Marantz CD63 & CD67 mods list

[SimontY]

C1 on DAC gives a large boost, divide-by-2 on servo gives a large boost, dedicated clock on servo gives a further large boost.

So the answer is yes, a divide by 2 circuit works well, but there's even more if/when you can afford it.

Simon

 

[Fidelity Audio]

Simon has pretty much summed it up, thanks.

The divide pcb comes with wires attached for ease of use but I do recommend using a thin coax from dac clock to divide input for that little extra detail.

Brent

 

[Fidelity Audio]

Hi Brent

Before I upgrade with a clock, I want to replicate your modds regarding the Servo +5v psu.

Can you suggest a TX ?
Should I use an encapsulated or a nude toroid type?

Also, can you explain how you fixed the front TX (the ones almost in contact with the display pcb) on your machine ?

I believe I will get a lot more detail and attack by feeding the servo on separate tx and two sregs.

Thank you for the inspiration and guidance.

Regards

Ricardo

Better off with a fully nude tx, you get a larger VA for the same physical size and similar cost.

My front txs are sat on a pcb which is on pcb stand offs.

You will love this upgrade

Brent

 

[jimh0612]

Increasing opamp supply voltages

I read somewhere that increasing the supply voltage for the opamps can improve the sound (unless you increase it too much!!).

I've got LME49720, which I think are just the renumbered LM4562.

Any comments or suggestions please?

 

[RCruz]

Better off with a fully nude tx, you get a larger VA for the same physical size and similar cost.

My front txs are sat on a pcb which is on pcb stand offs.

You will love this upgrade

Thank you Brent

Should I use 3.2VA or a 5VA can give better resuls ? They seem almost the same height.

Regards

Ricardo

 

[SimontY]

Should I use 3.2VA or a 5VA can give better results?

Ricardo,

1) Use the bigger one if it fits.
2) To get a "u" with umlauts you can type "Alt+0+252"

Simon

 

[RCruz]

Alt+0+252 = ü

Thank you Simon.

Can you suggest the best way to avoid ground loops ?

Should I use a unique common ground for the new TX and the two sregs on the servo ?

Ricardo

 

[SimontY]

Re: Increasing opamp supply voltages

I read somewhere that increasing the supply voltage for the opamps can improve the sound

I've heard of this. I think the distortion (the measured variety) drops with increased supply voltage. You could drop +/-15V regs in as the supply is +/-20V. Just make sure the caps are appropriately rated, preferably 25V.

ü

Über 😎

 

[SimontY]

Can you suggest the best way to avoid ground loops ?

I'm not the best person to ask, but once again for anyone reading I'll point out that external transformers can cause noise and ground problems (even whilst otherwise sounding great).

I'm aware that yours are internal, so as long as you're using a main star earth and mini star earths in the extra supplies things should work well. There are some good sites about that explain how it should be done (but I can't think where I saw them).

Simon

 

[jimh0612]

Thanks Simon.

Hadn't thought about the caps.

Was about to fit 470uF/16v BG STD I just got from Thomo.

I've got 470u/35v Silmics removed earlier (physically a bit large) or 100u/25v Cerafines from my CD50. The Cerafines haven't had much use, but they could be a bit small (got 6 though!).

Do you think I'd be better at 12v and using the BG's?

Jim

 

[RCruz]

über

Thank you again

 

[SimontY]

Do you think I'd be better at 12v and using the BG's?

Why not 14 or 15v and use the BG? 😉

I'd run 15V on a 16V cap any day, but some others wouldn't.

Simon

 

[jimh0612]

Yeah, I'd heard you like the smell of smoke!! 😀

I know it's within the range, Ray usually recommends leaving headroom, but it'd be a shame not to use the BG's as Brent especially feels they are a great match for the opamps.

I might just be a wuss and use the Silmic for now.

Sorely tempted though - I'm prone to taking risks myself! Tee Hee!

 

[6h5c]

I even run the 470u/16V at....... 16V! in my SA8400
Sounds good and they didn't pop yet 😀

Ray

 

[Thomo]

I reckon you'd be ok at around 16v with the BG's. A lot of those cheap Chinese made valve amps have been running 400v caps at >480v!

Lee.

 

[Fidelity Audio]

I've found Blackgates run @ max voltage no problem, cheap caps would start to bulge. I have run one blackgate 16V 1000uF @ 21V (by mistake) and realised my error weeks later. I took the cap out and it measured correctly!! I was quite amazed.

With regards to opamp voltage, well I have tried 12v 15v and 18v and the difference is slight, maybe a tiny bit more dynamic (and im talking tiny) on the higher voltage. Use 15V and the 16V BG.

Brent

 

[Fidelity Audio]

Thank you Brent

Should I use 3.2VA or a 5VA can give better resuls ? They seem almost the same height.

Regards

Ricardo

Use the 5VA ;-)

Can you suggest the best way to avoid ground loops ?

Should I use a unique common ground for the new TX and the two sregs on the servo ?

Ricardo

Always try to run all grounds to one common ground point. There is a large star point on the +10V rail before the 5v reg thats ideal or some people use the rca output star.

As long as they all go to the same point you should avoid loops

Brent

 

[jimh0612]

Opamp voltages

15 v and BG's it is then!

Thanks for all the advice guys.

Will post when its done with comments.

The opamps are already pretty well burnt in and sound so much more detailed and smoother than the OPA2134.

I've biased them into class A but not sure I can tell much difference if I'm honest.

Jim

 

[Fidelity Audio]

I found a slightly better attack to the sound running mine in a class A stylee. But like you said it's not much difference.

Brent

 

[jimh0612]

Yes now you put it into words that's how I'd describe it but on my system it's very subtle. My amp's a modded 66KI (almost!) like yours but I've only got standard Quad 11L's with Argos OFC speaker cable.

I know, shame on me!!!!!

Jim