P50 and P90 Passive Pre-Amplifiers
For turntable use you must use an NVA Phono 1 or Phono 2 external phono stage or equivalent. All 6 inputs are identical and hardwired to the selector switch using silver alloy cable with PTFE cover. The output of the switch is routed to the potentiometer and tape socket again with the silver alloy cable. The potentiometer is a very high quality cermet type 100k ohms linear with 10k ohms precision metal film resistors as by-pass to simulate log law. The signal is then routed to the output sockets using Sound Cord. There are three sets of output sockets in parallel to facilitate Bi or Tri amping. This pre-amp is entirely passive, this combined with the cermet pot means that there can be surface noise from the pot when being moved, this is normal. Cermet track is not as smooth as as conductive plastic film or carbon tracks but has a far superior sound quality.
Not all Power Amplifiers are suitable for use with a Passive Pre-Amp and the manufacture should be contacted to assess suitability.
The case design has been created for sonic reasons and is glued and insulated to stop induced circulating currents and static charge problems associated with normal case designs.
Move up to any more expensive NVA amplifier for just the difference between the two purchase prices.