My first ever DIY amp - 1981

[reubensm]

Dear all, thought I'd share a couple of pics with you. Built this amp in 1981, was my second ever DIY project (first one was a morse key, which was essentially a tone oscillator). Still have it in perfect working condition. It was a simple 1 watt power amp with an AC187/AC188 germanium output pair. The amp was put together with redundant components lying around in my dad's junk box.

My next amp was a TBA810S based stereo amplifier, built when I was in standard 9, 1987.

Great memories.

 

[Audiodoc]

Almost as old as me. By the way I think that the 810 IC was manufactured in India.

 

[iaudio]

reubensm, good lord, thats diy at quite a young age. So your dad must have taught you to solder and other electronics basics?

 

[reubensm]

reubensm, good lord, thats diy at quite a young age. So your dad must have taught you to solder and other electronics basics?

yes, he was an engineer with DOT (now BSNL) and he had all the stuff lying around. I learnt to solder when I was in Standard-4, 1981. Electronics basics came very early to me as I used to sit and watch my dad do his stuff (and ask him 100s of questions). In those days, PCBs were rare, hence he used to work without them. He started me off by giving me odd tasks like, identifying components from the junk box, cleaning the component contacts, straightening them out, applying solder coatings to the component contacts, etc. Then I learnt basic wiring, the rest was easy for me.

 

[reubensm]

Almost as old as me. By the way I think that the 810 IC was manufactured in India.

The first TBA810 IC, I ever bought was made by Hitachi, Japan. I built and amplifier and played around with it till it burnt out. Then got 2 TBA810S ICs which were both made in India, for my stereo amp. I also remember that Philipis India used to manufacture its own version, think it was called CA810

 

[nshankar]

Nostalgic. Very innovative to use aluminium L plate bolted to PCB. My first DIY was a crystal diode receiver.

 

[kaushik]

Great one ,
That 810 had a magic..may be depending on make I guess, as a matter of fact my 1st amp too was 810 based.

Philips 2in1 lineouts>810 kit >local fullrangers ,milton tweeters ,
1994 , I was at school,aah those were the best days ............

 

[reubensm]

Nostalgic. Very innovative to use aluminium L plate bolted to PCB. My first DIY was a crystal diode receiver.

If i remember correctly, that L-plate was salvaged from my dad from an old burnt out communications receiver (even the knob was from that receiver)

 

[anuragn]

Coincidently, I too did my first DIY when in 9th std in 1987! That was a dual-tone doorbell, circuit was published in EFY magazine.
I started with scratch with this one and then progressed thru' lots of LED flashers, sirens, small audio amps, tone control, FM receiver, power amp using TDA-7030, programmable on/off timer etc.
Though introduction to DIY happened at a much younger age when my Dad once bought a torch light bulb and a dry cell for me to experiment.

P.S. What better day than today to discuss our childhood memories !

 

[reubensm]

Great one ,
That 810 had a magic..may be depending on make I guess, as a matter of fact my 1st amp too was 810 based.

Philips 2in1 lineouts>810 kit >local fullrangers ,milton tweeters ,
1994 , I was at school,aah those were the best days ............

the 810 that i got first was by Hitachi Japan, it was far superior from a sound quality perspective but cost Rs.30/-. For my stereo amp project, I got 2 Indian ones for Rs.17 each, so with Rs. 4 more, I could buy 2. The sound quality was not that good but who cared, for a school boy buying stuff with pocket money, ever rupee mattered. Still remember the component prices as I went around to several shops enquiring the price before purchasing them.

my set up when I was in Standard-9 (1987), was:

home brewed cassette player (with a mechanism salvaged from an old portable cassette recorder, with a new stereo head and pre-assembled head preamp)
home brewed preamp (BC148B based)
home brewed power amp (TBA 810 based)
home brewed 2-way speaker system with home brewed cross-over
Also had an old Holland Philips Transistor radio

 

[reubensm]

Coincidently, I too did my first DIY when in 9th std in 1987! That was a dual-tone doorbell, circuit was published in EFY magazine.
I started with scratch with this one and then progressed thru' lots of LED flashers, sirens, small audio amps, tone control, FM receiver, power amp using TDA-7030, programmable on/off timer etc.
My true introduction to DIY happened at a much younger age when my Dad once bought a torch light bulb and a dry cell for me to experiment.

all my projects were built around circuits from EFY magazines, could not attempt the Elektor ones as components were not easily available

 

[Audiodoc]

My first DIY was a 555 based astable multivibrator in 1996. After it there was no end till med school. Made my cassette deck tried every available chip 4440, 4445, 1230, STK series before turning out some good elektor designs. The problem with elektor ones was the components and with the lack of online shopping services still have a few incomplete ones lying around. I think will complete them or put them on sale.

 

[omishra]

It is great feeling to look at old stuff while looking back in time. I too made progress in same way but entered to DIY dish antenna and 'C' band satellite receivers, modulators around 1992-93. After that not looked back till all converted to digital.

Those days PCB was designed on graph paper with keeping carbon copy paper upside down. Then reversing graph paper to make mirror image on copper clad using another carbon paper. Painting by hand to etching, drilling. OMG! how much time and patience we had that then.

 

[reubensm]

It is great feeling to look at old stuff while looking back in time. I too made progress in same way but entered to DIY dish antenna and 'C' band satellite receivers, modulators around 1992-93. After that not looked back till all converted to digital.

Those days PCB was designed on graph paper with keeping carbon copy paper upside down. Then reversing graph paper to make mirror image on copper clad using another carbon paper. Painting by hand to etching, drilling. OMG! how much time and patience we had that then.

interesting...have you tried receiving the good old Russian Ekran Satellite signals in UHF? I remember my father trying some stuff with a twin yagi design back in the 1980s...all he could get was a grainy picture without sound

 

[omishra]

interesting...have you tried receiving the good old Russian Ekran Satellite signals in UHF? I remember my father trying some stuff with a twin yagi design back in the 1980s...all he could get was a grainy picture without sound

No. I started with zee tv FTA on 'C' band, then that 1 meter dish was used to explore the complete equator.

 

[anuragn]

It was so much fun designing own pcbs.
I used nail paint to paint the pattern on copper clad board, then used Ferrous chloride solution to dissolve the copper and finally, Dad's hand drill to make holes.
The final result was always shoddy in appearance, but worked.
Now with everything going digital, "old school" DIY has become difficult. In most of the markets, small shops that used to sell electronic parts have converted to mobile accessory selling shops.

 

[anilva]

So many of the experiences written here resonate with mine. My dad was in P&T (BSNL now) and he was a big hobbyist dabbling in Tubes and then solid state. His passion was radios, amps, speakers etc. He put in all his savings in a room full of DIY stuff including tools. I started assisting him from very early days and picked up doing things myself.

My earliest projects were around 555, LM741, TBA810s, AC127/AC128, AD149s and so on. Then I started doing EFY (Visha and Vega kits) and then Elektor. I would make my own PCBs thanks to a permanent marking pen one of my relatives got from US. I would hand draw the pattern and etch. My biggest trip was to make a perfect cassette tape recorder (not just a player). I made so many of them but, could never achieve a perfect AC Bias based recording. I tried Glass Crystal, Ferrite, Permalloy and other esoteric tape heads and chips from Signetics, National and so on.

The biggest constraint was money and availability of components. In the absence of internet, only source of information was old, discarded & imported audio magazines from the pavements and I would look in awe at Linns, Meridians, Quads etc. Some of them formed basis of my designs. My real dekkho at a big system was when one of my relatives came back from the Middle East with full Akai rack system. What a piece of engineering it was then!

Later I moved to Bangalore and then I got to know of SP Road. I settled on STK459 based amps and Bolton DIY speakers and used it for a long while. International travel, earnings and internet all came together much later to be able to pursue my hobbies with much more intensity.

Cheers.

 

[reubensm]

So many of the experiences written here resonate with mine. My dad was in P&T (BSNL now) and he was a big hobbyist dabbling in Tubes and then solid state. His passion was radios, amps, speakers etc. He put in all his savings in a room full of DIY stuff including tools. I started assisting him from very early days and picked up doing things myself.

My earliest projects were around 555, LM741, TBA810s, AC127/AC128, AD149s and so on. Then I started doing EFY (Visha and Vega kits) and then Elektor. I would make my own PCBs thanks to a permanent marking pen one of my relatives got from US. I would hand draw the pattern and etch. My biggest trip was to make a perfect cassette tape recorder (not just a player). I made so many of them but, could never achieve a perfect AC Bias based recording. I tried Glass Crystal, Ferrite, Permalloy and other esoteric tape heads and chips from Signetics, National and so on.

The biggest constraint was money and availability of components. In the absence of internet, only source of information was old, discarded & imported audio magazines from the pavements and I would look in awe at Linns, Meridians, Quads etc. Some of them formed basis of my designs. My real dekkho at a big system was when one of my relatives came back from the Middle East with full Akai rack system. What a piece of engineering it was then!

Later I moved to Bangalore and then I got to know of SP Road. I settled on STK459 based amps and Bolton DIY speakers and used it for a long while. International travel, earnings and internet all came together much later to be able to pursue my hobbies with much more intensity.

Cheers.

Similar story this side...yes, becoming an Assistant Director and international travel changed the scenario for me

 

[quad]

My earliest projects were around 555, LM741, TBA810s, AC127/AC128, AD149s and so on. Then I started doing EFY (Visha and Vega kits) and then Elektor. I would make my own PCBs thanks to a permanent marking pen one of my relatives got from US. I would hand draw the pattern and etch. My biggest trip was to make a perfect cassette tape recorder (not just a player). I made so many of them but, could never achieve a perfect AC Bias based recording. I tried Glass Crystal, Ferrite, Permalloy and other esoteric tape heads and chips from Signetics, National and so on.

The biggest constraint was money and availability of components. In the absence of internet, only source of information was old, discarded & imported audio magazines from the pavements and I would look in awe at Linns, Meridians, Quads etc. Some of them formed basis of my designs. My real dekkho at a big system was when one of my relatives came back from the Middle East with full Akai rack system. What a piece of engineering it was then!

You brought back old memories of TBA810, LM381 etc. And the
infamous Delhi make cassette decks (Chawla mechanism etc). I
was so thrilled to get a hydraulic soft eject Japanese mechanism with
a glass ferrite head for my DIY casette player -
moved from a discrete pre to a LA3161, and amp was 2 * TBA810.
Even glass epoxy PCBs were such a rarity.

The 2N3055 based Philips 40W, or the STK amps
were too expensive for me.
Of course, I went through the obligatory bird bells, running LEDs,
misc 555 ckts, digital clock etc, AC128 based pocket radio and so on.
A huge discovery for me was TTL and CMOS (74xx and 4xxx)
series ICs.

I think Elecktor started the Indian edition in 1983?
I really lusted for the stuff in the UK editions and
the Elektor books (one on the micoprocessor kit and their
circuits collection, including a full TTL clock with alarm etc).

 

[anuragn]

Oh how can I forget those circuits assembled not on veroboards but on piece of cardboards! Those were the days. Now dont get enough time to devote, with the two small kids playing around in the house.