Hi,
I am rebuilding my LM3886. The goal is this one is to drive bass speakers (H frame with 2 Alpha15a per side, xover 12 db at 180 hz).
I changed toroid for a 300 Va (20 volt), add a safety loop breaker and checked the mounting of course !
I have LM3875 too, and for me it's sound more "warmer" than LM3886.
I do not say that it is the truth for everyone but maybe it depends of speakers, music, and taste.
I found this :
http://www.diyaudio.com/forums/pass-labs/103050-jfet-boz.html
jfet Boz small from Nelson Pass (mess 2). I have SJ74, so maybe I can use it ?
Or do you know another way to make LM3886 a little more "warmer" ?
Phil.
I am rebuilding my LM3886. The goal is this one is to drive bass speakers (H frame with 2 Alpha15a per side, xover 12 db at 180 hz).
I changed toroid for a 300 Va (20 volt), add a safety loop breaker and checked the mounting of course !
I have LM3875 too, and for me it's sound more "warmer" than LM3886.
I do not say that it is the truth for everyone but maybe it depends of speakers, music, and taste.
I found this :
http://www.diyaudio.com/forums/pass-labs/103050-jfet-boz.html
jfet Boz small from Nelson Pass (mess 2). I have SJ74, so maybe I can use it ?
Or do you know another way to make LM3886 a little more "warmer" ?
Phil.
An externally hosted image should be here but it was not working when we last tested it.
Other upgrade, change filtering caps, it's too big, 3x10000 uF per side !
Phil.
If your LM3886 needs more warmth, first thing to do is check the grounding and decoupling arrangements.
Hi,
I think it's good about that :
http://www.diyaudio.com/forums/chip-amps/247535-lm3886-kit-am-3.html#post3744138
I remove also input cap (3,3 uF)..
Details about dac, it give 2,2 volts with 47 Ohm impedance, as brand said.
Phil.
I think it's good about that :
http://www.diyaudio.com/forums/chip-amps/247535-lm3886-kit-am-3.html#post3744138
I remove also input cap (3,3 uF)..
Details about dac, it give 2,2 volts with 47 Ohm impedance, as brand said.
Phil.
I have those same amp boards which omit a lot of stuff needed. Where is the complete Zobel?
Hi ivandezande,
You are right, it has not zobel, only serial 0,1 Ohm at output..
But what would be the effect of a zobel circuit for low frequencies (35 to 300 hz in my use) ?
Phil.
You are right, it has not zobel, only serial 0,1 Ohm at output..
But what would be the effect of a zobel circuit for low frequencies (35 to 300 hz in my use) ?
Phil.
Good point, I did not catch that. However, in case you ever use it for full range, I would say it's good to make sure everything is there for stability in the future.
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