO 2 MM ; 2.5 mV/50 Kohms

TUNER ; 200 mV/100 Kohms (4 CH)

AUX 1,2 ; 200 mV/100 Kohms (4 CH)

TAPE MONITOR 1, 2 ; 200 mV/100 Kohms (4 CH)

Recording Output

TAPE REC 1,2 (pin jack) ; 200 mV (4CH)

BASS control ; - 10 dB, + 10 dB/100 Hz

TRABLE control ; −10 dB, + 10 dB/10 Hz

LOW Filter ; - 10 dB/50 HZ (6 dB/oct)

HIGH Filter ; - 10 dB/10 KHz

Equalization Curve ; PHONO ; RIAA S.T.D

Loudness Contour ; + 11 dB/100 Hz, +7 dB/10 KHz with volume control set at - 40 dB position

Muting ; - 20 dB

Hum and Noise (IHF)

PHONO ; more than 80 dB

TUNER, AUX ; more than 90 dB

Power Amplifier Section

Music Power Output (IHF) ; 204 watts (4 0hms), 144 watts (8 0hms)

Continuos Power Output ( 1 KHz, 2 channels driven)

34 watts + 34 watts / 34 watts + 34 watts (4 ohms)

27 watts + 27 watts / 27 watts + 27 watts (4 ohms)

Continuos Power Output ( 1 KHz, 4 channels driven)

24 watts x 4 (4 ohms), 20 watts x 4 (8 ohms)

Power in the range of 20 to 20.000 Hz (2 channels driven)

23 watts + 23 watts / 23 watts + 23 watts (8 ohms), harmonic distortion less than 0.5 %

Harmonic Distortion ; Less than 0.5 % (continuos power output)

Intermodulation Distortion ; Less than 0.8 % (continuos power output)

Power Bandwidth (IHF) (4 channels driven) ;

15 to 50.000 Hz (8 ohm), harmonic distortion less than 0.5 %

Frequency Response ; 8 to 70.000 Hz +/- 1 dB

Input Sensitivity/Impedance ; 500 mV/50 Kohms (1 KHz, continuos power output)

Speaker ; 4 to 16 ohms

Dumping factor ; 40 ( 8 ohms, 1 KHz)

Headphone Jacks ; Front and Rear

Miscellaneous

Power Requirements ; 110v, 120v, 130v, 220v, 240v (switchable) 50 − 60 Hz

Power Consumption ; 290 watts (max)

AC Outlets ; Switched 1, Unswitched 1

Dimensions (overall) ; 430 (w) x 138 (h) x 337 (d) mm

Weight ; without package 10.9 kg / 24 lb

Heads read / write preamplifiers

National Ignition Facility laser pulses at Lawrence Livermore National Laboratory are born in the master oscillator room, in which a compact laser oscillator generates low-energy (a few nanojoules) laser pulses. The oscillator pulse is shaped in time and frequency-broadened, using the small range of multiple wavelengths produced in the fiber laser, to help smooth the intensity of the laser beam when it is ultimately focused on the target. There are 48 independent pulse shaping systems, and each of the pulses is transported on separate fiber optic cables to 48 preamplifier modules for further amplification.

please visit

sakamatra.blogspot.com

for more details

Marantz SR 800 Stereophonic Receiver

www.youtube.com/user/sakamatra1

Specifications

Year circa 1979

Radio FM stereo 87.5 to 108 MHz, AM 515-1650 kHz

Antenna connections FM 300 Ohm balanced, MW 75 ohms unbalanced.

Inputs Tape1/Monitor, Tape2/Aux, phono (MM) Output Tape 1

Headphone Jack 6.35mm

Equalization Loudness

Speaker groups A and / or B (depending on the impedance)

Amplifier Power at 4 (8) Imp Ohm to DIN 2 x 28W (23W)

Preamplifier frequency response 20Hz - 35kHz

Amplifier 10 Hz - 40 kHz

Power supply 220V/50Hz

Power consumption at idle 20W, rated up to 90W

Dimensions 47 cm x 14 cm x 32 cm

Weight about 6kg

Front plate metal, body wood panel and base made of a composite material.

Little pocket radio, which is a bit hulking, what appears a small brick, with the front dial plate fully chromed with letters and Admiral logo engraved and painted in black. The chassis has seven transistors and is powered by a common 9V battery. This item is in very good cosmetic condition and when I bought did not work. I just cleaned up the volume control and changed the electrolytic capacitor which connects the volume control whith the base of the audio preamplifier transistor, and now works very well.

please visit

sakamatra.blogspot.com

for more details

Sansui AU 555 A solid state amplifier Specifications

Year 1970

Output power

Music power (IHF) : 85W (4ohm)

60W (8ohm)

Effective output : 33/33W (4ohm)

25/25W (8ohm)

THD 0.5% or less (Output power)

Cross modulation distortion (SMPTE, 60Hz:7000Hz=4:1) 0.5% or less (Output power)

Power Band Width (IHF) 20Hz - 40000Hz (8ohm)

Frequency characteristic 20Hz - 40000Hz, ±1dB

Channel separation 60dB or more (1kHz, Output power)

A hum and a noise (IHF) 100dB or more

Input sensitivity/impedance 1V (Output power) / 100 kohms or more

Load impedance 4ohm-16ohm

Dumping factor 50 (8-ohm load intensity)

Preamplifier parts

Output voltage Maximum output: 5V

Output power: 1V

THD 0.1 (Output-power voltage) or less

Frequency characteristic 20Hz - 30000Hz, ±1dB

Channel separation (1kHz, Output power) Phono1, 2:45dB or more

Tuner, AUX: 50dB or more

A hum and a noise (IHF) Phono1, 2:70dB or more

Tuner, AUX: 80dB or more

Input sensitivity/impedance (1kHz, Output-power voltage) Phono1, 2:2mV / 50kohm

Tuner: 180mV / 50kohm

AUX: 180mV / 50kohm

Tape Play(Pin): 180mV / 50kohm

Tape Recorder(Din): 180mV / 50kohm

Sound-recording output (1kHz, input voltage) Tape Rec(Pin):180mV

Tape Recorder(Din):30mV

Equalizer Phono:RIAA NF type

Control Bass: 30Hz, ±12dB

Midrange: 1.5kHz, ±5dB

Treble: 15kHz, ±10dB

Loudness: +3dB (10kHz), +8dB (50Hz)

Switchpoint A low filter: 50Hz-8dB

A high filter: 10kHz-7dB

Miscellaneous

Power source 220V, 50Hz/60Hz

Power consumption 130W

Dimensions

Width 395x height 127x depth of 278mm

Weight 8kg

Can also be seen in a Part Chimp radio session gallery here. According to the designer "My idea was to make it resemble a medieval battle axe because musicians at that time often referred to their instruments as their 'axe'." (from the Ovation Breadwinner Fansite). Serial number is E2782.

added a 'pimeta v2' (3 channel active ground headphone amp) to my VoluMaster(tm) preamp/stereo system.

also new is an orange backlit lcd display from mouser electronics ($10). I can control the brightness or even turn it off entirely, now, all under arduino software control.

on the left is a neutrik stereo 1/4" jack, fancy spring-lock style.

please visit

sakamatra.blogspot.com

for more details

Sansui AU 666 Solid State Stereo Amplifier

www.youtube.com/user/sakamatra1

Specifications

Year 1970

Output power

Music power (IHF) : 100W (4ohm)

80W (8ohm)

Effective output : 45/45W (4ohm)

35/35W (8ohm)

THD 0.5% or less (Output power)

Cross modulation distortion (SMPTE, 60Hz:7kHz=4:1) 0.5% or less (Output power)

Power Band Width (IHF) 10Hz - 40000Hz (8ohm)

Frequency characteristic 10Hz - 70000Hz, ±1dB

Channel separation 60dB or more (1kHz, Output power)

A hum and a noise (IHF) 100dB or more

Input sensitivity/impedance 1V (Output power) / 50 kohms or more

Load impedance 4ohm-16ohm

Dumping factor 40 (8-ohm load intensity)

Preamplifier parts

Output voltage Maximum output: 5V

Output power: 1V

THD 0.1% or less (Output-power voltage)

Frequency characteristic 20Hz - 40000Hz, ±1dB

Channel separation Phono1, 2:50dB or more

Tuner, AUX: 50dB or more

A hum and a noise (IHF) Phono1, 2:70dB or more

Tuner, AUX: 80dB or more

Input sensitivity (1kHz, Output-power voltage)/impedance Phono1, 2:2mV / 50kohm

MIC: 3mV / 50kohm

Tuner: 180mV / 100kohm

AUX: 180mV / 100kohm

Tape Play(Pin): 180mV / 100kohm

Tape Recorder(Din): 180mV / 100kohm

Sound-recording output Tape Rec(Pin):180mV

Tape Recorder(Din):30mV

Equalizer Phono:RIAA NF type

MIC:Flat NF type

Control Bass: 30Hz, ±16dB

Midrange: 1500Hz, ±5dB

Treble: 15000Hz, ±15dB

Switchpoint A low filter: 20Hz-10dB

A high filter: 20kHz-10dB

Muting -20dB

Synthesis

Stream composition Transistor: 31

Diode: Five

Miscellaneous

Supply voltage 220V, 50Hz/60Hz

Power consumption 240W

Dimensions Width 415x height 127x depth of 278mm

Weight 9.75kg

please visit

sakamatra.blogspot.com

for more details

Sansui Solid State Stereophonic AU 999

Specifications

Year 1970

Power amplifier part

Effective output 70W/70W (4ohm)

80W/80W (8ohm)

Music power (IHF) 180W (4ohm)

140W (8ohm)

THD 0.4%

Cross modulation distortion 0.4%

Power Band Width (IHF) 10Hz - 30kHz

Frequency characteristic 5Hz - 100kHz

Stereo separation 50dB

A hum and a noise 100dB

Input sensitivity/impedance 1V/40kohm

Load impedance 4ohm-16ohm

Dumping factor 45 (8ohm)

Preamplifier part

Output power 1V

THD 0.1%

Frequency characteristic 15Hz - 70kHz

A hum and a noise (IHF) Phono1, 2:80dB

Mic:80dB

Tuner, Aux: 85dB

Input sensitivity Phono1, 2:2mV

Mic:3mV

Tuner, Aux, Tape mon (Pin/Din): 200mV

Sound-recording output Tape rec(Pin):200mV

Tape rec(Din):30mV

Tone control Bass: +12dB--8dB (20Hz)

Midrange: ±5dB (1kHz, 2kHz)

Treble: +12dB--8dB (20kHz)

Tone selector Bass:Defeat, 200Hz, 400Hz

Midrange:Defeat, 1kHz, 2kHz

Treble:Defeat, 6kHz, 3kHz

A low filter -20dB(20Hz)

A high filter -18dB(20kHz)

Muting −20dB

Miscellaneous

Power consumption 370W

Dimensions

Width 461.5x height 155x depth of 316mm

Weight 17.5kg

Option Wood case C-17

Another sleeper brand from the 80s, I've always liked H/K's simple looks.

This is the inside.I don't know with what to change the video caps.

RCA germanium transistors for audio amplification. The 2N109 was the first widely used 'hobbyist' RCA transistor and was used in AM receiver and preamplifier circuits. RCA originally established transistor development and manufacturing at Harrison NJ, then built a dedicated solid state operation at Somerville NJ in 1955.

Internal view of dynamic microphone preamplifier prototype.

please visit

sakamatra.blogspot.com

for more details

Sansui AU 666 Solid State Stereo Amplifier

www.youtube.com/user/sakamatra1

Specifications

Year 1970

Output power

Music power (IHF) : 100W (4ohm)

80W (8ohm)

Effective output : 45/45W (4ohm)

35/35W (8ohm)

THD 0.5% or less (Output power)

Cross modulation distortion (SMPTE, 60Hz:7kHz=4:1) 0.5% or less (Output power)

Power Band Width (IHF) 10Hz - 40000Hz (8ohm)

Frequency characteristic 10Hz - 70000Hz, ±1dB

Channel separation 60dB or more (1kHz, Output power)

A hum and a noise (IHF) 100dB or more

Input sensitivity/impedance 1V (Output power) / 50 kohms or more

Load impedance 4ohm-16ohm

Dumping factor 40 (8-ohm load intensity)

Preamplifier parts

Output voltage Maximum output: 5V

Output power: 1V

THD 0.1% or less (Output-power voltage)

Frequency characteristic 20Hz - 40000Hz, ±1dB

Channel separation Phono1, 2:50dB or more

Tuner, AUX: 50dB or more

A hum and a noise (IHF) Phono1, 2:70dB or more

Tuner, AUX: 80dB or more

Input sensitivity (1kHz, Output-power voltage)/impedance Phono1, 2:2mV / 50kohm

MIC: 3mV / 50kohm

Tuner: 180mV / 100kohm

AUX: 180mV / 100kohm

Tape Play(Pin): 180mV / 100kohm

Tape Recorder(Din): 180mV / 100kohm

Sound-recording output Tape Rec(Pin):180mV

Tape Recorder(Din):30mV

Equalizer Phono:RIAA NF type

MIC:Flat NF type

Control Bass: 30Hz, ±16dB

Midrange: 1500Hz, ±5dB

Treble: 15000Hz, ±15dB

Switchpoint A low filter: 20Hz-10dB

A high filter: 20kHz-10dB

Muting -20dB

Synthesis

Stream composition Transistor: 31

Diode: Five

Miscellaneous

Supply voltage 220V, 50Hz/60Hz

Power consumption 240W

Dimensions Width 415x height 127x depth of 278mm

Weight 9.75kg

please visit

sakamatra.blogspot.com

for more details

Pioneer 4 Channel Receiver QX 4000

www.youtube.com/user/sakamatra1

Year 1974 − 1976

Specifications

FM Parts

Tuning range 87.5 − 108

Sensitivity (IHF) 2.2 micro volts

Equal wave selection 3 dB

Selectivity better than 40 dB

Image Frequency rejection better than 50 dB at 98 MHz

Spurious Response rejection better than 65 dB

Clear factor stereo better than 0.8% (100% Mod)

Stereo separation better than 40 dB

AM parts

Tuning range 525.5 − 1.605 KHz

Sensitivity (IHF) 1.5 micro volts

Equal wave selection (1000 KHz) better than 45 dB

Spurious Response rejection better than 50 dB

Amplifier parts

Continuos power output ( 1 KHz, 4 channels driven)

11 watts + 11 watts / 11 watts + 11 watts (4 ohms)

11 watts x 4 (4 ohms), 10 watts x 4 (8 ohms)

Power in the range of 20 to 20.000 Hz (2 channels driven)

10 watts + 10 watts / 10 watts + 10 watts (8 ohms),

Harmonic distortion less than 1 % (continuos power output)

Power Bandwidth (IHF) (4 channels driven)

15 to 20.000 Hz (8 ohm), harmonic distortion less than 1 %

Frequency Response 10 to 100.000 Hz +/- 3 dB

Dumping factor 40 ( 8 ohms 1 KHz)

Preamplifier parts

Input Sensitivity/Impedance (1KHz for rated output)

PHONO MAG 2.5 micro Volts/50 Kohms

TUNER 200 micro Volts/90 Kohms (4 Ch)

AUX 200 micro Volts/90 Kohms (4 Ch)

TAPE MONITOR 200 micro Volts/90 Kohms (4 Ch)

TAPE REC 200 micro Volts (4Ch)

TAPE REC DIN 35 micro Volts (4Ch)

Miscellaneous

Power Requirements 110v, 120v, 130v, 220v, 240v (switchable) 50 − 60 Hz

Power Consumption watts (max)

AC Outlets

Switched 1

Unswitched 1

Dimensions (overall) (w) x (h) x (d) mm

Weight without package kg

I don't know if it was designed this way or if the tube is defective, but the Magic Eye recording level indicator tube looks like an exclamation point.

Wooden cabinet covered in leatherette with visible stitches and aluminum faceplate with very simple graphics. It has handle to carry and shoulder strap, missing in this one. On the right side has two sliders switches for distant/ local stations and to select the type of power supply: batteries or 120 VAC.

The chassis has one integrated circuit TBA570A/L for Conversor, F.I, Detector, and Audio Preamplifier stages and the TBA820L for Audio Power.

A microphone preamplifier from municipal station WNYC

Just bought myself a new (to me) Carver C-1 preamp but I don't have speakers yet so this is where it resides. It is connected to the Carver PM 1.5 and a pair of Boston Acoustics A400's. My C-1 sounds better than the one above it (my dad's). It could have to do with the ~15K difference in serial numbers or that my dad's is just tired and in need of repair.

See more info here www.flickr.com/photos/chi_bellami/6888095797/