Marantz CD63 & CD67 mods list

Thomo said:
lol. I don't mean a little low hiss, I have that on my player and don't mind. I mean LOUD HISS, as loud as most of the music.

Lee.

That sounds like digitalis, like your outputstage is outputting the digital signal. Is it on both channels? Broken DAC? Did you take a look with a scope yet, to see what the signal looks like?

Check the current sink that's in the input section. A bad one can be very noisy too, as the tail of the differential pair is very sensitive.

Ray
 
Thanks for your help guys. It seems it was tiny, tiny solder bridge on the discrete input to ground. The hiss has gone away. One channel is louder, but I reckon that's an easy fix and I'll be having a look tomorrow. The smt resistors I've used are only about 2mm long so you have to be rather careful.

What's the recommended dc blocking cap on the output of the discrete? I use 6.8uF BG AC on mine, but I have fitted 0.1uF film caps on this other one and read no dc offset. Is it best to use the smallest cap possible?

Cheers, Lee.
 
Member
Joined 2006
Paid Member
6h5c said:
Those voltages look fine. Don't worry about a few digits difference, remember you are taking about tens of millivolts here!

I would not take a too big cap, as the voltage will come up very slowly at power-up. This could cause problems. A good small cap is better than a big bad one.
Hi Ray

I have finally built the +5v superreg with succes.

I will use it to drive the dac analog rail but need some advise:

I built the sreg with a 150uF 16v OsCon in the capacitor multiplier.

Should I install it as is or would a 220uF 16v BlackGate improve the sound ?

Best Regards

Ricardo
 
RCruz said:
Hi Ray

I have finally built the +5v superreg with succes.

I will use it to drive the dac analog rail but need some advise:

I built the sreg with a 150uF 16v OsCon in the capacitor multiplier.

Should I install it as is or would a 220uF 16v BlackGate improve the sound ?

Best Regards

Ricardo

Hi Ricardo,

Try it :D

Probably not much difference....
Congratulations on the superregs :happy1:!

Ray
 
Thomo said:
What's the recommended dc blocking cap on the output of the discrete? I use 6.8uF BG AC on mine, but I have fitted 0.1uF film caps on this other one and read no dc offset. Is it best to use the smallest cap possible?

Cheers, Lee.

Hey Lee,

Good to hear your problem went away.
The blocking cap is for blocking DC, but it also has to be quite big, to insure the low frequencies are not filtered out. You must have no bass with 0.1uF :clown:!

In theory, it depends on the load impedance after the cap. There is a formula that says: C = 1 / (2*pi*F*R). If you take 5Hz as the lowest frequency for example, and assume that R = 10k (which represents the input impedance of the preamp), C would be 3.18uF, which you can round off to the next higher value, 3.3uF. So this could be considered a safe minimum. 6.8uF is even better!

Regards,

Ray
 
Hi Ray.
Happy New Year to you.
Long time no speak!

I'm just about to start modding again and ordering up the caps for the latest CD63 list. :smash:

I have a question, but I'm not sure if it's already been answered a long time ago.

The additional bypass caps for the power supply Panasonics are X7R ceramic and for the opamp, DAC and decoder are PPS.

As they are the same value, and I have some X7R's left from my last attempts, how much difference would it make if I used the X7R instead of the PPS?

Sorry if it's a daft question but I'm not sure. :xeye:

Also comparing the Rubycon ZA, ZL and ZLH specs the ripple current ratings go from 1650mA for the ZA, to 1250mA and1330mA for the others. Which is better for ripple rejection? I think the ZA's are supposed to be better - certainly based on price the ZA's are way more expensive, more than BG's!!

I would appreciate any help as I can't seem to get the Elna RJH's any more. Farnell only have limited stock of certain values, like they have 120u/25v or 470u/63v as close to the value, and they recommend the Rubycon YXF as an alternative for the 470u/25v.

What do you guys recommend for the opamps which are LME49720NA? These are sounding much more open and detailed than the OPA2134 i just replaced. Also would you recommend the additional bypass under the socket?

Thanks in advance.

Jim
 
Hi Jim. These are my opinions and experiences:

Defo add 220nF bypass caps under the opamps, between pins 4 & 8, I have never failed to hear an improvement doing this.

Black Gate 220uF 16v or better still 470uF 16v are the finest choice for the main opamp caps.

Rubycon ZA have the best ripple rejection and are the best caps available for digital rails, giving the best tonal detail and natural sound. Also good on analog rails. ZL's are pretty good too.

Don't bypass the really good quality elco's like BG's or ZA's/ZL's. But PPS are fantastic at bypassing lesser caps, especially in sensitive areas like the dac and opamps.

Lee.
 
Thanks Jim, and all the best to you too in this year, and for everyone else of course. Already forgot it was newyear :guilty:, it's been only two weeks... I'm quite absorbed by the new ezDAC i'm building, but i'm lurking at the sideline. Wouldn't want to miss anything that's going on here :D.

Lee's answer covers most of it, I'd say. A good cap doesn't need bypassing, so I'd leave it out on BG's around the opamps for example.

The caps just after the diode rectifier in a PSU are in a less sensitive area, so I use cheaper X7Rs there to bypass. Around the DAC and decoder ICs I use 100n PPS instead of the cheap 100n ceramics that are often placed across the power pins.

Maybe if you had a really good cap you could also leave them out in the digital section, but at such high frequencies, I always try to place a really good SMD cap as close to the power pins as I can get. The induction of the wires and construction of an electrolytic are a limiting factor to their highest working frequency.

Regards,

Ray
 
6h5c said:
Hi Jim,

Maybe if you had a really good cap you could also leave them out in the digital section, but at such high frequencies, I always try to place a really good SMD cap as close to the power pins as I can get. The induction of the wires and construction of an electrolytic are a limiting factor to their highest working frequency.

Regards,

Ray


I used to have smd x7r's directly on the pins of the dac. I removed them when the BG's went in and things improved a lot, but that could just have been the analog rails. I reckon I'll stick 100n PPS on the digital supply pins and see if there's an improvement. Cheers Ray.

Lee.
 
Thanks for the answers guys.

If I wanted to use the RJH's on the opamps would the 470u/63v be slower sounding at all instead of the 16 or 25v versions?

If so I'll probably use the ZL's for now and put BG's in later.

I've been concentrating on adding LM317 Rayregs and it's given me good gains, so I'm going to adapt them into SuperRayregs.

Thanks for the answers guys, and Thomo I did the smd caps on the DAC pins (lifted a couple of legs in the process!!). I guess I'll leave well alone in future and concentrate on cleaner supplies through the regs etc.

Jim
 
Brent - got a C1 for Xmas!!

Hi Brent,

Glad to see you active on here again.

My wife, bless her, surprised me with a C1 master clock for Christmas :hug:
(and there was I thinking she was fed up of me spending hours hunched over the dead remains of my original KI and the laptop wading through this thread and PFM until the wee small hours!!)

My question is this. Among my Rayregs I also have an Audiocom superreg (the £17 eBay ones similar size to the clock PCB.)

Iwas thinking of connecting it directly on to the clock pcb near the top.

Should I do this to keep the traces as short as possible?

Also I am going to put in the divide by 2 circuit to reclock the servo, so should the divider have its own reg, or would the same supply be OK?

I don't want to cause any grounding issues.

Cheers
Jim
 
jimh0612 said:
If I wanted to use the RJH's on the opamps would the 470u/63v be slower sounding at all instead of the 16 or 25v versions?

Hi Jim,

I can't think why that would be the case. The 63V versions may have a lower ESR, which is a good thing. There may be some argument for not using caps so overrated, but I really don't think you should spend a moment longer thinking about it.

Simon
 
Re: Brent - got a C1 for Xmas!!

jimh0612 said:
My question is this. Among my Rayregs I also have an Audiocom superreg (the £17 eBay ones similar size to the clock PCB.)

Iwas thinking of connecting it directly on to the clock pcb near the top.

Should I do this to keep the traces as short as possible?

You mean like this? ;) Yes, do it! :D
 

Attachments

  • c1.jpg
    c1.jpg
    95.7 KB · Views: 277