GUIDANCE NEEDED to mod - MARANTZ SA 7001

[trehansid]

Hi friends,
My name is Sid. I am relatively very new to the forum and further to my two posts since last two days, i felt its better to start a new thread, since i would
rather ask questions, take pointers-views from fellow friends in here.

In my last posts, i had advised that I have Quad 99/909/11L2 with which i have Marantz 7001 as a source.

I was convinced with Ray's suggestions and hence going ahead with a few mods. And i had hence placed the order for the Black Gate & Nichigon caps to be going into the 7001. They have arrived and am thankful to Michael Percy to have been a thorough gentleman to have sent the stuff in most professional manner, everytime that i have bought from him.

Now,

1) Guidance on Mods that the 7001 can handle.

*Ray, may be you could take time out and assist please? or other friends who have handled this player.

I have the mod sheet enlisting parts, as published by Ray on his site. I just want to know which of the mods will make substantial change to the music.

If,
- I donot want bass to go heavy (as i 909's mods have taken care of it)
- A larger Sounstage is a miss probably as of now.
- Imaging is good for the price but certainly can be improved and you could advise on the needed mod for that please.
- I am yearning to have to give more body to the instruments.


Over to you.

Many thanks
Sid
..

[6h5c]

Originally Posted by trehansid

Thanks Ray.

Its only ur mod list and words shared on the website that got me some confidence to try n open my beloved player.

Might bother you again. Have actually started a new thread as didnt want to mix things up here on the thread. Over there, i could share pics of the board and my views post the listening session.

Pleasure to be here and many thanks for your kind words. I shall certainly follow pointers shared in here by you and other friends.

Thanks once again.

My regards
Sid
..

Ok, I added your new thread to my list

This is interesting, as I don't know a lot of people that tweaked SA7001/8400 players.

[trehansid]

ah, thanks so very much Ray.

Ideally, what do you suggest for the Phase-I that should be done w.r.t the mods.

What i wanted to ask is that per your experience, there could be a few mods that would work well together.

Pls let know. So that i can ask my friend to proceed per your advice.

brgds
Sid
..

[6h5c]

The 7001 sounds quite thin out of the box, and everytime you change a component for something better, some part of the nasty things you mentioned will go away.

As there are no opamps in the player (that would be a very easy swap), all easy things you can do is improve the power supply and the discrete HDAM circuit. In the end it may be better to replace the entire HDAM-thing by the DOS output stage, but maybe that's a bit too bold for now.

So that means replacing the electrolytic caps around the DAC and in the HDAM power supply, the caps after the rectifier diodes and after the regulators and not to forget the diodes themselves. Second stage could be the analog filter capacitors in the 'output filter' section of my list. As you can see, there are a lot of capacitors on the list, and it's best to start with the ones in the first section under 'Power supply'. Just work your way down the list and see what it does with the sound.

I'd leave the original regulators in for now, and don't replace too many components at once. A good clock can be added later, when the virus has it's claws in you...

A few good ones to start with are the 'remove only' mods. Those are the muting transistors (QN61 to 64) and the output caps (C616 and C666). Well, the two caps have to be replaced by a wire actually, but this will give some audible result quickly.

Ray

[trehansid]

Thanks for this Ray.
I have read about clocks. But whats the ideal for 7001's electronics? I may consider that in parallel if i may afford it and foremost ...if you approve of it.

Wishes
..

[6h5c]

Hi Sid,

You're welcome! The SA7001 needs a 33.8688MHz 3.3V clock signal, and any decent clock or oscillator that can provide that, will probably be an improvement over the standard on-board crystal. A simple and effective solution is to use a Tentlabs XO oscillator-can, I have good experience with those. You can then choose to use a simple discrete voltage regulator to feed it, or to go fancy and use a Tentlabs shunt, or build a Flea power supply for it. A cheaper solution is to use a standard oscillator instead of the Tentlabs, which also works very well if you pick the right type. They can be difficult to obtain sometimes. If you are on a really tight budget you could build the CD-clock FET oscillator with the original crystal. So there are plenty of possibilities here.

Regards,

Ray

[Thomo]

I modded my SA7001KI yesterday and discovered a simple, free tweak that really gave a large gain in sound quality.

I took the signal straight after the "Low Pass Differential" stage of the output section, and bypassed the HDAM and Current LPF sections. This really opened the sound up, and the bass is crazy in it's depth and power. It's not perfect as I'm pretty sure the filter is incorrect now, but it's a whole lot better than before.

Lee.

[Thomo]

I took the signal from the dac side of R622 and R672. Another benefit is that it has only a few mV dc offset and so doesn't need DC blocking caps, which is nice.

Lee.

[trehansid]

Ray,
Whenever you are free, please let me hear from you in detail on possibly a few (about 3) options on clock w.r.t. price & source please. Also how to go about power supply for the same?

And any mods, that i need to do before the clock's introduction.


Many thanks & appreciate your attention.
Wishes
..

[trehansid]

Lee,
Thanks very much for your input.
What amplification have u plugged the source with.

Wishes
..