2N3055 inside - commercial famous amplifier models, quasi complementary power output

[tiefbassuebertr]

The 2N3055 power transistor was introduced by the Radio Corporation of America (RCA) in the early 1960s. It was one of the first silicon power transistors, offered unrivalled second breakdown immunity and found many applications particularly in audio power amplifiers.

Under
http://www.diyaudio.com/forums/solid-state/10337-amplifier-based-2n3055.html
there is a circuit collection
check out also this thread:
https://www.diyaudio.com/community/threads/2n3055-the-early-years.382690/
early advertisement is on page 67 under
https://worldradiohistory.com/UK/Industrial-Electronics/60s/Industrial-Electronics-1965-01.pdf
(this page I have upload in post #505).
and last page (page 64, feb. 1964) under
https://worldradiohistory.com/Archive-Electronics/60s/64/Electronics-1964-02-28.pdf
(this page I have upload in post #518)

I want to have a bunch of such commercial famous power amplifier models and UK/US brand names made in the 1960s (only with quasi complementary output stages).

Thank you very much for your hints.

 

[nigelwright7557]

Maplin did a 225WRMS complimentary amplifier in the 1970;s.
I used one for disco work and it was very loud and very reliable.

 

[tiefbassuebertr]

Maplin did a 225WRMS complimentary amplifier in the 1970;s.
I used one for disco work and it was very loud and very reliable.

this brand (not the showed module) ??
200W Power Amplifier : Audio Amplifier Kits : Maplin

 

[picowallspeaker]

Hi Tiefbassuebertr.
Check out on this auction
Rcf af 6070 su eBay.it Amplificatori, Hi Fi e Home Theatre, Audio, TV, Elettronica
Works at 70 V supply ,very well engineered , the design is a plus .
I saw also a more powerful version ,too ,also larger cabinet ,but this one sounds very good . The add is not mine !!!
Bye

 

[nigelwright7557]

this brand (not the showed module) ??
200W Power Amplifier : Audio Amplifier Kits : Maplin

It was 225WRMS, they no longer do it.
Shame it was a good solid amp.
I am sure i have seen a picture of it on this forum at some time.

 

[tiefbassuebertr]

here very fine sounded receiver with 2N3055 as power devices:
Braun series "Regie"

 

[mjf]

hello.
from elektor:
edwin, equa and equin - power amps in the seventies.......
harman kardon (citation)........
grüsse

 

[event horizon]

It was 225WRMS, they no longer do it.
Shame it was a good solid amp.
I am sure i have seen a picture of it on this forum at some time.

I remember it though i never bought one

It used MJ2955 as the pnp compliments & a +/-55V approximately power supply. Lord knows how it didn't blow up as you can see the rail voltages were well in excess of the VCE of both the 2N3055 & the MJ2955. I guess they were relying on the reverse biasing of the output transistors to stop them exploding

60V transistor, 110V PSU

 

[bear]

The CM Labs 911 was among the very first commercially built solid state amps that made the unheard of power output of 100wRMS. It is a quasi complementary output stage with a big cap blocking DC. Nice amp actually.

The other amp of the day, that was also quasi complementary was of course the Dyna ST-120.

There really were not a lot of powerful solid state amps before 1970.

_-_-bear

 

[wg_ski]

60V transistor, 110V PSU

Back in those days, lots of amp makers would cheat by putting 2N3055's, 2N3772's etc. on a curve tracer and see if they took the 100+ volts they needed. The epitaxial versions usually would (now they just call it an MJ15015).

 

[godfrey]

Can't believe nobody's mentioned the Quad 303 yet!
NAD3020 used 2n3055s as well, but I think that was in the late 70s.

Sadly, when manufactures switched the 2n3055 to epitaxial, the 2'nd breakdown immunity went out the window.

edit: oops, maybe the NAD wasn't quasi? I can't remember.

 

[tomtt]

dynaco 120 -

An externally hosted image should be here but it was not working when we last tested it.

http://www.davidreaton.com/Dyna120/Dyna_120.pdf

 

[Don Hills]

In New Zealand about 1970, several models of the locally built "Fountain" brand amplifiers used 2N3055 transistors. My first amp was a Fountain 1550. I traced the power amp circuit, it was similar to the J Linsley Hood designs popular about that time.

 

[wakibaki]

I have a Rogers, I think it's a Ravensbrook, hopefully somewhere in the loft, I'm sure it had 2N3055s...

w

 

[burbeck]

Musical Fidelity Model A1, great sounding little amp.

used 2N3055 and its compliment, http://www.tcaas.btinternet.co.uk/mf-a1.gif

this is just the power amp stage here.

 

[nigelwright7557]

Maplin did a great 225Wrms 2n3055/mj2955 amplifier.
I used one on a disco for many years and it was very loud and reliable.

 

[Mosquito]

NAD3020 used 2n3055s as well, but I think that was in the late 70s..

(series 20 NAD3020)
wasn't quasi, but yes, used Motorola's 2N3055 and the complementary, except one that i saw using Matsushita brand 2N3055..

 

[Mosquito]

except one that i saw using Matsushita brand 2N3055..

Pardon, it was Toshiba 2n3055

 

[Steerpike]

Iv'e got a receiver "Sound System One" made by STC in kit form, that uses a 2N3055 push-pull OP.

 

[tomtt]

2n3055

$2.29US each -

An externally hosted image should be here but it was not working when we last tested it.

2N3055 NPN Transistor - RadioShack.com