Cambridge DACmagic 2 gold
Summer 2006


looking for a perfect base DAC unit for lampization ???

It had to be cheap, with Philips or Burr-Brown chips, with space inside and balanced config.
DACMAGIC fulfils all these criteria and more. It is a hell of a DAC - designed by Pink Triangle and made in UK. Very impressive inside - gold PCB, 3 transformers (after lampization - 4 !) fully digitally  balanced configuration - etc etc.
PHILIPS TDA1305 chip - sounds very promising indeed. Two of them ? Even more interesting ?



With external lampizator it sounds VERY good indeed. It beats hands down the Marantz 17SE which it replaces (as a DAC of course). The sound is more natural, more warm, details are "organized" in space in such way that they create credible natural soundscape. With the 1547 - the details are the same but not so naturally placed. A singing opera diva gives you goosebumps on 1305, on 1547 it just is an okay performance. The difference - to be sure - is VERY SUBTLE and small, but the preference is clearly towards Dacmagic.
Now all that is BEFORE lampization.
After lampization - the final verdict is the same but the difference is more apparent.
This combo was bought from me by a professional opera critic who owns most CD's of anybody I ever met.  He spends all his days and nights listening critically to classical music. That's something I appreciate.

Later I found out, that the TDA1305 DAC chip has identical datasheet and pinout and specs as the TDA1549T which I absolutely love. Maybe they share some technology. Read about the TDA1549T HERE

At first sight the TDA1305 seems to be U out DAC and that is how I lampized it - Voltage out taken to SRPP tubes 6N6P via a foil cap.
But the close inspection of the TDA1305 datasheet reveals a possibility of disabling the internal op-amp and stealing the I out current.
Some people say the DAC can be CONVERTED to current output status. Similarily - the TDA1543 and 1547 can be done like that.

In this case - after such microsurgery the tubes change to 6N2P or ECC81 and the cap before grid is gone.
I havent tried it yet although I sure will.



As you can see above, the temptation is to use pins 23 and 24 for I out and disable the opamps. We should probably float the pins 22 and 25 and kill the opamp supplies - one of the supplies drawn on the bottom of the diagram above. We should also remove the capacitors CEXT1 and CEXT2.


All below pictures concern the U out lampization of the DAC in voltage mode.






Eventually of course I put lampizator circuit inside the DAC box - there is plenty of room.

















The mighty king of transports - Kenwood 9010X drives the Cambridge DAC










This is what I found on the web about this product:


Cambridge Audio Digital Audio Converter


Model History:
DacMagic was designed by John Westlake, former Pink Triangle Tech, and digital conversion is accomplished by a pair of Philips TDA 1305 "18-bit" hybrid chips (the Naim CD 3.5 uses one).

DacMagic 2: Dual Philips TDA1305 hybrid DACs with symmetrical dual differential circuitry. Three separate transformers feeding 19 independent power supplies. DacMagic 2 is an improvement over the DacMagic 1.

DacMagic 2i: Many significant improvements. Design revisions resulted in reduction in distortion by as much as 50 per cent, gold-plated printed circuit boards and connectors, and better quality low-noise transformers. 

DacMagic 2 Mk II: same as DacMagic 2i but with Analogue Devices AD712JN output chips.
DacMagic 3: the last of the series.


Submitted by Job Chithalan

Dac Magic 2
Technical Data (taken from Instruction Manual) :

D/A Converter: Dual Philips TDA 1305 multi/single-bit hybrid
Sample Rates: 32, 44.1, 48khz, automatically traced and locked if within tolerance.
(for operate with CDPs, DVD players, FreeView Boxes, NICAM and Digital Audio Broadcasting (from satellite), DCC/DAT players.
LED Indicators (7): Locked, EQ, SCMS, 32, 44.1, 48 and power on/off
Digital inputs: 3 (2 BNC Electrical, 1 Optical)
Digital outputs: 1 (BNC) S/PDIF 75ohms
Analogue outputs: 2 pairs (1 phono pair, 1 balanced pair)
Frequency range: 4Hz to 20 Hz +/-0.5dB
Total Harmonic Distortion (typical): less than 0.005% at 1 kHz
Signal to Noise Ratio : greater than 110 dB
Dynamic Range: 100dB at 1kHz
Channel separation: greater than 130dB at 20kHz
Audio output level: 2.8V RMS
Inter Channel balance: =/- 0.5dB
Power consumption: 30W
Dimensions (mm): 430w x 315d x 92h



Reviews:
"Instant upgrade for a budget player but out of its depth within a properly designed hi-fi CD player." - Hi-Fi World, Jun 95, £150.

The Star Online : Audiofile review of DacMagic 2i is at
http://202.186.86.35/audio/story.asp?file=/1996/5/05dac

Cambridge Audio: DacMagic 3 review is at
http://www.audioweb.com

User Reviews and comments at
http://www.audioreview.com

Mods and Upgrades:
An illustrated 3-page article in the Jan 1999 edition of Hi-Fi News & Record Review covered modding a DacMagic II Mk 2. It can be downloaded as a .pdf file at http://lickham.co.uk/pdfs/dacmagic.pdf (922k)