RIAA By Edgar

[Salas]

Here's what my Preamp sounds like, within You Tube's limits, and my software's abilities, at 320kbs. "Love Alive" is a rock piece by Heart with a good bit of acoustic guitar and reasonable dynamics, as a demo piece.


Demo Piece YouTube - Rock On, Delin! 320kbs audio.mp4

You feed the A/D to make the file directly from phono line out, yes? What cart is that and what is its output level by the way?

 

[imfree707]

The Long Way Around

You feed the A/D to make the file directly from phono line out, yes?

Not quite that way, but close. I feed the output from my preamp directly into the line input of a DVD Recorder and use mp2-to-mp4 conversion software to make mp4 files, from my recorded DVD, to upload to You Tube.

 

[Salas]

And what is the cart?

 

[stocktrader200]

I am getting > 90 db signal to noise ratio using a similar setup but
with the stages reversed.
A LF353 does the RIAA equalization and output while a flat transistor
Av = 50 stage feeds the OP Amp. This works very well because the transistor amp has low noise and distortion on the (Reverse RIAA) signal while the 353 then works at much lower overall gain reducing noise and distortion.
I would think that the TL072 would be noisy (40 db noisier then mine) because of the 100x amp.

 

[Joachim Gerhard]

That is the message i got from You Tube. I can not play it in my country because the music is owned by Sony !
Move on Edgar, i find your efford way cool.

 

[Joachim Gerhard]

That -90dB noise stage i have to see. That whould be a revolution !

 

[imfree707]

Audio Technica

And what is the cart?

Hi Salas, the cartridge is an Audio Technica AT92ECD.

A user in amazon.com had one that was incompatible with his turntable and sold me a $50, retail, Cart for $13.95. Sweet deal on that one! Click specs.

AT92ECD Specs Audio-Technica 92 ECD Universal Cartridge. 1-800-229-0644.

 

[Salas]

To me is not prohibited, I saw it! Superstars from the 70's shiny record, level Leds blinking, AKAI TT and everything. I have Eq for my listening position, tuned with calibrated mic and an active sub for my desktop speakers and I cranked it up! Cool. Why you push so much level from an MM? Feeding a power amp directly?

 

[stocktrader200]

The noise figure is my preamp's contribution with cartridge connected.
Not the total noise figure from vinyl + preamp.

 

[imfree707]

SA-350, Gainclone Issues

To me is not prohibited, I saw it! Superstars from the 70's shiny record, level Leds blinking, AKAI TT and everything. I have Eq for my listening position, tuned with calibrated mic and an active sub for my desktop speakers and I cranked it up! Cool. Why you push so much level from an MM? Feeding a power amp directly?

Thanks for the kind words, Salas. I replaced the STK2038II DPP with a DIY, LM3886-based power amp and when I did, I had hum from the tone amps that does not seem power-supply related. I put a resistive pad ahead of my new power amp assembly and traded a bit of input sensitivity for lower noise. The receiver's amps still won't clip, even at 2 V P/P, about 700mv RMS, but get loud enough, with really clean sound. Thanks, again, Edgar

 

[imfree707]

Tut Mier Leid

That is the message i got from You Tube. I can not play it in my country because the music is owned by Sony !
Move on Edgar, i find your efford way cool.

Es tut mier leid dass, Sie kann mein video nicht sehen und hoerhen. Ich kann nicht GEMA bezahlen.

My German is rather rusty, as I haven't been there since 1971. I really wish you could have got it. Thank you for your kind words, Edgar

 

[Salas]

Thanks for the kind words, Salas. I replaced the STK2038II DPP with a DIY, LM3886-based power amp and when I did, I had hum from the tone amps that does not seem power-supply related. I put a resistive pad ahead of my new power amp assembly and traded a bit of input sensitivity for lower noise. The receiver's amps still won't clip, even at 2 V P/P, about 700mv RMS, but get loud enough, with really clean sound. Thanks, again, Edgar

So you spread the noise gain in the system gain structure for more even results. I don't know if we can trust that media conduit, but is it a bit soft for treble in reality?

 

[imfree707]

Perf Board Piracy

I am getting > 90 db signal to noise ratio using a similar setup but
with the stages reversed.
A LF353 does the RIAA equalization and output while a flat transistor
Av = 50 stage feeds the OP Amp. This works very well because the transistor amp has low noise and distortion on the (Reverse RIAA) signal while the 353 then works at much lower overall gain reducing noise and distortion.
I would think that the TL072 would be noisy (40 db noisier then mine) because of the 100x amp.

You have an amazingly interesting idea. My perf board circuit could be revised in the future, if I get restless and need to change it. A pair of 2SC1312's (I think that's what those super LN transistors were that Akai used in the 70/s), Darlington connected, loaded into 10k, then driving an LM4562, RIAA+10db, should really ROCK. Gotta' try that topology!

I do hear noise from my configuration through headphones, but my quiet computer fan covers the noise when I listen through speakers, even at my highest listening levels. I will try metal film 680k resistors, but I'm not sure if I can work up enough ambition to completely reconfigure that preamp.

Thanks, again your idea looks great!

 

[imfree707]

Treble A Bit Soft

So you spread the noise gain in the system gain structure for more even results. I don't know if we can trust that media conduit, but is it a bit soft for treble in reality?

So you have -54dB S/N - quite a poor result. The RIAA LF boost is supposed to rolloff from 50Hz, after boosting from 500Hz down. Yours will boost from around 300Hz down to 30Hz. RIAA also adds an optional rolloff from 20Hz down to reduce subsonics.

I would be surprised if the Pioneer RIAA is as inaccurate as this, but its your system and if your ears are happy with it . . .

It has a bit of a bass-heavy sound in reality and that could probably be corrected by going from .1uf, 100n, to the next lowest standard value in U-1's feedback network. C-1 could be "opened a little more" to increase the HF level some, as well. The You Tube rendition sounds a little "softer" than live, too.

 

[Salas]

Has more HF in this one video at least. Your first song. http://www.youtube.com/watch?v=MsW8rXPcnM0&feature=related

 

[imfree707]

Absolutely True

Has more HF in this one video at least. Your first song. YouTube - Summer Breeze - Seals & Croft #1 Hit(1972)

Agree! Upper mids and treble seem to be higher level in digital. I think deep bass is weaker or compressed in digital. Years ago I read that extreme low level signals are quite distorted in digital. I think compression and band shaping are used to keep audio within digital the formats' abilities. I really think digital is processed quite a bit differently from analog and pieces that I heard on both vinyl and digital seem to have these differences. RIAA pre-emphasis would overload at upper mid and treble levels that CD's use.

 

[Joachim Gerhard]

Stocktrader, i understand that it is only your preamp plus cartridge. It must be MM though and i thought MC. With MC something around 0.3nV qHz is the natural boundary for active stages and that transfers into around -80dB.

 

[imfree707]

New 320kbs Upload, Tweeks

Has more HF in this one video at least. Your first song. YouTube - Summer Breeze - Seals & Croft #1 Hit(1972)

Hi Guys, I went from 192-to-320 kbs on upload after raising pre-amp gain and using the Stevenson Protractor to readjust stylus overhang, in creating this new, improved demo video. It sounds brighter and clearer to me.

Akai & VinyLiberator Demo 320kbs YouTube - VinyLiberator-Rock On, Delin 320kbs audio+tweeks.mp4

 

[Salas]

Comes across brighter indeed.

 

[imfree707]

Hohren In Deutschland

That is the message i got from You Tube. I can not play it in my country because the music is owned by Sony !
Move on Edgar, i find your efford way cool.

Hi Joachim and Guys, I think this You Tube Video of my Akai AP-D2 and VinyLiberator pre amp playing the first 3 tracks of Little River Band's "Diamantina Cocktail", will play worldwide.

VinyLiberator-Freedom Cocktail... YouTube - VinyLiberator-Freedom Cocktail.mp4