Marantz CD63 & CD67 mods list

[Fidelity Audio]

Originally posted by 6h5c


Hi Phil!

Doesn't work?? How's that possible ? Did you screw it up ?

For now, I use the on-board regulators for the discrete stage, which are LM317/337 BTW. Then the series inductors (220uH) and four Elna Silmics that I stole from the output caps. Sounds quite nice for a prototype .

In the definitive version I want to use Black Gates, and maybe a differential FET input stage. When my FET's arrive i'm going to start testing that.

My new CD57 arrived yesterday
Another virgin PCB waiting to be mounted....

Regards,

Ray.

Ray are you trying to get this site shut down with your virgin pic. lol

Originally posted by 6h5c


Hey, what can I say, i'm not into opamps anymore anyway....

Ray.

Fair enough

Brent

[philpoole]

Doesn't work?? How's that possible ? Did you screw it up ?

No, don't panic. I haven't built it yet. I'm implying it won't work because its my design based on your tube version.
I designed it before you published your transistor version.
Its very similar though. A slightly different current source (using two bipolars), 6kohm collector resistors, and I designed it without a buffer, but will put one in - a series feedback pair with a current source (another one, I like current sources ).

I'm just so slow off the starting blocks. I haven't built it yet.

Cheers,
Phil

[philpoole]

Ray are you trying to get this site shut down with your virgin pic. lol

LOL!! Ray, you should be more careful.

[poynton]

Originally posted by 6h5c



Another virgin PCB waiting to be mounted....

??!!?? Really Rowe !! Who has the mind of a sewer then ???


Ray : What's going on this board??

[Griffymark]

This is one hell of a thread and I admit I have not follwoed the whole thing through ;-> .....but what is the conclusion of the best bangs-for-bucks (and for electrical novices!) mods for these players?

Cheers.

[6h5c]

Originally posted by rowemeister
Ray are you trying to get this site shut down with your virgin pic. lol

Brent

Originally posted by philpoole
LOL!! Ray, you should be more careful.

Hey, I was thinking about posting an even more explicit one.

But I have another one that shows some loose parts

Ray.

[6h5c]

Originally posted by philpoole
No, don't panic. I haven't built it yet. I'm implying it won't work because its my design based on your tube version.
I designed it before you published your transistor version.
Its very similar though. A slightly different current source (using two bipolars), 6kohm collector resistors, and I designed it without a buffer, but will put one in - a series feedback pair with a current source (another one, I like current sources ).

I'm just so slow off the starting blocks. I haven't built it yet.

Cheers,
Phil

Hi Phil,

Yeah, well, there's not much to say about a differential stage that's a bit different. It will work fine if you don't use too much soldering poo, like some of us tend to .

Current sink like this? I use it in my tubeamp, works very good. Nice and simple. I feed it off the +350V rail with a 470k resistor, and I've added a 22n cap from the BC547's collector to GND, to get rid of any noise coming through.

Ray.

[6h5c]

Originally posted by poynton
Ray : What's going on this board??

That would be the passive filter with tubestage, since the other CD57 holds the transistor stage. I'm swapping parts right now, and it will make a nice comparison when they are both finished. Then i'm going to decide which stage is going to be fitted in my "real" (CD67OSE) player. That one still has the opamp filter.

Originally posted by Griffymark
This is one hell of a thread and I admit I have not followed the whole thing through ;-> .....but what is the conclusion of the best bangs-for-bucks (and for electrical novices!) mods for these players?

Cheers.

Hi Griffy!

Glad you like the thread. I hate to be boring, but if you start from post #1 you'll get the answer to your question (and lot's more) . I'm afraid you are not the first to ask this....

Ray.

[philpoole]

Hi Ray,

Current sink like this?

That's the one! I like it because its easy to calculate the resistance required, and I 've used it before with good results. I tend to use BC182s (I tend to work at +/- 15V and they seem to work well).

One day, might look into cascoding and stuff, but I've never really measured performance, so maybe its fruitless until I understand the performance improvements?

Anyway, I built it last night on strip board. Now, my 4.7nF caps are relaltively big polyesters (Brent, its okay, I'll replace with silver mica when I'm happy with it ), and I wasn't trying to save much space, but its actually a big circuit board! I'm a bit worried about how it will fit. If I'm really pleased with it, I might rebuild it. It only took a couple of hours.

I did omit the buffer output, because, to start with, I'll be feeding my headphone amp - whose first stage is a buffer just like this (I was saving time there as I'd realised how big it was getting.

Anyway, its built, plugged it into a PSU and the voltages look good. Hopefully I'll attach it to the CD63 sometime in the next few days. Can't wait.

Cheers,
Phil

[philpoole]

This is one hell of a thread and I admit I have not follwoed the whole thing through ;-> .....but what is the conclusion of the best bangs-for-bucks (and for electrical novices!) mods for these players?

Cheers.

I think best thing to do is pick a reasonable one to do (i.e. upgrading the opamps with sockets so you can swap and experiment, or upgrading PSU caps) and take it from there.
I reckon you'll get hooked and want to take it further.
I've been modding mine, on and off, for over a year now, and I keep coming back to it.
Half the fun is working out what the next mod will be.
Look at Ray's and Brent's docs for inspiration (they're both somewhere in this thread).

Bang for buck mods. The cheapest ones (i.e. free) are probably removing the muting transistors, shorting the output caps, removing/bypassing the HDAM.
You can get a lot of mileage in other mods (many cost just a few pounds, some don't), and you shouldn't discount a decent clock. This can be pricey. However, there are different costs here. Mine's a Kwak Clock, and I built it myself for about £20-£30.

Cheers,
Phil