He who used to ask is safely away from the earth now...AndrewT, you are missed.
Oh my, I did not mean it like this, just wanted to be clear before someone asks. Only now I realise that he was the one asking about it all the time. I want to be clear that I didn't think of anyone by saying that. i miss him too. I read this forum since I was like 14 years old, and now I am 25. I always respected him.
LM1875 Stereo amp
Few pictures for the gallery. I posted build photos elsewhere but this the finished product now with 3A fast blow fuses on each rail between the PS and amplifier boards. Seems to work really well.
Few pictures for the gallery. I posted build photos elsewhere but this the finished product now with 3A fast blow fuses on each rail between the PS and amplifier boards. Seems to work really well.
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Yes. But what about your next apartment? 😀Hi
Just finished this little amp. Well, kinda finished, it still needs some deburing around all those holes in cover, and some flat front panel to hide those ugly holes in the front.
Talking about technical side, its very basic amp. I used KM TECH pcb from ebay, which is not perfect, but very close to datasheet, which is star grounded layout. Maybe sometime, I will make my own with improvements.
Parts used are mostly standard application stuff, except power supply caps. I used 1uF ceramics in place of "normal" 100 nF, and 22 uF instead of 10 uF. And ditched the 2.7 ohm resistor between signal and power grounds, because I don't see how it can do something good, if thinking based on feedback and ground routing suggestions, presented by forum member tomchr, it only can make things worse.
Amp has DC protection, since I had it laying around from unfinished project and because it has thiele network. Power supply PCB is from same project and has 12V regulator. Transformer is 2x17 VAC, 100VA.
DC protection need 12VDC, so I added 12.6V winding.
Before someone asks about safety earth, there isn't one in my apartment, so adding it to the projects is useless.
Why do you use such small ones to supply power to the modules, and yet thick wires to the speaker terminals?
All the current that flows to the speakers has to come from those tiny wires.
10 yrs later I pull them out of storage and assemble them with no documentation.
That is a great label job and attention to detail by the seller!
Thanks again Russ for making such an awesome kit.
HUGE, HUGE, HUGE thank you to the dear departed Mauro for sharing his design with us. This is my second pair as I have been enjoying the first for some time but now I need 6 channels for active XO.
That is a great label job and attention to detail by the seller!
Thanks again Russ for making such an awesome kit.
HUGE, HUGE, HUGE thank you to the dear departed Mauro for sharing his design with us. This is my second pair as I have been enjoying the first for some time but now I need 6 channels for active XO.
This amplifier took part in the Exhibition "Russian Hi-End-2018" and received very good reviews.
There are some chances to go to the Exhibition in Munich.There will be auditions on the subject soon.
Photo: the square wave of 100 kHz (in the kitchen🙂) the square wave of 300 kHz and 500 kHz square wave and some stages of assembly. Temperature on copper radiators not more than 50 degrees Celsius.
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Had a few of "00940" open source PCBs for the LM3886 made. An open source layout for LM3886? Stuffed them with pretty low spec components. 35v +- PSU. Source is a usb Behringer U-Phoria UM2. Heat sink is a bit OTT, but spare!
Sound pretty good powering a couple of near field monitor speakers.
Sound pretty good powering a couple of near field monitor speakers.
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Chip Amps Amplifiers based on integrated circuits
Here is my LM4780 Chip amp integrated with a tone control circuit.
Sounds fairly good and has ample power. LM4780 power amp layout was done on EAGLE SW. Aluminium cabinet top cover covered with black vinyl.
S. Ramdass
Here is my LM4780 Chip amp integrated with a tone control circuit.
Sounds fairly good and has ample power. LM4780 power amp layout was done on EAGLE SW. Aluminium cabinet top cover covered with black vinyl.
S. Ramdass
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Composite amps
Hi All,
Let me share some photos about my creations. From the time I listened a composite amplifier I'm experimenting with nothing else... 🙂
IMG 1..3: Composite OPA128+TDA7386 in 2.1 config (xover @120Hz 2nd order with NP0 caps in the satellite channels). With RC filter and some Kmultipliers (thx Keantoken!). In the pics there is OPA2134s for the test.
IMG 4..5: Composite OPA1642+TPA6120 with modified Meyer crossfeed and similar PSU system as above. Virtual ground using a diamond buffer (Walt Jung buffer).
IMG 6: Composite OPA140+LM3886 with solid wireing. Common passive filters+Kmultis and filtered Zener PSU for the OPAs. I applied a DC sopper in the primer circle.
IMG 7: My 2nd composite headphone amp for conducting OPA-test (listened more than 70 differend OPAs and buffers) and testing some supply rail filter designs for the distortion cancelling OPA. In the picture my first discrete OPA is attached with a diamond buffer. Cap-multi, Kmulti and passive VGND (virtual ground). For the 1st OPA I loved 2x220R+470uF rail filter: simple and efficient.
Hi All,
Let me share some photos about my creations. From the time I listened a composite amplifier I'm experimenting with nothing else... 🙂
IMG 1..3: Composite OPA128+TDA7386 in 2.1 config (xover @120Hz 2nd order with NP0 caps in the satellite channels). With RC filter and some Kmultipliers (thx Keantoken!). In the pics there is OPA2134s for the test.
IMG 4..5: Composite OPA1642+TPA6120 with modified Meyer crossfeed and similar PSU system as above. Virtual ground using a diamond buffer (Walt Jung buffer).
IMG 6: Composite OPA140+LM3886 with solid wireing. Common passive filters+Kmultis and filtered Zener PSU for the OPAs. I applied a DC sopper in the primer circle.
IMG 7: My 2nd composite headphone amp for conducting OPA-test (listened more than 70 differend OPAs and buffers) and testing some supply rail filter designs for the distortion cancelling OPA. In the picture my first discrete OPA is attached with a diamond buffer. Cap-multi, Kmulti and passive VGND (virtual ground). For the 1st OPA I loved 2x220R+470uF rail filter: simple and efficient.
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