Topic: RIAA Equalizer Preset

OK, this is a bit far-fetched, but I had this idea and find it very interesting: Adding an EQ preset to the ADI-2 Pro that implements an RIAA equalizer curve.

The idea is, that one could use a high quality mic preamp (like the RME - Quad Mic II for example), as a phono pre-amp, connect the output of the mic preamp to the ADI-2 Pro, set the EQ to an RIAA curve, and listen to or record vinyl.

I have just started reading about the possibility of implementing the RIAA equalization in DSP, and, from what I can see, it is quite possible.

However, I don't think this could be achieved by simply dialing in the EQ bands of the ADI-2 Pro, since some more complicated "biquads" etc. would be needed. Thus I am wondering if it would be possible to program a preset to the firmware, and allow this to be turned on individually.

I believe it is at least an interesting idea. Since the ADI-2 Pro is a serious choice for many HiFi enthusiasts, many of these would like this idea, since vinyl is still a very popular medium among these users. Good phono pre-amps are expensive, but high quality mic pre-amps are available in the pro-audio world at competitive prices and most likely at a much better cost/value.

I would love to hear your opinions!

2

Re: RIAA Equalizer Preset

That doesn't work.

1. The hardware characteristics required at the input (MM: 47 kOhm, 47 pF) are not present, so sound will be wrong.

2. The RIAA curve is quite simple and can be reproduced with the PEQ easily, except that it needs a lot more than the +-12 dB Gain available.

Good RIAA preamps are not expensive. Why fool around with half-baken solutions when the much better one is easy to get and handle, and achieves perfect results?

Regards
Matthias Carstens
RME

Re: RIAA Equalizer Preset

I think you have misunderstood my question.

The idea was not to connect a turntable directly to the ADI-2, but rather connecting it to a Mic pre-amp, and connect the mic-preamp to the ADI-2.

Also, I should add, I was thinking about MC cartridges. These most often have an output impedance of around 100 Ohms, which is suitable for a mic pre-amp.

There is a lengthy article about this method here: http://www.channld.com/pure-vinyl_faq.html
Apparently there are a few people who successfully use a mic pre-amp, so I think it would be worth a try.

Back to the ADI-2 Pro, so the max gain with the PEQ is 12 db? But if two bands are used, don't they add up to more?

4

Re: RIAA Equalizer Preset

I have no experience with MC, that might work then. I already tried to build the RIAA curve with the 5 band PEQ, but that was not possible.

Regards
Matthias Carstens
RME

Re: RIAA Equalizer Preset

MC wrote:

I have no experience with MC, that might work then. I already tried to build the RIAA curve with the 5 band PEQ, but that was not possible.

That's what I thought... the RIAA curve is a bit too complex to set up with a 5-band PEQ. I suppose it would be possible to do it "internally" with the DSP, and add it as an optional setting though... but I understand if this would be too much trouble for such rather rare cases (nevertheless, it would turn some heads in the Vinyl world!).

In the end I think you are right, why not use a dedicated phono stage. I am using one right now... from an old but wonderfully restored Accuphase E-206 smile

Anyway, I think it was worth to ask the question, it's always interesting to explore new areas with all the DSP possibilities these days.

Re: RIAA Equalizer Preset

Interesting RIAA project

https://sites.google.com/site/tarasconiprojects/

Re: RIAA Equalizer Preset

Wondering why he offers different settings for different sample rates.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13

Re: RIAA Equalizer Preset

Ask him.

Re: RIAA Equalizer Preset

drtebi wrote:
MC wrote:

I have no experience with MC, that might work then. I already tried to build the RIAA curve with the 5 band PEQ, but that was not possible.

That's what I thought... the RIAA curve is a bit too complex to set up with a 5-band PEQ. I suppose it would be possible to do it "internally" with the DSP, and add it as an optional setting though... but I understand if this would be too much trouble for such rather rare cases (nevertheless, it would turn some heads in the Vinyl world!).

In the end I think you are right, why not use a dedicated phono stage. I am using one right now... from an old but wonderfully restored Accuphase E-206 smile

Anyway, I think it was worth to ask the question, it's always interesting to explore new areas with all the DSP possibilities these days.


I'm right there with you, I've got the adi-2 pro and a flat phono pre, would love if rme could create some DSP RIAA curves, for playback and digitizing vinyl. Wherees the suggestion box?

10 (edited by pschelbert 2018-05-20 11:32:51)

Re: RIAA Equalizer Preset

Hi

I did that but with a Fireface UFX.

I have a Benz-Micro Wood MC (high output version). That one needs 47kOhm Impedance on the preamp.

The Mic inputs are to low impedance (2.5kOhm) for it. But the UFX- Instruments inputs work.

RIAA how to:
I used acourateconvolver for it, I generated the RIAA-filter with acouratepro see www.audiovero.de (has a lot of Vinyl curves not only RIAA).
It generates a FIR filter.
Loaded that filter in acourateconvolver.

Chain:
LP-Pickup (Benz Micro MC high output)-RME fireface UFX Instruments input-UFX USB out-Computer USB in- JRiver live in-acourateconvolver- back via USB to UFX- UFX outputs-power amps - loudspeakers

Results:
It works, RIAA precision is exceptional.
But: Noisewise its not optimal, would need an 47kOhm linear low-noise amp. With an MC however the RME mic inputs may work and give very low noise, may be even better than with a high quality preamp.

With a very low noise RIAA amp, I used Yamaha CX-1 (an old but still high precision low noise preamp) is better in my setup (Benz Micro MC high output) in noise. RIAA is rather good less than 0.25dB deviation) but not as good as RIAA with acourateconvolver.

Another way if you want to digitize Vinyl and RIAA electronicaly is:
Vinylstudio from www.alpinesoft.co.uk
Record linear with the RME.
Then equalize with software: Vinylstudio
or
Audacity (free software) has also RIAA curves built in buit I never tried.

Peter

Re: RIAA Equalizer Preset

Thanks pschelbert, I'll look into it, I bought a used channld seta L, have not made the leap yet it would be great to use the Rme ADI-2 pro as an Riaa and digital crossover for vinyl playback, and again for digitizing vinyl

Re: RIAA Equalizer Preset

hopefully you could got it at a decent price.
What pickup do you have?

Would be great to get feedback of RME users connecting a low output MC (low impedance) directly to RME equipment (UFX etc) on the Micro-inputs. I just have seen ADI2Pro has no Micro-inputs, so drocet connection of MC will not work. With the channelD preamp it should.

Peter

Re: RIAA Equalizer Preset

Just resurrecting this old thread. I would really appreciate a RIAA preset on the rme adi 2 black edition.

Sorting out the gain pre-the adc seems simple. I know rme won’t have legions of developers working in the firmware but as the hardware is already capable this should be relatively low hanging fruit shouldn’t it? smile

Re: RIAA Equalizer Preset

You shold check out these pages: http://www.channld.com/purevinyl/  Kind of defeats the purpouse of analog music though.

ADI-2 DAC, ADI-2 PRO, DigifaceUSB, UCXII, ARC, HEGEL.h80, KEF.ls50, HD650, ie400pro _,.\''/.,_

15 (edited by phorize 2021-06-22 13:27:31)

Re: RIAA Equalizer Preset

Happy_amateur wrote:

You shold check out these pages: http://www.channld.com/purevinyl/  Kind of defeats the purpouse of analog music though.

Thankyou for linking this. I was mainly interested in how I could use the rme adi accomplish as the hardware is already capable of doing the dsp,  provided that the firmware has a preset for the riaa curve and the input voltage incoming signal is correct. As the analogue signal from the tt is going straight into the adi adc anyway the analogue/digital question is moot. As far as I can tell dsp implementations of riaa are much more accurate than in most hardware.

I appreciate that very few users will be interested in this.