Marantz CD63 & CD67 mods list

[stvnharr]

Originally Posted by RCruz

Update the DOS.... I was not expecting this... Here I go again

Would you send us a revised schematic with real resistor values ?

What about some pics of the underside of your DOS ?

Be patient, Ray will soon have the information on his webpage for the CFP.

[6h5c]

The schematic is already here...

[6h5c]

Originally Posted by quincie

Ray, i need help!!!

First hello to everyone.

Quincie is my name (not realy:its Ruud)

I`m a newbee with electronics, but i love great music.

I have a Marantz cd67 MKII OSE and i want to upgrade this beatiful player.

I looked around youre site and i love it, but here is my problem.
I don`t understand a lot of your schema`s etcetc, but i want still upgrade my player.

Is there anyone, or do you know someone who can do that for me.

Please help meeeee!!!!

Quincie.

Hi Ruud, and welcome to this forum. Sorry for replying a bit late, but your post got lost in my DOS-tweak-upgrade-enthousiasm.

We will be very willing to help you to upgrade your CD67, but the first question is of course: can you solder? :-)

Ray

[stvnharr]

Originally Posted by 6h5c

The schematic is already here...

Okay, I have done things slightly different to the posted schematic in my 8260. I changed the values of the resistors R5 and R6 to 2.2k and R9 to 150R.
I also halved the gain resistors, R7 and R8. This will double the current into the CFP and is what I have done.
However, keeping the current the same will work just as good. I found that the most important thing is the resistor into the 170BL, and it needs to be around 6K.

Oh yes, you can also use a BC557 transistor if you don't have a 560, and the Hfe of the transistor is not important for this application. In my prototype model I used both the above transistors as I didn't have enough of each. I think my finished board uses 557's.

If you don't change any of the supply current resistors, it's pretty easy to solder up the CFP under the board. Just follow the schematic point to point.

I was quite surprised at both implementations of the CFP. The first implementation really opened up and uncompressed the music signal. Then after Ray did some simulations I tried a large resistor on the 170BL, and was completely shocked at the depth of the bass, and how loud it came out. However, I have to admit that I have a subwoofer that is flat to 20hz., which helps a bit. But most of the bass is realized thru the main speakers, which are just 7" two ways with good bass.

It will be interesting to hear other viewpoints once other have implemented the CFP in their DOS's. It made a significant difference for me, and I am assuming the same for others as well.

[RCruz]

I am now waiting for consensum... Would you review your schematic Ray ?

[guido]

Originally Posted by guido

I did put my pcb together and did some testing. And i did notice quite a bit of distortion on my SA. So i'll try this too and take some before/after pictures.

Probably sunday as tomorrow is the radio/electronics market here in the netherlands which will take most of my day. I'll figure out what i'm missing in a moment and then i can look for parts tomorrow if i do not have them lying around here.

I was at the market, but it's not easy to find those BC560's in all that junk
And i found that i need to go to the shop for more parts. For some reason i ended up with 7815 and 7915's on the pcb. Ooops. Maybe that's where the highish distortion comes from...

Not that much interesting stuff on the market, apart from one part that made my day: a 7A22 plugin for a tek mainframe. Very good condition and a reasonable price. It's ideal for audio: differential inputs going down to 10uV/div. DC offset compensation and high and low cutof filters. Happy

[stvnharr]

Originally Posted by RCruz

I am now waiting for consensum... Would you review your schematic Ray ?

Ricardo,
Ray knows about the current changing resistors.
He also knows about the 557/560 transistors, it makes no difference.
The 6.8k resistor into the 170BL is the way to go. You basically have a choice between 5.6k or 6.8k, as these are the most common values, and either one will work fine as both are close to the 6k desired value.
FWIW, my proto model had 5.38k of resistance, and it was phenomenal, but that had a string of resistors in it.

When I have some time I will write up some quick instructions for soldering up the CFP. I've taken my proto all apart, but still have the resistor and transistor soldered together. It's not all that hard, but I can't seem to do it off the top of my head, so I'll get back to it later today, as time allows.

Steve

[stvnharr]

Okay, here we go on soldering up the CFP:
1. Solder the 6.8k resister across P1 and P2 of the 557/560. Leave resistor leads long.
2. Solder the resistor lead that is soldered to P1 of 557/560 to P2 of R5.
3. Solder the resistor lead that is soldered to P2 of 557/560 to P1 of T1
4. Solder P3 of 557/560 to P1 of R7.

Do the same on the other side of the T2 side, just remember that it is a mirror image.

Adding these 4 parts to the circuit board requires a complete rework of the pcb. Doing it underneath like above will work just fine. Just keep good spacing with the leads and keep things as neat as possible.

[6h5c]

Originally Posted by stvnharr

Ricardo,
Ray knows about the current changing resistors.
He also knows about the 557/560 transistors, it makes no difference.
The 6.8k resistor into the 170BL is the way to go. You basically have a choice between 5.6k or 6.8k, as these are the most common values, and either one will work fine as both are close to the 6k desired value.
FWIW, my proto model had 5.38k of resistance, and it was phenomenal, but that had a string of resistors in it.

When I have some time I will write up some quick instructions for soldering up the CFP. I've taken my proto all apart, but still have the resistor and transistor soldered together. It's not all that hard, but I can't seem to do it off the top of my head, so I'll get back to it later today, as time allows.

Steve

To confirm the consensus: that's all correct

[shepperd]

Just thought I'd drop ths into the mix
NewClassD Discrete OPAMPs
I guess that's uncouth of me but it's not often I find something.