Marantz CD63 & CD67 mods list

[Glenn2]

Originally posted by YoungSC
Thanks Pete,

If I use the formula in the datasheet and apply it to the resistor values in the Super-Raygulators I get 1.25(1+1500/120) = 16.875 Vout

This is where I'm getting confused becuase there should be 12Vout.

However, if I use the resistor values in the first Raygulators then I get the following 1.25(1+1050/120) = 12.1875 Vout

This is more like it.

Now does that mean that R1 in the Super-Raygulators is incorrectly labelled 1.5k instead on 1.05k, or does the sum of my knowledge equal very little?

If the formula above works for the Super-Raygulators, and I want to get 5 Vout, then my calculations show that I want a 3:1 ratio for R1:R2. Am I better off using the lowest resistors I can find, or just go for a pair such as 300 ohm and 100 ohm?

Thanks again.

The Raygulator is the plain LM317/337 implementation as on the data sheet. The o/p voltage is the ratio of the divider resistors, +1, x 1.25V. So, say (1+ (360/120)) x 1.25 = 5V

The Super Raygulator, the resistor between o/p and adj pin has no bearing on the voltage. The voltage is the drop across the diodes + 1.25V (I believe - though not 100% sure). The other resistor is part of the gyrator.

Does this help?

[avr300]

Correct, the LM3xx will maintain 1.25v over the resistor placed between output and adjust. And with the zeners and the diode the adjust pin is 10v + 0.7v up, hence the output will be 10.7v + 1.25v = 11.95v.

The 1k5 - 4u7 and the transistor is the gyrator,

[poynton]

Slightly Off-Topic



Pinkmouse is trying to start a UK DiyAudio.com meet etc in 2007.
Somewhere in the Midlands.

See :-

http://www.diyaudio.com/forums/show...&threadid=94337


Andy

[YoungSC]

Originally posted by avr300
Correct, the LM3xx will maintain 1.25v over the resistor placed between output and adjust. And with the zeners and the diode the adjust pin is 10v + 0.7v up, hence the output will be 10.7v + 1.25v = 11.95v.

The 1k5 - 4u7 and the transistor is the gyrator,

Alright, so for 5V I keep all the components the same except the Zener diodes. The LM317 will provide 1.25V, the 1N4148 will provide 0.7V, so I need to changethe 2 Zener diodes to 3V to get:

1.25 + 0.7 + 3 = 4.95V

Am I correct?

Sorry to labour the point, but I want to be sure, and I bet there are other people who will find this useful.

Thanks

[jksmurf]

Originally posted by YoungSC
Sorry to labour the point, but I want to be sure, and I bet there are other people who will find this useful. Thanks

Keep hammering away cobber, I'm finding this very useful.

k.

[SimontY]

Originally posted by poynton
See :-

http://www.diyaudio.com/forums/show...&threadid=94337

Andy

That URL is borked mate, it aint doing nothing for me!

Simon

[adfinni]

Originally posted by SimontY


That URL is borked mate, it aint doing nothing for me!

Simon

ditto

[martin clark]

so for 5V I keep all the components the same except the Zener diodes. The LM317 will provide 1.25V, the 1N4148 will provide 0.7V, so I need to changethe 2 Zener diodes to 3V to get:

1.25 + 0.7 + 3 = 4.95V

Am I correct?

Spot-on! Or you could use an LED with a forward voltage of 3.0v, if you want visual indication of the thing working. Some blue/white LEds are in this range , IIRC.

Note that with the the exact voltage you'll get out depends on the current through the diode (zeners typically have 10-30ohms resistance at c.5mA) and to a lesser extent, temperature (they drift as they warm-up) - but don't worry about it.

[poynton]

Originally posted by SimontY


That URL is borked mate, it aint doing nothing for me!

Simon

OOOH!!!!


Anyone up for a UK diyAudio Meet?


This one works.


Andy


PS Simon.
Know any suitable venues UP NORTH ?

[SimontY]

Originally posted by poynton



OOOH!!!!


Anyone up for a UK diyAudio Meet?


This one works.


Andy


PS Simon.
Know any suitable venues UP NORTH ?

That link does indeed work, thanks Andy.

I'm not sure what a suitable venue is to be honest, I've never done any kind of meetup, except meeting Brent and hearing his kit! I will post on that thread to keep the off-topic-ness away.

Simon