|
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: My take on the phono board posted by Flyquail56 on March 19, 2007 at 05:25:27:
Interesting alternative. The potential problem with an active RIAA phono stage using feedback is variations in RIAA accuracy due to variations/aging in the tubes. Because the two 12AX7 tubes have a relatively limited overall gain, there isn't much feedback at low frequencies to control the variation. If you look at Lipshitz' JAES article on RIAA EQ, you'll find that the open loop gain is part of the equation to generate the values of the EQ components, so substituting a new tube with a different gain, or aging of the tubes can result in variations. Although passive EQ is not immune from variations, it can be designed to have less variation with tube aging or replacement. OTOH, the feedback design probably has a lower output impedance. Swings and roundabouts, as the British would say.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Re: My take on the phono board - JimL 18:13:10 03/19/07 (1)
- Re: My take on the phono board - Flyquail56 20:01:40 03/19/07 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
