"Audio Empire" wrote in message
...
The Citation 12 was a later generation device, which enhanced the Lin
circuit by upgrading to a differential input stage.
But, IIRC, it still used a pair of complementary drivers and NPN outputs,
Yes, it had a quasi-complementary output stage, just like the *good* Dyna
120s and just about every other SS amp of the day.
Full complementary output transistor sets with enough power handling
capacity to be interesting came in the mid-1970s.
As nice and symmetrical as these devices made schematic diagrams appear,
they provided no audible or reliability benefits.
like the ST120 (seemed to me that they were still 2N3055s, but I could be
misremembering here, I haven't laid eyes on that amp for 35 years).
The originional ST-120 schematics showed 2N3055s, but the *good* ST-120s
used the later and beefier 2N3443 devices.
Please see figure 5 at
http://cygnus.ipal.org/mirror/www.pa...s/citation.pdf
Thanks. Yes, I see what they did. Q6 and Q7 have the number 40636 next to
them. Is that an H-K part number? Doesn't sound like any transistor number
with which I'm familiar.
40636 looks to me like a RCA part designation. An early member of this
product line was the 40411 AKA "411" which was, no surprise a beefier
2N3055.
http://alltransistors.com/transistor...ansistor=20869
RCA was an early leader in producing extra-beefy NPN power transistors, but
they did not have a lot to offer in corresponding full complementary pairs.
Motorola took over, with parts like the MJE150xx series.
http://www.diyaudio.com/forums/solid...ansistors.html