Dear all,
I'm operating an vintage ML LNP-2 pre-amp with the meters.
All line sources work fine but one phono-channel is almost dead and the other one works fine.
Strange thing is though that apart from the two Dick Burwen VU modules all modules are the same Line Drivers LD-2 or Fet Input Amplifier Module as they are called.
I've no glue how they get any RIAA correction and what extra phono-stage there is because I can't find any active part apart from one little IC.
Is anyone familiar with this pre-amp and perhaps knows how the phono (MM) works?
Thanks in advance,
Robert
I'm operating an vintage ML LNP-2 pre-amp with the meters.
All line sources work fine but one phono-channel is almost dead and the other one works fine.
Strange thing is though that apart from the two Dick Burwen VU modules all modules are the same Line Drivers LD-2 or Fet Input Amplifier Module as they are called.
I've no glue how they get any RIAA correction and what extra phono-stage there is because I can't find any active part apart from one little IC.
Is anyone familiar with this pre-amp and perhaps knows how the phono (MM) works?
Thanks in advance,
Robert
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Your picture of the units bottom shows the RIAA caps soldered under the modules. Swap the phono modules and if the problem reverses you have a bad module. Our unit had no phono modules so I came up with a two-IC plug-in replacement. Then, did get the phono working using the ML-1 RIAA feedback circuitry. I doubt that the "simple" phono circuit in your LNP (and the schematic) followed the playback curve very well.
ML did have two different amplifier modules. The LD was made for output/driver purposes and was used for the record amp module in their ML-5. The other module was for higher gain preamp circuits.
ML did have two different amplifier modules. The LD was made for output/driver purposes and was used for the record amp module in their ML-5. The other module was for higher gain preamp circuits.