Marantz CD63 & CD67 mods list

[awpagan]

Originally posted by poynton


Only after a couple of vodka's

then you need a couple more.


allan

[6h5c]

Originally posted by rowemeister
Hi all.

I have done a mod which many of you will just laugh at
And its no where near has complex as the tube mod, but I am keeping an open mind.
The LED mod

I will test this fully to see if there is any difference.

Wooow, ----pimp my player----

I know a fellow-DIY'er that put green LED's in his player and told me the bass had improved considerably. He also uses the greem marker on the edges of his cd's. I haven't had the chance to hear the differences, but if you detect any, i'm going to try it too .

Ray.

[6h5c]

Originally posted by awpagan
ray

"Allan, no luck with the scanner yet, will try again tomorrow. Some nasty XP driver problem with my parallel port scanner."

no problem and thank you for your help.

Hi Allan,

I managed to fix my scanner bug, and I have the board lay-out for you. It's a bit too big to post here, if you drop me a PM I will send it to you.

Ray.

[poynton]

Originally posted by poynton


So, I am now going to try the small tubes.........

Hi.

Another day .....had to repair the power supply this morning - somehow the Tx developed a primary short. Luckily I had a New TX to hand so I could repair it.

Worth the wait though !!!!!!!!!

Now using one of the minature tubes ( 6BF7W ).

Really excellent sound - possibly a little lighter on the bass than the E88CC but only a RCH !

B+ is incredible - it does not seem to distort (audibly) until B+ goes down to 3.5v - Correct 3.5v !! then it cuts off anyway ! I will keep it at B+ = 25v - audible performance does not seem to improve above this.

Heater is running a bit bright for my liking and gets HOT. I will try on 5v regulated supply rather than 6.3v AC

Andy

[poynton]

Originally posted by 6h5c


Did you measure any noise residue at the output that I experienced earlier?

Ray.

Hi Ray,

Do you still have the hiss??

I have been playing with the latest incarnation with interesting results!

Refering to Thorsten's circuit...

I used a probe connected to my amp at various points.
I could only detect significant hiss at the input at the junction of the choke and the DAC output ( where you would expect - no filtering whatsoever).

The interesting part is that after the choke, some hiss, slight buzz - and perfectly acceptable music !

Have I just found the ultimate minimalist mod?? straight off the DAC with a filter - no op amps, tubes etc??

Try it.

Andy

[6h5c]

Hi Andy!

Nice results! Especially at this low voltage.
Did you use a current sink for the kathodes, or a resistor?

You really got me going on this!
I went to the dump-store this afternoon, and I picked up some 5672 and 6418 pencil-tubes. They are low-voltage direct-heated penthodes that use 1,25V heater supply! I don't know if they're any good, but one of them has got very nice triode characteristics!
As soon as I have the passive part finished i'm going to try them.

Regards,

Ray.

[poynton]

Originally posted by 6h5c
Hi Andy!


I went to the dump-store this afternoon, and I picked up some 5672 and 6418 pencil-tubes. They are low-voltage direct-heated penthodes that use 1,25V heater supply! I don't know if they're any good, but one of them has got very nice triode characteristics!
As soon as I have the passive part finished i'm going to try them.

Regards,

Ray.

What is a dump store??? How much??

Just a resistor - no ccd

[6h5c]

Originally posted by poynton
Hi Ray,
Do you still have the hiss??
Andy

Yes, it is still there. But it is not audible with music playing. I only noticed it when I turned the volume of my amp to 100%, to see if the tubestage was humming/making noise. But my CD63, which uses the standard opamps + filter also produces the same hiss. So I THINK it is a HF residue caused by the DAC. It was about 22mV in amplitude, and Brent also measured it. Did you check with a scope yet?

Originally posted by poynton
What is a dump store??? How much??

Ehm, a shop with lots of junk, where they sell old army stuff and surplus parts, I don't know the exact word in english. They have at least two boxes full of these, they only cost me € 1,00 each! So I bought four of both types.

Ray.

[Fidelity Audio]

The connector on my main pcb to the transport pcb is playing up.
Its defo connector as I have changed the ribbon.

Will it be worth wiring this connection out with silver wire?

Or silver wire for just the RF out?

[6h5c]

Hi Brent,

I don't know if silver will add anything there. It's mostly servo signals going though. I'd rather go for a shielded connection, like a piece of shielded ribbon. Maybe a separate coax for HF??

Any big sound-changes detected yet, with the blue LED's?

Ray.