I have tried out Dacmagic models and also Isomagic. But better ones to be had these days at about the same price.
At the link below, you will find a full model history and also a reply I got from John Weslake, the designer of Dacmagic., in response to my mod enquiry.
http://www.diyaudio.com/forums/showthread.php?s=&postid=470310#post470310
In the ending "credits" of the article, Andrew Harrison thanks me – unfortunately, I've never met or spoken with Andrew Harrison – not to mention know anything about the article before it was published.
Changing the electrolytics to better quality types such as OSCON's will always help, but don't waste money changing C115, the 100n SPDIF input Cap to Polypropylene as recommended in the article.
Unfortunately, the designs biggest weakness is the TDA1315 – the SPDIF input receiver. The TDA1315 has very poor jitter performance – despite claims otherwise from Philips, by the time this was realised; the front panels and casework had already been manufactured (the front panel has LED's for sampling rate and copy protection). Changing the design to the better performing CS8412 was not an option, as the CS8412 has no direct method to drive the front panel sampling rate LED's – and the budget was already very limited (original retail price was £149).
If possible, modifying the unit to "clock-lock" with the transport will bring enormous improvements – then the quality of the DAC becomes the limiting factor.
The first pre-production version of the design used Burr Brown devices (I seem to recall the PCM1710), I much preferred the sound of these DAC's over the TDA1305's, however the Burr brown DAC's had a STUPID design fault that prevented them being used in dual differential mode.
The Burr Brown devices internal mute circuit was designed to detect all zeros – and not "change of data". During "Mute" in dual differential mode, one DAC receives "all zeros" – and the second DAC "all ones". This meant one side would go into Mute – while the other side still operated – resulting in DC offset on the outputs during "Mute". As a result was that I was forced into using the TDA1305 as there where no other good performing "budget" DAC's on the market at the time. Still many liked the sound of the TDA1305 – but Naim using it their CD3.5 is really stretching it way too far – these are BUDGET DAC's – limited by there internal digital filtering. They have a very muddled Bass heavy sound, with poor sound stage – possibly, why Naim selected them?
My best DAC design for Cambridge Audio was the HDCD ISOmagic – if you can get hold of one, then it's a unit worthy of modifications! If you have an ISOmagic or CD4SE - don't let go of them - or you will find yourself regretting it later - just ask those who have...
John Westlake <
[email protected]>
