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.
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.
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.
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 AP2Hi,
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.
Have you tried the LME49990? What was the result?
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.
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 AP2Hi, 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.
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.
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.
That said I have yet to hear any amp better than the MC1250.
to get more informations about different circuit topologies of discrete (actually quasi-discrete) solutions instead integrated solutions, I start this threads:
http://www.diyaudio.com/forums/clas...made-ics-like-tripath-ta2020.html#post2158225
http://www.diyaudio.com/forums/clas...ic-about-rev-engin-not-complete-finished.html
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.
http://www.diyaudio.com/forums/clas...made-ics-like-tripath-ta2020.html#post2158225
http://www.diyaudio.com/forums/clas...ic-about-rev-engin-not-complete-finished.html
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.
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Dynaudio Acoustics air series studio monitor used lab gruppen class D amp
Is it true?
Is it same leauge as MC2 MC 1250 amp?
Some eng. said the sound of lab gruppen better than MC2 MC 1250.
What is your opinion?
I have not really got an opinion as I have not so far been able to compare both directly.
That said I have heard a few opposing opinions ie that MC2s sound better than LabGruppen.
One was regarding Tannoy-badged amps. Tannoy chose to use MC2 amps to sell under their brand until Tannoy too was bought by TC Group after which they obviously had to use LabGruppen who are also owned by TC Group.
Andi Munro who started the DynaudioAcoustics range of monitors on behalf of Dynaudio chose MC2 as the best sounding amps. Roger Quested of Quested Audio (highly regarded studio monitors which were used by Abbey Road until Abbey Road got paid to use B&W systems by the powers that be) swears blind that MC2 MC series amps are the best amps made today bar none.
Personally I have been able to a/b MC2 amps directly to Quad, Phase Linear, QSC and Bryston and they bettered all of those easily and I know of two people who replaced their substantially more costly Chord amps with MC2 MC1250s after hearing them.
Personally I stopped worrying about amps altogether since I got three MC2s for my stereo.
I have got no idea how many amps LabGruppen produces per year but there are always plenty on the s/h market. MC2 makes around 10 000 but they are a rare find s/h.
That said I have heard a few opposing opinions ie that MC2s sound better than LabGruppen.
One was regarding Tannoy-badged amps. Tannoy chose to use MC2 amps to sell under their brand until Tannoy too was bought by TC Group after which they obviously had to use LabGruppen who are also owned by TC Group.
Andi Munro who started the DynaudioAcoustics range of monitors on behalf of Dynaudio chose MC2 as the best sounding amps. Roger Quested of Quested Audio (highly regarded studio monitors which were used by Abbey Road until Abbey Road got paid to use B&W systems by the powers that be) swears blind that MC2 MC series amps are the best amps made today bar none.
Personally I have been able to a/b MC2 amps directly to Quad, Phase Linear, QSC and Bryston and they bettered all of those easily and I know of two people who replaced their substantially more costly Chord amps with MC2 MC1250s after hearing them.
Personally I stopped worrying about amps altogether since I got three MC2s for my stereo.
I have got no idea how many amps LabGruppen produces per year but there are always plenty on the s/h market. MC2 makes around 10 000 but they are a rare find s/h.
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