Thanks Andrew, it doesn't put me off.
I know just how much heat these chips can generate.
SPIKE is not a saviour, it is an absolute last resort for these chips to save themselves.
Frank
(With all his heatsink fins nice and cool, outside the box!)
I understand perfectly your points of view, guys, because I was also worried about heat and that's why I performed the tests. 10W are WAY too loud for my ears. The heatsink will be moved outside for sure, but in the future. I lack some tools for wood work and I'm too lazy to go buy them.
Heatsink in a box
Just look at this one:
Remember the laws of physics?
I truly believe that a lot of folk here think that heat disappears forever into a "heatsink" as its name implies!
http://www.diyaudio.com/forums/atta...ushbutton-hookup-chipamp-problem-dscf0182.jpg
Just look at this one:
Remember the laws of physics?
I truly believe that a lot of folk here think that heat disappears forever into a "heatsink" as its name implies!
http://www.diyaudio.com/forums/atta...ushbutton-hookup-chipamp-problem-dscf0182.jpg
pentium II heatsink!!!
Well done good sir!
LM1875s as well. You have decent speakers i would imagine!
Well done good sir!
LM1875s as well. You have decent speakers i would imagine!
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Yessir ! 🙂
saying the truth, it came from an ancient Celeron (Slot A) 300MHz..
(cooling enough for this 2xLM1875, but not enough for my former 2xLM3886 🙁 )
and (talking about Truth 😀) you can see my ufficial speakers ( BEHRINGER: B2031P )
EntryLevel but so honest speakers..
former photos showed you a no-cost recycling experiment, taking speakers and xover from an unused car audio setup.. 😎
saying the truth, it came from an ancient Celeron (Slot A) 300MHz..
(cooling enough for this 2xLM1875, but not enough for my former 2xLM3886 🙁 )
and (talking about Truth 😀) you can see my ufficial speakers ( BEHRINGER: B2031P )
EntryLevel but so honest speakers..
former photos showed you a no-cost recycling experiment, taking speakers and xover from an unused car audio setup.. 😎
Attachments
My new 3875T Chipamp
While I was waiting for some OPT's to arrive for another project, I decided to revisit my little chip amp and redo it. I built the orginal version about 8 years ago. Since then I have learned alot and decided to rebuild it into the form you see.
The LM3875 is operated in inverted mode and has +/- 25V rails with 4500uF on each rail. 1000uF of it is right at the chip. Had some HexFred diodes laying around so I threw them in as well. To put the mandatory Blue LED needed for a chip amp I wound an extra coil on the tranny. Used 8 wraps to get enough juice to light it properly.
The bottom plate is 1/2" thick aluminum plate. The chip is clamped to the plate and insulated with a mica insulator. Pretty pleased for a weekend worth of work to keep me out of trouble.
While it doesn't sound like my 300bSET it does sound good. Solid bass and good detail. Good enough to go to college with my son.
I have some spikes for feet to allow air to flow underneath, but need to get a M6-1 tap on Monday
While I was waiting for some OPT's to arrive for another project, I decided to revisit my little chip amp and redo it. I built the orginal version about 8 years ago. Since then I have learned alot and decided to rebuild it into the form you see.
The LM3875 is operated in inverted mode and has +/- 25V rails with 4500uF on each rail. 1000uF of it is right at the chip. Had some HexFred diodes laying around so I threw them in as well. To put the mandatory Blue LED needed for a chip amp I wound an extra coil on the tranny. Used 8 wraps to get enough juice to light it properly.
The bottom plate is 1/2" thick aluminum plate. The chip is clamped to the plate and insulated with a mica insulator. Pretty pleased for a weekend worth of work to keep me out of trouble.
While it doesn't sound like my 300bSET it does sound good. Solid bass and good detail. Good enough to go to college with my son.
I have some spikes for feet to allow air to flow underneath, but need to get a M6-1 tap on Monday
Attachments
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Hi Renato,
I've bought this case from this ebay seller, but as I can see he currently doesn't have the box that you can see on my pictures.
Regards Ales
Here's my build thread.
http://www.diyaudio.com/forums/chip-amps/156829-lm3886-chipamp-project-resurrected.html
And some pictures.
http://www.diyaudio.com/forums/chip-amps/156829-lm3886-chipamp-project-resurrected.html
And some pictures.
that's some power supply, infact your capacitors must be heavier than your transformer ... I bet they store enough charge to last you through black outs
The amp played (at low output though) half a minute after power-off....
Dont remember the cap size anymore, but I guess they are 47.000 uF each, or maybe even bigger.
Dont remember the cap size anymore, but I guess they are 47.000 uF each, or maybe even bigger.
I bet they do 😀... u should also have 0.1 uf soldered right onto the last caps ...if u don't have them already
Here's my build thread.
http://www.diyaudio.com/forums/chip-amps/156829-lm3886-chipamp-project-resurrected.html
And some pictures.
i really like that 😎. Not to sure how safe the top 'grill' is though, also maybe treat the wood like a guitar neck