Marantz CD63 & CD67 mods list

[awpagan]

Originally posted by ash_dac


Allan,

I found this website very useful!

http://tangentsoft.net/elec/opamp-linreg.html

I think AD825 is used most often as the op amp.

It's probably used for a number of reasons, and one being the fact that if you are also building op amp modules you can bulk buy AD825!

actually the best place for an opamp is probably psu or dc servo
That comment should upset someone
seen tangent's site, some very helpful info.

I've thinking about doing this

allan

[6h5c]

Originally posted by poynton
Hi ,

Ray - where is the quote from??

Andy

Hi Andy,

The quote is from this thread, post 14. It's the thread that Allan posted. Very interesting read. It also has some interesting links to other threads.

Regards,

Ray.

[6h5c]

Originally posted by rowemeister
also not sure what value to use on R1 yet.

Ray if you have some good advice its welcome.
I specialise in lots of areas of electronics but im not major in dc ripple and its filtering.

What I have come up with is my own idea but am unsure of exact values without spending ages with scope.

cheers

Hi Brent,

Well, I read all this wisdom in the datasheet, nothing fancy...

The proposed value for R1 is 120R. The 1.25V reference voltage is across this resistor, so there will be a little over 10mA idle current drawn, which is the minimum load current for the regulator to maintain regulation. So that takes care of that. It won't hurt to use 100R.

If you calculate the bypass cap according to C = 1/(2*pi*f*R) you will get 13uF at a ripple frequency of 100Hz and 120R. So your cap is a bit on the low side.

Regards,

Ray.

[6h5c]

Originally posted by awpagan
I've thinking about doing this

allan

Hey, that looks a lot like this:
(Guido Tent's XO supply)

I use it to supply a Kwak-clock. How ironic

Ray.

[poynton]

Originally posted by ash_dac


Allan,

I found this website very useful!

http://tangentsoft.net/elec/opamp-linreg.html

I think AD825 is used most often as the op amp.

It's probably used for a number of reasons, and one being the fact that if you are also building op amp modules you can bulk buy AD825!

Isn't that the site I gave in post 1180 ?

[awpagan]

Originally posted by 6h5c


Hey, that looks a lot like this:
(Guido Tent's XO supply)

I use it to supply a Kwak-clock. How ironic

Ray.

yes ray
with separate analogue digital earths

yes andy

It's come back to haunt you

allan

[poynton]

Originally posted by awpagan



with separate analogue digital earths

This is interesting - I wonder how much difference it makes?

With this circuit, the regulation is performed by the 78XX, the transistor is , I think, called a capacitor multiplier.

Andy

[awpagan]

Originally posted by poynton


This is interesting - I wonder how much difference it makes?

With this circuit, the regulation is performed by the 78XX, the transistor is , I think, called a capacitor multiplier.

Andy

i've seen ripple been very low on a lm317 with good earthing just in the the overall circuit

ALW in his tests with the lm317 recommends separate earth for the base.
If use the same earths as digital it doesn't give a decent earth,
too much noise.
so the regulation ref point fluctuates.
I was going to use tent's psu just for starters, until i made a super reg.
comments in his posts and test made me think about the 7808,
and how much it may improve?

could be a simple upgrade on a standard cdp.

should transfer to the 317


any thoughts

allan

[poynton]

Hi.

I've just finished reading through all the various links posted over the last 24hrs !!!


What a difference there is between the LCclock3 and the LCclock2!!!!

Each stage fed from its own 'regulator' with a common reference voltage.

This idea is useable for anyone wanting to feed tha analog, digital, RF, etc stages from their own supply.


The Pat's Lab. clock is similar to Jocko's.

But which gives lowesy rail noise? - I'm confused!!

Andy

[awpagan]

Originally posted by poynton
Hi.

I've just finished reading through all the various links posted over the last 24hrs !!!


What a difference there is between the LCclock3 and the LCclock2!!!!

Each stage fed from its own 'regulator' with a common reference voltage.

This idea is useable for anyone wanting to feed tha analog, digital, RF, etc stages from their own supply.


The Pat's Lab. clock is similar to Jocko's.

But which gives lowesy rail noise? - I'm confused!!

Andy

I use the lclock3 in the cd850, just over 1 year now.
Knew it was a 4 layer pcb. just recently saw the schematic
Seeing the schematic, i see why it's 4 layers

Pat's Lab and Jocco's????

Pcb layout may have a lot to do with it?
Digital current pulses affecting analogue or other earth's

CD63/67?
use the earth plane for digital separate from analogue, star grd common.

allan
also