JLM 60Watt Power AMP Kit
Moderator: Joe Malone
- Joe Malone
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JLM 60Watt Power AMP Kit
Simple 60watt into 8 or 4ohm with low THD amp with balanced input.
More info here
http://www.jlmaudio.com/shop/index.php? ... oductId=18
PCB Measures 3" (76.2mm) x 1.5" (38.1mm).
Mounting holes 2.02" (51.31mm) apart and are in 0.49” (12.45mm) from edge and down 0.51” (12.95mm).
Allow 1” (25.4mm) above PCB height and at least 0.2” (5.08mm) under PCB
More info here
http://www.jlmaudio.com/shop/index.php? ... oductId=18
PCB Measures 3" (76.2mm) x 1.5" (38.1mm).
Mounting holes 2.02" (51.31mm) apart and are in 0.49” (12.45mm) from edge and down 0.51” (12.95mm).
Allow 1” (25.4mm) above PCB height and at least 0.2” (5.08mm) under PCB
Last edited by Joe Malone on Sun Oct 28, 2007 7:59 pm, edited 1 time in total.
Joe
JLM Audio
Capturing Audio without Injury
JLM Audio
Capturing Audio without Injury
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- Joe Malone
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Yes that what it is for as well as driving 20+ headphones etc.I think i just found a way to power a second set of monitors
It is just a LM3886TF which is fully insulated all over so requires no mica insulation kit. But the trick is in the circuit as it allows for balanced input and volume control with no extra IC's and keeps the LM3886 stable in all conditions. The LM3886 oscillates below the gain of 10 so the normal way to balance a LM3886 works fine until you unplug the input and then it goes supersonic oscillation at full power which tweeters don't like.
The number $2000+ Amps I have seen with the LM3886 chip in them these days is huge.
Yes and at low THD. Also you can wire a pair of AMP modules bridged and get 120watt by lowering the transformer to 2 x 18vac.That tiny little sucker is 60w??
What is a gainclone?I smell gainclone
Joe
JLM Audio
Capturing Audio without Injury
JLM Audio
Capturing Audio without Injury
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Google it. Its a clone of this expensive sucker: http://www.sakurasystems.com/products/47amp.htmlJoe Malone wrote: What is a gainclone?
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Have you though of doing an amp with the LM4780? It is basically two LM3886's in the same package. A couple cool things you can do:
1. Stereo amp on a single chip.
2. Balanced bridged amp on a single chip for 8ohm loads and higher.
3. Balanced bridged amp on two chips for loads under 4ohms by running both chips in parallel mode, and bridging two chips.
Cheers,
Zach
1. Stereo amp on a single chip.
2. Balanced bridged amp on a single chip for 8ohm loads and higher.
3. Balanced bridged amp on two chips for loads under 4ohms by running both chips in parallel mode, and bridging two chips.
Cheers,
Zach
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So, quality wise, this would not be out of place pushing a pricey set of speakers for some high quality sound, yes? I see plenty of chip amps getting around these days, all with good figures/specs.Joe Malone wrote:The number $2000+ Amps I have seen with the LM3886 chip in them these days is huge.
My DIY bug has moved from pre's and things to speakers and amps, it's infecting every part of my studio!
Oh, and it's my first post!
heath.
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Joe / Matt
(1) What the heat issue like? Do I need to bolt it to the Eiffel tower or anything?
(2) What the transformer current rating? How about the bridge rectifier?
(2) What the transformer current rating? How about the bridge rectifier?
Chris P
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I do lots of things. I believe eclectic skills are best.
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I do lots of things. I believe eclectic skills are best.
- Joe Malone
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Yes it is a good chip but not as easy to get as the LM3886 and also more difficult to heatsink well enough to keep the thermal protection from cutting in earlier than 2 x LM3886 just due to the surface area in contact with the heatsink. But would be great for a compact active monitor.Have you thought of doing an amp with the LM4780?
The LM3886 amp is good and would take a lot more $ to get a small percentage better. Still the largest percent of error is in speakers themselves.So, quality wise, this would not be out of place pushing a pricey set of speakers for some high quality sound, yes? I see plenty of chip amps getting around these days, all with good figures/specs.
No the amp runs in AB mode so it can get away with medium size heatsink but always use as much as you fit easily into the given area. A 300mm length to radial fin heatsink will look after 2 amps running fairly hard all day.What the heat issue like? Do I need to bolt it to the Eiffel tower or anything?
A 160VA will do 2 amplifiers running as a stereo pair or if you are the overkill type then use 300VA. We use 35A 400v bridge rectifiers just because they are only about $5 and if you short anything the fuse will blow before the rectifiers.What the transformer current rating? How about the bridge rectifier?
Joe
JLM Audio
Capturing Audio without Injury
JLM Audio
Capturing Audio without Injury
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Thanks for the reply, Mr Malone sir.
Do you want the community here to put up its "top 5" wish list in order? FWIW, mine would be
(1) Opto compressor
(2) EQ
(3) Simple zener regulator
(4) This beast
(5) Micro champ
Do you want the community here to put up its "top 5" wish list in order? FWIW, mine would be
(1) Opto compressor
(2) EQ
(3) Simple zener regulator
(4) This beast
(5) Micro champ
Chris P
---------------------------------------------------------
I do lots of things. I believe eclectic skills are best.
---------------------------------------------------------
I do lots of things. I believe eclectic skills are best.
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- Joined: Fri Apr 20, 2007 9:07 pm
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- Posts: 184
- Joined: Sun Mar 04, 2007 11:46 am
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Joe / Matt
I'm sketching a powered monitor idea. Mute/volume will be handled remotely.
The mute terminals can just be left unconnected, but I'm not sure what to do with the volume terminals. Should I just bridge them, or place a small value resistor there. Signal in will be 0dbVU = +4dbu.
How are these boards coming along?
I'm sketching a powered monitor idea. Mute/volume will be handled remotely.
The mute terminals can just be left unconnected, but I'm not sure what to do with the volume terminals. Should I just bridge them, or place a small value resistor there. Signal in will be 0dbVU = +4dbu.
How are these boards coming along?
Chris P
---------------------------------------------------------
I do lots of things. I believe eclectic skills are best.
---------------------------------------------------------
I do lots of things. I believe eclectic skills are best.