Audioman54
With your references you will not stay long unemployed.!
May I take the ( sad) opportunity to ask some questions I have on the LME serie.
First when you mention that the lme49811 is better sounding that the LME49810, was it with the same ouput power stage and bjt or mos ?
It looks to me that the lme49811 is more or less the mono version of the 4702.
Reading the specs, the LME49811 and 49810 are very close with one exception: the open loop dominant pole is larger for the 49811/4702 than the 49810 Is this the reason of sound difference?
Is the baker clamp usefull from a sound quality point of view?
In the system I am designing ( 10 amplifiers to be used in the Orion Linkwitz speaker), the amplifers are monitored by a pic controller. The dc on ouput, fsoa and short circuit detect are monitored by the pic that will shutdown the chip. Can we consider the mute input on the LME49810 as having the same performances as the shutdown pin in the LME489811 for this use.
In other words can we use the mute input as an efficient shutdown to be used as output protection in case of short circuit.
In the application note you wrote on the use of the 4702, you mentionned the bad effect of the input coupling capacitor, is this a major effect or a subtle one?
Can you describe the output stage of the LME 49811, the one of the LME49810 has been given. As I understand, it is the same as the 4702, a VAS stage current source loaded.
I am using the LME49810 with a T ouput stage triple ( Locanthi/Leach). I use the output stage of the LME49810 as first driver of the triple with thermaltracks as ouput. Do you think that it would be worth to use the LME49811 instead and use a discrete out of chip first driver stage.
As a side comment, it is a pitty that two ouput diodes where included on the chip to compensate for the vbe drops of the ouput buffer. Without them, we would have more headroom in the design of the Vbe multiplier. multiplication factor. This is important if we use the thermaltracks and if we intend to adjust the thermal tracking of the diodes.
A last and very important question: is the output current seen on the bias pins very stable in operation such that the biasing can be done with a potentiometer and diodes without Vbe multiplier.
Do you expect some degradation by bringing the Vas collector signal far away from the chip in the diodes of the thermatrack transistors. Will a shunting capacitor help there?
A lot of questions sorry, but thanks in advance for your comments
JPV
