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JCF AD8: What PEP does to audio?
Old 17th July 2013
  #1
Gear Head
 

JCF AD8: What PEP does to audio?

From AD8 manual:
Quote:
1) What does PEP actually do to my audio files/waves?
We aren't telling you. There are plenty of smart folks out there who will be able to fig- ure it out.
So what's behind the marketing hype?

I understand this is a purely digital, high-latency process, which theoretically could be performed by a separate dsp box and applied to any digital signal.
PEP doesn't affect the analog to digital conversion (unless it happens before the digital decimation filters), it's just the digital signal post-processing.

What do you guys think?
Old 17th July 2013
  #3
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seaneldon's Avatar
 

Marketing hype?

I'd bet that the average person spends more on coffee every week than JCF spends on marketing in one year.

Amazing box. Worth the bread. Gotta pay to play.
Old 18th July 2013
  #4
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This is from the manual. To me it makes no sense whatsoever. Digital recording has not removed the need for audio engineers to understand the path sound takes through electronic equipment. If anything, it has increased that need.
______________________________________________
However, the "progress" of digital recording came with unforeseen consequences. Recording music is not merely making a copy of sound, it is the art and science of capturing sound to a specific medium. Audio engineers no longer need to understand the path sound takes through electronic
equipment to achieve a result; they now see waveforms on a screen and manipulate musical representation without a tangible understanding their actions (read: playing video games). Analog recording forced the engineer to physically confront the medium and tools that they were recording to and
through. Digital recording adds a degree of separation that allows engineers to base their decisions on what makers of hardware and software tell them they need to buy in order to get a desired sound. This
easily usurps the necessity to use audio equipment effectively and efficiently.

The benefits of recording digitally displaced the science of recording quickly enough that the ramifications of the shift are still being unravelled.
_______________________________________

The benefits of recording digitally has not displaced the science of recording.

Can someone explain to me what he's talking about?

-R
Old 18th July 2013
  #5
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RKrizman's Avatar
 

Josh was kind enough to take a session of mine and process the individual tracks through PEP. I lined them up in the original session, dry and at the same levels and did a couple of bounces to 44.1/16. No reverb, no processing on the 2 bus, so the levels are somewhat low.

So hear for yourself and see what you think. I'm tempted to say which is which to avoid a "gotcha" thread, but better to keep it blind at first so you can form your own impressions.

I have a theory as to what he's doing, but I have to think a bit before I articulate it.

-R
Attached Files

Say-PEP test Blue (short).wav (8.67 MB, 4660 views)

Say-PEP test Red (short).wav (8.67 MB, 4554 views)

Old 18th July 2013
  #6
Gear Head
 

I read both the manual and the aboutpep.pdf and it all just sounds like snake oil for the audiophile market. I'm not trying to discredit the company, I'm just saying their description is confusing.
Old 18th July 2013
  #7
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RKrizman's Avatar
 

Yes, it's confusing. I don't really understand the following statement either, from the manual:

<The medium of tape imparts an fortuitous time-based phenomenon onto the recording that gives it a certain "feel" that is not incidental to the listening experience. PEP was developed from our ability to apply mathematics to achieve an even better result without tape.>

What is this "fortuitous time-based phenomenon"? (plus I wish people would proofread their brochure copy)

-R
Old 18th July 2013
  #8
Gear Head
 

I prefer the Blue version.
however, the difference between the two is not subtle.
Blue sounds like a mastered file.

your session was already in digital domain,
so how exactly was is processed?
Can AD8 process an external digital signal through PEP?
Old 18th July 2013
  #9
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RKrizman's Avatar
 

Yes it can be processed after the fact.

-R
Old 18th July 2013
  #10
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heyman's Avatar
Huge difference on ****ty laptop speakers, Blue sounds rounder, has more definition, space and the highs are a lot smoother.

My guess is Blue is the JCM tracks.

I would hate to hear the difference on really good speakers.
Old 18th July 2013
  #11
Gear Head
 

I listened on a laptop first, and then on Barefoots MM27 through a Weiss DAC1-MK3.
My first impression from a laptop, Blue had more definition and detail.
Then on Barefoots, I was surprised how much the midrange was scooped in Red, making the bass guitar cloud everything else.

Again, it feels like the processing is much heavier then tracking to a real tape would have been.
Old 18th July 2013
  #12
The blue one (I think it was the blue one) sounds thicker in the bass guitar, and more difficult to separate the bass from from the kick drum. Also, the bass seems a bit more dynamic in the blue one, during the crescendos.

I prefer the red one (or at least the one I think was the red one). I like having the subtle extra sense of space between the bass and kick. Although, to be honest, the differences between both are subtle to my ears.
Old 18th July 2013
  #13
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BradM's Avatar
Quote:
Originally Posted by RKrizman View Post
Yes, it's confusing. I don't really understand the following statement either, from the manual:

<The medium of tape imparts an fortuitous time-based phenomenon onto the recording that gives it a certain "feel" that is not incidental to the listening experience. PEP was developed from our ability to apply mathematics to achieve an even better result without tape.>

What is this "fortuitous time-based phenomenon"? (plus I wish people would proofread their brochure copy)

-R
Yeah, I'm at a loss too. All of these PEP descriptions read like audiophile magazine reviews.

What "fortuitous time-based phenomenon" does tape impart onto a recording? I really want to know. I use tape. Are they referring to wow and flutter? Is that the secret sauce? Some subtle semi-random pitch variations?

Brad
Old 18th July 2013
  #14
Gear Maniac
 

Blue for me and not subtle imo.
Old 18th July 2013
  #15
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RKrizman's Avatar
 

I don't get it. If it's a digital processing thing then why does it have to be linked to the A/D converter. It could be a plugin, or a separate digital processing box. They might be onto something good, but doing themselves a disservice with the mysterioso marketing language.

-R
Old 18th July 2013
  #16
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RKrizman's Avatar
 

If you weigh in about the files I posted I'll IM you which is which.

-R
Old 18th July 2013
  #17
Gear Head
 

From the manual:
Quote:
2) Why don't don't we make PEP a plug-in?
It will encourage people to consider what they are monitoring and as of present day and for the future in view, the process is so computationally intensive it will not work without a dedicated processor for a number of channels commensurate with the AD8's intended use.
Old 18th July 2013
  #18
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RKrizman's Avatar
 

But what does that mean?
Old 18th July 2013
  #19
Gear Head
 

I think the logic behind PEP is weak.
The assumption is that recording to digital is inferior to recording to analog tape.
The proposed solution is a DAC, which converts analog to digital using exactly the same principles as any other, then PEP recalculates the digital signal.
But the damage has already been done, the pre-PEP signal is already digital, so what's the point? A one-fits-all preset that is supposed to magically change digital into analog?
Whatever detailed was lost capturing to PCM, it is lost.

A better/different digital technology, which feels closer to analog already exist, it's DSD.
Old 18th July 2013
  #20
Fezzle
Guest
Quote:
Originally Posted by Sugar View Post
I think the logic behind PEP is weak.
The assumption is that recording to digital is inferior to recording to analog tape.
The proposed solution is a DAC, which converts analog to digital using exactly the same principles as any other, then PEP recalculates the digital signal.
But the damage has already been done, the pre-PEP signal is already digital, so what's the point? A one-fits-all preset that is supposed to magically change digital into analog?
Whatever detailed was lost capturing to PCM, it is lost.

A better/different digital technology, which feels closer to analog already exist, it's DSD.
Sensory perception and maths, hard to figure out sometimes whether measurements/presumptions correlate to what is "better".
Doug Sax one of the best mastering engineers on the planet begs to differ, he chose JCF's PCM conversion over Meitner DSD to make his living, because he felt they sounded better. Interesting how a converter design based on older technology that on paper says it 'shouldnt' sound better, does. Im with the punks on this. Even if you are right and the logic behind PEP is weak, perhaps logic is a poor model for good sound.
Old 18th July 2013
  #21
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claend's Avatar
 

Quote:
Originally Posted by heyman View Post
on ****ty laptop speakers,
Oh please... not you!
Old 18th July 2013
  #22
Sorry Rick, I'm gonna hafta pass on listening to the examples you posted, having used this hardware enough times to know what it does.

In my understanding the PEP technology is to be strictly used with the AD8 and nothing else. I could have missed something about doing that, it's possible. Obviously, it's running through the process regardless, but I really don't think it's meant to be used this way, as once you've encoded to digital, you can't go back.

Sending your already pre-recorded tracks [with another AD converter?] through the all digital PEP process is not how you use the AD8 or PEP mode. The only way that is kosher, in my experience, is if you've recorded all your tracks with the Low Latency Mode of the AD8 and you want to send them through the PEP D/D loop.

But here, you've already went through another brand of AD conversion! The AD8 is a passive design, and uses no operational amplifier in the signal path. Only a Custom Input Transformer that sounds "lovely". This is about 98.756743% of its vibe. The PEP feature is like the icing on the cake. Seems like you guys are listening to icing, that you put on another cake.

So I really don't think this would be an accurate indicator about how the AD8 will work in your room. I'm just saying it's unsafe to judge without first hand experience. You might hate the thing, who knows?? I'm not really losing sleep either way, I am just warning you. You need to use the unit for AD conversion [in both modes and D/D] in your own studio.

As I always expect, highly creative thinking outside the realm of traditional thinking is met with resistance. But it's all good, because dem are just words, and words don't make records. I am glad there is a digital box around that "forces you to think" about what your doing and how your doing it. Not to mention, the fact that it sounds nothing like any AD converter I've ever used.

JCF Audio developed PEP technology from their own musical experience. It's their proprietary design. They don't care to discuss what exactly it is. I don't blame them. There is no need for me to know what it is. All I need to know is how to use it and why. I hear what it does and I get why I would use it. As they say "if your smart, you'll figure it out"...

Its actually pretty easy,
If you want to use PEP while tracking, you need to have the musicians monitor the signals in analog, and the engineer can monitor post DAW. The musicians hear the mix you build from the analog signals, and the engineer shapes the recorded signal through the "power equalization process" and his chosen DA converter.

Can't do that? OK, then you record with the Low Latency mode, with musicians and engineers monitoring from the DAW and later on, you can send your AD8 Converted Tracks through the PEP mode's D/D [Digital to Digital] processing, back into new audio tracks in the workstation. Viola.

peace
a.j.b
Old 18th July 2013
  #23
Gear Head
 

Quote:
Originally Posted by Doc Mixwell View Post
Sending your already pre-recorded tracks [with another AD converter?] through the all digital PEP process is not how you use the AD8 or PEP mode. The only way that is kosher, in my experience, is if you've recorded all your tracks with the Low Latency Mode of the AD8 and you want to send them through the PEP D/D loop.
A PCM signal from any ADC has exactly the same format, unless they use some proprietary audio watermarking. So how is the AD8's digital signal different?
please elaborate.
Old 18th July 2013
  #24
Gear Head
 

from JCF website
Quote:
  • No active analog audio path electronics
  • Cinemag analog input transformers
a contradiction?
Old 18th July 2013
  #25
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RKrizman's Avatar
 

Quote:
Originally Posted by Doc Mixwell View Post
Sorry Rick, I'm gonna hafta pass on listening to the examples you posted, having used this hardware enough times to know what it does.

In my understanding the PEP technology is to be strictly used with the AD8 and nothing else. I could have missed something about doing that, it's possible. Obviously, it's running through the process regardless, but I really don't think it's meant to be used this way, as once you've encoded to digital, you can't go back. ........


.......you record with the Low Latency mode, with musicians and engineers monitoring from the DAW and later on, you can send your AD8 Converted Tracks through the PEP mode's D/D [Digital to Digital] processing, back into new audio tracks in the workstation. Viola.

peace
a.j.b
I see a contradiction in these two paragraphs.

To clarify, Josh, the "J" of JCF, apparently thinks it's valid to process tracks after the fact, as he contacted me and offered to process my tracks and send them back to me in order to demonstrate the process, which is what you are hearing. Or in your case, not hearing (wtf?)

To reiterate, PEP can work on digital tracks created by other converters. Evaluating PEP and evaluating the JCF converter can be done independently, and the former is what we're exploring here.

-R
Old 18th July 2013
  #26
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RKrizman's Avatar
 

As I said, I'm sharing these files only as a matter of providing interesting content to the thread, not to create a "Gotcha" situation, so I'll just tell you now that the Red file is PEP.

-R
Old 18th July 2013
  #27
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RKrizman's Avatar
 

Quote:
Originally Posted by Sugar View Post
from JCF website


a contradiction?
I believe a transformer is a passive device.

-R
Old 18th July 2013
  #28
Gear Head
 

Quote:
Originally Posted by RKrizman View Post
I believe a transformer is a passive device.

-R
yes, my mistake
Old 18th July 2013
  #29
Quote:
Originally Posted by RKrizman View Post
As I said, I'm sharing these files only as a matter of providing interesting content to the thread, not to create a "Gotcha" situation, so I'll just tell you now that the Red file is PEP.

-R
I love it.

So many convinced that Blue was. So much for the bandwagon. I like the PEP thing, and I'm glad to know that I liked it all along, even not knowing which "it" was.
Old 18th July 2013
  #30
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RKrizman's Avatar
 

Quote:
Originally Posted by Doc Mixwell View Post
I've ever used.

JCF Audio developed PEP technology from their own musical experience. It's their proprietary design. They don't care to discuss what exactly it is. I don't blame them. There is no need for me to know what it is. All I need to know is how to use it and why. I hear what it does and I get why I would use it. As they say "if your smart, you'll figure it out"...
First of all, if "your smart" you'll use the word "you're". (I'm not correcting spelling here, I'm pointing out an irony)

Secondly, so if you don't figure it out, you're stupid?

One thing that's easy to figure out is that this is dsp processing that could exist independently of the converters. And since there is no reasonable explanation of what it does, the only way to address the OP's question is to demonstrate what it sounds like.

Finally, one more quote from the manual:

<Digital recording adds a degree of separation that allows engineers to base their decisions on what makers of hardware and software tell them they need to buy in order to get a desired sound. This easily usurps the necessity to use audio equipment effectively and efficiently.>

I think we have an example of this in this very product.

-R
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