OTL Asylum

OTL, Output Transformerless Amplifier User Group.

Use this form to submit comments directly to the Asylum moderators for this forum. We're particularly interested in truly outstanding posts that might be added to our FAQs.
You may also use this form to provide feedback or to call attention to messages that may be in violation of our content rules.

You must login to use this feature.

Inmate Login

By default, logging in will set a session cookie that disappears when you close your browser. Clicking on the 'Remember my Moniker & Password' below will cause a permanent 'Login Cookie' to be set.

Moniker/Username: The Name that you picked or by default, your email. Forgot Moniker?	Examples "Rapper", "Bob W", "joe@aol.com".
Password:	Forgot Password?
	Remember my Moniker & Password ( What's this?)

If you don't have an Asylum Account, you can create one by clicking Here.

Our privacy policy can be reviewed by clicking Here.

Inmate Comments

From:
Your Email:
Subject:

Message Comments

Original Message

RE: Sorry for the misunderstanding...

Posted by Lew on June 4, 2012 at 07:00:51:
So, before Will first contacted me by email to tell me about the Australian transformers, I was wondering whether I could even just remove that parallel resistor in the hi-pass filter for the OEM SL treble toroid. Dr. West had repeatedly warned against doing that, for reasons having to do with the toroid, but it was clear to me that the major problem with driving the SL speakers using my OTLs had to do with that resistor. In fact, Will reported to me that he did remove the parallel resistor successfully in his early experiments, and upon hearing that he got away with it, I did the same, while waiting for the new transformers to get to me from Australia. You are quite correct; it's a big improvement vs with the resistor in place. What I did also was to reduce the series capacitance to 22uF so as not to change the -3db point of the hi-pass filter. (Accounting for the intrinsic impedance of the speaker at the crossover point, 22uF gives about the same "knee" as does 36uF plus the 8-ohm parallel resistor.) I think Will completely removed that capacitor on the primary of the toroid; I cannot recall what he said about that. I did not try it.