Ian Finch

Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW
I think that in practical applications with single pairs. There are really only 3 types of common, economical output transistor in use. They are available in fab. variations of VCE to permit multiple arrays with much higher rails than are safe to use with single pairs.

Look closely at the specs of all the types available for the basic MJ21193/4. They vary only in Package...(that means dissipation limits with TO3, T0267 or TO247 being available,) and VCE/VCB limits -(that means numbers of units possible in a multiple array). Thermaltrak diodes are another variation
egs MJ21193, MJL21193, MJW21193, NJW21193.

It's the same deal for MJL3281/1302 and 2SC5200/A1493 groupings. There are a few different packages, VCE/VCB variations and different part numbers. eg 2SC 5198/A1491 but the basic chip and performance limits are substantially the same for each part number series.
Read the numbers...kinda similar, eh? 4281,3281,0281. Sure, they are clones of the obsolete Toshiba 2SC3281/A1302 pair.

Sanken give you an alternative with the larger format M200 outline 2SC 2922 etc and a couple of similar types. This gives best dissipation and potential power output for a single device as mt490 suggests. When thinking of pushing any transistor, regardless of die size or heatsink/backplate thermal conduction, SOA and the likelihood of exceeding is the main concern. This takes real expertise IMHO.

With not a lot of genuine alternatives, Wahab's 2 x 2SC 5200 or any TO267 pair may be the safer, higher performance and more economical plan.


2010-06-09 2:32 pm
Actually as I see it the major manufacturers typically have three distinct offerings of interest to audio.

1. General purpose audio output
2. Extra-linear or RET transistor
3. Motor driver applications

Number 3 has poor gain linearity and sometimes slow speed, but whether this matters depends on if you can design your topology around it or not.

Sanyo is perhaps the odd one out, they discontinued their number 2 with no true replacement in sight. Well I guess their practical replacement is ON Semi ;)