|
Tubes Asylum Questions about tubes and gear that glows. FAQ |
|
|
|
Tubes Asylum Questions about tubes and gear that glows. FAQ |
|
In Reply to: Re: 6bq5 triode configuration? (Longer and longer) posted by chopper87 on March 10, 2002 at 13:48:17:
Murphy`s law: "If anything can go wrong, it will". It`s such a simple circuit and this mod is so easy that it`s probably some stupid mistake like bad soldering, short circuit, disconect B+ for 7247 tube together with screen grids supply, soldering the wrong pins, forgot to remove jumpers between pins 9, etc. I too "dicovered" the schematic too late. Try later, easy, and looking in the schematic.
Feedback loop - try desolder 33k resistors and solder 47 k. For now, don`t change the value of the 68 pF condensers - solder them parallel with 47 k resistors (like it was before with 33 k). The purpose of this cap is to make high frequency neg. feedback different from the low frequency feedback, and prevent oscillations on very high frequency. We will change the feedback resistor just a little, and I hope that old value of the cap will be OK. Again, it`s no easy task without some knowledge and test equipment. If it is necessary, the "right" value is often sought with experiments in small steps. Good luck again!
P.S. Don`t hestitate to ask if something should go wrong again, ha...
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Re: 6bq5 triode configuration? (Longer and longer) - Damir 03/11/0206:16:36 03/11/02 (0)
- Re: 6bq5 triode configuration? (Longer and longer) - chopper87 09:36:58 03/11/02 (0)
- Re: 6bq5 triode configuration? (Longer and longer) - chopper87 07:58:42 03/11/02 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
