DIY Audio Designs -- Crown POOGE's -- The IC150A Preamplifier
Crown IC150 POOGE -- the Rationale:  

 

Pre-POOGE pictures  
This crown was in beautiful cosmetic shape both inside and out.

Not too happy with this setup for the input connectors - -

all of the RCA jacks are connected to the chassis.

Step attenuator was in very good shape, as was the selector switch

The accessory a.c. connectors are pretty superfluous.  Space in the basement for some high performance regulators.

The LM301 opamps were au courant back when I was in college -- the Siemens Silvercaps are really wonderful devices, however.

Transformer is shielded,  In our initial testing we could detect some line artifacts with the spectrum analyzer. It is likely that these result from placement of the power supply rectifiers, filter caps and voltage regulators on the main printed circuit board.

   
   
 
   
Some Pre-POOGE performance analysis:
Frequency Output Voltage THD+N%
     
     
     
Spectrum plot from 20 Hz to 100 kHz -- note that the vertical resolution is 0.05dB per interval.

Distortion Residuals -- 10 Hz to 500 Hz -- 100 mV output.  Note power supply artifacts:

Distortion Residuals -- 1kHz input signal, 1 Volt output.

   
Distortion Residuals 10kHz 1 Volt output.

 
 
Schematics (Link to Big Schematic)
 
 
 
 
New RCA Jacks Installed