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zmix

Aqua Marine

Posts: 4,066 Member Since:20/01/2011

#61 [url]

May 12 15 8:19 AM

drknob wrote:

dcollins wrote:

I personally wouldn’t settle for anything as slow as 3,000V/us, but if it’s ok for you who am I to judge?


 

Last time I heard anything that slow, I think it was called 'lightning'. Sounded good for about, oh, a microsecond.

Lightning might seem good at the time, but it's always followed by the (thunder)clap....

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Hermetech Mastering

Gold Finger

Posts: 385 Member Since:22/02/2011

#62 [url]

Jun 4 15 3:24 AM

Been searching for where I read it, but can't find it now. Anyway, what I read was someone saying that the phase response of vinyl was superb, and much better than digital. Does anyone here know if this is indeed the case, why that would be, and what the possible effects of that would be on perceived sound quality? Could it account for why so many people still prefer the sound of vinyl?

Gregg Janman, Hermetech Mastering

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dcollins

Platinum Blonde

Posts: 2,343 Member Since:27/01/2011

#63 [url]

Jun 5 15 1:23 PM

Hermetech Mastering wrote:
Been searching for where I read it, but can't find it now. Anyway, what I read was someone saying that the phase response of vinyl was superb, and much better than digital. Does anyone here know if this is indeed the case, why that would be, and what the possible effects of that would be on perceived sound quality? Could it account for why so many people still prefer the sound of vinyl?
Sometimes I hear people say that vinyl has great phase response because the RIAA encode and decode are conjugates of one another, i.e. the phase-shift of the cutters EQ is cancelled by the opposite one in the playback decode.  Which is great in theory, but no two cutters have the same encode curve as it's adjusted, one way or another, to be flat on the particular system and does not look exactly like the textbook RIAA decode curve.

In the olden days, magazines would publish pictures of the squarewave response of cartridges from a test record (the record actually has a triangle wave cut on it, but that's a story for another day) and some looked pretty good.  Faithful squarewave always means good phase response.

I think those tests were at 1kHz, but PG could verify that value and I'm sure add much more to the discussion.

Although I think it's safe to say that well-implemented digital beats vinyl in every _measured_ parameter.

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gold

Platinum Blonde

Posts: 1,505 Member Since:27/01/2011

#64 [url]

Jun 5 15 5:07 PM

I have no idea why people would say the phase response is better with vinyl. A cutterhead is pretty messy phase wise with tons of negative feedback and more than one resonance point. One of the things the Neumann ad copy bragged about was that the SX-74 only had a single resonance point in the audio band. The secondary resonance point on a Westrex is about 11k. On an SX-4 it's about 16k. They defined it out of the audio band. EBU broadcast standart flat to 15K.

 

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gold

Platinum Blonde

Posts: 1,505 Member Since:27/01/2011

#65 [url]

Jun 5 15 5:21 PM

I posted in the 33 + 45 =78 thread that I discovered something I have and thought was useless is useful. I have a NOS Panasonic CD4 quad playback system. It has a 7" NOS CD4 calibration record. Gotta be close to the only one. I have no interest in quad so I just put it on a shelf. 

I have been interested in The Soundsmith "strain gauge" cartridges. There was discussion of them but I can't find the thread. They are a cermic/crystal/piezo stylus. They are also very expensive and behave very differently than a "motor" like an MM or MC.

Turns out the Panasonic SE-405 I have is a strain gauge system. Can't wait to check it out.

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gr

Gold Finger

Posts: 356 Member Since:21/02/2011

#66 [url]

Jun 5 15 8:45 PM

I've acquired five Panasonic strain gauge cartiridges but have never found a pre for them. They're supposed to sound great if you're OK with the fact that they don't quite conform to the RIAA curve. Reallly interrested to learn what you hear.

Last Edited By: gr Jun 8 15 8:57 AM. Edited 1 time.

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dcollins

Platinum Blonde

Posts: 2,343 Member Since:27/01/2011

#67 [url]

Jun 5 15 9:14 PM

Back in the 1870's I used to run a Micro-Acoustics cartridge, same company that made the styli, and it was a piezo design. Sounded good.

http://www.roger-russell.com/sonopg/micropg.htm

The Soundsmith seems like an interesting idea. Istr the issue was it doesn't follow the RIAA curve exactly.

http://www.stereophile.com/content/soundsmith-strain-gauge-sg-200-phono-cartridge-system

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gold

Platinum Blonde

Posts: 1,505 Member Since:27/01/2011

#68 [url]

Jun 5 15 9:50 PM

The model I have is a Panasonic SE-405. It came with a cartridge, stylus, CD4 7" calibration record and the Disk Demodulator. I would think that the preamp and cartridge would have to be part of a system. The piezo needs a bias current. Markrob over on Lathe Trolls knows a lot about them. I'm still getting a lot of it wrong. I think there may be different flavors of this type.

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dcollins

Platinum Blonde

Posts: 2,343 Member Since:27/01/2011

#69 [url]

Jun 6 15 1:22 PM

The Micro-Acoustics is an electret so no external power is needed. It did have a passive network inside the cartridge for EQ. There is more in that Roger Russell link.

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gold

Platinum Blonde

Posts: 1,505 Member Since:27/01/2011

#70 [url]

Jun 6 15 8:22 PM

It seems like there are two basic varieties of these piezo cartridges. The Micro-Acoustics style that uses the piezo to generate a current and the strain gauge style like the Panasonic which biases the piezo with a current and uses the change in resisitence to directly generate a voltage. The Micro-Acoustics style as long as it has the passive componants needed to flatten out frequency response (and I to V conversion) built in could use any preamp. The strain gauge style would be a cartridge and preamp system.

 

Last Edited By: gold Jun 6 15 8:53 PM. Edited 1 time.

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gold

Platinum Blonde

Posts: 1,505 Member Since:27/01/2011

#72 [url]

Aug 13 15 5:01 PM

Wayne Kirkwood is almost done with his phono preamp system. It will be able to be built up in a lot of different ways to cover a lot of different applications. I think it's super fabulous but of course I'm biased as I've wanted something like this for years.

Highlights include two separate audio paths. A flat record path and a monitor path. RIAA EQ can be switched between them.

Remote located head amp. Typically noise is introduced in the cable run. Then head amp has audio and power on an umbillical and can be located right at the tonearm with the rest of the circuitry in a base station. The front end can also be balanced. A short run of twisted pair from the cartridge to the preamp input should keep it whisper quiet.

Lots of other posssiblities including reverse RIAA EQ. With a summing amp it could be used as a cutting preamp.

http://www.proaudiodesignforum.com/forum/php/viewtopic.php?f=6&t=423&start=160

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gold

Platinum Blonde

Posts: 1,505 Member Since:27/01/2011

#74 [url]

Sep 23 15 12:46 PM

There is some more contruction information up if you haven't looked in a few days. Yesterday I removed my old phono playback. A Shure SE22 with Lundahl step up transformers. This is way better. It looks like I'll be putting together "demo unit" to pass around and offer one off builds.

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gold

Platinum Blonde

Posts: 1,505 Member Since:27/01/2011

#75 [url]

Sep 29 15 12:10 PM

I've had this up for a little while now. It's stunning. If you ever wanted noise free playback that interfaces to a proffesional setup, this is your thing. When I say noise free I mean noise free. The noise floor is hiss with no other measureable noise componant. With monitors on stun just the slightest hiss. Take a look a Wayne's noise measurements. Mine are better than what i posted. I re did the wiring and changed a couple of things.

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gold

Platinum Blonde

Posts: 1,505 Member Since:27/01/2011

#78 [url]

Sep 29 15 4:19 PM

Hermetech Mastering wrote:
Want! And noise reduction definitely works better before you apply the RIAA curve?

I've never tried it. Wayne wanted that. I wanted the balanced front end on an umbillical. I certainly will give it a shot next time I have to do it. It would add time on becuse I would feed the processed audio back out through the RIAA decode in line level mode and record that. I don't quite trust the software RIAA I've seen.

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dcollins

Platinum Blonde

Posts: 2,343 Member Since:27/01/2011

#79 [url]

Sep 29 15 11:21 PM

Some mistakenly run linear-phase de-RIAA when the curve was put on with non-linear phase. The curves should be easy enough to match in digital though.

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