Discrete Dual Differential DAC?

dantwomey · 5th December 2007, 09:01 PM

EMM Labs claims to have

Quote:

the world’s first and only discrete dual differential D-to-A conversion circuit.

Is this claim true?

Regards,
Dan

fizzard · 5th December 2007, 09:08 PM

It's the first I've heard, at least in the audio realm.

I interpret "dual differential" as one per polarity per channel, or four DACs. Really all a DSD DAC is an RC filter, so this isn't a huge breakthrough.

The only discrete audio DAC I know of is a little dated by todays standards, and was of the one-DAC-per channel variety with S/H.

Gasho · 5th December 2007, 09:37 PM

Discrette DAC circuit can or can´t be better solution than integrated ciruit. It is more expensive way. longer traces, component selection, temperature stability are problem that must be solved.

Arcam, Spectral, Audio Syntesist allready go discrette. Ultra Analog and Anagram produced discrette DACs in big chips which are encapsulated discrette DACs.

OliverD · 5th December 2007, 09:42 PM

The first generations of Accuphase digital gear all had discrete DACs...

JohnW · 6th December 2007, 02:41 AM

I believe the Pink Triangle Dacapo was the worlds first commercial 1 Bit Discrete Dual Differential DAC; I designed the original version in 1990 - 1991.

The EMM Labs DAC rate is claimed to be 128Fs – Even back in 1990 – 91 the Dacapo Discrete DAC’s operated at 3 times this rate @ 384Fs

Discrete Dual Differential DAC is old news. The latest Dacapo DAC (to be launched Q1 next year) has 16x "Discrete Dual Differential DAC's" per channel, making a total of 64 DAC elements per channel – 128 DAC’s per stereo unit!

JohnW

oshifis · 6th December 2007, 06:55 AM

Not dual and not commercial (still in development phase, but works):

http://www.freeweb.hu/tube/DDAC.pdf

aparatusonitus · 6th December 2007, 07:24 AM

Quote:

Originally posted by JohnW
The latest Dacapo DAC (to be launched Q1 next year) has 16x "Discrete Dual Differential DAC's" per channel, making a total of 64 DAC elements per channel – 128 DAC’s per stereo unit!

Hi John,

Could you define Q1 next year for as not familiar with this english term?

Also, have you received my mail sent thru diyaudio about S700 Isomagic service manual?

Ivo

JohnW · 6th December 2007, 09:41 AM

Hi Ivo,

"Q1" Means first quarter next year (which in reality is always toward the end of the quarter)...

Sorry - I do recall receiving a request recently for the Schematics for IsoMagic - however it was design more then 10 years ago - and I no longer have them to hand (many changes of PC and crashed HDD's since).

If I do stumble across them, I will forward to you.

John

aparatusonitus · 6th December 2007, 10:32 AM

Quote:

Originally posted by JohnW

Sorry - I do recall receiving a request recently for the Schematics for IsoMagic - however it was design more then 10 years ago - and I no longer have them to hand (many changes of PC and crashed HDD's since).

If I do stumble across them, I will forward to you.

I know you don' have them John...but I was about to send you one (not the best copy, bur anyway), thanks to nice gay from Cambridge Audio (customer care manager).

And gays, if and when I get a clearance from John, I will upload a manual somewhere.

Ivo

oshifis · 6th December 2007, 10:42 AM

Quote:

Originally posted by aparatusonitus
And gays...

Me not...

6th December 2007, 02:41 AM	#5
JohnW diyAudio Member Join Date: Jan 2004 Location: Discovery Bay, Prague, Paris...	I believe the Pink Triangle Dacapo was the worlds first commercial 1 Bit Discrete Dual Differential DAC; I designed the original version in 1990 - 1991. The EMM Labs DAC rate is claimed to be 128Fs – Even back in 1990 – 91 the Dacapo Discrete DAC’s operated at 3 times this rate @ 384Fs Discrete Dual Differential DAC is old news. The latest Dacapo DAC (to be launched Q1 next year) has 16x "Discrete Dual Differential DAC's" per channel, making a total of 64 DAC elements per channel – 128 DAC’s per stereo unit! JohnW __________________ !!! Hi-Fi !!! I may not be a psychiatrist but I know insanity when I see it - what ever happened to the normal old pervert who was content to sniff bicycle seats and collect women's shoes anyway?

6th December 2007, 09:41 AM	#8
JohnW diyAudio Member Join Date: Jan 2004 Location: Discovery Bay, Prague, Paris...	Hi Ivo, "Q1" Means first quarter next year (which in reality is always toward the end of the quarter)... Sorry - I do recall receiving a request recently for the Schematics for IsoMagic - however it was design more then 10 years ago - and I no longer have them to hand (many changes of PC and crashed HDD's since). If I do stumble across them, I will forward to you. John __________________ !!! Hi-Fi !!! I may not be a psychiatrist but I know insanity when I see it - what ever happened to the normal old pervert who was content to sniff bicycle seats and collect women's shoes anyway?

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5th December 2007, 09:08 PM	#2
fizzard diyAudio Member Join Date: Nov 2006	It's the first I've heard, at least in the audio realm. I interpret "dual differential" as one per polarity per channel, or four DACs. Really all a DSD DAC is an RC filter, so this isn't a huge breakthrough. The only discrete audio DAC I know of is a little dated by todays standards, and was of the one-DAC-per channel variety with S/H.

5th December 2007, 09:37 PM	#3
Gasho diyAudio Member Join Date: Nov 2004 Location: Western Zagreb	Discrette DAC circuit can or can´t be better solution than integrated ciruit. It is more expensive way. longer traces, component selection, temperature stability are problem that must be solved. Arcam, Spectral, Audio Syntesist allready go discrette. Ultra Analog and Anagram produced discrette DACs in big chips which are encapsulated discrette DACs.

5th December 2007, 09:42 PM	#4
OliverD diyAudio Member Join Date: Nov 2002 Location: Germany	The first generations of Accuphase digital gear all had discrete DACs...

6th December 2007, 06:55 AM	#6
oshifis diyAudio Member Join Date: Mar 2004 Location: Budapest, Hungary	Not dual and not commercial (still in development phase, but works): http://www.freeweb.hu/tube/DDAC.pdf

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