Express supply dropping chain - power ratings

[xk49w]

I am looking at ways to shrink an Express layout because it is going in a small chassis. Looking at the Kelly sch. and based on the shown voltage drops those resistors have a lot of margin. The 1k/25W is burning only 1/4W or so and I want to put in a 2W or 3W part. What am I missing?

-- Bradley

[mhuss]

The quarter-watt you speak of is only at idle. When a hearty signal is banging the output tubes around, the current drawn by the screens will be significantly higher.

That said, a 5 watt or so would probably do the job, as long as you had free air around it so it could dissipate heat (i.e., not mounted flush against the board).

Speaking of tight places, I did a totally non-traditional PS board layout, mounted on the side of the chassis. The 5w 1k is foreground left, and it gets hot.

--mark

[drhulsey]

... ways to shrink an Express layout...

Dana Hall (UR12) has used can caps on the top of the chassis to get the filter caps out of the inner chassis, evidently without any degradation in tone.

[fishy]

I am looking at ways to shrink an Express layout because it is going in a small chassis.

How big is small

[fishy]

I am looking at ways to shrink an Express layout because it is going in a small chassis.

How big is small

[xk49w]

I am looking at ways to shrink an Express layout because it is going in a small chassis.

How big is small

It's going into an AO-35 Hammond reverb amp chassis. 6V6 or 6CA7, Hammond iron.