GUIDANCE NEEDED to mod - MARANTZ SA 7001

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Ty ;)

Got my C3 clock yesterday along with a couple more 22,000uF SI's and some sepc for the mech.
Hopefully the 47,000uF Mundorf will arrive today and I'll get all the on board smoothing sorted.

I've got the psu ready for the clock so that will go in tonight along with a sprinkling of sepc. I'll also start looking at the regulation for the mech to see what I can do there.

I've taken a gamble (kind of educated!!) on some 1000uF cerefine caps too. I've not got any large value BG's and so a coupe of the larger post reg caps will get these. The other option I have is some rubycons ZL's but I'll try the cerefine a 1st and I'm guessing they'll stay in!!!! Lol

Already looking ahead to the caps through the output stage and planning mica based on my experience with the DOS and cd63 in general.

Can someone elaborate on the trim pot that can be used to zero any DC offset on the out put (assuming I've understood previous posts) as I do believe the best cap is no cap ;-)
 
Been busy the last couple of evenings! Completed the recap of the main board. Now got 1000uf cerefine after the regs, sepc on the dac vrefs to go with the BG FK's and std sprinkled throughout. I'm also now running 47,000uF mundorf smoothing on the main servo rail and 22,000uF on the others. Clock on its own tx and psu (hexfreds, and another 22,000uF mundorf) and this will get one of my regs to pre reg the line tomorrow. The new C3 is quite an eye opener even without a pre reg and additional jitter that will be present due to 2 buffers inline with the clock feed!

Jobs for tomorrow are to bypass the obsolete logic and feed the clock direct after the buffer (ic405) add some more sepc to the mech and fit the low noise pre reg between the clock and its PSU. I fully expect to hear the difference when this is done. I know the clock is not running in optimal configuration at the moment!!!

All I can say is WOW! This is outperforming my audio aero!!!!!!!!!! It's very full and very fluid and very tight!! Still can't make my oasis cd's sound like the sound engineer could actually hear tho!!!! Lmao......

67a164079f7edba6208c091c794e49bc.jpg


68d2dcef9ffdccb9ba8071429bbab378.jpg


f0d6e80901fdf10e3f442a04b8ff61f2.jpg


366e483f5e65cc41c9a320bc37655d65.jpg


3a90f6a7f07d2c0c36885e0fa230c024.jpg


746c766f546736d92eebecbfa1bed281.jpg
 
You've been quite busy indeed! :D

Good to hear it sounds so great already. I'm planning to do some more work on my 8400 soon. These are very nice players to tweak. There's plenty of room in the case and on the board. Only the PCB under the mech is a bit harder to do. I've ordered some OS-CONs to replace the small 22uF SMD caps as well, it will be a lot of work...

Have you considered replacing the four SMD regulators? The Rohm BA-series is not a very outstanding type of regulator... I used LT1963A for them, they are pin-compatible. The package is a bit smaller SOT-223 housing, but they can be fitted right on the board. Removing the original regs requires some patience though, the metal tab can be a bit difficult to unsolder. The difference was quite audible after the first run of tweaks on this board!

Regards,

Ray
 
Hi ray :) yep, I'm very excited with the performance in this player indeed (nice heads up lee ;) )
Got the clock psu a bit more sorted this evening and put one of my own 5v low noise regs between the PSU and C3. With respect to the SMS regs on the transport, I've ordered a couple of SPowerD's to try in there as my own regs don't do the low drop out required. They'll go in next week. I started the mechanical enhancements tonight while it was in bits too. Lots of bitumen damping and I've also ordered a 5mm aluminium plate for the base (remember this is not the KI!!!) I've added a few more caps on the transport too (still work in progress). Last thing to report is that I have clocked the DSD chip directly. The feed is now connected to a through hole point near the zero ohm link (r435) into pin 11. The through hole is right next to pin 3 of IC734 on the bottom side of the board. I've disconnected the output of the original circuit at IC405 on the other side of the board.

Listening to it now and it's making me smile lots!!!!!!! Cheers ;)

From this
2c7213e63d23f32fb3691258d3e4c502.jpg


To this!!!
29cec4e3e631d5431aa5752b0af31926.jpg
 
You missed a spot! :D just kidding...

The bottom plate is a good idea, the player can use a more rigid housing. A friend of mine with a SA8400 made one for me back then, he has access to a CNC punch machine at his work. He drew up the whole thing in Autocad and made two plates for us :)

Be careful with the ribbon cables from the transport. The bitumen material can be quite static as it is a good insulator. I killed the on-board uC once because the ribbon was dangling and touched the bitumen when I was putting it back together. It blew out a few input pins. Replacing that big SMD controller cost me a lot of sweat...

Now if I want to disassemble the player, I take out one ribbon at the time, first at the transport side and then immediately at the main board side.

Ray
 
Last edited:
Nothing so fancy as something CNC milled for me Ray, but hopefully will look decent enough on the front edge. I'll sandwich another layer of sound deadening between it and the base of the chassis for good measure. I'll be sure to keep my eye out with respect to static!!!!

I've been looking in to the dc offset as suggested a few pages back. Below are the diagrams for both HDAM's. I fitted a 22 turn 5k pot to the emitter of Q612 and Q613 and the wiper onto the +v rail. I was able to trim the DC offset down to about 0.1mV (assuming that my meter is that accurate which is highly unlikely!!!) and bypass the output caps. Nice spot on the HDAMs dannusch ;-)

5d160c3151eaeeb20f76dbacf29dbca9.jpg


40d4224fd543ecd7f8b26c8509e1e46e.jpg


c6d19395c2b2359a9a5e1e90d5fe2252.jpg


I've also added some 0.1uF PPS caps under the board on the DAC too. I can't put it down!!!!!! Lol ;-)
 
Yes, that will work. The input stage is just a common differential amplifier with a current sink, so any unbalance there will result in output offset.

I was just thinking the same thing the other day, my display is quite dim too. It's hardly visible during the day in my livingroom. You should not alter the heater voltage, it's a fixed value for that type display. But the -Vft can be lowered a bit (made more negative) and the display will become a bit brighter. The ML9207 display driver can handle -60V so that won't be a problem. DY65 is the component to be tweaked :)

Ray
 
Mmmm the are a couple more zeners there too. I would like to see what voltages change when you control the brightness but its not easy to establish what's cause and effect!!! I guess it's a nice to have but not important for the audio!!!

I've spent a fair bit of time with the manual on the transport. Looking through the various diagrams and I think I have a plan to replace the remaining caps!!!

I've already done the main reg ones and I'll concentrate on the RF, Decoder, DVD processor, motor driver & ram with the remaining caps I have. Think I need some more to finish the rest! I think I got to about 40 sepc's and a few BG and ZA on the other rails!!!

Hopefully the base plate will arrive later this week. I've also got oak cone feet on the way. Been looking at further splitting some of the rails too.........It's never ending lol!!
 
A little progress.......

New base plate fitted (almost!!!) ;)

64f84e9efd71f832ab874529728448c3.jpg


More sound deadening (like there wasn't enough!)

2ae3183f54ca8d8133e5dc7cde2ffc4b.jpg


Drilled to suit the protruding screws and oak cone feet fitted

ba859723bb8bac71e38f6ada3ea49e2a.jpg


Ignore the cable mess!!!

8c3d6d9537b915145eb1f679160a5444.jpg


Got a couple of SPowerD's to go in along with another 10 sepc's which I may get round to later in the weekend. Just going to listen again now........

Still got a dim display, not sure how to attack that if its PWM controlled by the processor!!!!
 
What vents? I'm sure I'd have noticed any I was covering??????

Very good. My 8260 is well vented in the bottom plate and I assumed the 8001/7001 was same, but clearly it is not. I think I should have revisited your pics as I recall seeing that same pic yesterday.
I'm following this thread for additional ideas for my player.
BTW, are you considering using Ray's DOS for the output stage?
 
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 ;)
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.