GUIDANCE NEEDED to mod - MARANTZ SA 7001

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I've got a a few DOS boards inc your CFP but with a slight modification that I built for my old 63. I quite like the the output stage in this player and being fully discrete and also knowing what Thomo achieved, I'm going to use the original circuit to start with. I will swap the filter and signal path caps and replace the regs with my own but right now I'm concentrating on the transport. Not enough hours in the day for me the moment ;)

If you use my board, be sure to either turn T7 and T8 around if using a pin 3 emitter transistor, or else use a transistor with pin 1 as emitter.
 
I guess it's just the input filter that just needs adjusting ;)

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Little update!!!

No change on the dim display but a rework of the entire output stage with 1% mica (except the 1200pf which is 1% styrene because I couldn't get mica!). Just waiting to listen now!

Also before Xmas, I added the SPowerD's (3) onto the transport. Not only are they ideal here due to the very low dropout, they are absolutely superb!!

I've also now added another 10 SEPC's. This player is really quite sublime now! Still got a few bits I want to do too!!!! I think I might also fit some HDAM covers too as I have spare. Don't think it will make any difference but it might look nice lmao!!!

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Cheers :D

I also got rid of the original transformer by adding an additional winding for the display to the new output stage transformer. Still more I want to do like the final caps on the transport and I've still not regged the output stage. Now I have a higher voltage transformer, its next on the list! I'll probably drop another reg onto the DAC too like in Lee's :D

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Very nice.

What VA tx's have you fitted there then?

Lee.

9v 7va both windings for the clock 0.778A
12v 30va both for servo (3AC11 and 5AC11) 2.5A
12v 30va for audio output stage (8AC12 and 10AC12) 1.25A for each rail
Additional winding for the display
9v 15va both windings for the rest (1AC8 and 2AC8) although I want to split the supply to each bridge and add another transformer.

Not sure it's optimal yet but it's what I had available.




You've got an extra winding for the display heater on the tranny for the analog output supply?

I wouldn't do that, the heater voltage is directly connected to the -VFT voltage for the display. This will inject large amounts of noise from the display controller in the analog supply :eek: You should keep the analog supply as clean as possible.

Ray

I did ask the question elsewhere with respect to transformer windings but I wasn't specific enough with the initial question and there was very little "advise" given with respect to adding additional windings. Surely it can't be any worse that the original set up??? Ultimately, I will add another small transformer for the display :D
 
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