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Nac92/90.3 Service+

I'd be interested to know what capacitance value the old ones are now giving.

I've just tested the old Tantalum and Reservoir capacitors and they measure as follows (LC = Left Channel etc):

LC 10.23μF / 0.83Ω Buffer In
RC 09.96μF / 0.81Ω " "

LC 09.81μF / 0.85Ω Buffer Out
RC 10.09μF / 0.79Ω " "

LC 10.16μF / 0.92Ω Gain in
RC 10.03μF / 0.71Ω " "

LC 09.73μF / 0.90Ω Gain Out
RC 10.02μF / 0.83Ω " "

LC 10.52μF / 0.74Ω Poweramp In
RC 10.16μF / 0.76Ω " "

LC 49.16μF / 0.56Ω Poweramp Feedback
RC 50.53μF / 0.68Ω " "

317 10.23μF / 0.75Ω
10.67μF / 0.70Ω

92 4399μF / 0.15Ω

PSU 9834μF / 0.15Ω
PSU 9742μF / 0.09Ω

I wasn't sure if my tester was out so I ran a few new caps of various brands and ESR and the all sit close to the data sheets.

I thought the Blue 10μF Tantalums (Panasonic?) Naim used were around 1-2Ω and tended to increase with age?
 
Soldering complete:

10uF coupling Tantalums were replaced like for like with Kemet beads. Rail decoupling for Sanyo OS-con 47uF. Feedback pre/power replaced with 47uF Nichicon KZ. Output Transistors decoupled with 470uF KZ's. BHC/Kemet ALC 10,000/3,300uF for PSU. Removed the Phono boards and replaced the Mica/paste for new as they were past their best.

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Initial impressions were disappointing. I thought I must have a polarity wrong somewhere but I triple checked everything and all was correct. I left it playing on loop for an hour under load and there was a vast improvement, strangely though it seems to have lost the edge on the mid kick it had and the low notes seem to be a bit much, but worth the time if only to know the reservoir caps are within spec. Suppose time will tell on the rest?
 


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