●OPアンプ シングル to デュアル変換アダプター通販 ASE-Audiotuning ttp://www.audiotuning.de/english/index.html?1-2-adap.html Soundlabs Group ttp://www.soundlabsgroup.com.au/browndog/browndog_single_dual_opamp_smt.htm Cimarron Technology, Inc. ttp://cimarrontechnology.com/
Using alternative OP-AMP type for the input stage. [OPTIONAL] Be Careful... The input OP-AMP has significant effect on the sound quality. We have chosen LM6172 as the standard type, based on it’s good performance, and high stability. Some features of LM6172 is UGBW of 100 MHz, and a slew rate of 3000 V/uS. Other types may have better performance, and therefore we have placed the LM6172 in a socket, so it’s easy to experiment with other types. The LM6172 has a standard pin-out for a DUAL op-amp in 8 pin DIP package. This is also the same pin-out as NE5532, TL072, OPA2134, AD712 etc. etc. Some of these op-amps will actually work in a NewClassD amplifier, however of course with lower performance than LM6172. To get a good result from another OP-AMP here are the features of that OP-AMP, you should look for: High Unity Gain Bandwidth ( > 50 MHz ). Low Group Delay / High slew rate. ( > 100 V/uS ). Stable at +/- 4.5V to at least +/- 6V. Low input noise ( < 10 nV/Hz ). Low input current noise ( < 3 pA/Hz ). Low input BIAS current (as this can otherwise lead to DC offset on the output ). We have had good results from using LM4562 (also from National Semiconductor ), even though it exhibits much higher THD than LM6172 in a NewClassD amplifier (because it's slower than LM6172 ), it has a warmer and more pleasant sound to it, but still with myriads of detail. We have also heard people who had very good experience with a OPA627 DUAL module, and described it as sounding 'simply heavenly'.