On an undertaking of this scale it's important to add a light/dim bulb limiter to the start up procedure, plenty of links out there explaining. A socket spliced into an extension cord with wire nuts is plenty fine. In this day and age might need to mention must be incandescent, Edison base halogens should work, I never tried. Hopefully save some Naits for the next generation of fiddley monkeys to let the smoke out.A few more tweaks added -- all the above and some extra material on setting bias, including a video.
how about replacing that rectifier with 4 diodes instead? generally and IME, it benefits in better musicality (and in the other hi-fi attributes, as well)...Only one suggestion - you might want to consider changing the 6A/100PIV bridge rectifier when you next have it apart...
positioning them vertically is doable. and yes, no problem with the original rectifer, agreed - but here the aim is better sonics, ain't itOnly tiny space allowance - about 18 x 18mm.
- and there;s no much wrong with the original, imo.
I have not changed anything that canāt be undone. I even have a bag of NOS Roe caps should they be needed.Jo - seriously - don't butcher the amp. PM me - I'll buy it from you.
Another huge win - if you find it has too much gain then snip the 1k resistor in line with the 47uF feedback cap in the preamp. The gain stage is now a buffer instead and can use far more of the not-very-well-tracking volume pot.
It's a tiny TO92 with 2 tants next to itInteresting Pete, there's no 317 that I can find...thereās just the large 2700uF axial cap on the pre-amp rectifier diodes output which feeds both channels.
You can, although replacing it with 3k3 might be a better compromise.Can I do this also to the NA321 or even to a Starfish?
Some have gone with mounting blue alps to the front panel upside down with short leads to the PCB.If I can pile in: I was looking at this last week (see photo) and wondering if it was worth some time to get up and running. A few bits missing Vol and balance pots (blue alps will not fit) and some output transistors.. Then I stumble on this thread...sounds like it's worth a little TLC, all be it a Nait 1
Anyone know where I can source a Vol pot that would fit and best modern outputs if any.
TIA
Used exactly that cap. Now wondering about the CCS mod.......And for goodness sake please replace that awful radial cap supplying the pre-amp. Axials are available still https://www.mouser.co.uk/ProductDetail/Vishay-BC-Components/MAL202117332E3?qs=herSbFlu8j2m%2BUN59NsjgQ==