TC Electronics Switch amp

[Hurtig]

LME49990 seems like an interesting op-amp....

[KLe]

Hi AP2 and Hurtig,

The LME49990 symmetrical arrangement looks very good. What are your thoughts?

[KLe]

Hi AP2 and Hurtig

Also, the inverting slew rate is faster, so the LME49990 is probably best run in inverting mode. The symmetrical pair of LME49990s probably could be other opamps, although this would require investigation and testing.

PSRR = 144dB is excellent, THD/IMD of 0.00003/0.000017 are excellent, and it can easily drive a 600R load.

[AP2]

Hi,
Next week I will try on new project (USB input on Class D amplifier), we see how it behaves on post-DAC (192kHz).
low imp. out is good,bias current is high but this is normal for good linearity etc.
Not always the good features of a chip, guarantee a good performance of the circuit where it is used.

[KLe]

Originally Posted by AP2

Hi,
Next week I will try on new project (USB input on Class D amplifier), we see how it behaves on post-DAC (192kHz).
low imp. out is good,bias current is high but this is normal for good linearity etc.
Not always the good features of a chip, guarantee a good performance of the circuit where it is used.

Hi AP2
Have you tried the LME49990? What was the result?

[AP2]

Hi, Kle you remembered my test.
yes, I tested opamp (simple filter / buffer) on DAC, unfortunately the result is not good, I have a lot of noise in the base of the signal (op-is very good) usual problem of the DAC statement.
I also tried with simple NE5532 getting the same result.
After much deliberation we decided to test the "DSP-ADAU-1702. contains 4 "DAC" low noise / thd. and good power for the code. (firmware)
this ambitious project, create a standard port usb2 on amplifier for future / upcoming developments.
I've used / programmed Blackfin 547AD for other uses.
see how it goes.

[KLe]

Originally Posted by AP2

Hi, Kle you remembered my test.
yes, I tested opamp (simple filter / buffer) on DAC, unfortunately the result is not good, I have a lot of noise in the base of the signal (op-is very good) usual problem of the DAC statement.
I also tried with simple NE5532 getting the same result.
After much deliberation we decided to test the "DSP-ADAU-1702. contains 4 "DAC" low noise / thd. and good power for the code. (firmware)
this ambitious project, create a standard port usb2 on amplifier for future / upcoming developments.
I've used / programmed Blackfin 547AD for other uses.
see how it goes.

Hi AP2
Thanks for the feedback. Please keep us informed.

Kurt and Hurtig have given any further consideration as to how LME49990 can be used with the TC module.

[mbl]

How new TC switiching power amp (e.g. dynaudio acoustics air series)compare with MC2 MC 1250 power amp(previous dynaudio acoustics active power amp)?

[Charles Darwin]

I have not compared them but bear in mind that the reason Dynaudio Acoustics switched from MC2 to TC amps is not because they thought it is a better amp, it is because TC Group bought Dynaudio Acoustics. That was why Dynaudio stopped selling drivers to the diy community and doubled the prices for spares too.

That said I have yet to hear any amp better than the MC1250.

[tiefbassuebertr]

to get more informations about different circuit topologies of discrete (actually quasi-discrete) solutions instead integrated solutions, I start this threads:

Ultimate sounded Class D for diy without custom made IC's like Tripath TA2020
Sanyo/B&O Icepower 200AC Rev.D, schematic about rev. engin., not complete finished

The most filed Class-D subjects here on diyaudio unfortunately mainly integrated solutions like IRF, TI or Tripath. This isn't of interest for me, because there are no many possibilities for evaluations. I want to have discrete topologies and evaluation kits for P-spice simulations and real life tests.
If you have informations about this, please send your replies by my first mentioned thread here - thank you very much in advance.