CORDA COUNTRY
Jun 25, 2019 at 7:26 AM Thread Starter Post #1 of 62

Jan Meier

King Corda
Member of the Trade: Meier Audio
Joined
Jun 21, 2001
Posts
854
Likes
182
Dear friends,

here I come with a somewhat unusual request. And the reason is that I'm currently working on a somewhat unusual device. It's a signal processor that allows to add crossfeed, tone controls, reverb, bass enhancement, ... to a digital audio-signal without the need of a PC.

This device, project name CORDA COUNTRY, is rather unique in its concept and therefore decision making is not always easy. What features do people need/want, how strong should certain effects be, what inputs and outputs are needed, ... ?

My request therefore is to provide me with as much feedback on the design as possible. A description of the current status can be found at:

http://www.meier-audio.homepage.t-online.de/country.htm

Some actual questions:

- Do you think the psychoacoustic bass-enhancement is a valuable feature? Please take a listen to the examples on my website. Have you been able to identify which file (TestA or TestB) uses bass-enhancement and how easy was it?

- The same with reverb. Do you see any use for it? If so, do you feel the low and medium reverb levels to be adequate? The reverb algorithm takes up a lot of computational resources so it should only be implemented if people feel a real need for it.

- Right now all algorithms are separately tested with audio signals upsampled to 192/24. However, due to limitations in computing power the implementation of all algorithms suggested into one single DSP-chip will only be possible when upsampling is limited to 96/24. Can you live with this lower frequency or should one try for a two-chip implementation? Or leave the reverberation out?

- Are there any other algorithms/features that you would like to see implemented?

I'm sure many of you would like to see analog outputs (internal DA-conversion). This is possible but would increase costs considerably. How strongly do you need this feature?

For me the COUNTRY is a fun-project and it will only be produced (by Lake People) when there are enough people interested in getting one. Of course there will be a special pre-order price (like I did with the SOUL-project) but it can not be calculated yet, as the design is not finalized.

If you have a special interest in this device, please let me know.

Cheers

Jan
 
Jun 25, 2019 at 12:04 PM Post #2 of 62
what inputs and outputs are needed, ... ?
The current ones are correct.

Dear friends,

- Do you think the psychoacoustic bass-enhancement is a valuable feature? Please take a listen to the examples on my website. Have you been able to identify which file (TestA or TestB) uses bass-enhancement and how easy was it?

- The same with reverb. Do you see any use for it? If so, do you feel the low and medium reverb levels to be adequate? The reverb algorithm takes up a lot of computational resources so it should only be implemented if people feel a real need for it.

Responding to these questions is difficult without testing a significative amount of my music library. You have this possibility with yours, therefore, how would respond to your questions ? Are these features effective on a consequent part of your music ?

If not, are they still worth it in your opinion ? Why ?

- Right now all algorithms are separately tested with audio signals upsampled to 192/24. However, due to limitations in computing power the implementation of all algorithms suggested into one single DSP-chip will only be possible when upsampling is limited to 96/24. Can you live with this lower frequency or should one try for a two-chip implementation? Or leave the reverberation out?

Buying quality elements at cheap prices is always cool, buying half assed ones at cheap prices isn't. But once again, it should be test dependant : is it audible ? Would it make of this device the weaker link in a high end chain ? etc...

Should one try for a two-chip implementation? Or leave the reverberation out?

Yes, if you lacks needed possibilities with one. It has to be usable with the most revealing chains.

Or leave the reverberation out?

No if it's useful.

- Are there any other algorithms/features that you would like to see implemented?

All useful DSP functions that you know. Let's begin with what is in the Soul and not in the Country (DAC/Amp apart obviously)

I'm sure many of you would like to see analog outputs (internal DA-conversion). This is possible but would increase costs considerably. How strongly do you need this feature?

I don't need a DAC with it. I would be interested in the best DSP that you can do ( we are in the high end section lol ).

Cordially
 
Jun 27, 2019 at 4:39 AM Post #3 of 62
Dear Friends,

just corrected my website. For those who tried before, the reverb-files now also will run.

Dear Jokostyle,

thanks for your comments.

It's true that the use and effect of bass-enhancement and reverb strongly depend on the recordings.

As for the bass-enhancement example, this is one of the very few recordings where signals below 60 Hz can be found. If you would analyze the frequency contents of a large number of recordings you would be surprised how little there is below 60 Hz. If you do not feel any benefits with the test sampe, then this feature is simply not for you.

As for the reverb, the recording choosen is relatively dry and thus the effect of the reverb pretty noticable and (in my opinion) pretty effective. Sure, I could present more examples, but for a first impressions I feel the files presented are quite adequate.

As for 96/24 versus 192/24. I strongly doubt that many people are able to hear the difference between the two formats. Even modern remasters are often done in 96/24. But there are always people that want the "numbers" to be optimized. They lack the option to go for 384/32 and DSD. The "numbers" are better so it should sound better, right?

As for SOUL versus COUNTRY. Right now the design of the COUNTRY offers all the functionality of that of the digital section of the SOUL. And as a bonus reverb and bass-enhancement is added.

" All useful DSP functions that you know. "

The ones implemented are the most useful for me. But your opinion may well be different. So if you have suggestions .....

Cheers

Jan
 
Aug 19, 2019 at 1:05 PM Post #4 of 62
...
- Do you think the psychoacoustic bass-enhancement is a valuable feature? Please take a listen to the examples on my website. Have you been able to identify which file (TestA or TestB) uses bass-enhancement and how easy was it?
I'm not a fan of most bass enhancement. This one was one of the best most natural I have heard, but even so I would not use it much.

As for the bass-enhancement example, this is one of the very few recordings where signals below 60 Hz can be found.
Try Drums & Bells, by Dutz & Wabich. Tracks 2, 5 and several others have a bass drum with lots of energy around 35 Hz. And it's a natural acoustic sound rather than synthesized pop, so quality and realism can be more easily assessed. It's one of the best recordings I have ever heard. The timbre, impulse attack and decay is incredibly lifelike.
I have no relationship with them other than being blown away by the sound quality. For speaker evaluation especially in the extreme bass & treble, every audio engineer and audiophile should have this:
https://www.madisoundspeakerstore.com/books/drums-bells-loudspeaker-evaluation-cd/

- The same with reverb. Do you see any use for it? If so, do you feel the low and medium reverb levels to be adequate? The reverb algorithm takes up a lot of computational resources so it should only be implemented if people feel a real need for it.
I tend to prefer "dry" recordings having less reverb or room effect. Not completely dry, but a little bit goes a long way, and most recordings already have some, so I would probably not use this feature much.

- Right now all algorithms are separately tested with audio signals upsampled to 192/24. However, due to limitations in computing power the implementation of all algorithms suggested into one single DSP-chip will only be possible when upsampling is limited to 96/24. Can you live with this lower frequency or should one try for a two-chip implementation? Or leave the reverberation out?
No problem at all. 96/24 is more than enough, so long as resampling algorithms (up or down) are properly implemented.

- Are there any other algorithms/features that you would like to see implemented?
Considering how common it is for modern recordings to use heavy-handed dynamic compression that squeezes the life out of the music, dynamic expansion or similar effects would be a great feature.

I'm sure many of you would like to see analog outputs (internal DA-conversion). This is possible but would increase costs considerably. How strongly do you need this feature? For me the COUNTRY is a fun-project and it will only be produced (by Lake People) ...
An analog stage would be useful, and since the COUNTRY doesn't have to be a TOTL/SOTA device (you already have the SOUL for that), it doesn't have to be expensive or as clean as the digital stage, just good quality. Lake People is high quality, but will make it expensive. If you have the COUNTRY built in China like the rest of the product line it should save money with no compromise in sound quality.
 
Last edited:
Aug 28, 2019 at 10:27 AM Post #5 of 62
Dear friends,

a few days ago I finally got the prototypes of the final design working. And yes, they sound very (!) decent even without a break-in. Right now I'm very satisfied with the results. If you like to hear them, please visit the AudioVista headphone show on 14/15 September in Krefeld/Germany.

prototypescountry.jpg
prototypescountry.jpg


Dear Mike,

"dynamic expansion or similar effects"

Yes, would be a nice feature. However, with compression algorithms there are many parameters that are set by the sound engineer and that are unknown to the COUNTRY. This makes decompression a very difficult, if not impossible task.

"Lake People is high quality, but will make it expensive."

Production batches nowadays are small so any chinese manufacturer is not a real option.

Besides, although the SOUL is very similar prices as the Nimbus, there is much more in it. I don't think this amp/DAC/DSP would be much cheaper when produced in Asia.

Cheers

Jan
 
Aug 28, 2019 at 11:17 AM Post #6 of 62
As I see it, there are two ways to do eq:

1. You make the device easy to use for the non-technical people (as in knobs for rumble, thump, punch, fullness, honk, whack, crunch, sibilance, definition, air etc. - each implemented to the best of your knowledge / dsp resources). Then you add global stuff like loudness, cross-feed, balance, tilt etc.
2. You make device programmable.

Option 2 already exists in the market. Option 1, not so much.
 
Aug 28, 2019 at 12:43 PM Post #7 of 62
Hi Jan,
Would this device be able to correct the channel separation issue of headphones?
You know, the unnatural stereo image when playing recordings mastered with speakers in mind, but on headphones
I know crossfeed is suppose to help. But more can be done on that, just like what SPL implements on their phonitors.
I love their product a lot (using one actually), but sometimes I miss the warmth of a tube amp.
If the Country can achieve the same thing in digital domain, it'd be fantastic because I can just put this in my signal chain and enjoy correct stereo image with any amps.
 
Aug 28, 2019 at 12:50 PM Post #8 of 62
Dear Rekun,

There are basically two versions of the natural crossfeed filter found in my products:

1. Standard version
2. Extended version

Please check http://www.meier-audio.homepage.t-online.de/crossfeed.htm for a read.

SPL uses the standard version of this filter (without ever asking for permission! They even used the pictures from my spreadsheet that was published on Headwize without modifications in the user-manual of their first crossfeed amp without asking) but made various components variable.

Of course the crossfeed of the COUNTRY is the much better extended version. And there are 7 different levels of headphone crossfeed. But the delay time is fixed.

Cheers

Jan
 
Aug 28, 2019 at 1:27 PM Post #9 of 62
Dear Rekun,

There are basically two versions of the natural crossfeed filter found in my products:

1. Standard version
2. Extended version

Please check http://www.meier-audio.homepage.t-online.de/crossfeed.htm for a read.

SPL uses the standard version of this filter (without ever asking for permission! They even used the pictures from my spreadsheet that was published on Headwize without modifications in the user-manual of their first crossfeed amp without asking) but made various components variable.

Of course the crossfeed of the COUNTRY is the much better extended version. And there are 7 different levels of headphone crossfeed. But the delay time is fixed.

Cheers

Jan
Oh I didn't know that SPL uses your design. (awkward)
I'm glad to hear this device is going to be better. So the extended crossfeed filter is also an analog implementation?
Now I'm very interested:o2smile: When will you start shipping them?
I also think it's a good idea that Lake People makes them (in Germany I presume?). I have a Violectric and it's built perfectly.
 
Aug 28, 2019 at 2:38 PM Post #10 of 62
Dear Rekun,

" I didn't know that SPL uses your design. (awkward) "

I was very surprised myself when I saw the user-manual. They even didn't bother to edit the pictures from the spreadsheet. Simply took them as they were.

:frowning2:

" When will you start shipping them? "

There will be a pre-order period, like as I did with the SOUL. Prices will depend on the number of pre-orders (and of course on the offers of Lake People).

Cheers

Jan
 
Aug 29, 2019 at 10:08 AM Post #11 of 62
Hi ,, can i use it only as D/D convertor ?
i dont need the headphone or analog output
 
Aug 29, 2019 at 10:16 AM Post #12 of 62
Dear Gu1Do,

yes, the COUNTRY does have digital outputs (both Toslink and coaxial Cinch).

Output resolution is 96/24.

An alternative version without the reverb is possible. Then Output resolution can be set to 192/24.

Cheers

Jan
 
Aug 29, 2019 at 12:44 PM Post #13 of 62
Hi,

I have plenty questions about what became the Country project.

As it is a DAC/Amp/DSP now, let's consider these functions separately :

As an amp, even if it hasn't analog entries, where do you rank it amongst the more recent ones that you produced (Rock-Jazz-Classic all FF) ?

As a DAC, can you compare it to the Daccord FF ?

As a Dac/Amp how would you compare it to the Daccord FF + Classic FF ?

As a DSP :

-how does it compete with the one which is in the Soul ( considering the common functions ) ? Did you do transparency tests using the Country as the Soul DSP ?
-Would it have been the same without the DAC/Amp additions ?
-Special request : you will have access to a lot of high end gear at Audiovista, so can you, if you have the possibility, make a test of the Country used as a DSP feeding a chain with the Chord MScaler ( TT2 + MScaler - Dave + MScaler) to hear if it works without negative effects ?

- Right now all algorithms are separately tested with audio signals upsampled to 192/24. However, due to limitations in computing power the implementation of all algorithms suggested into one single DSP-chip will only be possible when upsampling is limited to 96/24. Can you live with this lower frequency or should one try for a two-chip implementation? Or leave the reverberation out?
-I assume that you did the first choice. Do you think that the difference between 96/24 and 192/24 would be noticeable on the Soul or the other most revealing DACs and Amps ?

Output resolution is 96/24.

An alternative version without the reverb is possible. Then Output resolution can be set to 192/24.
-Would you make a version with an output resolution of 192/24 PLUS the reverb ( so, the two chips solution) and if needed without the AMP/DAC ? It would make more sense to pay some extra money for that than for functions that i won't use in the long run ( if i buy the Soul for example or if i have better options currently ).

The left upper dial allows to add reverberation. Especially with recordings made in relatively small venues, often very little natural reverberation is added by the sound engineer because our own living room already adds some of its own when listening to loudspeakers. However, when using headphones this extra reverberation is missing and sound can be a little bit dry. Adding some (high quality) artificial reverberation by the DSP then definitely can have a positive effect. Right now this feature only needs some fine tuning.

As an example listen to the three tracks to the right. It's a real pop-classic. The first file is the original track. The second and third file have different levels of reverb. Again, your impressions are much welcome.

In its middle position the dial does not add any reverb. Turning to the left or right will increase Reverb in three steps.

The left upper dial also allows to activate a psychoacoustic bass-enhancer by turning to the left.

Perhaps i misunderstood something so :

Can the bass-enhancer be activated alone ?
And more globally, can each function be used alone AND with a group of the other functions which goes from one of the rest to ALL the rest ? Did you do cumulative tests ? Does it work ?

Thanks very much in advance for your responses !!!
 
Last edited:
Aug 29, 2019 at 4:53 PM Post #14 of 62
Beefing up the analog headphone output with higher current capacity to drive a wider variety of different headphones would add to the cost. Some of the less efficient big orthos need more than 100 mA. But if you're taking the COUNTRY to the higher level of functionality and build quality discussed here, the marginal cost of doing that makes less difference as it becomes a smaller % of the overall price. Yet as the price goes up it becomes a vicious cycle as it reduces volume which further increases per-unit prices. Also, most of the people who would be interested in the COUNTRY already have good headphones and a good amp. So all they need is the DSP.

So, perhaps make 2 versions of the COUNTRY. One DSP only, the other with the exact same DSP but also with an analog section: headphone amp and line-level output. The former is what most headphone enthusiasts want. The latter can serve as a line stage preamp and headphone amp, effectively the blue-collar version of the Soul.
 
Aug 30, 2019 at 5:31 AM Post #15 of 62
Dear Mike,

> Beefing up the analog headphone output with higher current capacity to drive a wider variety of different headphones would add to the cost.

Definitely! But for this there is the SOUL!! As you know yourself, this amp/DAC/DSP has plenty of power to drive even the most demanding headphones.

> Some of the less efficient big orthos need more than 100 mA.

Yes, but there are only few of them and they are normally in a price range where people also can afford the SOUL.

The output power of the COUNTRY is enough to drive at least 98% of all headphones most adequatly. I use it with the ARYA, which is quite inefficient, and do not feel any power lacking.

> Yet as the price goes up it becomes a vicious cycle as it reduces volume which further increases per-unit prices.

Exactly, especially if no extra functionality is added.

People have argued that it's better to leave the analog sections out, as they feel it's an unnessary increase in costs. However, the analog section adds functionality and thereby makes the COUNTRY interesting for more people. So if this means that more units can be sold, then a larger batch can be produced and development costs can be spread over more units. At the end it could well mean that this makes the unit cheaper, as strange as it may sound.

But beefing up the analog stages just to fit the last 2% of headphones ........

Dear Jokostyle,

> As an amp, even if it hasn't analog entries, where do you rank it amongst the more recent ones that you produced (Rock-Jazz-Classic all FF) ?

To be honest, I haven't made the comparison yet.

I'm sure though, that he CLASSIC-FF will be on top. It has enormous power and a superb volume control.

The JAZZ-FF, like the CLASSIC-FF, of course benefits from active balanced ground. And it also does have more power. So I expect it to be superior to the COUNTRY. But not by a wide margin though.

> As a DAC, can you compare it to the Daccord FF ?

Again, I haven't made any comparison yet.

The DACCORD-FF uses the WM8741 in dual mono mode. The COUNTRY uses a simpler WM8716 in stereomode.

However, the COUNTRY has the big advantage that the first stage of the FF-technique is done in the digital domain by the DSP. Thereby the analog stages of the DAC-chip have a much easier job to do. And that can be heard.

> As a DSP :

> -how does it compete with the one which is in the Soul ( considering the common functions ) ? Did you do transparency tests using the Country as the Soul DSP ?

There is one major difference in the processing between SOUL and COUNTRY.

The SOUL does not use upsampling. All processing is done at the native sampling frequency of the incoming signal. When the SOUL was developed I tested both and found the upsampling to slightly degrade transparancy. However, differences were small and only became audible because of the extremely high resolution of the SOUL. With "standard" headphone amplifiers the differences most probably can not be heard.

The COUNTRY uses upsampling because it offers more functionality than the SOUL (bass-extension, reverb, seven-band equalizer instead of 5 bands) and the upsampling makes the algorithms more easy to implement and make them fit within the computational hardware limits. Implementing all algorithms at native frequencies simply wouldn't fit.

> Would it have been the same without the DAC/Amp additions ?

Yes, the analog circuitry does not limit the DSP-functionality.

> -Special request : you will have access to a lot of high end gear at Audiovista, so can you, if you have the possibility, make a test of the Country used as a DSP feeding a chain with the Chord MScaler ( TT2 + MScaler - Dave + MScaler) to hear if it works without negative effects ?

As I have a one-man stand myself it will not possible for me to walk around and test other equipment. Sorry!

Cheers

Jan
 

Users who are viewing this thread

Back
Top