in article , John Byrns
at wrote on 3/12/05 8:17 PM:


I have scored the three current entrants in the KISS amp design
competition in accordance with the design parameters that Andre originally
set down. As you would expect Andre's original "KISS" design scored the
full 100 points, my KISSASS design scored 83 points, and Stewart's KISASS
design brought up the rear with only 50 points.

The scoring was based on meeting the following 6 design goals established
by Andre.

1. KISS
2. All Class A
3. Zero Negative Feedback
4. Single Ended Output Stage
5. 3 Watt Power Output
6. 2 Volt Input Sensitivity

Andre explicitly stated all but the first goal which was implicit. Each
goal that was meet garnered 1/6 of the maximum 100 points.

Most of the goals are obvious, except the first which was scored based on
the total parts count not being more than 10% greater than the parts count
of Andre's reference design, which I assumed has 22 parts.

For scoring purposes I considered NFB to exist only if two or more stages
were enclosed in a NFB loop, local NFB as in a triode tube or transistor
emitter follower, was not counted as NFB. Stewart's KISASS design failed
the NFB test because two stages, Tr1 & Tr2 were enclosed in the single NFB
loop formed by R7.

The following table shows how the scoring broke down.

Andre's John's Stewart's
KISS 300B KISSASS KISASS

1. KISS YES YES NO

2. All Class A YES YES YES

3. Zero NFB YES NO NO

4. SE Output YES YES NO

5. 3 Watts Out YES YES YES

6. 2 Volt Sens YES YES YES

Score 6/6 5/6 3/6


Parts Count 22 21 33


Regards,

John Byrns


Surf my web pages at, http://users.rcn.com/jbyrns/


Well, I guess it ain't no secret who one the ass kissin' contest . . . .