Phono Termination Calculations and Calculator

[jackinnj]

Reference Recording LP's are available from their website (but note that some are 45 rpm, not 33's)

 

[jackinnj]

Noise should be about 6dB higher with the resistively loaded case.

Both are resistively loaded.

 

[billshurv]

I have enough RR, Wilson, Sheffield labs and Crystal clear on vinyl for any collection, although the Don Mclean albums on CD more recently are superb, if needing to have the HDCD decoded.



What I meant was that in loading low enough to get a passive 75us rolloff you get a chunk noisier. That's why Bob only went to 8kHz, although it was shown here that a cooled load does work well here.

 

[jackinnj]

track #3 of that RR recording of Slavonic Dances -- when me and my buds did the listening test for the regulator article in Linear Audio you could un-mistakenly decipher the issues with some of the designs.

 

[billshurv]

Doesn't look like the LP is currently available. Shame as always helps to have same test music as others.

 

[jan.didden]

So, we can do this -- substitute LM4562 for LME49710 in each case. The gain setting resistor in the T5 compensated amplifier is lowered to 88 ohms so that the gains of both amplifiers are almost exactly equal. a 1us pole replaces the 75us pole so that some of the values change.

I'm open to suggested recording torture tests. We've used "Rachmaninoff Symphonic Dances, Funeral March Andante con moto (tempo di valse), Reference Recordings 5" -- good (excellent) if you can find it.

Jack what happens if you add a few 100 pF to the input as cable cap in each case?

Jan

 

[jackinnj]

Jack what happens if you add a few 100 pF to the input as cable cap in each case?

Jan

Just theoretical -- the actual charts from the Bode 100 were created using a Shure M78 cartridge -- the simulations are close to what to expect from a Shure V15:

 

[jackinnj]

Noise (simulated) is higher with the damped input: