Arny Krueger wrote:
wrote in message
You can't even buy the transistors I use in surface mount.
So what? Are you saying that the transistor type you use is totally unique
and a comparable SMD does not and cannot exist?
Yes, older-style large area transistors are disappearing off the market.
Most of them are NOT available in surface mount even though something with
an equivalent curve and a lower surface area are.
I suppose I could "sub" some surface mount transistors, but
the noise floor would rise.
Why?
Because customers want cheap transistors, not good ones, and so semiconductor
manufacturers are going berserk to get as many transistors onto a die as
possible.
If you ordered a 2N5088 from Motorola ten years ago, you got a part with
something like five times the surface area as what you get if you order an
SMT 2N5088 from them today. The SMT parts have incredibly high flicker noise
and are totally unacceptable for audio. Yes, they meet the specs on the
data sheet, but the specs do not include flicker noise.
As far as I know, there are not any good SMT discrete transistors available
although you can get the THAT transistor arrays in SMT.
Excluded-middle argument, since it has been established that SMD film
capacitors are now common.
In some values. The PPS film types from ITW Paktron aren't half bad, though.
If Mouser and Digi-Key will sell DMD film caps to me, why won't they sell
them to anybody else?
http://www.mouser.com/catalog/631/704.pdf
Notice the very limited set of values, though. You don't get them in 10 uF...
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."