I'm looking to build my first proper solid-state (non-chipamp) amplifier, and the LM4702 looks like a good starting point.
http://www.national.com/an/AN/AN-1490.pdf
I'm thinking of building an exact copy, but with four channels, and using a 30-0-30 transformer for lower voltage rails and power output.
Any thoughts/advice?
Thanks!
http://www.national.com/an/AN/AN-1490.pdf
I'm thinking of building an exact copy, but with four channels, and using a 30-0-30 transformer for lower voltage rails and power output.
Any thoughts/advice?
Thanks!
Spasticteapot said:I'm looking to build my first proper solid-state (non-chipamp) amplifier, and the LM4702 looks like a good starting point.
http://www.national.com/an/AN/AN-1490.pdf
I'm thinking of building an exact copy, but with four channels, and using a 30-0-30 transformer for lower voltage rails and power output.
Any thoughts/advice?
Thanks!
Hi,
Goto Chip Amps >LME49810 - a new cousin for LM4702 thread and you will get lot of information
Regards KC
Leolabs said:What kind of power transistors are u interested in??
MN2488/MP1620s. They're about $2.50 each, but I'm not quite sure how I'm going to match them.
Might want to try the LME49810, mono so easier to layout a board. Seems to be easier to get fully stable too. The mono version of the LM4702 is not far away from release. Also might be easier to work with. Laying out a stereo board can be a little bit of a pain. IF you use Darlington devices, don't try to use more than one device per side in the output stage or you may never get it stable.
-SL
-SL
SpittinLLama said:Might want to try the LME49810, mono so easier to layout a board. Seems to be easier to get fully stable too. The mono version of the LM4702 is not far away from release. Also might be easier to work with. Laying out a stereo board can be a little bit of a pain. IF you use Darlington devices, don't try to use more than one device per side in the output stage or you may never get it stable.
-SL
I won't. I'm following the reference design to the letter, aside from decreasing the voltage rails (which I have been told won't cause any problems aside from a lower power output.)
Hey Spasticteapot, did this ever work out? I'm doing almost exactly the same thing.
I've got a bunch of chip amps laying around, knocked together a dual LM3886 (sounds alright) and am now doing an LM4702 + STD03 pair, or 2SB1560/2SD2390.
Was wondering about issues like:
1. Stability (board layout and other factors)
2. Current limit of OP stage (STD03=15A, 2SB/D=10A) and it's effect on quality
3. DC servos, speaker protection etc - what did you do here?
Just wondering really...
I've got a bunch of chip amps laying around, knocked together a dual LM3886 (sounds alright) and am now doing an LM4702 + STD03 pair, or 2SB1560/2SD2390.
Was wondering about issues like:
1. Stability (board layout and other factors)
2. Current limit of OP stage (STD03=15A, 2SB/D=10A) and it's effect on quality
3. DC servos, speaker protection etc - what did you do here?
Just wondering really...
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