Marantz CD63 & CD67 mods list - Page 104 - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 27th February 2006, 12:24 PM   #1031
ash_dac is offline ash_dac  United Kingdom
diyAudio Member
 
Join Date: Jan 2005
Location: UK
Default Re: Re: Analogue supply to the DAC

Quote:
Originally posted by 6h5c


Hi Ashley,

It's not a reference, more like a DC offset. The outputs of the DAC seem to be at 2.5V, because the duty-cycle of the output is 50% at no signal. That "offset" is divided by the low-pass filter at the outputs and that leaves 1.4V on the opamp's inputs.

Regards,

Ray.
Hi Ray,

So internally there is a resistor divider (dividing 5v to 2.5V), and this feeds an opamp to keep the dac's outputs at 2.5v constant?

These outputs are then low pass filtered to 1.4v ?

Doesn't this mean the 5V analogue dac supply must be very low noise, and impedance ?
  Reply With Quote
Old 27th February 2006, 05:08 PM   #1032
avr300 is offline avr300  Denmark
diyAudio Member
 
avr300's Avatar
 
Join Date: Sep 2005
Location: DK
Quote:
Originally posted by 6h5c


Hi avr,

1. At first, I replaced the opamp's Cerafines with the Silmic's but it didn't make much difference. A good low-ESR cap with bypassing or a BG sounds much better there. What's silk doing in a cap anyway? Do they expect it to sound "smoother"?? Smells like HDAM: marketing stuff...

2. The Kwak and the Tent clock both bring considerable improvement to the sound. More quiet background, extended highs, more detail. I have both, but it's hard to say which one's better. Neither takes out the magic, they add magic!
The Kwak is the cheapest to build, but more work, and the Tent XO is very simple, but a bit more expensive.

Regards,

Ray.
and

Quote:
Originally posted by poynton



There is a lot of hype around, isn't there?

If Marantz had got the spec of the '63 right in the first place, they would not have needed the Dham module! But then there would not have been the '43, '53, SE etc.

Silmics and Cerafines are ( like Black Gates) recommended for certain applications and not others. I have doubts about the BG supercap - if it works for BG, why not other makes of NP caps?

Andy
There IS a lot of hype, and well to many models.

Get a good OPAMP, and the HDAM is a hype. BTW, the LT1361 is sounding great, waiting for my AD8620, hmmm

I'll just stay with the Clerafines until now, doesn't sounds like the Silmics is worth the efford.

I'll start with the Kwak. If it really adds PRaT, then in my opinion it's better.

/avr300
  Reply With Quote
Old 27th February 2006, 05:51 PM   #1033
ash_dac is offline ash_dac  United Kingdom
diyAudio Member
 
Join Date: Jan 2005
Location: UK
Default Re: Re: Re: Analogue supply to the DAC

Quote:
Originally posted by ash_dac


Hi Ray,

So internally there is a resistor divider (dividing 5v to 2.5V), and this feeds an opamp to keep the dac's outputs at 2.5v constant?

These outputs are then low pass filtered to 1.4v ?

Doesn't this mean the 5V analogue dac supply must be very low noise, and impedance ?
Hi,

Opps.....I've been reading this wrong!

These are digital outputs (buffered, and referenced to the internal system clock).

Could we not reclock the outputs ?
Attached Images
File Type: jpg sm5872_2.jpg (24.6 KB, 480 views)
  Reply With Quote
Old 27th February 2006, 09:04 PM   #1034
6h5c is offline 6h5c  Netherlands
One Seriously Addicted to Audio and Electronics
diyAudio Member
 
6h5c's Avatar
 
Join Date: Apr 2004
Location: Heerhugowaard
Quote:
Originally posted by mickie
I agree with "over the top" but i thought this is what we are doing anyway
I have some 0,1uF BG's lying around from my old Rega in which i implemented them successfully, noise-level went noticeably down...so why not use them.....

yours,
mickie
Hi mickie,

I can imagine your point of view, but you should be careful where you replace a ceramic cap with an electrolytic. The high-frequency properties of electrolytics are a lot worse compared to ceramics. They have much more parasitic induction because of their rolled cilinder construction. A ceramic will perform much better at higher frequencies. Just thought you should know.

Here's an example of a 1u multilayer ceramic (MLCC) vs. a 1u tantalum.

Regards,

Ray.
Attached Images
File Type: jpg mlcc_vs_tant.jpg (15.4 KB, 464 views)
__________________
Gonna buy my little girl a pink soldering-iron
The new DOS-CFP board is out!
  Reply With Quote
Old 27th February 2006, 09:10 PM   #1035
6h5c is offline 6h5c  Netherlands
One Seriously Addicted to Audio and Electronics
diyAudio Member
 
6h5c's Avatar
 
Join Date: Apr 2004
Location: Heerhugowaard
Default Re: Analogue supply to the DAC

Quote:
Originally posted by ash_dac
Hi Ray,

So internally there is a resistor divider (dividing 5v to 2.5V), and this feeds an opamp to keep the dac's outputs at 2.5v constant?
These outputs are then low pass filtered to 1.4v ?
Doesn't this mean the 5V analogue dac supply must be very low noise, and impedance ?
Quote:
Opps.....I've been reading this wrong!
These are digital outputs (buffered, and referenced to the internal system clock).
Could we not reclock the outputs ?
Yes, they are digital
There's a nice 5V square wave on the outputs, but if the duty-cycle is 50% a voltmeter will measure 2.5V.
No analog reference whatsoever...

BUT....the "analog" supply IS as critical as you mention!

Hmmm...reclocking...don't know if that will gain something.
Need another stable clock then. And more stable PSU's.

Regards,

Ray.
__________________
Gonna buy my little girl a pink soldering-iron
The new DOS-CFP board is out!
  Reply With Quote
Old 27th February 2006, 11:37 PM   #1036
SimontY is offline SimontY  United Kingdom
diyAudio Member
 
SimontY's Avatar
 
Join Date: May 2003
Location: Sheffield, North England
Send a message via MSN to SimontY
Quote:
Originally posted by avr300
I could refine my question.

Would you go for the Kwak or the Tent (in diy version)?

Hopefully, neither of these takes out the magic of the CDP ?
Takes the magic out??? IMHO there's no magic till it's got a new clock and new other bits and no hdam.

Just been listening to Harvest (Neil Young) and my word there's so much detail and so much space! Some of the harder busy parts are a lot more focused and I think less glassy now too. I think these improvements were mainly from taking the hdam out actually, I'd just not listened to this album yet. It's like hearing it in hi-fi for the first time... To be honest tho one of the biggest changes is hearing more distortion on it and more noise (from the recording/production). (that doesn't distract me generally tho).

I too, btw, have noise on pause when I turn the volume to full, but I have to put my head near to the speaker (<15") to hear it. Having said that, my pre doesn't have much gain.
  Reply With Quote
Old 28th February 2006, 08:15 AM   #1037
diyAudio Member
 
Join Date: Oct 2004
Hi,

Well, last night I popped the lid again...
I need to order some parts to upgrade the HF and RF amps and I'm not interested in doing coax until the end. So, having seen Rowemeister had considerably upped the reservoir caps around the DAC and decoder, and that I hadn't as I tend to leave digital supplies unchanged, thought I'd give it a go.
So, upped the DAC caps to 2700uF (think they were 220uF) and the decoder caps to 470uF (couldn't go much higher as my clock is mounted above), and the 470uf after the 12v regs for 2200uF Elna Stargets (the 470uF Silmics were replaced beforehand with some 4000uF Pana FCs).

I wasn't expecting too much improvement as the DAC is fed by three independent regulators anyway, but wow! Really noticeable improvement.

Really going to make the effort with seperate regulation for the decoder, and the rf and HF amps.

Rowemeister, I like silver mica too, but around the HF and RF amps (except for maybe the filters) surely 1% resistors would do? I used 0.1% in my audio filters, because I want both channels to match as closely as possible to improve the soundstage, but surely for these two stages, just lower noise is the priority?
Obviously 0.1% is nice, but not crucial at this point in the circuit? Maybe I've missed a point, my RF knowledge is quite poor.

Anyway, still enjoying modding this player, and I'm sure there is a lot of progress to be made.

Phil.
  Reply With Quote
Old 28th February 2006, 08:39 AM   #1038
diyAudio Member
 
Fidelity Audio's Avatar
 
Join Date: Dec 2005
Location: Doncaster England
Quote:
Originally posted by philpoole
Hi,

Well, last night I popped the lid again...
I need to order some parts to upgrade the HF and RF amps and I'm not interested in doing coax until the end. So, having seen Rowemeister had considerably upped the reservoir caps around the DAC and decoder, and that I hadn't as I tend to leave digital supplies unchanged, thought I'd give it a go.
So, upped the DAC caps to 2700uF (think they were 220uF) and the decoder caps to 470uF (couldn't go much higher as my clock is mounted above), and the 470uf after the 12v regs for 2200uF Elna Stargets (the 470uF Silmics were replaced beforehand with some 4000uF Pana FCs).

I wasn't expecting too much improvement as the DAC is fed by three independent regulators anyway, but wow! Really noticeable improvement.

Really going to make the effort with seperate regulation for the decoder, and the rf and HF amps.

Rowemeister, I like silver mica too, but around the HF and RF amps (except for maybe the filters) surely 1% resistors would do? I used 0.1% in my audio filters, because I want both channels to match as closely as possible to improve the soundstage, but surely for these two stages, just lower noise is the priority?
Obviously 0.1% is nice, but not crucial at this point in the circuit? Maybe I've missed a point, my RF knowledge is quite poor.

Anyway, still enjoying modding this player, and I'm sure there is a lot of progress to be made.

Phil.
Phil

Nice to see others wanting to work around the servo HF and RF.

I used 0.1% tol resistors because I had them in at work and thought why not

Im not sure which parts gave what on the HF RF but I got much better resonance in bass and a nicer more articulate treble. Its probably down to the silver micas.

Using seperate regs there brought more of the same, which was nice.

I havent done one mod that has not improved the player in some way.

What improvements did you get from the latest mod?
  Reply With Quote
Old 28th February 2006, 09:00 AM   #1039
diyAudio Member
 
Join Date: Oct 2004
Well, I didn't get much chance to listen, but I did notice more clarity in instrument seperation.For instance, not only able to hear new things, but also able to follow them amongst everything else going on.

Listened to a bit of Tom Waits, and just heard things I'd never heard before. Especially loads more detail in the voice, more breathing, etc. After a few mods, you really notice, there's actually a lot going on in a piece of music.

The bass was a lot tighter maybe as well.

Need to hear it a bit more.

Even before this mod (there have been many) Iwas shocked the other week when I dug out an old James album (laid) and listened to 'one of the three'. Not only was I impressed by the drastic improvement (really can hear a lot of the guitar work going on and can follow it as well) but also for the first time, heard a backing singer with a very low bass voice. In 13 years of owning that album I have never heard him before!

Things like Tori Amos sound brilliant as well, but her stuff is often well recorded. And one surprise I had was Paul Weller's Wild Wood - I've always found it a very dull recording, very muffled (even on a bright marantz). But now, it sounds like the producer actually knew what he was doing.

I could go on. Music is suddenly more interesting, more than it is disappointing when you discover a badly produced/mastered CD.

What do people use to listen to their Marantz? I have an old Radford amp and some Mission 751. I'll probably replace that lot one day, but I mainly use my own headphone amp and some Grado SR80s (sleeping young children don't mix well with hifi). I'm really pleased that so far, the headphones and their amp are not the weakest link (yet).
Does anyone feel the need to upgrade the rest of their kit yet?
  Reply With Quote
Old 28th February 2006, 09:18 AM   #1040
6h5c is offline 6h5c  Netherlands
One Seriously Addicted to Audio and Electronics
diyAudio Member
 
6h5c's Avatar
 
Join Date: Apr 2004
Location: Heerhugowaard
Quote:
Originally posted by philpoole
Does anyone feel the need to upgrade the rest of their kit yet?
Did that years ago...

That's one of the risks of modding these players, before you know it the rest of your kit is the bottleneck

Ray.
Attached Images
File Type: jpg buizenbak_kt88.jpg (79.4 KB, 417 views)
__________________
Gonna buy my little girl a pink soldering-iron
The new DOS-CFP board is out!
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 03:20 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2