Does RIAA software Equalizer exist? Options

[johnsonlam]

Hello,

I'm now transfer the Vinyl to the PC through my DIY phono. But I'm thinking ... can I skip the phono and record directly to PC, and then apply a software RIAA EQ?

But I fail to find any software EQ, even CoolEditPro didn't have such a preset or plug-in!

Anyone know about this?

Please advise, thanks in advance.


Rgds,
Johnson.

This post has been edited by johnsonlam: Apr 27 2005, 04:07

[woody_woodward]

Audacity can do RIAA Eq. You're likely still going to need a pre-amp, with EQ or without. A phono cartridge puts out such a small signal, I know of no sound cards that can accept it directly.

[DigitalMan]

Not only is the signal that comes out of a phono cartridge very weak but it requires a specific loading (resistance and capaticance) otherwise the frequency response and output level can be significantly affected. Also, the reverse RIAA curve is pretty extreme attenuation - you may lose quite a bit of resolution if you went straight into a typical 16 bit A/D and tried to do the RIAA curve in software. But, it might sound fine, and a software RIAA curve would likely be more accurate than a hardware one.

[johnsonlam]

Audacity can do RIAA Eq.  You're likely still going to need a pre-amp, with EQ or without.  A phono cartridge puts out such a small signal, I know of no sound cards that can accept it directly.

Thanks Digital Man and Woody woodward.

I've borrow my friend's M-Audio Firewire 430, the signal seems enough to feed into the line in.

Not only is the signal that comes out of a phono cartridge very weak but it requires a specific loading (resistance and capaticance) otherwise the frequency response and output level can be significantly affected. Also, the reverse RIAA curve is pretty extreme attenuation - you may lose quite a bit of resolution if you went straight into a typical 16 bit A/D and tried to do the RIAA curve in software. But, it might sound fine, and a software RIAA curve would likely be more accurate than a hardware one.

I don't have enough information about these. So I'll try both and compare the result.

[[JAZ]]

What about getting/borrowing a Mixer table? I would find very strange that one doesn't have the phono input.

[slangtruth]

Not only is the signal that comes out of a phono cartridge very weak but it requires a specific loading (resistance and capaticance) otherwise the frequency response and output level can be significantly affected.  Also, the reverse RIAA curve is pretty extreme attenuation - you may lose quite a bit of resolution if you went straight into a typical 16 bit A/D and tried to do the RIAA curve in software.  But, it might sound fine, and a software RIAA curve would likely be more accurate than a hardware one.

Over 20 years ago I worked for a medium-high-end audio manufacturer, and our spec for RIAA curve matching was very tight - I forget exactly what the published spec was, but in practice we were usually within +/- .1 to at most +/- .2 dB over the 20-20K range (and yes, we did have the proper equipment to accurately measure this). Considering that within the analog realm this spec held at all signal levels, I'd actually be kind of surprised if a DSP software function could do as well.

[Woodinville]

Considering that within the analog realm this spec held at all signal levels, I'd actually be kind of surprised if a DSP software function could do as well.

Now this I don't understand. It would seem to me that given the deterministic behavior of a DSP algorithm, it would be much easier (perhaps using spline or impulse invariant mapping, instead of matchz or binlinearz) to assure one's self that the RIAA curve in-band was as close to exact as you would want.

The problem I see is one of noise floor and dynamic range. Even assuming you can fill all bits of the ADC and it's 20 bits, the degree of spectral slope in the RIAA curve is going to really mess up the noise floor something awful, and perhaps result in massive slew limiting as well, if you wind up clipping the ADC. For that reason alone I'd say you have to do this in the low-level analog domain.

This post has been edited by Woodinville: Apr 28 2005, 21:47

[slangtruth]

Considering that within the analog realm this spec held at all signal levels, I'd actually be kind of surprised if a DSP software function could do as well.

Now this I don't understand. It would seem to me that given the deterministic behavior of a DSP algorithm, it would be much easier (perhaps using spline or impulse invariant mapping, instead of matchz or binlinearz) to assure one's self that the RIAA curve in-band was as close to exact as you would want.

The problem I see is one of noise floor and dynamic range. Even assuming you can fill all bits of the ADC and it's 20 bits, the degree of spectral slope in the RIAA curve is going to really mess up the noise floor something awful, and perhaps result in massive slew limiting as well, if you wind up clipping the ADC. For that reason alone I'd say you have to do this in the low-level analog domain.

Exactly. Me no mathematician, but an 8KHz (easily audible in music) signal on the RIAA curve is already about 25db down from a 100 Hz signal which is to be reproduced at the same level, and even that 100 Hz signal is down about 6dB from a 30 Hz note on the same record. Now assume that both the 100 and 8K signals are 30 db down from the peak level on the record, again, not unreasonable with real music - are you left with enough bits to be able to say with certainty whether or not your 8K signal is within .2 dB of the ideal? The mathematics of the RIAA curve are calculable, but in practice with present day equipment available to consumers I don't think you could pull it off.

[antz]

Not only is the signal that comes out of a phono cartridge very weak but it requires a specific loading (resistance and capaticance) otherwise the frequency response and output level can be significantly affected.  Also, the reverse RIAA curve is pretty extreme attenuation - you may lose quite a bit of resolution if you went straight into a typical 16 bit A/D and tried to do the RIAA curve in software.  But, it might sound fine, and a software RIAA curve would likely be more accurate than a hardware one.

I'd second this in terms of a cartridge needing specific loadings and having a low output. A pre-amp is pretty essential, although most sound cards have a mic input that might have an adequate sensitivity if there's no other choice. Don't know where that'd leave you in terms of frequency response however!

It'd definitely be easier to do the RIAA equalisation within a pre-amp though, rather than in software. I agree with later posts on this thread that a digital solution is likely to be poor at best. The line-out from an integrated amplifier would likely be the best source for the AD input. It wouldn't be too difficult to make an RIAA-compensated pre-amp of reasonable quality for very little cost either.

[johnsonlam]

,Apr 28 2005, 03:24 AM]What about getting/borrowing a Mixer table? I would find very strange that one doesn't have the phono input.

A mixer is too expensive for me and consuming too much space (bad living standard)!
Also I seldom "mix" sources (only have one source!), in my city only the "professional" use mixer because it's big and cost too much.

This post has been edited by johnsonlam: May 1 2005, 20:51

[johnsonlam]

It'd definitely be easier to do the RIAA equalisation within a pre-amp though, rather than in software. I agree with later posts on this thread that a digital solution is likely to be poor at best. The line-out from an integrated amplifier would likely be the best source for the AD input. It wouldn't be too difficult to make an RIAA-compensated pre-amp of reasonable quality for very little cost either.

I made one already, but playing with my friends M-Audio Firewire 430 we found that the input was too high (using the input on the back), that input is a direct through so nothing can be adjust.

Later, we change the input to the front and found that the gain can be adjusted, but the result is not so good, so I want to bypass the phone stage.

The phono sounds good with my pre-amp but matching the A/D converter is difficult since the output too large.

[antz]

It'd definitely be easier to do the RIAA equalisation within a pre-amp though, rather than in software. I agree with later posts on this thread that a digital solution is likely to be poor at best. The line-out from an integrated amplifier would likely be the best source for the AD input. It wouldn't be too difficult to make an RIAA-compensated pre-amp of reasonable quality for very little cost either.

I made one already, but playing with my friends M-Audio Firewire 430 we found that the input was too high (using the input on the back), that input is a direct through so nothing can be adjust.

Later, we change the input to the front and found that the gain can be adjusted, but the result is not so good, so I want to bypass the phone stage.

The phono sounds good with my pre-amp but matching the A/D converter is difficult since the output too large.

Put an attenuator in the line then?

[PSD192]

Take a look at www.behold-highend.de. They can solve your problem!!!

You will see the new PSD192 - a full digital phono stage for MC and MM at 192kHz/24Bits. The equaliziation will be done by a DSP.

Also the PSD192 has digital and analog outputs. Recording via USB is also possible.

Greetings
Peter

[cliveb]

Take a look at www.behold-highend.de. They can solve your problem!!!

You will see the new PSD192 - a full digital phono stage for MC and MM at 192kHz/24Bits. The equaliziation will be done by a DSP.

Peter:
1. Welcome to HA.
2. Be careful about spreading your commercial posts too widely. It would be a shame for you to be branded a spammer on your first day here!
3. The PSD192 does indeed look like an interesting device. How much does it cost?

[PSD192]

Take a look at www.behold-highend.de. They can solve your problem!!!

You will see the new PSD192 - a full digital phono stage for MC and MM at 192kHz/24Bits. The equaliziation will be done by a DSP.

Peter:
1. Welcome to HA.
2. Be careful about spreading your commercial posts too widely. It would be a shame for you to be branded a spammer on your first day here!
3. The PSD192 does indeed look like an interesting device. How much does it cost?

The PSD192 is a highend audio device with an interesting price. There are two version. The full version has a digital phono stage and a digital motor control unit for one synchronous motor an costs 2100 EUR. Without motor control unit the price is 1800 EUR.
The PSD192 was shown first at the highend 2005 in munich.

Greetinfs Peter

[johnsonlam]

Put an attenuator in the line then?

That will reduce the clarity and transparent of the signal. Now I'm start working on LP->CD slowly, since the FireWire can use the front input to adjust input gain, but click and pop is another problem.

Thanks.

[johnsonlam]

The PSD192 is a highend audio device with an interesting price. There are two version. The full version has a digital phono stage and a digital motor control unit for one synchronous motor an costs 2100 EUR. Without motor control unit the price is 1800 EUR.
The PSD192 was shown first at the highend 2005 in munich.

Sounds like a good idea, but the price really high.

It should be a very HIGH-END product, but sorry that I can't afford except there're discount

[mas528]

Hello,

I'm now transfer the Vinyl to the PC through my DIY phono. But I'm thinking ... can I skip the phono and record directly to PC, and then apply a software RIAA EQ?

But I fail to find any software EQ, even CoolEditPro didn't have such a preset or plug-in!

Anyone know about this?

Please advise, thanks in advance.


Rgds,
Johnson.

Yes, you can apply the RIAA curve in software, and surprise , you can also remove it.

DC6 from Diamond Cut will do this for you, quite easily.

I am not sure what the standard version costs, but from memory it is about 200 dollars.

There is also info on the net about how to create both RIAA and Reverse RIAA in CEP.