|
Tubes Asylum Questions about tubes and gear that glows. FAQ |
|
|
|
Tubes Asylum Questions about tubes and gear that glows. FAQ |
|
In Reply to: Audio Research D76a without and with AR SP3 pre? posted by fwitkowski@wp.pl on April 13, 2007 at 13:31:01:
Unless you match impedance carefully, you'll roll off the top. The D-76 has relatively low input impedance at high frequencies (30k), so you likely do not have a very good output to input multiplier. Some of that roll off effect also depends upon the capacitance of your interconnects. The lower the better. DACT offers an Excel based calculator on their website to provide the response curves.What will you lose? Some resolution and likely separation when using a traditional ganged pot which affects soundstage width. That is what I experience when I put my SP-9MKIII in the signal vs. using precision attenuators alone. I have a fortuitous combination of using a high output, low impedance source (4 volt/75 ohms) through 10k attenuators with a short 2 meter run of low cap ICs to a sensitive and high input impedance amp (1.2 v / 132k). I use the preamp solely for the phono section.
On the other hand, your passive arrangement may not have enough gain to fully drive the amp. The preamp may provide better high level dynamics in that case. That is the case with my vintage system where I drive the amp directly from a DAC. It doesn't matter to me because I rarely run the amp past the -25 db level.
rw
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Well the issues with using attenuators are well known - E-Stat 09:07:20 04/14/07 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
