diytube ST35 Rev D EFB Mod Notes
10/27/11

1) Screen resistors: Cut traces from J2-2, J3-2, J4-2 & J5-2 going to their respective pin 9 (at V3 through V6). Verify they are open with a DMM. Jumper the above cuts with 100 ohm screen resistors (e.g. Mouser pn# 273-100-RC).
2) Grid Stoppers: Cut traces right after R13-R16 before the socket. Verify they are open with a DMM. Scrape off solder mask on both sides of cut trace, tin with solder and then solder 1K grid stoppers. You can use axials (e.g. Mouser pn# 273-1K-RC) or even use 1206-sized surface mount resistors (e.g. Mouser pn# 71-CRCW12061K00FKEB).
3) Cuts (verify cuts with DMM): 
- The connection between pins 2 and 3 on R19, R22, R25 & R28
- The connection between R17 & R43, R20 & R44, R23 & R45 and R26 & R46
- The star ground connection on one pad of R29 (this will be our 360K resistor)
- The connection between the Vout pad (U1-U4) and R17, R20, R23 & R26

4) Parts and their locations:

C5,C6,C7,C8
140-XRL35V470	
This part should be modified with a much smaller value. I would use a Nichicon.

Cx100,Cx101,Cx102,Cx103
647-TVX1H4R7MAD1LS 
These 4.7uF, 50V axial caps will be mounted under the board from the LM337 Adj pin to the ground at C5-C8. (respectively).

R43,R44,R45,R46
15K 273-15K-RC

R19,R22,R25,R28
72-T93YB-5K 

R29
294-360K-RC 

Ux100,Ux101,Ux102,Ux103
512-LM337T
These are mounted using the footprint at R17, R20, R23 and R26. Pin 1 (Adj) connects to the pad located closest to the coupling caps (inside of the board). Pin 2 (Vin) goes to the center pad marked 'Vout'. Pin 3 (Vout) connects to the pad on the outside of the board, running to pin 3 (the cathodes). Note: the silkscreen for U1-U4 is for a LM317 CCS, *not* the LM337. 

Rx100,Rx101,Rx102,Rx103
273-10-RC
These solder from center pin of the LM337 (Vin) to ground (use the ground lug at R43-R46). These are our bias resistors

5) Jumpers (most easily run under PCB):
- Connect resistor wipers to the LM337 adj pin. This will go from:
	-R19 pin 2 to R17 inside pad (aka LM337 adj)
	-R22 pin 2 to R20 inside pad (aka LM337 adj)
	-R25 pin 2 to R23 inside pad (aka LM337 adj)
	-R28 pin 2 to R26 inside pad (aka LM337 adj)
	-Connect pad of R29 (that we freed from the ground plane) to inside (and unused) pad at R18, R21, R24 & R27. This pad connects to the top leg of our adjustable 5K resistors.