GC 0,22R output resistor

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
In one of my Gainclones I use Caddocks MP915 0,22R in output with this schematics: http://home.comcast.net/~greggbaker/invertedLM3875.gif
Those Caddocks are quite expensive. In another of my Gainclones I used an inexpensive 0,2R power resistor, and I'm rebuilding this one, so maybe I should use the opportunity to switch to Caddocks while I'm at it, however I'm not sure I could hear any difference compared to the Caddocks....

My question is: Does the quality of the 0,22R resistor have any importance on the sound quality of this amp, at all..?

I am gonna use this 0,22r, and I won't leave it out as many have suggested :angel:

Thanks
Jan
 
the best you can do for your reputation on diyaudio.com is to post the GC sound much better with the expensive resistor, and you will never go back and use cheap resistors anymore. You even can´t understand how you ever listened to any music before with pleasure.

I personally don´t belive you or anyone human is able to hear any difference between resistors, but oops, it was a big mistake of mine to admit this here in public.
 
At the moment with my speakers and all my other gear, I cannot hear any difference. Perhaps If I tried those two configurations on some other gear I could tell a difference, who knows.

Music is what matters for me, not components. And I wonder if I was a fool spending that money on the Caddocks in the first place ;-)
Being hooked on DIY, sometimes I find myself loosing my ground control, and presuming expensier is better, instead of using my time on listening to music, that's for sure.
I trust my ears and my feelings when I listen to good music. I'm not sure I trust my ears when I have to audition audio gear.

But most importantly: I'm happy with my DIY amps and that's what counts for me, and I believe I've found in the Gainclone an amplifier I can live with for many years.

Yes Leadbelly, this posting was a waste of time.
 
Do not use a 0.22R series resistor at the output by itself. This resistor is only meant to be used in conjunction with an output inductor.

1) Output inductor is used to to provide a stable load when driving highly capacitative loads, e.g. long speaker wires.

2) Series resistor (paralled with the inductor) is to damp the LC combination.

Zobel network is for a totally different purpose. It's to provide a load at very high frequencies (where the speaker is no longer 8R).

For highly stable amplifiers like these (if used correctly), output inductor/resistor combo is not needed. Neither is Zobel.
 
I just wonder why the all schematics I've seen on
http://www.ampchipdiy.com/phpBB2/viewforum.php?f=2
includes this resistor...?

Also the most updated one http://ampchipdiy.com/invertedLM3875_r2_1.gif

:scratch:

But perhaps I should ask this question on the ampchipdiy.com forum itself...

I guess quite a few who have build this variation of the IGC have included this resistor. At least those not so experienced DIY builders like me, who stick to the book to be on the safe side ;)

If one uses this resistor, and since it's more a part of the speaker system than the GC circuit, a good non-inductive resistor must be an advantage then, and maybe my Caddocks was not such a bad pick after all...

/Jan
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.