Sign in   |  Join   |  Help

Beolab 50 and Turntables - Is the sound digitised

rated by 0 users
Not Answered This post has 0 verified answers | 91 Replies | 0 Followers

Epsilon20
Not Ranked
49 Posts
OFFLINE
Silver Member
Epsilon20 posted on Thu, Jun 27 2019 3:19 PM

Hi Guys, I've been offered a LINN Sondek LP12 at a great price to use with my Beolab 50s  and considering buying it however. The Beolab 50s and more recent speakers  as i understand it is a digital speaker and if i were to connect the turntable to the speakers via the phono in (first through a phono stage) the speaker would digitise the sound which takes away the whole reason of getting a Turnable /analogue source.

Am i correct in thinking that turntables with B&O systems of recent times 17s, 18s, 20,50's & 90s is pointless if you want an analogue sound? I hope not Crying 

I've already bought Vinyls and was about to pay for the Linn sondek which is an absolutely beautiful and great sounding turntable.

Beovision Eclipse 55 Brass Edition with Oak covers and Brass Orbital stand

Beolab 50s silver & Oak, Beolab 18 Brass with Smoked Oak, Beolab 18 Rose Gold with Maple Covers, Beolab 19 Black.

All Replies

Carolpa
Top 100 Contributor
980 Posts
OFFLINE
Bronze Member

BEOVOX141:
Carolpa:

BEOVOX141:
Jeff:
How do these wonderful ANALOG record companies drive the cutting lathes that make the LP master
I dont know how its done today, but they used to be all mechanical supported by basic analog feedback loops in the electronics, just like any piece of CNC  equipment is today. They will without a doubt be controlled digitally though...

Use the "ignorance is bliss" gently, it cuts both ways!

But still the master was digitalized. So the reissued vinyl has somehow a digitalized origin. So this point/discussion has no meaning what so ever!

Words and terms are flying left and right...

This is what i consider the Master! (Jeff : "cutting lathe")  How does "digitalized" apply here?

Related image

In my opinion this is the MASTER, the tape from which te vinyl-negative is cut.

OR the file containing the digitalised (and processed) info of this MASTER tape

Epsilon20
Not Ranked
49 Posts
OFFLINE
Silver Member

For sure Some vinyl produced in the last 20 years have been pressed from digital sources. However A few niche record labels like the ones I posted are re-issuing  vinyl sourced from analogue master tapes. These companies pride themselves on pure analogue releases and are marketing their records based on having no digitisation throughout the process. 

https://www.musicmattersjazz.com/the-sound-s/45.htm

I just realised the solutions to my problem may potentially lie with older speakers assuming they are not digital speakers. 

Would a set of Beolab 3s work as analogue speakers? Ie are these analogue ? 

 

Beovision Eclipse 55 Brass Edition with Oak covers and Brass Orbital stand

Beolab 50s silver & Oak, Beolab 18 Brass with Smoked Oak, Beolab 18 Rose Gold with Maple Covers, Beolab 19 Black.

Jeff
Top 25 Contributor
USA
3,752 Posts
OFFLINE
Silver Member
Jeff replied on Sun, Jun 30 2019 4:07 PM

Carolpa:

BEOVOX141:
Jeff:
How do these wonderful ANALOG record companies drive the cutting lathes that make the LP master
I dont know how its done today, but they used to be all mechanical supported by basic analog feedback loops in the electronics, just like any piece of CNC  equipment is today. They will without a doubt be controlled digitally though...

Use the "ignorance is bliss" gently, it cuts both ways!

But still the master was digitalized. So the reissued vinyl has somehow a digitalized origin. So this point/discussion has no meaning what so ever!

 

The original master tape is not the thing used to drive the final LP master cut. First it has to be tailored to the LP format, which means introducing RIAA equalization, summing the bass to mono below a certain frequency, etc. Some LP producers started doing that in the digital domain quite a while ago from what I have been told in order to apply the RIAA and other changes more accurately. But I freely admit I am not up on all the current incarnations of this particularly obsolescent technology.

If the OP wants a pure analog system, more power to him, even if I disagree that it will sound as good as a set of 5's or 50's or 90's, and that he may be shocked to find out that his pure analog sound chain has some digitization in it somewhere. It's like a story I read about a person who was convinced AC power was the devil incarnate, and had built a whole system using modified high end car amplifiers and such run off of batteries. He was showing the hifi writer this system and railing against AC, when the writer asked him, how do you charge the batteries. Which the guy had never considered, he was using AC wall power to charge the batteries!

But, as I say, if the OP wants to indulge a particular philosophical approach to audio, I can grok that. I happen to have a setup in my workroom using a single ended 6L6GC based tube amp, a whopping stomping 7.5 w/ch, driving a pair of single full range driver speakers I built using these old but fascinating Sansui drivers. To me it's like technological archeology, it's fun, and I like having at least one tube amp around. Doesn't sound as good as my half rack width Parasound preamp and 40 watt solid state amp driving a pair of Beovox P30s, but it brings a smile to my face nonetheless. And I also have a Karlsson speaker cabinet I'm building a mono tube amp for.

Back to the OP, all the older speakers up to and including the Beolab 9 are pure analog. If you want full range performance I can recommend the 9's, great performance and sound, analog crossovers and only a Class D amp for the bass, the mid and tweeter amps are more conventional. Same for the 3's, analog.

Jeff

I'm afraid I'm recovering from the BeoVirus. Sad

Puncher
Top 10 Contributor
Durham
11,650 Posts
OFFLINE
Bronze Member

But is Class D analogue or Digital!?Big Smile

Forget about it all and just buy the best speakers your budget can stand -  ultimately you'll be happier than having to explain  to all your friends that you could've had better but you sacrificed it all for an all analogue chain to play what you hope are all analogue recordings!

Ban boring signatures!

Jeff
Top 25 Contributor
USA
3,752 Posts
OFFLINE
Silver Member
Jeff replied on Sun, Jun 30 2019 6:24 PM

Puncher:

But is Class D analogue or Digital!?Big Smile

Forget about it all and just buy the best speakers your budget can stand -  ultimately you'll be happier than having to explain  to all your friends that you could've had better but you sacrificed it all for an all analogue chain to play what you hope are all analogue recordings!

I agree, the whole threads topic and such is kind of what I think of as anti-B&O, as in traditionally B&O has eschewed obsession over just how the music gets to your ears, it's there to let you kind of ignore the how and enjoy the what, that is good sounding music that's easy to access.

But audio nervosa takes many forms, and considering I have a weird single ended tube/full range single driver speaker setup, albeit a cheap one, just because, leaves me not too much room to talk. But I do anyway. Smile

Jeff

I'm afraid I'm recovering from the BeoVirus. Sad

Epsilon20
Not Ranked
49 Posts
OFFLINE
Silver Member

Thanks to all that inputted into this discussion, its certainly kicked up a debate.

Beovision Eclipse 55 Brass Edition with Oak covers and Brass Orbital stand

Beolab 50s silver & Oak, Beolab 18 Brass with Smoked Oak, Beolab 18 Rose Gold with Maple Covers, Beolab 19 Black.

BEOVOX141
Top 150 Contributor
Denmark, West
702 Posts
OFFLINE
Silver Member

An interesting and highly flammable discussion for sure.

I am slightly disappointed in the fact that no one seems to know for sure exactly how the 50s work, which I entirely attribute to the lack of accurate documentation. Today it seems like all the technical details from B&O are hearsay at best, from someone who listened to someone who listened to the grapevine, etc... and thus very difficult to assess.  

Jeff
Top 25 Contributor
USA
3,752 Posts
OFFLINE
Silver Member
Jeff replied on Mon, Jul 1 2019 7:27 PM

Has B&O ever been that forthcoming about what's under the hood? Granted it was simpler in the past, but still, their entire philosophy used to be, don't worry about the tech, listen to the music, ease of use, and style.

As for the original poster, I'd say either just hook the table to the speakers and enjoy it as is, it will sound marvelous I'm sure. Or, if you philosophically want a completely analog setup (ignoring the fact that digital may have snuck into the woodpile somewhere along the recording chain), you might seriously consider going truly backwards in tech. A table, hooked to a tube amp/preamp, and simple passive speakers. If you go farther and go with single ended tube amps and full range single driver speakers, it will be as pure a setup as you can get, in a philosophical/ideological sense. Will never sound as good, but they can be magical in their own way and fun to play with and own. As I said I have such a system myself and despite its limitations it always makes me smile. For serious listening though I always revert back to my BL9s and digital sources.

But it is fun to have both!

Jeff

I'm afraid I'm recovering from the BeoVirus. Sad

Millemissen
Top 10 Contributor
Flensborg, Denmark
13,124 Posts
OFFLINE
Bronze Member

BEOVOX141:

An interesting and highly flammable discussion for sure.

I am slightly disappointed in the fact that no one seems to know for sure exactly how the 50s work, which I entirely attribute to the lack of accurate documentation. Today it seems like all the technical details from B&O are hearsay at best, from someone who listened to someone who listened to the grapevine, etc... and thus very difficult to assess.  

What more ‘documentation’ do you need than what is in the white paper/BeoLab 50

https://www.bang-olufsen.com/~/mediaV3/home/speakers/BeoLab-50/bang-olufsen-beolab50-whitepaper-v5.pdf

....and why?

MM

There is a tv - and there is a BV.

Geoff Martin
Top 150 Contributor
Struer, Denmark
578 Posts
OFFLINE
Bronze Member

Epsilon20:
 I know this solution defeats part of the purpose of playing pure vinyl but I’d feel better as the analogue to digital converter in the 50s isnt audiophile grade in my opinion and can’t compete with standalone units.

Hi everyone,

There are MANY incorrect assumptions, errors, and mis-understandings throughout this thread. I'll try to address them one at a time, in chronological order...

This is the one that caught my eye first.

The BL50 does not have a DAC. It has many. There is one DAC channel per loudspeaker driver in each loudspeaker - plus two more for calibration. Since each BL50 has 7 drivers (3 woofers, 3 midrange, and 1 tweeter) + 2 calibration DAC channels = 9 DAC channels. The DAC's themselves are 2-channel devices, so this is why 5 of them are used (because 5 x 2 > 9).

Whether or not they are "audiophile grade" raises and argument / discussion about what, exactly, "audiophile grade" means. Since this would involve a discussion of issues such as (but not exclusive to):

  • supported sampling rates (which is irrelevant in this case, since the DAC's are only fed one sampling rate)
  • supported formats (which is irrelevant in this case, since the DAC's are only fed one format)
  • supported bit depths (which is irrelevant in this case, since the DAC's are only fed one bit depth)
  • signal-to-noise ratio (or dynamic range - depending on your definition) - which typically vary with sampling rate and therefore possibly measurement bandwidth
  • frequency response (includes both magnitude and phase) at different levels
  • DAC linearity
  • and more...

However, I will say that, in any system (a loudspeaker, a chain, a bicycle, a car, a spaceship, a chair, a pair of pants... anything) it makes little-to-no sense to have one component that is significantly better or worse than any other component in the system. This is one of the nice things about developing a fully active loudspeaker... We can ensure that no single part is much better (therefore raising the cost without benefit) or much worse (therefore reducing some aspect of the overall quality/performance of the entire system). The DAC's in the BL90 & 50 were carefully chosen with the rest of the system in mind, and also knowing that they would be limited in the demands placed on them by the input signal (with its fixed sampling rate, fixed bit depth, and fixed format).

For example, you cannot compare a diesel engine that is designed to go in a truck to one that goes in a backup generator for a hospital. The demands on the two are very different. The truck engine will be started and stopped every day, it will have to run at different RPM's, with different loads, and will be shaken and jostled. The generator engine is designed to run at 1 speed (the optimal one for the electric generator to which it's connected), it is rarely started and stopped, and it will never move. There's no point in comparing those two engines, even if they're the same brand, same number of cylinders, same amount of horsepower (at some RPM), same amount of torque (at some other RPM), etc...

cheers
-geoff

Geoff Martin
Top 150 Contributor
Struer, Denmark
578 Posts
OFFLINE
Bronze Member

Epsilon20:
I agree that CDs, SACDs and certainly uncompressed digital sound is superior to Vinyl. With Vinyl its a lottery of what you will get in terms of sound quality especially when buying older records.

At the risk of appearing to imply that you said something that you didn't... (see the wrap-up in italics below...)

One thing to be careful of here is to not conflate the content with the package it's in. If you're going to compare one distribution format to another (e.g. vinyl to CD to SACD) then you have to make sure that the content is exactly the same. There are very few options to do this, since the mastering done for vinyl is typically different from a digital distribution...

If you DO want to make this comparison, then one option is to try a recording from https://stockfisch-records.de. The last time I checked,  they:

  • do a recording to hard disc using high-sampling rate PCM
  • master that recording to a metal master on a lathe for the vinyl release
  • put a stylus on the metal master and record the output as a high-sampling rate PCM
  • convert the high-sampling rate PCM to DSD for the SACD release
  • convert the high-sampling rate PCM to a >44.1/16 PCM for sale as a download
  • down-sample the high-sampling rate PCM to 44.1 / 16 for the CD release

So, in these four cases, you have the same master (the metal master made for the vinyl release). You can then, with a reasonable amount of confidence, compare the 4 to find out if you hear a difference.

THEN: if you DO hear a difference, it may not be because of "digital" vs. "analogue." It might be due to the specific specifications of, say, the DAC on your CD player, or the sampling rate converter in your streaming device... Or it might just be because one of them was played 1 dB louder than the others... You have to be very careful when making such comparisons, (1) to be fair, and (2) to not jump to conclusions about the source of the difference...

Note that I know that you didn't say that "vinyl is better/worse than digital" - you and I are making the same point - that the recording is the determining factor in "how things sound"... unless something else in the chain is much worse (whatever "worse" means).

Cheers
-geoff

Geoff Martin
Top 150 Contributor
Struer, Denmark
578 Posts
OFFLINE
Bronze Member

AdamS:

I have a turntable plugged into my Beolab 90s via a phono preamp and preamplifier (not a cheap one, either!). I also worried that it was pointless due to the digitisation of the signal.

I needn't have worried - it sounds stunning and blows all the other sources into the weeds!

 

Hi,

As someone else pointed out - if BL90's and 50's weren't digitising the signal, they wouldn't work...

But glad to hear that your worries were unfounded... or at least dispelled. :-)

Cheers
-geoff 

 

Geoff Martin
Top 150 Contributor
Struer, Denmark
578 Posts
OFFLINE
Bronze Member

BEOVOX141:

@ DMacri

DMacri:
and there would be no influence from another signal to contend with - no cross-talk from the alternate signal channel

120dB is considered threshold of pain for sound.....

 

120 dB SPL is the typical number listed as the threshold of pain.

but that SPL is important. 120 dB SPL means 120 decibels louder than the quietest sound you can hear when the signal is a sine wave at 1 kHz which is another way of saying 1,000,000 times louder than the quietest sound you can hear when the signal is a sine wave at 1 kHz

120 dB means 1,000,000 times louder than...

-120 dB means 0.000,001 times louder than (which is the same as saying 1,000,000 time quieter than...)

The specification shown in the plot above tells us that if you feed an analogue signal into one input channel of the PCM4220 at one frequency (therefore, it's a sine wave) and feed nothing into the other input channel, and you measure the difference in level between the two channels of its digital output, that difference will be a factor of 1,000,000 at 70 kHz, when the ADC is running at a sampling rate of 192 kHz. (in other words, the left channel's input signal will "bleed" out of the right channel output, 1,000,000 times quieter than the output of the left channel.)

This says nothing about the actual level - just about the difference in level.

If we want to make and example that converts this to the implications in the real world:

 

  • IF you sent a 1 kHz sine tone into the left channel of the ADC and 
  • you send silence to the right channel of the same ADC and
  • you sent its digital output to a system that was (eventually) connected to two loudspeakers or headphones (one for left and one for right) and
  • this ADC was the limiting factor in the entire chain and
  • you turned up the volume of the two loudspeakers so that the 1 kHz sine tone in the left channel was at 120 dB SPL (the threshold of pain, depending on you...)
  • THEN the output of the right loudspeaker would be at about -20 dB SPL or, 20 decibels quieter than the threshold of hearing, which is a factor of 0.1.
  • So, you would have to turn up the volume by another 20 dB (or 10 times) to make the right loudspeaker play loud enough for you to hear it (assuming that the left loudspeaker was not playing anything - which it is...)

 

Note that, for the above example, I'm assuming that the crosstalk of the ADC is about -140 dB at 1 kHz - which is a guess, since it's hard to read on that plot...

 

The reason I want through all this is mostly not because of what you wrote, but because one of my "hobby horses" is when people say something like "80 dB" when they mean "80 dB SPL".

"dB" is a relative unit (actually a factor) whereas "dB SPL" (and "dB FS" and "dBV" and "dBu" and others) are absolute units (because the "SPL", "FS", "V", and "u" indicate an absolute value to which the written value is relative). 

Note as well that the typical crosstalk of a good phono stylus is about -30 to -40 dB. So, if you have something on the vinyl record that is ONLY in the left channel (assuming that this is possible) and you play it with a very good cartridge (I looked at the spec's for this one as an example) then there will be a "copycat" signal on the right output of your stylus that is 0.0316 times the level of the left channel (= -30 dB). In this case, one could certainly argue that a 140 dB channel separation on an ADC that's downstream is overkill... :-)

cheers
-geoff 

Geoff Martin
Top 150 Contributor
Struer, Denmark
578 Posts
OFFLINE
Bronze Member

Mikipidia:
The 50’s have one dsp(chip) for both speakers in the master speaker. So the master does all the computation, processing and room comp and then sends the finished signal of to the slave speaker.

The 90’s have a dsp chip in both speakers and each one does it’s own calculation and dsp stuff.

I meant to say that it’s passive in a computational sense, not in the old fashioned sense.

 

 

This is not correct.

 

In a normal operating mode (meaning, that the speaker is not running its room compensation measurements, for example... You're just sitting and listening to music...):

  1. If the input signal is analogue: The two audio channels are converted to 192/24 PCM by the 2-channel ADC in the Master loudspeaker. These two audio channels are both sent to the DSP in the Master loudspeaker and the DSP in the Slave speaker (via the DPL cable). This means that both audio channels are sent to the inputs of each loudspeaker's DSP.
  2. If the input signal is digital: The two audio channels are re-sampled to 192/24 PCM by the sampling rate converter in the Master loudspeaker. These two audio channels are both sent to the DSP in the Master loudspeaker and the DSP in the Slave speaker (via the DPL cable). This means that both audio channels are sent to the inputs of each loudspeaker's DSP.
  3. If the input signal is WiSA / WPL: Each loudspeaker individually receives a single digital audio channel from the WiSA receiver and sends it to its local DSP. This means that each loudspeaker's DSP receives only one audio channel at its input. There is no inter-speaker communication of the audio signal, even if the DPL cable is connected.

 

From there, each loudspeaker's DSP does its own signal processing, which includes (but is not exclusive to) (and in no particular order):

  • signal routing (aka Speaker Role)
  • gain (for Speaker Level and Volume)
  • delay (Speaker Distance and internal time alignment)
  • magnitude and phase correction for the individual drivers (equalisation)
  • directivity control
  • room compensation
  • other stuff

Each DSP then outputs one audio channel per driver (7 for the BL50, 18 for the BL90).

 

This "helicopter view" description is true of the BeoLab 90's and of the BeoLab 50's. There is no difference between the two loudspeaker models within the limitations of what I've described here.

 

One important thing to note here is the difference between WiSA/WPL and the other inputs. The ARC (Adaptive Room Compensation) algorithm in the BL50/90's uses both audio channels to create a single output channel for each loudspeaker's room compensation signal. In other words, the left loudspeaker is compensating for both the left and the right loudspeakers' interaction with the room. (Ditto for the right loudspeaker.) However, this is only possible if each loudspeaker gets both audio channels at its input - which is true for analogue and wired digital connections, but not for WiSA/WPL (see point #3 above). If you are using a WiSA/WPL connection, then a portion of the room compensation is not working, since each loudspeaker only receives one audio input channel.

So, for example, I have seen some "reviews" or comparisons done by people online where the 50's or 90's are connected to an audio source via the wireless connection. This means that the ARC algorithm is not doing everything it can  - and so the comparison may not be completely fair (assuming that the intention is to do a best-case-to-best-case A/B comparison). Whether or not this will affect the conclusions of the comparison is impossible to predict, since a 1 or 2 dB difference in listening level, or a change in loudspeaker and/or relative listening position will also influence the perceived sound.

Cheers
-geoff 

 

Page 5 of 7 (92 items) « First ... < Previous 3 4 5 6 7 Next > | RSS
Beoworld Security Certificate

SSL