Who has tested more than one DSP1 digital input and upsampling/interpolation filter on audio-gd DACs?
On some threads we have found, that the revisions DSP1 digital filters are crucial to the "sound signature" of the audio-gd dacs. (E.G. on this discussion: http://www.head-fi.org/forum/thread/519510 ).
For instance, PoisonMate did some testing with different revisions exchanged between different DACs, and he got to the conclusion, that his DACs sounded very different after changing the DSP1 filter from one revision to the other. In particular, he found, that the supposed "musical", more "forgiving" or more mellow sound of his "diamond output stage" - type Reference 8 DAC got more to the analytical and perhaps too hard, bright side after upgrading the DSP1 filter to rev. 5 (up to revision 4 it maintained the "warm" characteristics).
I think it might be helpful, to systematize a bit the experiences and answer the following questions:
- What is the sound signature of the different DACs with the different DSP1 revisions?
- How "user replaceable" are the DSP1 modules in the different audio-dg DAC models? Is technical know-how required to do that switch?
- Which is the current version of DSP1 revision?
- Who knows about new revisions planned by Kingwa? What are the changes to come?
- Who has made experiences ordering just a new DSP1 module? Is Kingwa keen to deliver them? At what prices...?
- Is there other useful know how to be shared about the DSP1 modules, like useful jumper settings, etc?
Thanks for sharing your experiences!