BOM Questions for Express clone

[bentonar18]

Guys, I'm preparing my bill of materials to do a Mouser order and have some questions. My goal here is to find less expensive substitutes that have little or no effect on tone. I'm using the Kelly90 schematic and layout as my guide. Here goes:

1) Electrolytics: Sprague Atoms cost more than Xicons, but Xicons at Mouser are not stocked as deeply in the 450V arena. I feel safe sub'ing a 22uF Xicon for a 20uF Sprague, but the closest Xicon value for the 40uF Atom is a 47uF Xicon. If I do this, do I need to change other values in the resistors that go with these electrolytics? Will tone suffer for doing so?
2) The Mallory 150's are acceptable to me, but the schematic specs .02uF and .002uF, and Mouser only stocks .022 and .0022. This is a 10% value shift; is this acceptable? If not, should I adjust other components to compensate? Will there be noticeable affect on tone (I ain't got golden ears!).
3) I see a 20KL pot in the power section; can someone recommend a part number for this? I assume this is for biasing the amp...

You guys are right about one thing: sitting down with a schematic first is making me do some thinking, and that's a good thing. Thanks for your help!
John

[goodtone77]

1- a version of the the two rock ruby uses 2-47uf and 3 22uf caps for filtering(one thing i heard that xicon caps are loosley rated a 22uf rated cap might not a 22uf cap)

2- it should be fine

3- it is for the bias circuit(i ordered mine through tubesandmore.com)

i would order some extra caps and resistors values to tweak with.It might just be me but i will build an amp buy the schematic. Then i will play with values, cutting the highs or lows here and there or boosting them,same for the pre and power amp distortion try the komet .68uf with 2.7k resistor on the first stage see if you like it better. This is the part of building amps i love