*REV B*- Capacitor sizes (Physical)

[snitch56]

Looking at some photos of assembled ST70 diy driver cards I noticed that C1 and C2 are physically smaller than C7-C10. With the capacitors specified for *REV B* C1 and C2 should be physically larger than C7-C10. Am I correct in assuming this if I am using either Sprague or Auricap capacitors?
Thanks in advance for the help.

[Shannon Parks]

You are correct, sir. Using the Rev B parts list with 600V Sprague 715Ps, C1 & C2 (.1uF) will be fatter than the four other coupling caps (.047uF). They all have approximately the same length.

Couple of thoughts behind my methodology:

1) I wanted to spec 600V caps in case the builder went with solid state rectification or a DIY build. With a standard ST70 with 5AR4, you can use 450V rated caps. I may just list the 450V caps in the standard parts list and make a note for the other builders (ie the space for huge caps in the original footprint isn't easy).

2) Generally, folks don't like the .047uF coupling caps in my design, as 'typical' coupling caps and the original's were .1uF. So I plan to probably change the four coupling caps to .1uF and the grid resistors to 100k. But the tuning at this stage is critical for low frequency stability (sub 10Hz ringing).

3) We want the caps at C1 & C2 to be as large as possible, so >.1uF is fine for subbing.

[TerrySmith]

I wonder why Mouser doesn't sell the 716P orange drops? They are quite a bit smaller. Are the 225P caps any good for audio?

[snitch56]

Thanks for the quick reply Shannon.
I thought I was going crazy looking at the old pictures verses the new parts. Yellow_Light_Colorz_PDT_09
I got the new orange drops today (C1 and C2) and they fit perfectly in the board.