|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
|
|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
In Reply to: RE: Good pick-up Jeff. posted by banpuku on February 24, 2017 at 07:45:22:
Yes Pat. Now, you need to figure out what sized resistor to use, and how much B+ voltage you need to drop across it, to get ABOUT 1 mVAC at the "C3" spot with the higher driver current you use. "C3" can be a DC LINK WIMA 50 uF, bypassed.
So, your entire supply will be like so: L1/C1/L2/C2/R1/C3. C3 can be shared L-R or split into two R1s and 2 C3s, you likely don't have chassis room to do that splitting.
So, model the supply in PSUD, and change the value or R3 with 50 uF held steady as C3, till you get 1 mVAC at C3. That will be the value, "ball park" needed of R1 ( AND a voltage drop across it ) that you will need.
So Pat, lets say you need to drop 50 to 100 VDC across R1, ( for 1 mVAC at C3) where will you get an extra 50 - 100 VDC , with a fixed power transformer and tube rectifier ???
Easy, Model "645 mHy at 10 Ohms" for L1, ( Hammond 159Y ) and SEE what that does to raise your C2 B+ VDC value. THAT is how you get the extra B+, with a smaller value, lower mHY, lower DCR L1. The VDC at C2 will then dictate the R1 value you need.
Also, Pat, with eg: a 50-100 VDC higher B+ at C2, you will need to use a higher value 2A3 Rk, to maintain 265 VDC at 43 mA. P-K across the JJ 2A3-40.
Go for it. But when you are doing this, remember one thing, one truth. A cap couple is the worst way to couple two stages. A transformer couple is better than a cap couple, easily. And, a direct couple is THE best way to couple two stages. Have fun.
Jeff Medwin
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- RE: Good pick-up Jeff. - drlowmu 08:45:35 02/24/17 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
