JM preamp only differences/similiarities.

  1. Home
  2. Forums
  3. Ask Ted
  4. JM preamp only differences/similiarities.

Home Forums Ask Ted JM preamp only differences/similiarities.

Viewing 4 posts - 1 through 4 (of 4 total)
  • Author
    Posts
  • #15175
    AvatarVambo Sound
    Participant

      Hi Ted,
      Can you give me a quick rundown of the difference between only the Mic Preamp sections of the Brick, VC1,VC6,VC2,VC3. (excluding the CS versions)
      I Imagine some have transformers while others don’t… Info like that,
      Thanks a ton!!
      Love my VC3q but was wondering if there was a step up in the other above mentioned models
      Myke

      #15499
      Ted FletcherTed Fletcher
      Keymaster

        This is a brief history of the mic amps in JM equipment…
        The first mic amp was the VC1 ‘Brick’. This circuit was a conventional transformer into a multi-stage integrated circuit amplifier. This gave a very low noise and low distortion amp, very suitable for recording and broadcasting.
        The same amplifier was used in the early VC1 2U rack units.
        In 1999 I introduced a new transformerless amplifier in the VC1 (called the VC1QCS) this was actually very slightly more noisy than the earlier type, but had a couple of huge advantages…. it was almost impossible to overload, and it works very well with very long mic cables. In addition, the distortion is very low and does not increase at low frequencies like the transformer.
        The VC2 was a special low-gain mic amp using a transformer, but the main gain section was a valve (vacuum tube).
        The circuit of the VC1QCS was taken over to the ‘VC Twin’, and became the standard mic-amp circuit; it proved to be extremely rugged and versatile.
        I designed a new version of it for the VC3, with a better ‘feel’ to the mic gain control and this same circuit was used in the VC6.
        The mic transformers used were all made by ‘OEP’ in the UK and were of a type normally used for line level circuits… I configured the circuitry so that the noise, distortion and overload margins were all optimised.

        To complete the picture, I need to mention the present generation of mic amps used in TFPRO gear….. These are all transformer based, but with circuitry that eliminates overload…. present mic amps will easily take +26dB at all frequencies!
        In terms of quality and ‘sound’, there is no doubt that the early ‘Brick’ was very good, but I think it is equalled by the P110. :)

        #15500
        AvatarVambo Sound
        Participant

          Thanks for the clearing a few things up.
          I guess if I never find a brick I can still get the same quality out of an early VC1.
          I REALLY want to get a VC2, but they don’t seem to be around.
          Who deals TFPRO stuff in Canada?
          Thanks…Myke

          #15501
          Ted FletcherTed Fletcher
          Keymaster

            We don’t have any distribution deals in USA or Canada…… I find that with communications being so good, we can service users from the UK…. after all, it’s closer from Torquay to Toronto than it is from Toronto to Vancouver!
            But I don’t have any VC2s!
            But I can do you a good deal on a P110 or a P10. :)

          Viewing 4 posts - 1 through 4 (of 4 total)
          • You must be logged in to reply to this topic.
          Menu