Home
AudioAsylum Trader
Tube DIY Asylum

Do It Yourself (DIY) paradise for tube and SET project builders.

For Sale Ads

FAQ / News

 

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


Login to access features only available to registered Asylum Inmates.
    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: Bypassing Output Caps in Preamps

Posted by Sector-7G on September 28, 2002 at 13:50:48:

I did understand the amp in question is a phono pre. The input impedance of the linestage is the important thing. At 20 Hz it must be large compared to the 8 kOhm impedance of the 1 uF cap. 100 kOhm is probably enough, but, the linestage folks with 100-200k imput impedance amps still want around 3uF of output capacitor. Just try a 20:1 ratio,so your linestage will want about 150 k Ohm impedance, if not then increase the cap size and use a good one. SCR Tin and polyprop is a good palce to start and they come in 1.5 uF size. The internal circuit mods may be necessary if this( 20:1 linestage input impedance to cap impedance ratio at 20 Hz) does not help, as I would then say that it's not the cap causing poor bass response.

the small TFE will probably not help bass much as you mentioned but I'd try it anyway if they are relatively easy for you to get, the better performing the cap the better the sound.
regards,
Douglas