Amp/Preamp Asylum

Looking for a new Amp or Preamp? If you're after tubes, post over here.

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: Actually

Posted by Charles Hansen on April 13, 2006 at 12:06:03:
I'm not quite following you. You are presumably using VTL MB-450 amps. The passive preamp is apparently a DACT stepped attenuator of unknown value. I'm unclear as to what active preamp you are using, and also what sonic differences you found between the active and the passive.
I guess what would be relevant would be the result of your listening tests of (say) the DACT stepped attenuator versus (say) the CJ ART2. I have not done this specific comparison, but I would imagine that the CJ would give better overall sonic results in most systems. And at the same time, I'm sure that the DACT would give very good sonic results in many systems and would be far and away a better value.
As an aside, please note that an active preamp will have a constant output impedance, regardless of the volume setting. On the other hand a passive will exhibit a variable output impedance that depends on the volume setting. For series attenuators (such as the DACT), the highest output impedance (ie, maximum interaction with cables and power amp) will be 1/4 of the input impedance, and is achieved at a volume level that is 6 dB below maximum. (This is typically in the range often used for listening.)