Rod Elliotts P3A Rev C

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hifisucks

hifisucks

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Joined 2009
Hi, I am waiting already 4 weeks for my board... maybe interesting for someone else too... :)
Well, I bought a plain board today and will start thinking about doing it without the ready one...
My question is about the MJL21193/4 and BC546 pinouts...
Emitter arrow always stays pin 3...??? Is that right?
Because sometimes the curcuit diagram shows the emitter on top or bottom... :)
I dont understand much about these transisters... :)
And sorry for the unqualified questioning...
Cheers
 

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PRR

PRR

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Joined 2003
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The schematic drawing is NOT the physical layout.

Get the Spec Sheet for the specific part you will use. That will tell you which leg is E B or C. Study carefully: sometimes the drawing is an odd angle or otherwise not as clear as it could be.
 
hifisucks

hifisucks

Member
Joined 2009
Good morning and thankyou for your replies!
Nobody needs to panic! I'm a musician and not a rocket scientist... :)
I guess I will order again :)
I messed up some valve projects thinking I can read the curcuit diagram... :)
But I'm still alive... :)
A bit too tricky for me...
Thanks again!
All the best!
 
B

bandol83

R.I.P.
Joined 2004
Be careful, the pinout is different for transistors from USA, Europe or Japan as you can see in the attached document :confused:

I have already made this mistake on the Quasi amplifier when I replaced the Japanese transistor KSC1845 by an American one, the 2N5551, because both reference were indicated on the schema :mad:

Rgds,
Marc
 

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R

rsavas

Member
Joined 2012
This is legacy.
As an example the old, obsolete, popular 2sc945 from NEC is currently available from Onsemi as ksc945 and ksc945c, which has center lead collector to match the original 2sc945.
Thank god when they went to smt, the popular SOT-23 has all the mfgs following the same pinouts.
 
Mark Johnson

Mark Johnson

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Joined 2011
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I've got several hundred KSC945C's in my drawer and I'm happy to report that the cheap and cheerful "328" component tester, link in post #9, correctly reports the pinout of every single one. It's actually faster than doing a quick lookup in a notebook. The fact that it measures inductance, capacitance, and resistance too, is just an unexpected but pleasant bonus.

Poke around eBay, you'll find many of them. Some with enclosures, some without. Some with newer firmware revision number. Some with fancier pushbuttons. Some with free shipping.
 
hifisucks

hifisucks

Member
Joined 2009
The board arrived after 4 weeks... I was happy, Rod too... :)
Easy put together, was like drawing by numbers...
This is a great amp! It is very well frequency balanced performance...
I always new, that my Beymas 15XA38Nd need more beafier power source for wakeing up... :)
Ideling current is now 30mV... 50mVs sounded somehow harsh...
All the best!
Cheers...
 
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