I think I already got that. There's a couple of plastic caps right after the regulators, between rail and ground. Later there's a 47uF electrolytic cap in parallell with a 100nF plasic just before the supplypins of the OP-amps. Since I etched the PCBs mirrorimaged I had to mount the OPs on the copperside while the other components are on the other.
Here's the layout.
The Freebird by Russ White
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kmj:
Yes, I see: 100 nF (0.1 uF) right there on your silk screen/board designations ... 😎
Looks like a very good board layout as well ... plenty of ground plane around the output, etc.
One might assume then that the hum is from an outside radiation source ... 😕
Yes, I see: 100 nF (0.1 uF) right there on your silk screen/board designations ... 😎
Looks like a very good board layout as well ... plenty of ground plane around the output, etc.
One might assume then that the hum is from an outside radiation source ... 😕
..hi to everybody..
this wonderfull "chip amp" thread motivated me to use my scrap pile and assemble one to acompany a small woofer for my experimental esl's ..
.. so i take the opportunity to present you my "sandwich" realisation..
all in one chassis-monoblock, transformers are doubled to get center tap from 17vac outputs and 220vac (2x110) input, rectifiers are doubled because i had them, capacitor bank is not that big as they are 470ìf/200v each from pc psu's x12, tda1514 is shelded from ps with unetched grounded boards ..
here is what i mean :
this wonderfull "chip amp" thread motivated me to use my scrap pile and assemble one to acompany a small woofer for my experimental esl's ..
.. so i take the opportunity to present you my "sandwich" realisation..
all in one chassis-monoblock, transformers are doubled to get center tap from 17vac outputs and 220vac (2x110) input, rectifiers are doubled because i had them, capacitor bank is not that big as they are 470ìf/200v each from pc psu's x12, tda1514 is shelded from ps with unetched grounded boards ..
here is what i mean :
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.. and a closer shot of the chips wires and parts..
this is the simplest of the datasheets application cirquit without the bootstrap .. i dont know if this is better or not, except for the comment of the datasheet saying i'll loose some 4 watts of output..
..if someone could explain in simple words the bootstrap effect on cirquirtry and audio quality i would appreciate it mucho..
this is the simplest of the datasheets application cirquit without the bootstrap .. i dont know if this is better or not, except for the comment of the datasheet saying i'll loose some 4 watts of output..
..if someone could explain in simple words the bootstrap effect on cirquirtry and audio quality i would appreciate it mucho..
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My First NIGC
Just sharing my first kit I got from Madaboutsound.
NIGC Monoblocks
I'll change the casing for the monoblocks if I find a better one
thanks for looking...🙂
Just sharing my first kit I got from Madaboutsound.
NIGC Monoblocks
I'll change the casing for the monoblocks if I find a better one
thanks for looking...🙂
Hi Audio Chippers
My first post.
I am very excited to have joined this wonderful community.
This is my first LM3875 based amp (hoping the photo uploaded) built in Jan 2003 before I had heard of GC or diyAudio, Parts and PCB are far from ideal but it sounds better than many Hi Fi amps I have auditioned.
PS is through the DB25, +/-42v. Also tried with +/-36v batteries but sounds much the same.
Have built 7 more amps with the LM3886 and another 3 using paralleled LM4780 the first in Aug 2003, They all sound much the same with just very subtle differences.
I have more photos if anyone is interested?
Just finished a paralleled LM4780 with regulated power supplies (+/- 38v), Sounds very warm and probably the best sounding amp so far.
Now working with the LM4702
My first post.
I am very excited to have joined this wonderful community.
This is my first LM3875 based amp (hoping the photo uploaded) built in Jan 2003 before I had heard of GC or diyAudio, Parts and PCB are far from ideal but it sounds better than many Hi Fi amps I have auditioned.
PS is through the DB25, +/-42v. Also tried with +/-36v batteries but sounds much the same.
Have built 7 more amps with the LM3886 and another 3 using paralleled LM4780 the first in Aug 2003, They all sound much the same with just very subtle differences.
I have more photos if anyone is interested?
Just finished a paralleled LM4780 with regulated power supplies (+/- 38v), Sounds very warm and probably the best sounding amp so far.
Now working with the LM4702
Attachments
Kooka: Very clean! ... very sanitary ...
That power line moduler line filter = a nice touch, often overlooked and it works as you probably know ... likewise, the "bulkhead firewall" shielding the amp stage from the transformer & power supply & power switch (!!). (Also noticed: the common power / chassis ground connection is the center mount lug of your torrid transformer = good thinking = shielded from the amp at center of the major electro-magnetic field ... )
Good show!
That power line moduler line filter = a nice touch, often overlooked and it works as you probably know ... likewise, the "bulkhead firewall" shielding the amp stage from the transformer & power supply & power switch (!!). (Also noticed: the common power / chassis ground connection is the center mount lug of your torrid transformer = good thinking = shielded from the amp at center of the major electro-magnetic field ... )
Good show!
Thanks guys for the nice comments.
What made a big difference after installing them are the 2 big extra capacitors on the supply. I am a newby in GC world, so nothing new to you all...
What made a big difference after installing them are the 2 big extra capacitors on the supply. I am a newby in GC world, so nothing new to you all...
