I tested the signal level and frequency response of a short chain of true bypass pedals against the same number of buffered Boss pedals. See the full article in my Lab Notebook.
[1230] Bypass Systems Measured
Date: April 11th, 2012 | Comments : [7] | Categories: DIY.I tested the signal level and frequency response of a short chain of true bypass pedals against the same number of buffered Boss pedals. See the full article in my Lab Notebook.
7 Responses to “Bypass Systems Measured”
Search
View a Random Post
from the archive.
Comments
Email List
Archives
Categories
Blogroll
Author
Jack Orman has been involved in FX design and construction since the mid-1970s.
Meta
If you want to jump straight to the article, it is here:
http://www.muzique.com/lab/bypass.htm
I am curious what the frequency response of 4 well designed buffered bypass pedal would be. like 4 mini buffers from that AMZ newsletter or 4 klon style buffers.
Four well-designed opamp buffers in series would have very good response and unity gain. It would not be exactly like 4 switches in series but good enough that you certainly could not hear the difference. This is quite a bit different than the multiple transistor buffers put into many commercial pedals, which will have a significant impact on the sound as illustrated above.
I did a freq response test of 10 individual Boss pedals, then ran them all in series & repeated the test. Hilarious results!
FWIW, the buffered bypass used by Tech21 in their SansAmps is fantastic – barely deviates from the loopback response.
Ahha, here’s my graph: http://rudemechanicaloz.files.wordpress.com/2010/07/including-10-boss-pedals.png
Thanks for posting the graph, Chris.
The 10 Boss pedal response is revealing and in line with what I found with 4 Boss pedals. The high end roll off is -3db at about 8.8k Hz, compared to the mid-range response, and I’m wondering if a particular one of the 10 pedals is contributing most of that loss.
-Jack