On Mon, Feb 1, 2010 at 4:20 PM, <fons@xxxxxxxxxxxxxxx> wrote: > On Mon, Feb 01, 2010 at 01:10:03PM -0800, Kevin Cosgrove wrote: > >> On 1 February 2010 at 21:58, fons@xxxxxxxxxxxxxxx wrote: >> >> > 99 and 106 are *very bad* - how does one design a mic preamp to >> > be that bad ? Use a 714 >> >> 741? > > !!! Indeed. Or the 'wideband' 748 IIRC. This just goes to show > how old these things are... As a true Belgian I was of course > thinking of the Tintin album 'Flight 714' > <http://en.wikipedia.org/wiki/Flight_714>. General lack of design, ground routing, lack of shielding, etc. You could use an OPA627 and still shoot yourself in the foot by picking up bus noise becasue you didn't shiled low RF. Or by 'hardening' the inputs by using, eg, 1M input source current limiting resistors. Any of a million things, probably more than one of them. Really deep S/N audio circuit design takes an awful lot effort. Cost cutting, deadlines and outright supersition (One transistor is better than a whole opamp!) ruin what could have been good designs all the time. Monty _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
