Marantz CD63 & CD67 mods list - Page 1748 - 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 20th September 2011, 08:39 AM   #17471
UV101 is offline UV101  England
diyAudio Member
 
UV101's Avatar
 
Join Date: Dec 2008
Location: Oxford
Quote:
Originally Posted by 6h5c View Post
Hi, i'm back

Good to see there's plenty DOS-talk around

Seems the current sink needs some experimenting? Theoretically, it should be an improvement over a resistor. Maybe i'll implement a transistor-LED version in the next batch of boards, just like the one in the input stage. This would be even more versatile, and more easy to tweak to the correct current.

I'm glad you sorted out the sound now, Brent and others. Is it possible you guys could test the board with such a current sink? It's fairly simple to do: replace the FET T7 by a BC550C, replace the 100R resistor (R13) by a LED and insert a 10k resistor from the LED's anode to the +12V. R14 sets the current, it should be around 100R for 10mA to flow through the output buffer.

If you want to do it really quick-and-dirty you could even use the LED's voltage from the input stage and tie T7 base to T5 base .

Ray
Did you try with and without Ray?

Also, did you see my question about the transistors used? Could a BC640 be used in place of the 560?
__________________
When Bitstream came out, I thought, “my God, what are we going to do...?” Ken Ishiwata http://www.hifisounds.co.uk
JA-88D Class A, Audio Aero Capitole MKII, Focal and Kimber "Leave Nothing as Standard"
  Reply With Quote
Old 20th September 2011, 10:58 AM   #17472
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 UV101 View Post
Did you try with and without Ray?

Also, did you see my question about the transistors used? Could a BC640 be used in place of the 560?
No, not yet. I'm just back from my holiday . It was horrible, no wireless internet in the forest

Plus that i'm happy with the sound of the CFP-DOS so far, in my SA8400. But that doesn't mean there's no room for improvement

The BC640 is a 1A-current device, with much lower gain than the BC547...560 series. Not recommended. But you could use the BC556, 557, 558 or 559 as long as they are 'C' class with high gain. The 549/550 and 559/560 are low noise, that's why I picked them.

Ray
__________________
Gonna buy my little girl a pink soldering-iron
The new DOS-CFP board is out!
  Reply With Quote
Old 20th September 2011, 08:15 PM   #17473
diyAudio Member
 
bikeral10's Avatar
 
Join Date: Oct 2010
Location: walsall west mids uk
My cd52se has stopped working?
disc spins laser trys to focus but no toc keep getting error P122 any ideas.
cheer guys alan
__________________
Aint broke it yet but im tryin. ( favs Fast women and even faster bikes)
  Reply With Quote
Old 21st September 2011, 02:59 PM   #17474
gareth is offline gareth  Wales
diyAudio Member
 
gareth's Avatar
 
Join Date: Jan 2008
I noticed on the previous page that there was mention of valve output stages.

There are some well designed professional (studio) grade pre-amp's on the market using 12AX7 valves. These pre-amps come with the usual line-level (and Hi-Z Mic) inputs, phase adjustment and Class A/B variable biasing if you want to, amongst other pro grade adjustments.

These pre's start at around the €40 and go up to €400 depending on what you are looking for. I know they may be a bit over board but I was wondering if anyone had tried something like this on their output stages ?

All the valve heater circuits etc are sorted for you and some offer Class A - B variable output biasing and other pro-grade options for tweaking. Anybody got any comments on this ?

Cheers guys
Gareth
  Reply With Quote
Old 21st September 2011, 03:12 PM   #17475
gareth is offline gareth  Wales
diyAudio Member
 
gareth's Avatar
 
Join Date: Jan 2008
Stupid idea maybe ?

I liked the fact that you could get to try the valve, albeit after your own existing output devices/circuitry, sound and they are well designed and built and some of them are really rather cheap to buy, with the option of tweaking too.
  Reply With Quote
Old 21st September 2011, 03:19 PM   #17476
gareth is offline gareth  Wales
diyAudio Member
 
gareth's Avatar
 
Join Date: Jan 2008
Ray 6h5c,

I had scanned that clock design in to the PC the other day, choice of .jpg, .pdf (through Adobe) to send over to you but someone has deleted them but I will get them scanned back in a.s.a.p. and forward it to you.
  Reply With Quote
Old 21st September 2011, 07:06 PM   #17477
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 gareth View Post
I know they may be a bit over board but I was wondering if anyone had tried something like this on their output stages ?
I tried that once, I used a differential stage with a double triode instead of the two FET's of the DOS. It sounded very nice, but I dare to say that the solid-state version sounds at least as good. Given the fact that tubes need a high voltage supply (= extra transformer) and a heater supply (= another extra transformer) and the solid state version runs on a comfortable +/- 15V or so, I chose the FET's. But it looks very cool

Quote:
Ray 6h5c,

I had scanned that clock design in to the PC the other day, choice of .jpg, .pdf (through Adobe) to send over to you but someone has deleted them but I will get them scanned back in a.s.a.p. and forward it to you.
Doesn't matter what file-type, as long as it's clear

Regards,

Ray
Attached Images
File Type: jpg CD67OSE_Tubestage_6.jpg (203.8 KB, 145 views)
__________________
Gonna buy my little girl a pink soldering-iron
The new DOS-CFP board is out!
  Reply With Quote
Old 21st September 2011, 07:09 PM   #17478
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 bikeral10 View Post
My cd52se has stopped working?
disc spins laser trys to focus but no toc keep getting error P122 any ideas.
cheer guys alan
P122 is a bit general, isn't there a specific error number in the display? There's a list in the service manual, maybe this can point you in the right direction.

Ray
__________________
Gonna buy my little girl a pink soldering-iron
The new DOS-CFP board is out!
  Reply With Quote
Old 21st September 2011, 07:10 PM   #17479
diyAudio Member
 
Malefoda's Avatar
 
Join Date: Jun 2006
Send a message via MSN to Malefoda
And at that time a kind of second sight has shown you the next type of caps you may offer to your dearest...
__________________
QED T260, Thorens TD-318, Marantz CD-43, TK2050, JBL 4313B & MJK's OB: music!
  Reply With Quote
Old 21st September 2011, 07:49 PM   #17480
6h5c is offline 6h5c  Netherlands
One Seriously Addicted to Audio and Electronics
diyAudio Member
 
6h5c's Avatar
 
Join Date: Apr 2004
Location: Heerhugowaard
Sorry, they are not for sale
__________________
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 06:18 AM.


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