[Mikey01]

I have an interesting question. I have just recieved my modded Denon 3910 DVD player. It is now fully broken in. It still has the op-amp output stage in it, although the op-amps were switched out for better ones. However, not content with leaving any stone unturned, I would like to know if "Diamond buffers" could be added to the audio output stage of this Denon, like LaRocco uses in there Headphone amps. If it can, would this be only for the most "electronic engineer proefficient" type of person to do, or could most "DIY'ers", who have built op-amp headphone kits do it? Any body interested in the job? Can it even be done?

 

[guzzler]

Buffers are used to boost the output current available from a circuit (they are convertors of high impedance to low impedance). Your CD player is only delivering a tiny amount of current to your amplifier as the input impedance to the amplifier will be in the 10,000s range. Also, it is likely the opamp is providing some voltage gain for the output, which the buffer can't do.

What you could do is try a discrete opamp..............

Hope that helps

 

[Mikey01]

Thanks for the reply. Any body want to expand on the "discrete opamp" theroy?

 

[thedoctor]

Quote:

Originally Posted by Mikey01 Thanks for the reply. Any body want to expand on the "discrete opamp" theroy?

something like a transistor based gain stage i suppose?

you could swap the Opamp with a diamond buffer if should the Opamp is used in unity-gain to just beef-up the current for the output. to check whether it's in unity gain (working as buffers), try checking for continuity between the opamp output legs and the -signal.

 

[tyre]

a few discrete opamps...

http://www.forsselltech.com/JFET990-2.htm
http://www.johnhardyco.com/990OpAmpDetails.html

 

[thedoctor]

Quote:

Originally Posted by tyre a few discrete opamps... http://www.forsselltech.com/JFET990-2.htm http://www.johnhardyco.com/990OpAmpDetails.html

LoL.. check out the prices.