Riaa component calculator

[hacknet]

hey guys,

i've been toying around with a couple phono stage simulations and i've been looking for a calculator that can help me churn out component values for the eq network.

be it a composite on or a split one. has anyone see any around?

thanks a million!!!

 

[AndrewT]

Hi,
try some of these for background & info.
http://www.diyaudio.com/forums/attachment.php?s=&postid=836387&stamp=1139076552
http://www.diyaudio.com/forums/attachment.php?s=&postid=839305&stamp=1139341846
http://www.diyaudio.com/forums/attachment.php?s=&postid=854668&stamp=1140854548

http://www.diyaudio.com/forums/showthread.php?s=&threadid=73126&perpage=10&pagenumber=3

 

[hacknet]

hey! thanks a million!!

 

[AndrewT]

Hi,
the Harms' excel sheet is much easier to use than the optimal, since optimal is designed specifically for ultra low error and to show the results.
I have posted my version with slightly tweaked values to see just how low the errors could be made and what error is permissible with component selection.

Resistor accuracy will require a good DMM, but required cap accuracy is beyond my test equipment. But the display will let me see what errors will result from component spread.

 

[hagtech]

Try this:

http://www.hagtech.com/equalization.html

jh

 

[tcqanh]

Hi all,

I'm doing adjust my RIAA circuit in my pre tube phono. my circuit is like in this http://www.mh-audio.nl/CalculateRIAA.asp.

with standard components based on that link was showed, I feel not satisfied on the bass.

So I need a software or some can estimate the result in chart.

Could any one help me ?

thanks a lot.

 

[andyr]

Hi all,

I feel not satisfied on the bass.

So I need a software or some can estimate the result in chart.

Could any one help me ?

thanks a lot.

Can I suggest the best way to get the bass you want is to either use SPICE to simulate the circuit - and then you can see what result you get from changing component values - or feed a signal from 20K to 20KHz through it (via a reverse RIAA board like Jim Hagerman's) and measure the output at each frequency on a 'scope. Then you can see what your phono stage is actually doing.

(For perfect RIAA equalisation, the output will be the same level for each frequency between 20 and 20KHz, using a reverse RIAA board.)

BTW, the passive composite RIAA network you linked to, lacks Allen Wright's "50KHz pole". This is an additional resistor R3.18 in series with C2.

This paper gives the equations to calculate the values:
SJS Electroacoustics Home Page - Makers of Arcadia Valve Amplifiers

(Click on "Read it" and then "Phono Stage Design & Schematics".)

Regards,

Andy

 

[andyr]

hey guys,

i've been toying around with a couple phono stage simulations and i've been looking for a calculator that can help me churn out component values for the eq network.

be it a composite on or a split one. has anyone see any around?

thanks a million!!!

This paper gives the equations to calculate the values for a passive composite network:
SJS Electroacoustics Home Page - Makers of Arcadia Valve Amplifiers

(Click on "Read it" and then "Phono Stage Design & Schematics".)

Regards,

Andy