Hi everyone.
I've noticed that KF used the same value of input coupling caps on both halves of the phase inverter. (Or on several of his variations). I've notived Marshall uses .02 and 0.1. Also on the tech pages at Aiken amps he suggests the second cap be 10x the primary cap.
Any thoughts??
Stew
Coupling caps on the LTP
Moderators: pompeiisneaks, Colossal
Re: Coupling caps on the LTP
Hi!
as the preceding stage 0,002uF/150K cap/resistor design is already cutting the bass, i think he used the big cap feeding the PI (high input impedance) to tame the high a bit...i may be wrong...
Aiken Tech pages are great!
as the preceding stage 0,002uF/150K cap/resistor design is already cutting the bass, i think he used the big cap feeding the PI (high input impedance) to tame the high a bit...i may be wrong...
Aiken Tech pages are great!
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David Root
- Posts: 3540
- Joined: Fri Aug 04, 2006 3:00 pm
- Location: Chilliwack BC
Re: Coupling caps on the LTP
The standard argument for the 0.1 value is to ensure the input resistor is fully bypassed, so that both inputs have a balanced low end frequency response. It's overkill but safe. It could be lower and still work OK in that respect.
Maybe KF wanted an unbalanced frequency response for some reason eg different harmonic content? Maybe he just wanted to have lower than "standard" bass response on both sides, to avoid blocking distortion at the output coupling caps?
Maybe KF wanted an unbalanced frequency response for some reason eg different harmonic content? Maybe he just wanted to have lower than "standard" bass response on both sides, to avoid blocking distortion at the output coupling caps?