Re: Any reason to build discrete OpAmps for High Quality Audio?

From: Ban (bansuri_at_web.de)
Date: 07/26/04 

Date: Mon, 26 Jul 2004 14:02:29 GMT

John Woodgate wrote:
> I read in sci.electronics.design that Ban <bansuri@web.de> wrote (in
> <D26Nc.53498$5D1.2536091@news4.tin.it>) about 'Any reason to build
> discrete OpAmps for High Quality Audio?', on Mon, 26 Jul 2004:
>
>> And when you make a cartridge preamp for your ultimate HiFi
>> turntable, you have to boost the low frequency quite a lot (at least
>> 60dB) because of the RIAA eq.
>
> The curve is +18 dB at 30 Hz and -18 dB at 16 kHz, both ref. 1 kHz.
> That's 36 dB if you count all the EQ as 'bass boost', which is not
> reasonable. No 60 dB anywhere.

Right, a V15III has 3mV at 5cm/s output, which should be amplified to a
suitable level say 500mV to get the same output as a CD-player. This makes
+62.44dB. Now you can put a little less gain to -10dBV which is 14dB less,
but nowhere near 36dB. I prefer the higher gain to not overload the amp when
switching sources without turning down the volume pot. Anyway even 40dB gain
is a lot and a low noise corner and low offset will give more satisfying
results. It is actually quite a challenging task and IMHO really needs a
good opamp in this application.
If we operate the opamps at +/- 15V we still have 25dB headroom with 500mV
output. 

-- 
ciao Ban
Bordighera, Italy

Relevant Pages

  • Re: Confused about Pole Zero Compensation of Double Integrator
    ... > integrators has 180 degrees of phase shift at all frequencies. ... > compensator has run out of puff, ... > integrator has plenty of gain. ... but it still snakes back to graze the jw axis at low frequency ...
    (sci.engr.control)
  • Re: Connecting to neighbors wireless
    ... I get a weak signal now but need to be able to boost ... I bought a Hawking Hi gain directional antenna that plugs into the ... Did you get the nighbors permission to use their wireless system? ... John Navas FAQ for Wi-Fi: ...
    (alt.internet.wireless)
  • Re: the inevitable xmas music backlash thread
    ... that most of it is a shallow attempt by washed up singers/bands trying to gain at least a little boost in sales. ...
    (rec.music.phish)
  • Re: 1st try kt88 amp
    ... found in the original Mullard circuits where we find 6L6, 5881, Etc. ... To get the loop gain well below ... unity at the low frequency where the phase lead becomes 180 degrees ...
    (rec.audio.tubes)
  • Re: the inevitable xmas music backlash thread
    ... that most of it is a shallow attempt by washed up singers/bands trying to gain at least a little boost in sales. ... the whole holiday has been warped into a momument to our consumer society. ...
    (rec.music.phish)