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Old 12th April 2018, 07:55 PM   #1
percival007 is offline percival007  England
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Default Philips Engineers

It was suggested by another Forum Member in another thread that there may be (ex) Philips Engineers who frequent this Forum.

If this is the case, firstly a huge thank-you for the CD !!

Also, if they are members on here then do they have and can they post any information and/or pics on CD's early mock-ups/proto-types?
And also the same of their early attempts at DAC chips.
I would be very interested to see/hear of their trials and tribulations getting it 'right'. Especially the associated problems and how they over-came them.

Also, as Non-Over-Sampling has become something of the norm, why did they continue with the process once they has a working 16 bit DAC chip?
The TDA1541/A is sooo good in NOS Mode why soldier on with feeding it Over-Sampled DATA?

Looking forward, hopefully to some excellent stories.

P.
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Old 12th April 2018, 08:04 PM   #2
brig001 is offline brig001  United Kingdom
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Another source of Philips info is the excellent Philips Museum in Eindhoven, Netherlands. I even arranged a family holiday so we would "accidentally" drive past and then we could have a look . Seems to be staffed by retired Philips guys who are interesting to talk to about the various products

Brian
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Old 12th April 2018, 09:51 PM   #3
billshurv is online now billshurv  United Kingdom
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Quote:
Originally Posted by percival007 View Post

Also, as Non-Over-Sampling has become something of the norm, why did they continue with the process once they has a working 16 bit DAC chip?
The TDA1541/A is sooo good in NOS Mode why soldier on with feeding it Over-Sampled DATA?
I have to disagree with you on this. NOS is not the norm, it's a small and vocal cult who seem to think that getting back to the original waveform is not the way forwards and accept a crippled performance in return for some mystic magic.

There are exceedingly good reasons for oversampling which is the reason everyone continued with it until DS took over.
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Old 12th April 2018, 11:02 PM   #4
zenelectro is offline zenelectro  Australia
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Have you listened to a well implemented TDA1541 0 x OS DAC in a good system?

T
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Old 12th April 2018, 11:08 PM   #5
billshurv is online now billshurv  United Kingdom
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I've yet to see a non-oversampling implementation that has a steep enough output filter on. All the measurements I have seen show Aliasing hell breaking loose. I don't want to listen to that when I get get superlative performance with well engineered solutions.

I used a Marantz CD80 for 20 odd years. I don't miss it sonically and really not interested in hunting out less well implemented solutions than that.
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Old 13th April 2018, 06:50 AM   #6
percival007 is offline percival007  England
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But as the above poster said, have you listened to one? Measurements are not everything.

However, it was not my intention to start a OS vs non OS debate.

billshurv, are you an ex Philips Engineer, do you have any stories to tell from the early days of experiments on CD? Please tell us more if so.

P.
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Old 13th April 2018, 06:56 AM   #7
MarcelvdG is offline MarcelvdG  Netherlands
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Quote:
Originally Posted by percival007 View Post
Also, as Non-Over-Sampling has become something of the norm, why did they continue with the process once they has a working 16 bit DAC chip?
The TDA1541/A is sooo good in NOS Mode why soldier on with feeding it Over-Sampled DATA?
I'm no Philips or ex-Philips engineer - I know a few people who used to work for Philips, but not on the CD - but as far as I know the phase linearity of Philips CD players was a selling point in the early 1980's. Other manufacturers used non-oversampling DACs with steep analogue reconstruction filters that had a terrible phase response. Philips used a phase-linear oversampling filter and a Bessel analogue reconstruction filter, making the whole thing nearly phase linear.
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Old 13th April 2018, 08:50 AM   #8
diyralf is online now diyralf
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Unfortunately, most of the reconstruction filters here in DIY or shown in the DAC specs are very poorly designed. They do a lot of THD. Philips and Technics once had very good filters.
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Old 13th April 2018, 10:52 AM   #9
billshurv is online now billshurv  United Kingdom
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Originally Posted by percival007 View Post
But as the above poster said, have you listened to one? Measurements are not everything.

However, it was not my intention to start a OS vs non OS debate.

P.
You should have avoided saying 'NOS is the norm' then! Sorry but when something that is clearly rubbish is posted someone is going to correct it. This time it was me!
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Old 13th April 2018, 02:50 PM   #10
Mike P is offline Mike P  England
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Quote:
Originally Posted by billshurv View Post
I have to disagree with you on this. NOS is not the norm, it's a small and vocal cult who seem to think that getting back to the original waveform is not the way forwards and accept a crippled performance in return for some mystic magic.

There are exceedingly good reasons for oversampling which is the reason everyone continued with it until DS took over.
Excellent post!
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