Search found 11 matches

by carlalex
Mon Oct 12, 2015 11:46 am
Forum: Pro Audio Design
Topic: LM4562, LME49710, LME49720 Start-up Behavior
Replies: 42
Views: 116707

Re: LM4562, LME49710, LME49720 Start-up Behavior

Yeah. I was already planning to change to a dual package for the one place I am using it. And when it comes down to it, I don't think alternative parts would require much change.
by carlalex
Mon Oct 12, 2015 9:58 am
Forum: Pro Audio Design
Topic: LM4562, LME49710, LME49720 Start-up Behavior
Replies: 42
Views: 116707

Re: LM4562, LME49710, LME49720 Start-up Behavior

Bummer. Although, it seems from the announcement that was posted that the LME49720MAX is the designated replacement; Wonder how long that will stick around. No replacement for the single opmp version, which I was actually planning to use over a package with an unused opamp I'd have to power. No thro...
by carlalex
Tue Sep 22, 2015 10:08 am
Forum: Pro Audio Design
Topic: LM4562, LME49710, LME49720 Start-up Behavior
Replies: 42
Views: 116707

Re: LM4562, LME49710, LME49720 Start-up Behavior

I don't know the model number but hear that Bruno also makes a plate amp version of the hypex amp with a DSP built in , so that would be mission designed and cover the crossover with even more capability. I've designed analog crossovers and there are things that digital just does better (like delay...
by carlalex
Tue Sep 22, 2015 9:42 am
Forum: Pro Audio Design
Topic: LM4562, LME49710, LME49720 Start-up Behavior
Replies: 42
Views: 116707

Re: LM4562, LME49710, LME49720 Start-up Behavior

I didn't see anything particularly strange when I hit the 2072 with very high signals when I was playing with prefixing gain stages. I was interested in the low-end sensitivity, but hit it with over 20v out of thoroughness since that would be the other effect of a high gain stage in front of it. Bu...
by carlalex
Tue Sep 22, 2015 12:09 am
Forum: Pro Audio Design
Topic: LM4562, LME49710, LME49720 Start-up Behavior
Replies: 42
Views: 116707

Re: LM4562, LME49710, LME49720 Start-up Behavior

I was wondering if a low-power 5V standby voltage-powered op amp could be used as a comparator to detect signal presence and then bootstrap itself and the higher-current balanced input to +15V (and -15V) supply levels. An input that powers itself down and provides a power on, mute output and/or sig...
by carlalex
Mon Sep 21, 2015 11:59 pm
Forum: Pro Audio Design
Topic: LM4562, LME49710, LME49720 Start-up Behavior
Replies: 42
Views: 116707

Re: LM4562, LME49710, LME49720 Start-up Behavior

I see the NJM2072 has 20K input resistors: http://www.njr.com/semicon/PDF/NJM2072_E.pdf Unless I read that wrong it's "input resistor" as in just one resistor. I guess you could use two 2072s and hang one off both inputs, but that raises a second issue. The 2072 looks like inverting with ...
by carlalex
Mon Sep 21, 2015 11:41 pm
Forum: Pro Audio Design
Topic: LM4562, LME49710, LME49720 Start-up Behavior
Replies: 42
Views: 116707

Re: LM4562, LME49710, LME49720 Start-up Behavior

I see the NJM2072 has 20K input resistors: http://www.njr.com/semicon/PDF/NJM2072_E.pdf Do you suppose that the NJM2072 could be bridged across the +In directly allowing the balanced input stage to be powered down? I realize in this application the 10 mA of the first LM4562 doesn't represent a lot ...
by carlalex
Mon Sep 21, 2015 11:17 pm
Forum: Pro Audio Design
Topic: LM4562, LME49710, LME49720 Start-up Behavior
Replies: 42
Views: 116707

Re: LM4562, LME49710, LME49720 Start-up Behavior

My current project: designing some loud speakers with integrated amplifiers for home use. Making saw dust is always fun but hard to improve upon decent commercial designs, while many consumer speakers are less than optimal. Crossover design is much too complex for a brief post.but includes multiple...
by carlalex
Mon Sep 21, 2015 10:19 am
Forum: Pro Audio Design
Topic: LM4562, LME49710, LME49720 Start-up Behavior
Replies: 42
Views: 116707

Re: LM4562, LME49710, LME49720 Start-up Behavior

My followers are also lm4562s. I'm using those for everything in the signal path. Unit cost is less of an issue when it's a hobby. The one place I was considering using something else was the input stage I posted. Since it's not in the audio path and on all the time I was going to look for something...
by carlalex
Mon Sep 21, 2015 9:14 am
Forum: Pro Audio Design
Topic: LM4562, LME49710, LME49720 Start-up Behavior
Replies: 42
Views: 116707

Re: LM4562, LME49710, LME49720 Start-up Behavior

Thanks for the tip on the unused stage; I'll do that. Maybe I should have been clearer. That stage will almost never be shut down. The stages that will see more on and off cycles are the ones behind the "to low noise input and crossover" outputs. This is the stage that I see that wacky 90 ...