 
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
|
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
I'm thinking about making opamps according Pass's DIY Opamp article in AA. I want to try them of the ouput buffer of my tuner. Currently, the opamps are AD825s powered by Jung's regulators. Wondering those simple DIY Opamps sound better than very good sounding AD825?
I've tried building a pair of discrete opamps. I tried a bipolar version consisting of 3 transistors: a pair of low noise 2SC1775(NPN) for input stage, and 2SA817(1W,100MHz,PNP)for the output. I used resistors(as opposing to active current sources) for biasing.I then tried these DIY Opamps in my tuner. It worked at the first try. I listened to my tuner with these simple discrete opamps and this is my impression in comparision to the sonic of the same tuner with AD825.
Strength: The mid is fuller. no fatique after long listening session
Weakness: Lacking extension on hi/lo ends. The hi doesn't have airiness and smoothness of the AD825. Sounstage is closed in.Although the simple discrete diy opamp doesn't sound bad at all, the AD828 sounds clearly better. I have not tried to optimize the discrete opams (eg. active current sources, more biase, higher rail voltage, cascoding). I think it's fair to conclude that it takes more than a simple discrete design to sound better than good ic opamps.
What really striked me for the discrete opamp is that it's very easy to build one. I hardwired the components (3 transistors, 3 resistors)and soldered them on an ic socket. It took me less than an hour to make a pair of them.
I plan to discover more on this subject. Thanks for all the comments.
NT
Don't know much about OpAmps but all by RF friends and acquaintances (mostly from defence industry) always told me the quickest, simplest way to improve any RF reception is the antenna. Bigger and higher. Anything else is just doing it the hardway or padding costs.
DIY Preamp stages have better current drive and you can control component quality. In my experience, all opamps need biasing into class A operation to sound better. One can hear easily the improvement.
I think the only way to improve your tuner is to maximise your reception.[assuming you've not do that!] If its the descrete component version of the op amp yes it will sond better ,if you can produce near perfect solder joints and use the best quality components.
This post is made possible by the generous support of people like you and our sponsors:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
