deHavilland / KE Engineering

Model 222 MkII 

Vacuum Tube Magnetic Tape Playback Preamplifier

"We master hundreds of tapes a year, and Kara's 222 tape preamp is our "GO-TO"

preamp when we do our mastering. It always is the most musical and best sounding

to make our titles the best they can be. It is a primary key in our mastering chain

 to get the best sound for our releases."

----Robert Witrak, Chief Engineer, High Definition Tape Transfers (Oct. 2018)

         

 

 

 

    "Pardon my Corroboree, [Antill on Everest Recordings] but the sound

        was istakootik (that's how Corroborees say f**king) fabulous. The depth

        was tremendously exciting, the air around instruments nothing short of 

        amazing. The sound was just as involving as I've always experienced from

        deHavilland electronics, and gratifyingly less dark. It was analog heaven 

        without the $15,000 phono cartridge and the $150,000 platter. 

                       -- Jason Serinus , Stereophile Online Dagogo 2010 report.

 

 

              I wanted to include this note from a customer:

 

                Hi Kara, I just wanted to let you know that the Model 222 arrived safely,

          and itís sounding wonderful in my system!  It took me a while to get the heads

          wired up directly, and I had some hum/grounding problems ó but now all sorted out.  

          Thereís a lovely purity and clarity of tone to the tape sound now, and the overall dynamics

          are fantastic.  

                By the way, I love those NAB/IEC trim  pots: being able to adjust the treble is really

           useful, especially on Dolby tapes that otherwise often sound a little dull. 

           Also, I've tried running the 222 directly into my Macintosh 275 power amp:

           this really does give the best sound of all! For serious tape listening sessions,

           this definitely seems to be the way to go, even though it means re-routing 

           signal cables at the back each time. 

                So again, many thanks ó this is a beautifully built preamp

           and Iím delighted with the sounds coming out of my tapes now.

                                   Cheers,      Robin M , Taiwan , May 2016. 

 

    Model 222 MKII New Features:

    The MKII preamp has a wider chassis with better isolation of power supply components from the 

    high gain section. The new preamp incorporates three standard EQ choices and has an improved 

    head amp design. The gain is now switchable between 52 and 58dB. 

     

    Engineer's Notebook:

         The Model 222 preamplifier was developed out of my experience of owning

     many tape machines. My favorites were the full-on studio tube units from Ampex,  made 

     during the 1960s. If you look carefully at the jacket notes on RCA Living Stereo reissues, 

     they will proudly proclaim "mastered on an Ampex 350-3 or 351-3." 

     I based the sound and circuitry on these designs, and distilled them into this

     preamp. It achieves the huge, friendly Ampex sound -- and is actually more

     transparent and far quieter than the original , and in a compact form that  will fit in your

     livingroom !  

     Specifications:

    * Three Standard EQ settings switch Selected : NAB 15ips.,   IEC1(35us, 15ips.) and IEC(70us) .

    * Separate front panel HF trim controls for NAB and IEC.

    * Output level controls for each channel , mil-spec potentiometers throughout.

    * Gain switchable between 52 and 58db. 

    * 68 dB signal-to-noise ratio

    * Output approx 1v RMS for 0 dB tape level 250 nWb/m, 1.4mV PB head.

    * Vacuum Tube circuit with tube rectification.

    * Class A bipolar pre-preamp onboard

    * Rear panel RCA jacks standard.  

         (XLR jacks available for small upcharge. But unit remains single-ended topology.) 

    * Output topology is SE.

    * Tube Complement:  (2) 12AX7 (1) 5687 (1) 6X4

    * Standard output coupling capacitor, Sprague vintage series 118P Paper-in-oil. 

    * IEC power receptacle

    * Size: 18" x 10" x 4-1/2" , shipping weight 20 lbs.

 

    * Pricing Model 222 MKII  , $2295 plus shipping .

    * Options: Input XLR jacks, $60 upcharge, Output XLR jacks $60 upcharge 

    

 

 Contact Kara Chaffee directly at deHavilland .

 

            Additional Photos:

              

            222 MKII standard rear panel 

 

                222 MKII front panel EQ and Switches 

 

 

             Application notes:  Tape Heads and Tape Transports

 

    The Model 222 is designed to work with "classic high-impedance" tape heads as well as modern tape heads found in solid state tape decks.  A typical tape PB head from a tube type Ampex was a "high impedance" head with an inductance of 500 to 1000 mH . Later era PB heads range from 100mH to 400 mH inductance. With very minor adjustment, the 222 will accommodate heads below 100mH .

 

     Any tape machine in good working order can serve as a transport. Some machines such as the TEAC 7030 and 6010 have direct play head outputs. These cables are on the rear panel of the transport, and can simply be plugged into the Model 222, and you are ready to plug and play, without any modification needed.

  

    Any tape machine can have the PB head output disconnected from the onboard playback electronics, and this output can be routed to connectors/jacks on the rear panel . A good bench tech should not have any problem doing this. It is a minor modification. 

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