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Old 27th Oct 2021, 4:29 pm   #2
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Join Date: May 2009
Location: Stevenage, Herts. UK.
Posts: 1,120
Default Re: Bell & Howell 8D-655, amplifier question

The 8D prefix marks when production of the Anglicised projectors moved from the UK to Japan. I have the 8D644 which is based on the 644, the amplifier is still valve based but has been changed to use a solid state doubler rather than an EZ81 for HT rectification and a transistor has been added as an extra preamp stage for the optical sound.

The following TQ1 series used a low voltage lamp for greater screen illumination and all transistor anplifiers.
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