Turntable rca to USB audio interface 1/4 connection - options?

I'm trying to get good quality copies of my LP's in the digital domain. I tried the Rega fono analog to digital conveter, the Pro-ject Box USB V converter and finally the Alpha Design GT40, all of these very nice and well made, but the resulting ripped music sound sucks. I tried many resolutions, have pretty decent cables (transparent audio, cardas etc.) fiddles with lots of settings in Audacity, and the sound is still poor. Poor relative to e LP, and to a hi rez diwnkoad or purchase.

reading through the Pure Vinyl website it says that it is better to manage the RIAA equalization in the digital domain and that bypassing a phono preamplifier and using a good ADC is the way to go.

I have a Presonus usb interface I use for recording instruments and was wondering if I can connect my turntable directly to the Presonus, using the rca and an 1/8 adapter to plug in the intrface line in?

i see these adapters in the internet but something tells me that they will kill the signal quality, and how do the unbalanced to balanced work? Anyhow, you can tell I dont really know where to begin.

My table is a Rega RP6, I have a Creek OBH 18 MM pre and an Apple powerbook. The sounds from my vinyl is awesome, and when i get the equivalent HD Tracks hi rez download, the sound is ok, but the analog of the LP is better. I would like to know if there is a way to capture some of that sounds by transferring vinyl to the Mac, and use higher quality usb audio interfaces vs. these usb phone preamps that are in the market place.

thanks

 

No, you need a phono stage somewhere in that equation.

 

ok, thank you.

can i connect the rca's out of my phono stage to an adapter and then to the 1/4 line in of ,y usb interface?

 

just in case you are interested, I did connect the rca's out of my preamp to the Presonus VSL 44 using RCA to 1/4 adapters bought from Amazon. Then I recorded using Audacity. The results were much better than what I obtained with the Rega or Pro-ject phono preamps and analogue to digital converters. I suspect I'm losing some signal quality by using cheap rca-1/4 adapters so will research that some more.

Thus far this is the best set up I've tried to burn vinyl to hi rez flac files. The USB tuerntables including the Sony and AT are really bad in comparison.

Anyway, this seems to be a decent way to make copies of vinyl. The sound still is not as good as my tape recordings or as listening to the LP directly.

 

I'm very happy with my HRT Linestreamer.
Works like a champ with a PS Audio GCPH preamp.
Can hardly tell the difference between a vinyl and my needledrops.

I've since moved to an Avid phono preamp. Not as versital as the PS Audio, but another step up in quality.

 

Results I'm happy with-
Table-->Phono Pre (Lounge)-->(Using Monster RCA to 1/4) Focusrite 2i2-->USB to Computer
I was using adapters but was getting some interference, so I went with an all in one cable

 

I saw in another forum, a person asked an audio interface rep (from Apogee) if they could connect their turntable directly into the line inputs. The rep said it was possible if they used a plugin or app that applies the RIAA curve back to the signal. I forget the name of the program they linked to that would do it... Also, I think it was said, it would be better because you would eliminate some of the connections and sound stages.

The 1/4 input on the presonus will take either TS or TRS. You could fit the RCA with an adapter or rewire the TT with TS or TRS... I read somewhere that the signal from the tonearm is actually a balanced signal. I dont know enough about it, but thats what I gathered from the discussion.

 

With Vinylstudio, you can add the RIAA curves in the software. I think Purevinyl does it also.

 

Presonus interfaces are for only Mic or instrument (electric guitar) inputs, none of the models seem to have line in.

The balanced mic in is 1200 ohm, which, while providing enough level boost, will not properly load a phono cartridge requiring 47,000 ohms. The unbalanced instrument in is 500kΩ, also not correct. Besides the very low phono level making noise a concern, the cartridge response would not be anywhere near correctable when improperly loaded.

Take instead a Focusrite Scarlett, for example of a line-level ADC, has more appropriate input specs for a cartridge, impedance 52kΩ, but with capacitance unspecified (but probably low). It would seem that you could get 60dB+ of dynamic range from phono voltage levels, but remember that RIAA curve boosts treble by nearly +40dB, so comparatively, the bass may have very high electronic noise floor after a digital plugin's RIAA bass boost.

Fortunately RIAA curve doesn't rely on the signal level (like Dolby noise reduction, for example), so if you can record the cartridge with a electrically flat signal, any digital RIAA curve that does its job correctly will restore the original sound at any recording level.