My LM3886 Chip Amplifier
The implementation concept is from the Gaincard, one power supply unit (2x24v a.c 150VA, EI transformer), and one amplifier unit (Stereo). Overall filter cap 8800uF (2200uF in Power unit, 6600uF in the Amplifier unit). The two units are linked by a OCF three wires power cable (detachable). Some photos to share
Final product
The implementation concept is from the Gaincard, one power supply unit (2x24v a.c 150VA, EI transformer), and one amplifier unit (Stereo). Overall filter cap 8800uF (2200uF in Power unit, 6600uF in the Amplifier unit). The two units are linked by a OCF three wires power cable (detachable). Some photos to share
Final product
Here is a picture of some more capacitors in my Audio Sector amp. It has a bit more oomph and has lost none of the sweetness. Also it's a bit quieter. The value of the caps was chosen only because it was what I had on hand.
Here is a picture of some more capacitors in my Audio Sector amp. It has a bit more oomph and has lost none of the sweetness. Also it's a bit quieter. The value of the caps was chosen only because it was what I had on hand.
Very nice 6L6! it was a very good choice to put those caps instead leaving the "stock" ones. is that a TDK potentiometer there?
As this thread functions somewhat as a catch-all for several flavors of chip based projects, Here is a link to a new development that mihgt be of interest to many.
http://www.diyaudio.com/forums/chip...bolck-briangt-lm3886-upgrade.html#post2924833
http://www.diyaudio.com/forums/chip...bolck-briangt-lm3886-upgrade.html#post2924833
This is mine
Hi,
nothing special, but I like to show you.
LM3875 Audiosector premium kit;
dual mono configuration with stepped attenuator similar to the original 47 Labs Gaincard;
2 trafos 160VAx25V.
It sounds great!
Renato
Hi,
nothing special, but I like to show you.
LM3875 Audiosector premium kit;
dual mono configuration with stepped attenuator similar to the original 47 Labs Gaincard;
2 trafos 160VAx25V.
It sounds great!
Renato
Attachments
Renato -
That looks fabulous! A very nice construction.
Could you take a closer photo of the attenuator?
Is the heatsink adequate? Or is it getting hot in normal use? I'm only curious.
That looks fabulous! A very nice construction.
Could you take a closer photo of the attenuator?
Is the heatsink adequate? Or is it getting hot in normal use? I'm only curious.
I am attaching a picture of the Ebay seller Lasercollection from Hong Kong.
It is a 20K stereo log stepped attenuator with 21 steps.
For heatsinking I used two alluminium bars (one for each channels)
1cm thick and 8x5cm in size.
With the attenuator at 11 eleven o'clock the chassis is cold, at 1 o'clock it is getting warm, at 2 o'clock very warm, but never hot.
However I am a little bit worried because in summer I'll get 10deg Celsius more in ambient temperature.
I made another amp with same chassis and PCBs and I used alluminium bars a little bit longer 2-4cm and I remember a better cooling.
Renato
Attachments
LM1875 stereo "Oliva"
Here's the LM1875 stereo amplifier I built for my close friend last week. It follows a RETRO style with bakelite volume knob, tumbler power switch, 10mm amber led and all enclosed by cigar box. Led has separate transf. winding with half-wave rectifier. There's a heatsink salvaged from old PC that stays cool while listening on moderate levels with 4Ω speakers. PSU has 6 x 1800uf capacitance. Transf. salvaged from some USSR equipment.
Main problem was fitting all components in that very tight enclosure. I am very pleased with the results, both aesthetics and sound quality are good. Very low level audible hiss.
Heres some pics:
Here's the LM1875 stereo amplifier I built for my close friend last week. It follows a RETRO style with bakelite volume knob, tumbler power switch, 10mm amber led and all enclosed by cigar box. Led has separate transf. winding with half-wave rectifier. There's a heatsink salvaged from old PC that stays cool while listening on moderate levels with 4Ω speakers. PSU has 6 x 1800uf capacitance. Transf. salvaged from some USSR equipment.
Main problem was fitting all components in that very tight enclosure. I am very pleased with the results, both aesthetics and sound quality are good. Very low level audible hiss.
Heres some pics:
While I have them, I think I can share these photos.
Some time ago I built this toy for my work room and wasn’t interested in fine finish.
Heatsink was taken from blown DC/DC converter.
3 channels TDA2050V. Bipolar power supply 2x18V.
Two channels are high-passed by 2nd order 80Hz for 5.25 coaxial speakers.
One channel has the 4th order 80Hz low pass filter and used for similar, toy transmition line. (1.8 meters cardboard tube with 5.25 mid-woofer).
Pre-amplification and filtering were made with OP275GP op-amps.
I found these chips TDA2050V are not very stable. Initially, the amplifier was working, but there was problem with light instability in idle mode and post-oscillation caused by EMI from speakers. Instability was cured by capacitor in parallel with 22kOhm resistor, connecting the positive input with ground. And signs of post-oscillation were eliminated by replacing 2.2ohm resistors in zobel network by coils. Coils are approximately 5mkH, 60 turns of 0.5 mm diameter wire , coil internal diameter is 1mm and wire is wounded in 3 layers by 20 turns per layer.
Only three parts here: heatsink with power amp, chassis with power supply and frontal panel with preamplifier, very easy to take all apart.
http://www.diyaudio.com/forums/attachment.php?attachmentid=277139&d=1334437019
http://www.diyaudio.com/forums/attachment.php?attachmentid=277140&d=1334437019
http://www.diyaudio.com/forums/attachment.php?attachmentid=277141&d=1334437019
http://www.diyaudio.com/forums/attachment.php?attachmentid=277142&d=1334437019
Some time ago I built this toy for my work room and wasn’t interested in fine finish.
Heatsink was taken from blown DC/DC converter.
3 channels TDA2050V. Bipolar power supply 2x18V.
Two channels are high-passed by 2nd order 80Hz for 5.25 coaxial speakers.
One channel has the 4th order 80Hz low pass filter and used for similar, toy transmition line. (1.8 meters cardboard tube with 5.25 mid-woofer).
Pre-amplification and filtering were made with OP275GP op-amps.
I found these chips TDA2050V are not very stable. Initially, the amplifier was working, but there was problem with light instability in idle mode and post-oscillation caused by EMI from speakers. Instability was cured by capacitor in parallel with 22kOhm resistor, connecting the positive input with ground. And signs of post-oscillation were eliminated by replacing 2.2ohm resistors in zobel network by coils. Coils are approximately 5mkH, 60 turns of 0.5 mm diameter wire , coil internal diameter is 1mm and wire is wounded in 3 layers by 20 turns per layer.
Only three parts here: heatsink with power amp, chassis with power supply and frontal panel with preamplifier, very easy to take all apart.
http://www.diyaudio.com/forums/attachment.php?attachmentid=277139&d=1334437019
http://www.diyaudio.com/forums/attachment.php?attachmentid=277140&d=1334437019
http://www.diyaudio.com/forums/attachment.php?attachmentid=277141&d=1334437019
http://www.diyaudio.com/forums/attachment.php?attachmentid=277142&d=1334437019
None of your photos worked (at least not for me).
Hope you get them up, I wanna see.
-Nelson
I couldn't resist posting a link to a very nice DIY amp I found on the internet. It is a cMoy headphone amp (it uses an OpAmp, so does it count as a chipamp?) Anyway, take a look at this, it is very unique.
This amp is nothing to do with me, I just wanted to share someones amazing work:
Run Away Brainz: Audio: Crystal cMoy Freeform Headphone Amp
🙂
This amp is nothing to do with me, I just wanted to share someones amazing work:
Run Away Brainz: Audio: Crystal cMoy Freeform Headphone Amp
🙂
Thanks for sharing. Now I have to find out if I can do that with amber. And with Allen Bradley carbon comp resistors. And A TUBE. Hmm, I foresee lots of cursing if the tube dies on me.
I think I would have used a little less catalyst to allow for a cooler curing temperature, but it is an awesome looking amp all the same.