Jo Sharp
Pulls on doors marked push
I've managed to buy an Olive NAIT 2 in good condition as a Lock-Down project. It seems to be in good order and when powered up does not make any unpleasant noises - no scratchy volume or balance pots.
DC readings on the speaker sockets are both under 6mV. Plays music with no nasty sounds, so I think I have a good starting point!
All caps seem to be original factory fit (Elna 6800uF power caps without date codes - ROE purple caps in Pre-amp section etc) so no recap since built in approx 1990. Holden and Fisher Transformer. Inspection sticker initialled by JLC.
Here are some thoughts on what work I'm planning:
1. The mains plug earth connects to the 0V signal line - so when using a Naim CD player I'll get an earth loop. Will therefore disconnect the NAIT mains earth line at the plug.
2. Can't find Elna 6800 caps online - replace with Kemet 6800s or Vishay 10,000uFs?
3. Roederstein 47uF in pre-amp - can use some NOS ROEs or Nichicon Muse. Are the NOS going to be as good as the Muses? Take the feedback caps 0V line back to main star 0V point.
4. The various 10uF alu electrolytics can be replaced with Rubycons (50V) and Elnas (35V). Or use film caps for the Input/Output DC blocking?
5. Thinking of fitting Gyrators on the pre-amp supply lines in place of the 27R filter resistor. Probably not enough power rail voltage to allow a 317 type reg.
6. Thinking of doing the pre-amp power rail mods - which resistors to split and what value caps to add?
looking forward to comments and suggestions from the DIY gang.
DC readings on the speaker sockets are both under 6mV. Plays music with no nasty sounds, so I think I have a good starting point!
All caps seem to be original factory fit (Elna 6800uF power caps without date codes - ROE purple caps in Pre-amp section etc) so no recap since built in approx 1990. Holden and Fisher Transformer. Inspection sticker initialled by JLC.
Here are some thoughts on what work I'm planning:
1. The mains plug earth connects to the 0V signal line - so when using a Naim CD player I'll get an earth loop. Will therefore disconnect the NAIT mains earth line at the plug.
2. Can't find Elna 6800 caps online - replace with Kemet 6800s or Vishay 10,000uFs?
3. Roederstein 47uF in pre-amp - can use some NOS ROEs or Nichicon Muse. Are the NOS going to be as good as the Muses? Take the feedback caps 0V line back to main star 0V point.
4. The various 10uF alu electrolytics can be replaced with Rubycons (50V) and Elnas (35V). Or use film caps for the Input/Output DC blocking?
5. Thinking of fitting Gyrators on the pre-amp supply lines in place of the 27R filter resistor. Probably not enough power rail voltage to allow a 317 type reg.
6. Thinking of doing the pre-amp power rail mods - which resistors to split and what value caps to add?
looking forward to comments and suggestions from the DIY gang.