DSP-Based Phono Preamp/ADC with Digital Out?

[Soniclife]

I keep my TT in the same room as the speakers for the explicit purpose of inducing this effect.

Me too, I don't get why you would choose vinyl over CD unless you want the vinyl effect.

It's just occurred to me that maybe one of the things that leads me to massively prefer the Devialet phono stage over others I've heard, is that due to the DSP this reverb may be delayed slightly, and give the cleaner sound I perceive.

 

[dinglehoser]

As the title asks, I’m trying to find a standalone phono stage that both uses a DSP to perform the RIAA eq and outputs digital in some form.

I’ve found phono stages that A/D to do RIAA EQ in DSP, then D/A right back to output, and I can find phono stages that have a digital output, but I can’t find confirmation of a phono stage that does both. I’m intrigued by the idea of using DSP to make a better preamp, but it seems more useful to use my system’s existing DAC to d/a the signal back rather than rely on what is built-in.

Echoing other comments here, probably the cheapest and cleanest way to get both is a modded Puffin. I considered it for the same reasons, and I may yet go that direction in the future (likely when Shannon starts offering digital out as a regular option). For now, though, I'm really happy with a good analog phono pre (CA Solo) running through an Apogee Element 24 serving as an ADC (routed through its optical out).

 

[scott wurcer]

Echoing other comments here, probably the cheapest and cleanest way to get both is a modded Puffin. I considered it for the same reasons, and I may yet go that direction in the future (likely when Shannon starts offering digital out as a regular option). For now, though, I'm really happy with a good analog phono pre (CA Solo) running through an Apogee Element 24 serving as an ADC (routed through its optical out).

Has anyone tried something like a miniDSP 2X4 using the USB out? I does require a little DIY (flat gain of 100 or so pre-amp for MM). As a note to phono testers using the standard muti-tone with RIAA pre-emphasis done in the digital domain as an input is far easier and more accurate than trying to build and verify an analog filter and there are no effective noise resistance issues.

 

[Dant]

I believe the Parks audio Puffin is about to add a digital output, or at least has a DIY way to get one.
http://parksaudiollc.com

A bit of thread necromancy here, given it’s age, but Parks Audio has started selling the Puffin with a coaxial out already added. I figured it was worth updating the thread to note.

 

[bogart]

I was briefly excited by this guy - the Korg DS-DAC-10R, as I saw phono pre-amp with digital DSP for EQ!
https://www.korg.com/caen/products/audio/ds_dac_10r/

Then I finally found that the *software on the PC* handles the EQ. This device is really meant to get records onto your computer, and not really for direct playback.

Was really hoping this was the simple box analog pre-amp with digital RIAA --> DAC of my dreams. I'm posting this so the next person who has their eye on this box for the same purpose can rule it out faster

 

[bogart]

A bit of thread necromancy here, given it’s age, but Parks Audio has started selling the Puffin with a coaxial out already added. I figured it was worth updating the thread to note.

For some reason, I didn't see your post until my previous one about the Korg submitted. For only $50 more than market price on the KORG, the Puffin seems to be a feature complete digital pre-amp. Much better value, despite the price!

 

[jhaider]

For some reason, I didn't see your post until my previous one about the Korg submitted. For only $50 more than market price on the KORG, the Puffin seems to be a feature complete digital pre-amp. Much better value, despite the price!

I recently purchased a Puffin with coax output. Not for review (though I may write one of it) but necessitated by an upcoming review.

Despite an unrelated hiccup - my cartridge decided to fail contemporaneously with the phono pre replacement, sigh, so it’s now off to SoundSmith for a rebuild - I was able to try it briefly so far with my spare cartridge.

So far I like it! The top looks more subtle than it does in pictures. I prefer the connector ergonomics of my previous two phono pres - Emotiva measured here, iFi iPhono - but Puffin is quieter and the flexibility to tune to taste per album is remarkable.

 

[Jaimo]

Just thinking out aloud... what are the odds that a configuration with good (low noise) mic preamp / ADC fed into a VST plugin like UA’s Abbey Road will work well enough to replace a traditional phono pre?

Does a mic pre have enough gain?

 

[Willem]

Who knows. Why not opt for the simple solution, the Pro-ject Optical Box Ephono? https://www.project-audio.com/en/product/optical-box-e-phono/ Remember, it is not just gain, but also RIAA equalization. I really do not know of the Pro-ject box does this in the analogue or the digital domain. I am happy with mine, if only because I do not have high expectations about vinyl sound quality compared to what digital sources can and do achieve.

 

[watchnerd]

Just thinking out aloud... what are the odds that a configuration with good (low noise) mic preamp / ADC fed into a VST plugin like UA’s Abbey Road will work well enough to replace a traditional phono pre?

Does a mic pre have enough gain?

Gain aside:

How are you going to handle the cartridge loading using a mic pre?

There is no easy way to set resistance or capacitance.

 

[scott wurcer]

Gain aside:

How are you going to handle the cartridge loading using a mic pre?

There is no easy way to set resistance or capacitance.

It is easy to build a little battery powered dongle, but it is a DIY thing (buying parts, solder, etc.)

 

[watchnerd]

It is easy to build a little battery powered dongle, but it is a DIY thing (buying parts, solder, etc.)

That sounds like a complete PITA compared to the other options.

 

[scott wurcer]

That sounds like a complete PITA compared to the other options.

That's fine, ASR does not seem packed with DIY'ers.

 

[watchnerd]

That's fine, ASR does not seem packed with DIY'ers.

Sorry, I didn't mean to sound flippant.

 

[scott wurcer]

Sorry, I didn't mean to sound flippant.

Not at all, just observing a fact.

 

[jdubs]

Using

Just thinking out aloud... what are the odds that a configuration with good (low noise) mic preamp / ADC fed into a VST plugin like UA’s Abbey Road will work well enough to replace a traditional phono pre?

Does a mic pre have enough gain?

Yes, this has been done for a while now. Check out Pure Vinyl:

http://www.channld.com/purevinyl/


-Jim

 

[scott wurcer]

Using


Yes, this has been done for a while now. Check out Pure Vinyl:

http://www.channld.com/purevinyl/


-Jim

They don't sell mic-pre's. Unfortunately the mic-pre's in just about any USB device like the Scarlett 2i2 are just fine for a MM/MI cartridge except their input impedance is too low. You can make a proper cartridge interface in a small box that runs on the built-in phantom power for <$10 in parts but DIY hardware seems to scare folks off here. The result (I used a mini-DSP with two tandem IIR filters in each channel) is very good. Any DSP platform like VST should work as well or better.

Channel D sells flat phono pre-amps at quite a high price and have their own software DSP.

 

[jdubs]

Actually, take a look here:

http://www.channld.com/pure-vinyl_support_ttc.html

and here:

http://www.channld.com/computeraudio.html

I've used several regular mic preamps / audio interfaces with their software as well as with something that can host a VST or use biquad coefficients. With both MM and MC cartridges.

-Jim

 

[jdubs]

You can make a proper cartridge interface in a small box that runs on the built-in phantom power for <$10 in parts but DIY hardware seems to scare folks off here. The result (I used a mini-DSP with two tandem IIR filters in each channel) is very good. Any DSP platform like VST should work as well or better.

Scott, mind posting details re: this box?

-Jim

 

[scott wurcer]

Actually, take a look here:


-Jim

From your link...

Channel D Seta Model H Direct Coupled Wide Bandwidth Phono Preamplifier
[*]or any preamplifier or audio interface with balanced, high impedance (47 k ohms or greater) inputs and 20 dB or more gain on those inputs.*

*Preamplifiers meeting this requirement are not as common as those with microphone inputs, which is the reason why we recommend using a low output moving coil cartridge, which will work with a wider selection of computer audio gear.

Most mic pre-amps have 1k - 2k input impedance and of course will work but mis-terminate a MM cart badly and have a large effect on the frequency response, an MI cart like a Grado fares better. You don't need a balanced input since balanced connected TT's are very rare unless you re-wire them yourself.

EDIT - I don't know why they recommend the TC Impact Twin, from the specs neither the line or mic inputs can offer the correct load to a MM cart. I'll try to find my old drawings.