A blast from the past (my first amplifier)

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Audiovista

A blast from the past (my first amplifier)
« on: 3 Sep 2015, 04:52 pm »
Digging through the attic a few days ago, I stumbled upon few interesting relics... the most interesting of which is the first amplifier I ever completed: PC boards, power supply, chassis... when I was 14 or 15 years old, some... I'm dating myself now... 25-26 years before Vista Audio was founded.



10Wpc with Germanium transistors and stabilized power supply (very rare and exotic for a power amplifier). Learned how not to do a lot of things (chassis, painting, component selection,... :nono: :duh:) and how to do others (design and make power transformer, eliminate hum, minimize noise,...). I used the amplifier for about 1-1.5 years before I built the next one, and this unit ended with my friends who used to play folk music at weddings  :violin: :drums: :guitar:... they used and abused it until they made enough money to buy new equipment, and this one came back to me. Fond memories....

I put more pics on FB (https://www.facebook.com/vistaaudio), maybe I should be embarrassed with quality of workmanship, but instead I am quite proud of what I was able to pull off as an 8th grader.  8)

Audiovista

Re: A blast from the past (my first amplifier)
« Reply #1 on: 4 Sep 2015, 11:20 am »
With cover removed.


JohnR

Re: A blast from the past (my first amplifier)
« Reply #2 on: 4 Sep 2015, 04:54 pm »
8th grade?! Somewhere around here I have something I made a few years older, it's a little... cough, well primitive. But... germanium transistors?  :o

Devil Doc

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Re: A blast from the past (my first amplifier)
« Reply #3 on: 4 Sep 2015, 06:11 pm »
I made some dynamite macaroni sculptures in the 8th grade. :lol:

Doc

Audiovista

Re: A blast from the past (my first amplifier)
« Reply #4 on: 4 Sep 2015, 07:21 pm »
8th grade?! Somewhere around here I have something I made a few years older, it's a little... cough, well primitive. But... germanium transistors?  :o

Well, you can tell a lot about my experience when you take a closer look at soldering and wiring .... even though I had some previous experience with small FM transmitters, electronic doorbells... typical beginner stuff.



Luckily, I have a couple of EE's in the family, so getting literature (nomograms for transformers, etc.) and understanding when old TV's needed cannibalizing was easy to get. And my dad had a decent workshop, although not equipped for electronics - mostly high power motors, welders, etc.

At that time my choices were limited to AD161/162 (complementary Germanium pair) and 2N3055 (Silicone technology and still a workhorse transistor). Working with complementary pair was much easier, and lower power and voltage looked much less frightening. I used 2N3055 in the stabilizer.

My next project (and I shall take pictures of that monstrous box), couple of years later, was with 2N3055, 100Wpc, but I never managed to make it work right (struggled with bias, offset and temperature compensation), or sound right. I guess that's where I realized that I'm not quite ready for serious projects.

Audiovista

Re: A blast from the past (my first amplifier)
« Reply #5 on: 4 Sep 2015, 07:36 pm »
I made some dynamite macaroni sculptures in the 8th grade. :lol:

Doc

 :lol:

I remember my first electrical experiment, I was maybe 10-11 years old... somebody told me that choke can limit current and magnetize metallic stuff... so, naturally, I took a very small coil from a transistor radio (seemed like a good idea to use miniature stuff - modern times, no?), formed the leads, and stuck both ends in the power outlet... the rest of the story is little fuzzy ... I remember bright light, some smoke, then running away cause my grandmother was going toward me with a stick (she always had one handy) - I happen to have interrupted her favorite radio show with the power outage I caused... later that day my dad was scraping charred plastics and melted copper, replacing fuses... I suppose he was happy that I was ok, but he hid it very well  :?

Then I "graduated" to breaking old car batteries... to melt lead for fishing weights (nothing wrong with that, just Sulfuric acid and Lead, what could possibly go wrong?) :) Real electronics came a few years later... 

xsb7244

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Re: A blast from the past (my first amplifier)
« Reply #6 on: 29 Feb 2016, 09:53 pm »
Did you find your 2N3055 100W amp?  What was your first speaker?  What was your first turntable?  What was your first tape deck?

Audiovista

Re: A blast from the past (my first amplifier)
« Reply #7 on: 1 Mar 2016, 04:44 pm »
Oh man, I hope you were not kidding, cause you sure got me going  :lol:

My partners already criticized me for posting "ugly" pictures related to our business, but who else can I argue with - certainly not with the wife or teenage kids  :D

All the pictures were lifted from the web, but I looked for identical models and colors...

First turntable (made by Iskra, former Yugoslavia)...






Now, the first turntable that I bought after getting hooked up on hi-fi (first year of college) - still have it and it still works well, in range with low end Pro-Ject stuff. Made by company in former Yugoslavia on a license from a Polish audio company:



I do not yet have pictures from home-made amplifier, but here is the first one I purchased (made by Korting, Austria) - still have it... somewhere:




And tuner from the same company (yeas, I had mismatched colors of tuner and amplifier...). Digital AND analog scale - also have it:





Cassette deck from a former YU company - still have it:





And DIY speakers - the only difference is that in my box drivers were arranged vertically, in a cabinet 3.5 ft (1 meter) tall. All drivers made by a YU company, on a license from Philips. Box design was my own. Still have them, but various visitors made a point to investigate them the way proctologists do, so  fingers ended up in the tweeter domes, and through midrange and bass cones :(




 


Audiovista

Re: A blast from the past (my first amplifier)
« Reply #8 on: 1 Mar 2016, 04:45 pm »
Do you have pictures of your first hi-fi gear?

Guy 13

Re: A blast from the past (my first amplifier)
« Reply #9 on: 1 Mar 2016, 05:42 pm »
My first real (Hi-end) system when I was 20 years old (1968)
Soney tape deck (Model ???) Dual model 1019 turntable with Ortophon (MM) cartridge (Model ???)
Make SOUND ss amplifier 35wpc with matching SOUND AM-FM stereo tuner.
Speakers not shown RSC (Radio Speaker Company - Made in Canada)
sealed with two 4'' extended range drivers.
Speakers wires and interconnects, make El Cheapo  :lol:



xsb7244

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Re: A blast from the past (my first amplifier)
« Reply #10 on: 1 Mar 2016, 09:48 pm »
Please find your 2N3055 amp.  You did it.  Cheap but super phono.  Cheap but super integrated solid state amp.  What is missing?  A cheap but super speaker for $500.00 or less. 

xsb7244

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Re: A blast from the past (my first amplifier)
« Reply #11 on: 1 Mar 2016, 09:59 pm »
I forgot.  From Vista Audio, a turntable that does not cost an arm and a leg.  Just a finger.

Audiovista

Re: A blast from the past (my first amplifier)
« Reply #12 on: 2 Mar 2016, 03:16 pm »
Hey Guy 13,
I would have killed for that system, even in the 80's   :)

xsb7244 - that's a lot of homework!  :D  But speaker may be within realm of possibility. Although, I think that there are many good speakers in the sub $500 range. Still, there are some niche segments that may welcome something little different. In the mean time I'll work some more on electronics.

And I owe you picture of the 100W amp... I am leaving on a long-ish trip, will need to bring it from the attic when I return. If you really like to see more bad pictures...  :lol:

Guy 13

Re: A blast from the past (my first amplifier)
« Reply #13 on: 2 Mar 2016, 03:34 pm »
Hey Guy 13,
I would have killed for that system, even in the 80's   :)

xsb7244 - that's a lot of homework!  :D  But speaker may be within realm of possibility. Although, I think that there are many good speakers in the sub $500 range. Still, there are some niche segments that may welcome something little different. In the mean time I'll work some more on electronics.

And I owe you picture of the 100W amp... I am leaving on a long-ish trip, will need to bring it from the attic when I return. If you really like to see more bad pictures...  :lol:

Bad pictures - good pictures - any pictures for me (And others I am sure) is good.
Therefore venture yourself in the attic and dust off the spider webs and bring that stuff
so we can see what you've done in the past.
Very much interested.

Guy 13
 

Audiovista

Re: A blast from the past (my first amplifier)
« Reply #14 on: 3 Mar 2016, 11:49 am »
Bad pictures - good pictures - any pictures for me (And others I am sure) is good.
Therefore venture yourself in the attic and dust off the spider webs and bring that stuff
so we can see what you've done in the past.
Very much interested.

Guy 13

Thank you - that is very kind!

I will do that as soon as I return from a trip. In the meantime, everyone is welcome to post embarrassing pictures about their first steps into magic of audio :)


Audiovista

Re: A blast from the past (my first amplifier)
« Reply #15 on: 18 Apr 2016, 04:18 pm »
I finally found time to go through my parent's attic and dig out my second self-made amplifier. 100W per channel - a ten-fold upgrade from the first project! After unpacking and dusting it off, it does not look so bad for a 30-year old DIY unit. It is a big beast - approximately 19" wide and over 6 inch tall.

Of all the amplifiers that I had, I spent most time actually listening to music with this one. At first it was mostly with a tuner. Next was a turntable. Then I started recording radio shows on a reel-to-reel and stuck with that for a while.



VU meters on the front, but I am not really sure what they were showing... VU units, Watts... whatever it was, I think it made sense to me at that time  8)



DIN terminals on the rear panel (the two tiny protrusions are speaker terminals - probably not the best choice for 100Wrms  :o):


Guy 13

Re: A blast from the past (my first amplifier)
« Reply #16 on: 18 Apr 2016, 05:03 pm »
Thanks for showing us that DIY unit of yours.
How about being lucky and have a look under the hood ????

Guy 13
Yes, I know, I am asking for a lot.

Audiovista

Re: A blast from the past (my first amplifier)
« Reply #17 on: 18 Apr 2016, 09:46 pm »
Thank you for the kind words. I'll definitely post a few pics of the electronics inside. Can't say that I am proud of the quality of work, but it did serve me reliably for a number of years.