I just completed the mod. All I can say initially is Wow, what a substantial difference in the sound. I listened to some FM and 2 albums (Heartsfield and the Beatles blue album). Vert crisp, clean highs and smooth bass...
My only issue I had was I ordered the wrong caps for the Flat amp C25 and C26 so I reused the original caps. I checked and double checked the list before I placed the order with Mouser and still missed them; right size wrong type (should be Nichion Muse). I don't know if the originals have that much effect on the overall sound. I will order the correct ones with my next order and replace them. One other notable issue are the 1uF Panasonic stacked polyester film capacitors are no longer available. Neither Mouser or DigiKey carries them.
I also want to thank Leestereo for all the upfront work to make this mod a reality. Thank you.
Don't know if you got it Dave but I sent you a PMFor those following this thread I placed my order for the additional Muse ES bi-polar caps for C25 and C26 (that I mis-ordered) plus the 2 new ones by the subsonic filter switch C18 and C19 last night. Once I get those replaced and do another "sonic sound" check I'll upload the completed component list. I'm thinking by Friday it will be available. I hope the delay is acceptable.
Sounds good Dave. I was just gonna take em off your hands if you had no use for them. Will do on your above recommendation.Sorry I am out of town on business and haven't kept up with my emails. I have another C1 I'm going to mod, plus recap my M2 and it has several 1uF 50v, plus my RT-707 reel needs 4. I am going to hang on to these. On eBay they are 7.99 for 25 that may be better for you if you are modding 3 plus having some spares.
Dave
I have often found that the preamplifer impacts the final "sound" of the system more than the power amplifier. In this particular case, the changing of the active devices (the op amps), probably accounts for most of the improvement/change.I'm *assuming* that the biggest bank for the buck is doing the C1 updates?
If the main power capacitors are retained, the updates to the amplifier board are quite easy to do and the solder side of the board is more readily accessible in the M1 compared to the C1.Looks like the M1 updates (even though there are fewer parts) are more complex.