My deepest gratitude to "some folks" as I went down this evening as per your comment, Rob, and removed the tube in the Minimax DAC Plus. Those people are absolutely correct; the resultant improvement is stunning. I rolled one tube, the Siemens Silver Plate and it had nowhere near as powerful a result as removal of the entire tube.
My assessment is the effect of this tweak is to make the DAC Plus perform on a power basis similar to the adjustment I did to the original but did not speak of publicly - after commenting ad nauseum about Opamp rolling the unit in the end removal of one set of Opamps was how I ran it. I took out the SS Opamp set, rendering SS output lame, but this shunted all the power supply to the tube output with far better results.
Now, recognizing that the removal of the tube of the Minimax DAC Plus is effectively accomplishing the same thing, only without the marginal hassle of Opamp removal, my guess is the power supplies are operating in tandem to elevate the performance of the SS output. If that is not the explanation I really want to know why there is a radical improvement in sound quality across the board.
This is THE most unorthodox and unexpected, as well as effective, tweak I can recall doing. It's free, easy, and VERY powerful in effect. In a word it's the perfect tweak!
So, THANK YOU to the bright one(s) who thought of it. I'm just ticked off I didn't think of it so I could write a special article about it! :)
I do not wish to be hyperbolic in my description of what this tube removal tweak does (BTW, THIS MAY VOID THE WARRANTY; I KNOW THAT BILL O'CONNELL AT MORNINGSTAR AUDIO, THE DISTRIBUTOR IN N. AMERICA IS CONCERNED THAT PEOPLE TAKE RESPONSIBIITY FOR THEIR OWN ACTIONS/TWEAKS! Morningstar is NOT responsible if YOU screw up your DAC. I'm not responsible either, because this is "do at your own risk" tweak!) but in a few words it mulitplies the characteristics I speak about in my review of this unit at Dagogo.com.
I am not one given to mamby-pamby tweaks. I find most of them not efficatious. However, this one IS VERY efficacious! What is most striking is the tremendously smooth, silky and voluptuously full character of the music. One gets a huge dose of appreciation of two things:
1. The phenomenal potential of 32 bit processing
2. How much "digititis" still exists even in good DACs
Gentlemen and Ladies, once again the ceiling has been shattered in terms of performance. I admonish audiophiles to never set limits on how much improvement can be obtained (and thus listening pleasure and involvement in and appreciation of the music) in an audio system.
My rig is well past the place where I initially thought it could go. I have blown past performance levels many times over. This is some thick icing on the cake.
Now, a reviewer's critical comment about this particular tweak: I can see many audiophiles reacting negatively to it due to feeling that it's "information overload." Some listeners seem to actually prefer less detail/definition as long as tonality is correct. When I first switched over to the "tubeless" DAC Plus I was struck by the immense amount of intensity in the upper-mid/treble region. I went through a lot of my quick test pieces and found that on the whole the change is far more beneficial than detrimental. The classic parameters of excellent sound are here in dump-truck-fulls (as opposed to merely bucketfulls).
One thing which struck me is the effect on the 3-D placement of performers. In SO many rigs the center image is really tough to have on an even plane with the L/R. The phantom image is tremendously difficult to get to be similar intensity, thus making the soundstage seem consistently deep across from L-C-R. This tweak nails it! It's simply gorgeous in terms of spatial relations in the soundstage.
And treble - wow, how delicate. Really, we're nearly talking a paradigm shift in experience with such a revelatory clarity happening across the board with the tubeless unit. Mind you, I've only used the DAC Plus this evening with one set of amps and transport etc. But I have no problem urging owners try (do this at your OWN RISK!) remove the tube and run SS output. Perhaps you will adore it, perhaps you will hate it, but either way if you can't hear the difference then go get some fun looking vintage gear because you've got major hearing problems!
This commentary was about using the DAC Plus with Redbook and dig coax to the DAC. I haven't used USB with it yet as I'm looking at new options for server/streaming music.
Rob, if ou think the SS output of the DAC Plus is good, just wait until you hear it without the tube. Where did you see discussion taking place about tube removal?