Sonodyne SCR-2065 Ampli Deck Circuit Schematic Diagram

[anirban420]

Hello Cassette Lovers,

Sonodyne SCR-2065 was among the firstly released Made in India Ampli-Deck. There were three to four models in this line-up, possibly the model numbers ranged from 2061 to 2065. The model 2065 was the top-most among them. It is a feature pack model. Full auto stop transport, Metal/Chrome/Normal cassette tape type selector, Dolby B noise reduction, both Ceramic & Magnetic phono input stages are some of its features. Sadly, the service manual of this deck is not available on the internet. I have deciphered its circuitry and made a hand-drawn schematic diagram of the deck. I am sharing it here. Hope it will benefit all.



Sonodyne SCR-2065 Front



Sonodyne SCR-2065 Back



Block Diagram



Power Section



Tape Head Preamp



Recording Switch and associated Circuitry



Ceramic Phono Input Buffer Stage



Magnetic Phono Input



Source selector rotary switch and associated circuitry



Dolby B circuitry



Tone Control (Bass/Treble)



Amplifier module



Recording amp



Record Bias and Erase Head circuitry



Tape Type Selector Circuitry



LED VU Meter



Muting Circuitry to mute Tape Head Output during Recording


I am also attaching the PDF of the above-posted files herewith. Due to attachment size limitation of HFV, I could not provide high-quality PDF. I will provide that on personal communication.

Regards,
Anirban

 

[bhaskarcan]

Excellent research Anirban. This gives a nice insight to Indian audio designing thought process. Thanks for sharing.

 

[subhashis_1980]

Nice one @anirban420 my dad had scr 2601/02. A non dolby model not sure which one

 

[Bhaskar Jyoti Talapatra]

Excellent job done Anirban. Your endeavour will be of immense help to many tape deck enthusiasts.

 

[anirban420]

Thanks @bhaskarcan @subhashis_1980 @Bhaskar Jyoti Talapatra for appreciating my effort

 

[reubensm]

This is an excellent job and a valuable contribution, not just for those with this deck but for those hoping to build some of the circuits.

 

[anuragn]

Whoa! Now that is something.
Excellent job anirban

 

[anirban420]

Thanks @reubensm @anuragn

 

[Bloom@83]

This is really a great schematic. This shows the difference between theoretical knowledge and actual on-hands practical knowledge.

 

[manjula]

What type transformer used voltage and amps please

 

[anirban420]

What type transformer used voltage and amps please

The transformer is an E-I core type. It has two secondary windings. One gives 0-27.5 V AC and the other gives 23.5-0-23.5 V AC output. These two voltages are distributed in many sections. Please see the "Power Section" of the schematic for the exact details. Ampere rating is not mentioned on the transformer. The output power IC STK 4131 is a 20+20 W amplifier. One amp current for the other sections should be adequate. Therefore the ampere ratings of the transformer can be somewhat reverse calculated.

 

[adityapm]

Many many thanks for this full-spirited & priceless contribution.
This is certainly a pointer towards the emergence of certain types of patterns for the future.

Thanks again.

 

[samim_kp]

Hello Cassette Lovers,

Sonodyne SCR-2065 was among the firstly released Made in India Ampli-Deck. There were three to four models in this line-up, possibly the model numbers ranged from 2061 to 2065. The model 2065 was the top-most among them. It is a feature pack model. Full auto stop transport, Metal/Chrome/Normal cassette tape type selector, Dolby B noise reduction, both Ceramic & Magnetic phono input stages are some of its features. Sadly, the service manual of this deck is not available on the internet. I have deciphered its circuitry and made a hand-drawn schematic diagram of the deck. I am sharing it here. Hope it will benefit all.


View attachment 47425
Sonodyne SCR-2065 Front


View attachment 47426
Sonodyne SCR-2065 Back


View attachment 47427
Block Diagram


View attachment 47428
Power Section


View attachment 47429
Tape Head Preamp


View attachment 47430
Recording Switch and associated Circuitry


View attachment 47431
Ceramic Phono Input Buffer Stage


View attachment 47432
Magnetic Phono Input


View attachment 47433
Source selector rotary switch and associated circuitry


View attachment 47434
Dolby B circuitry


View attachment 47435
Tone Control (Bass/Treble)


View attachment 47436
Amplifier module


View attachment 47437
Recording amp


View attachment 47438
Record Bias and Erase Head circuitry


View attachment 47439
Tape Type Selector Circuitry


View attachment 47440
LED VU Meter


View attachment 47441
Muting Circuitry to mute Tape Head Output during Recording


I am also attaching the PDF of the above-posted files herewith. Due to attachment size limitation of HFV, I could not provide high-quality PDF. I will provide that on personal communication.

Regards,
Anirban

Excellent Anirban. Hat's off for the efforts made by you in detailing all the sections. I really appreciate the valuable time for your contribution. I had like this model Sonodyne SCR-2061 purely transistorised output Amplifier section with an excellent Recording. I will certainly make the like effort done by you. However, I have the complete circuit diagram that was there with it's Operating Manual.

Thanks & Regards,
Shamim Ahmed

 

[anirban420]

I have the complete circuit diagram that was there with it's Operating Manual

Please upload it. These things are hardly found on the internet these days.

 

[Bhanu Prasad Swain]

Thank you Mr. Ariban. i appreciate your work. It's really very difficult to draw this circuit by hand, even without a service manual or schematic diagram. However everything you have done is a success and also useful for other people. Thank you very much for this. One more thing, just let you know if it can be available the same as the schematic for the SONODYNE SC1020 model because I use this model and also I don't have a service manual or schematic diagram. Therefore it is very difficult to drive during maintenance or also any upgrade etc. Therefore, I ask you to let me know if you have any ideas or solutions in this regard please.

Thanks
B.P Swain