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? |
I should add that if a person is modding the Minimax DAC or DAC Plus then all bets are off in regards to pulling the tube. I'm working with a stock unit and will be speaking about that, as I did with Opamp rolling. At this point I do not plan on Opamp rolling the DAC Plus, especially since I have stumbled upon this easy, yet just as efficacious, tweak.
It should be noted that at Bill's request I did not discuss Opamp rolling, etc. in the DAC Plus review. However, he had no problem with my exploring such things on my own. I said I might discuss them but not in an official capacity for Dagogo. So, people can take this discussion as post-review tweakery.
After running through a lot of test material I'm not inclined so far to put the tube back in. Over time we'll see how it goes with several other system configurations but so far the results are extremely encouraging. |
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Quickie test on secondary system shows tube removal works well for original Minimax DAC as well! This is not a definitive answer but good initial result.
This is with ALL Opamps IN the machine! I have not tried running the unit with tube out as well as some Opamps out. :) |
Chayro, sometimes the most counter-intuitive things can be beneficial. I wouldn't advocate that approach for most things in life, but in building audio systems within reason it can work.
I went over to a friend's home last night; he also has the original Minimax DAC. We tried the removal of the tube but it did not pass my Law of Efficacy. We did not hear the hug jump in sound quality which I expected. We did notice a distinct difference in gain, there being much lower gain with the tube removed. However, we felt there was an incremental improvement with the tube out and the Phase inverted on the unit. In his system this did improve things marginally.
I wonder about the impact of my original unit having upgraded Opamps and how that might effect the tube removal tweak. His unit has the LME49710/LME49720 sets which did not improve the DAC as much as the later sets I rolled in and mention in my Audio Blast: Eastern Electric Minimax DAC Tube Rolling article.
I had an email asking which Opamps I ended up removing when I used the original model with Tube output only. The removed Opamps WERE those at the U6/U7 positions. I say "were" since I put them back into their positions in order to do the tube removal tweak. So, now I am running all the Opamps in their normal positions, but with no tube in the unit.
It never ends... :) |
Abruce, What's interesting about the tube removal tweak for the DAC Plus is that the unit becomes much more liquid, more analogue-smooth without the tube and running SS output. The difference is so extreme as to make the tubed output of the SS sound like it's choppy/full of digital artifacts. |
Ok, Gianc, you're the expert now! Kindly let us know the numbering of the Opamp sockets where the single and dual opamps to be replaced go.
Please be extremely specific in regards to the location of the sockets on the board and the numbering of the sockets with which Opamps (single/dual). Much appreciated!
Also, for the sake of getting it right the first time, please confirm the orientation of the opamp to the front of the unit. Again, appreciated.
Sounds like I've got some Opamp rolling to do! Good thing I held on to that tube I removed... ;) |
Gianc, ah, very good; thanks for the timely response! The clear indications of location and numbering were precisely what I was looking for - thank you!
It sounds like you have some Opamps which have the legs splayed out a bit; yes, you have to settle them in carefully prior to applying the gentle pressure to seat them. It's good that the numbering has stayed the same between the Plus and the original unit; makes things less confusing.
As cheap as the opamp extraction tool is I strongly recommend it over toothpicks and pliers. Remember, the average person has some trepidation about this anyway, so stuffing crude tools into the unit is not recommended imo. I understand if you have experience and feel comfortable with it, but many would see that advice and perhaps shy away from the attempt. Others are more clumsy and might damage something with a larger tool. It's always best to use the right tool. Case in point, the socket for the opamp can be pulled/damaged if one latches onto it rather than the opamp base. It would be harder to ensure you have the opamp and not the base when pulling if you have a needle nose pliers. The extraction tool has a little bent end which is placed right under the opamp whereas the pliers are straight - a greater risk of pulling on the socket. This is just an observation for those without experience.
Interesting idea with the razor and scraping the legs prior to insertion; I'll not endorse that officially but it's creative and certainly makes sense that it would make for a better connection, like getting corrosion off of speaker cable spades, etc.
Gainc, so, why not remove the tube now, with the upgraded Opamps, and see if there is an improvement in the SS output? I most certainly will try that. Again, as if it hasn't been said enough(to the general public)... at your own risk. I think the other interesting tweak was to remove the tube Opamps and run the unit completely SS. When I tried them the tube removal with the tube Opamps in the unit was the best result.
Knowing myself I likely will be opamp rolling several sets again, but at least its easy work for exceptional results. :)
Once again, I'm not speaking here in any offical capacity for Dagogo.com or Morningstar Audio. Bill at Morningstar doesn't mind my futzing personally but wants it universally known that all these activities are beyond the scope of the warranty. So, let no one mess up a unit - i.e. by taking a pliers to it - and then come running back to Morningstar feigning need for a repair due to some defect. It's sad that I have to say that, but with the last unit there were some who tried some home surgery and then went to Bill to seek reparations. We need people with more integrity than that. |
Foster 9, I disagree that it's too DIY. One of the things which I feel separates this upgrade is that no knowledge of schematics or soldering is required, two things that are very DIY. It's literally "plug N Play" stuff we're discussing. I wouldn't promote it as a tweak for the masses if it was more difficult.
Jult52, the Opamps can be purchased from a variety of places; I wrote in the article about securing them from Cimarron Technology, which makes the Brown Dog Adapters for the double Opamps. But others have discussed online at places like Audiocircle alternatives.
The pricing on Opamps for the original unit for 4 of them from Cimarron ranged from about $40-90 depending on brands/model. It seems the primary factor in cost is how old the opamp design. From my article re: the tool... "Opamp extraction device called DIP/IC Extraction Tool - S-340 made by Jonard Industries Corp. from Digikey.com" |
Let's consider this my unofficial Opamp rolling discussion, seeing as how Morningstar has concerns about it.
I was so pleased with the results of Opamp rolling last night I am motivated enough to delay my morning workout a few minutes to pen, err... write... err, type this up.
Ah glorious joy! You can get the same benefit for the EE DAC Plus that was obtainable with the original via Opamp rolling! Alex Yeung has kept the circuit board it appears pretty much unchanged in regards to the four opamps, at least when it comes to Opamp rolling. i.e. the pairs are still labeled U1 & U2 and U6 & U7. They are located smack in the middle of the board in plain sight. They all are socketed (I was under the impression prior to the release of this unit that only two of the four would be socketed. With all four "rollable" this is terrific news for the audiophile community!).
Last night I rolled in 8620's into the U1/U2 positions and 827's into the U6/U7 positions. SWEET! Just like last time with the original, superb improvements. How superb? Game changing potential for an entire rig. You can literally take a system you do not like the sound of and with Opamp rolling turn it into one which you do like the sound.
Now, if it's too much trouble to secure a $4 tool, to protect against static, take a lid off the unit, pull out four Opamps and carefully push in four new ones - well, then so be it. Your loss. :(
Well, actually, it's not a loss as you will still have your wonderful sound of the stock unit - you just won't have anywhere near what this unit, or your system, could be.
With these new Opamps installed I pulled the tube out and ran it SS. With very little time in the assessment my first incination is that this maneuver failed the Law of Efficacy; I didn't hear a marked improvement over the quality with the tube in the socket. I'll probably repeat the test and may change my opinion; as I said, it was a quick take.
But the Opamp upgrade is something of which I would assert if you do so and cannot hear a difference then you have either a rig which is far below top quality sound to dig out the differences and/or hearing loss. There is a high degree of likelihood that if a person can't hear such a change as this then they do have hearing loss. I would also suggest that for such a person they not bother wasting their time on tweaks because that person will not hear them, their hearing deficiency will dictate that for them such things are not sufficient enough to perceive.
I would expect that for approx. 20% or even more of people coducting such a tweak as this Opamp rolling may not be able to hear the difference or consider it to be of little benefit. In fact, the benefit of this Opamp rolling is nearly exponential in terms of the potential to benefit a rig. The more "powerful" as in capable you rig is, the better the result will be and it can be every bit as compelling as a component or entire cable suite change.
Case in point, I built a system yesterday which has very fine components which no one with any experience in the high end would dismiss, yet the system was unsatisfactory, very thin and tilted to the top in an unacceptable manner. With only the Opamp change the rig's character completely changed such that this same pairing of gear was now far weightier, lush and approaching an ideal balance between the top/mid/bottom. That may sound incredible or unbelievable, but those who have Opamp rolled will nod in agreement; it certainly is possible.
An exercise like this should humble an audiophile to hear how much a rig can be improved by such seemingly (i.e. "I don't think it would make that much difference," you know, the classic arrogant line.) insignificant gestures. It also shows how much more can be wrested from a rig before throwing in the towel and swapping components. I'm not impressed by the majority of oddities posing as significant tweaks; this is not of the same ilk. This is a serious improvement worthy of the time/$.
But, hey, you've probably heard it before - IT WILL VOID YOUR WARRANTY! So, there you have it, the great spectre of fear and forbidding on one hand, the potential for glorious advancement on the other.
In reality the audiophile community should be discussing the stock original and Plus Minimax DACs and the Opamp enhanced ones nearly as different products, the change is so dramatic between them. While I have not compared the Minimax to some of the other currently hot DACs it is not to be concluded that if the stock unit falls short Opamp rolling would be of little use/benefit. That would be imo a very poor conclusion.
Finally, thanks to Gianc, who prodded me by his posts here on the Gon and was enthusiastically helpful to me in identifying the placement of the Opamps; saved me a lot of time and effort. Having rolled Opamps in the unit prior it took about five minutes or less to install the new ones. In addition, Gianc is one of the most genial of Audiogoners I've conversed with. :) |
Tubegroover, yes, absoltely a lovely increase in weight and density with the 8620/827 combo I have rolled. I would expect similar incrase in density of images and various widening of soundstage, increase in clarity and micro/macrodynamics etc. with other Opamp combos rolled into the proper slots.
The 8620/827 combo was one of my top four or five favorites when I did my dozens of tests back when I opamp rolled the original unit. So, I went to that combo immediately instead of retracing all the way back to my beginning sets with the original unit. I'm very positively inclined toward the result. That's not to say this is the ultimate set by any means, and with any given system a different pairing might result in a more favorable mix of attributes. One set I might try yet is the hyper-detailed LME49990 in all locations it's one of the newer chips and it's clearly more distinct imo, but would likely depend on the rig whether it would be too bright. |
Regarding Opamp rolling the EE Minimax DAC Plus; NOTE: I have been in contact with Morningstar Audio about the opamps used for the Plus version; It is not acceptable to simply use any of the opamps which worked for the original version.
For instnace, the LME49990 is not suitable for the Plus version of the Minimax DAC and could damage it. I am seeking a listing of appropriate Opamps for the Plus version and will post it when it is available.
I am posting this in several places as there are owners of the original DAC who may have opamp rolled, then secured the Plus version and may be interested in opamp rolling it. Please wait until a listing of appropriate opamps becomes available. One set which does work fine is the 8620/827 combination. :) |
Tubegroover, even though it would make sense that all opamps which work with one unit might work with the other, a person should not risk it. That assumption could be drastically wrong given the circuit boards/circuit are not identical. The same nomenclature may be used and general pattern but the circuit might be different enough that any given inappropriate opamp might cause failure of the opamp or unit.
As I'm discussing it publicly I'm checking to ensure which are appropriate sets for the DAC Plus. I do not want there to be any chance of incompatibility. There are variances in opamps and it should be determined if those variances are within tolerance for the DAC Plus. I do not know those parameters which is why I am checking with those in the know.
There is vanishingly small chance of problems when the appropriate opamps are used with the proper unit; in fact, I know of no unit which has had problems when "approved" selections of opamps have been used. However, the use of a wrong opamp can have damaging effects; I believe others have pointed that out as well. I'm trying to cover all the bases and make sure no one has a negative surprise. It's not worth making an assumption and blowing a DAC. Better to get the word from designers/opamp experts and work from that.
I would liken it to the use of a 2 Cycle engine which must have a mix of oil and gas. If used inappropriately, with straight gas you'll ruin the engine. But if used correctly there is no danger. So also, owners should await the appropriate listing of opamps so that there is no chance of running the unit and damaging it. :) |
I have confirmed the LME49990 should work fine with the Plus version, and I'm seeking a longer list. |
I just posted a separate thread detailing the proper Opamps and locations for them as recommended by Cimmaron Technology.
I agree; Alex Yeung should do an all out effort at a SS only Minimax DAC. |
I hasten to add, I do not agree with the statements of comparison of the EE to some other DACs here; I can't, as I have not yet heard it in comparison. :)
However, the Minimax DAC Plus when Opamp rolled is QUITE the different DAC from stock version. |
