thank you for starting this thread ! Im about to make the same upgrade on my Inkel MD2200 = Sherwood 6040. Im looking forward to hear more about your upgrade and the sonic effects . I have some Low level hiss on my inkell / Sherwood which is constant regardless output. Do you reconise this from your amps?
At the beginning, it was the necessary repair for one of the 3 beloved Sherwood 6040. It turns out to be a very nice upgrade to the sound too. I completed 2 of the recap. Both show audibly lower noise floor and more open sound. Along the way, I increase the storage capacitance from 20,000uF to 36,000uF per channel which can only help.
I have not try any measurement of the THD/N yet. It may be a while before I do them.
I was very lucky to find the drop-in replacement capacitors. I ordered 12 Panasonic ECE-T1JP183EA from Digi-Key. After Priority Mail shipping and tax, total is just under $114, which makes it less than $10 per cap. It is not to say that removing the old caps was easy. But it can be done with minimum damage to the PCB using the right tools and lots of care. A strong suction desoldering pump is a must. (Many of the cheap desoldering pump may not work due to weak suction.) The amount of solder at high capacity power cap is quite big. After I removed MOST of the solder, I used an old chisel to plie up the cap terminals. I straightened them with a small plier before I removed the residual solder. Sherwood used a small amount of rubber glue on the component side. Rock the cap a little to loosen it. Take the usual care to avoid damaging the soldering pad on the foil side. It is NOT difficult, just do not rush it.
Sherwood used 4 (1/4" thick) rubber pad each under the cap and on top. The cover and bottom plate are pressed against these pads. It may serve the purpose of reducing mechanical noise. I used the chisel to carefully plie off the pads for re-use. I used 3M spread-on glue (on the pads only) to reattach them.
The power capacitors are polarity keyed (4 terminals, 2 active, 2 dummy) which makes it impossible to make mistake. If you also recap some of the smaller caps, watch out for polarity.
Please, share your experience and some pictures once you recap the Inkel MD2200. Best wishes.
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p.s. The DC voltages are not high. It is only 62V for the voltage section and 54V for the output section. With 40,000uF of capacitors in each chassis, it takes a long time to discharge. Before you start any work, check the voltage across each cap. Discharge all of them properly before you start.
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