July 20, 2012

• conrad-johnson Premier 140 Amplifier: Part 1

  My Premier 140 amplifier has finally returned from its month-long stay at the conrad-johnson design, inc. facility in Fairfax, Virginia.  The amp was having some repair work done and what they refer to as a C1 Capacitor Upgrade. 

  The upgrade entails the installation of proprietary CJD Teflon capacitors about which their web site says:

  “The latest CJD Teflon* capacitors offer unique materials and construction simply not available in other capacitors. The dielectric film is a proprietary DuPont Teflon* film made to our specifications. A proprietary copper-rich end spray optimizes the electrical contact between end-cap and foil. Even the leads and solder for attachment were developed specifically for conrad-johnson. Our capacitors are fabricated by a top manufacturer with a proven commitment to the manufacture of audiophile quality capacitors. The CJD caps are hand wound by technicians with twenty years or more of experience, and each finished capacitor is subjected to inspection at three separate QC stations. These unique capacitors are, to the best of our knowledge, not equaled by any other capacitor available today.”

  * Teflon is a registered trademark of E.I. DuPont deNemours & Co

   

  These are the basics regarding the Premier 140:

  • Power: 140 watts per channel from 30 Hz to 15 KHz at no more than 1.5 % THD or IMD, both channels driven into 4 ohms (also available connected for 8 or 16 ohm loads)
  • Sensitivity: 1.1 volt rms to rated power
  • Frequency Response (at 10 watts): 20 Hz to 20 kHz, +/- .1 dB
  • Hum and Noise: 104 dB below rated power
  • Input Impedance: 100 KOhms
  • Tube Complement: 1 6922, 2 6N30, 8 6550
  • Dimensions: 19D x 19W x 8H inches
  • Weight: 85 Lb.

   

  As you can tell from the last two bullet points, this is a big and heavy sucker.  It also generates enough heat to raise the temperature a couple of degrees in a medium-sized room.  Handy in the winter, not so nice during the summer.

  The following professional review of the Premier 140 from the February, 2004 online magazine SoundStage!, is recommended to those readers looking for additional information and thoughts on the amp.  I find it particularly useful in that reviewer paired the amp with the c-j Premier 16LS preamplifier, the original incarnation of my own preamp.

  Here are some photos documenting its arrival and set-up at my apartment:

  Lassie comes home                                                                           I manage to get it out of the shipping carton
       
  

  Rear view:  note single-ended connections                                           Uncaged
       
  

  One of the new capacitors                                                                  Hoisted onto the rack
       
  

  All dressed up
  
  

  From left to right, the rear features the right and left RCA input connectors, the serial number and model plaque, right and left 1 amp fast-blow fuse holders with problem lights, right and left 5-way speaker binding posts, and the IEC receptacle.  The front of the amp has a single rocker switch to power the unit.  There is no standby mode.  conrad-johnson recommends and supplies two rubber O-rings for the single input tube to help dampen vibration and the resulting microphonics.

  This is going to be a protracted break-in period for the Teflon capacitors.  Estimates for full break-in range from 300 hours (conrad-johnson) to 1,000+ hours (owners).  The next installment will cover my initial impressions using the stock input tubes (1 x 6922EH and 2 x Sovtek 6H30) and the 8 SED =C= 6550C power tubes.

  Stay tuned.

   

   

   

  • 9:26 am
  • 3 Comments