Anyone know which opamp is the right channel, u1 or u2? thanks |
I agree 100% with Jmbatkh's assessment. The discrete opamps I've tried (both Dexas and Bursons) sound more analog like than any of the IC opamps I've tried. I don't think you will necessarily get any more resolution with Dexas over 49990's but the presentation is more relaxed and organic. I can listen to the Dexa upgraded Dac Plus for hours without any listener fatigue.
The Dexas sound to me cleaner and clearer with more sparkle than the Bursons. The Bursons will add more body and weight to the music with better bass than the Dexas. Both are wonderful and dependent on personal taste.
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Hi,
I used the 49990s happily for several months on my Plus. I liked them a lot but tried the Dexas anyway (Bought from the mfr. site for about $245 total).
The upshot- I easily preferred the Dexas (after 50 hr break in). Interestingly, they sound most like the 49990s of anything I've tried- detailed, very fast and transparent.
But they also are a bit easier and organic sounding- not softer or rolled off, but more analog-like? They also do a better job of letting through the ambience and tiniest harmonic details. Overall, they sound a lot like the 49990s but more refined. Is it worth the $? To me they made the sound a bit more relaxed, which was what I was looking for. So in my case, yes, they were worth it. Day and night difference, once size fits all? Not in my opinion. Good luck! |
With the exception of the discrete opamps, I perfer the 49990's. Would the Dexa or Bursons have the resolution of the 49990's with more body? Thanks |
After several days of mixing and matching the Dexas and Bursons in the Minmax plus it has become pretty clear that I prefer the Dexas in both U1/U2 and U6/U7 in both tube and SS mode. The Dexas have a crispness and clarity that I really enjoy in my system while being much less fatiguing than any of the IC opamps I've tried. Those looking for more body and weight to the music should try out the Burson's.
After a bunch of experimenting, my current default listening setting (subject to change) is tube mode with NOS Mullard and all Dexa opamps. In addition to the stock EH tube, I have tried Amperex, Mazda/Cifte and Mullard. I prefer the Mullard but all NOS were a clear improvement over the stock tube. Will more than likely try a few other tubes for curiosity sake. For those looking for the utmost clarity and resolution, going all Dexas in SS mode with tube removed is a great choice as well.
That's it for now.
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This is a crazy price difference but has anybody did a comparison to the AMR DP-777 |
inregards to the Lampi having slightly more body it was just a slight difference and was not really anything that concerned me, in my system with a Rotel RC-1550 pre and a Rotel RB-1582 with Wharfedale 9.6's that difference is gone but i still have an incredible amount of detail without any harshness. As you can probably tell I'm loving it |
Nothing1:
Agree with your asessment of the Dexas. You mentioned the level 3 Lampi had slightly more body than the Minimax. If you like that fuller sound, get a pair of Bursons. Compared to the Dexas the Bursons add (at least in my system) more body and weight to the sound. Having both Dexas and Bursons allows for tremendous flexibility. |
Time for a quick update. I've been running my minmiax dac + with Dexas for about 3 months and thought they were a significant upgrade over any of the IC opamps I tried. After reading Doug's review, I decided to try out the Burson's and report back.
First off I'll list my system for reference. Preamp is Shindo Vosne-Romanee. Amp is Shindo Haut-Brion (25W). Speakers are Tonian Labs Classic 12's (96db speaker featuring PHY driver with supertweeter). When listening to redbook CD I used PS Audio PWT as transport. When listening via USB through my windows computer I used flac files via JPLAY.
When I originally read Doug's review I was a little disappointed and thought he was hedging his bets by not declaring a clear preference. After living with both the Dexas and Bursons for a while I now understand his position. The Dexas and Bursons are to my ears a clear step up over any of the IC' opamps I've used. In addition, the inclusion of the discrete opamps makes digital more listenable over an extended time frame. The digital "edge" is gone. The music sounds more analog like than ever.
That being said, the Dexas and Bursons clearly sounded different in my system. With Dexas, the sound was clearer and cleaner with greater extention in the higher frequencies. With the Burson's swapped in, the sound was weighter, with more meat on the bone. The low end was also more impactful. I realize I'm pretty well echoing the comments that Doug made in his article. He pretty much nailed it.
Which do I prefer? If a gun was held to my head and I had to choose one I would probably pick the Dexas today based on my system. My Shindo electronics do a good job conveying weight and body to the music so I like the clean sound of the Dexas. However, if your system is on the lean side, I can easily see you prefering the Burson's.
My next step is to mix and match between the Dexas and Bursons to see if the combo can give me the best of both worlds. Will report back again with my thoughts in a few weeks.
For those of you who have the Minimax or Mimimax plus, go out and get some discrete opamps ASAP. The sonic bang for the buck is as high as anything I've tried in the 20+ years I've been dabbling in this hobby. |
The other day i had the opportunity to compare my Minimax plus modified with the dexa's, psvane grade A tube and a Hi-Fi tuning extreme fuse, with a level 3 Lampi at a hifi store near me. The comparison was done with some large magneplanars(don't know the model no)and some other high end pre and power amps, if anyone is interested i can get the relevant info. Anyway i was very surprised to hear that the Minimax plus sound was so close to the Lampi level 3 in detail retrieval and tone, in fact in regards to detail i would say that they where identical and if there was a difference i couldn't hear it! tone wise the Lampi had slightly more body(by a very small amount)but the Minimax had better bass. Soundstage wise once again the Lampi one by a very small amount, one difference was that the Lampi placed everything a bit higher up(like they where up on a stage) and the Minimax was lower as if they where on the floor in front of you but other than that nothing else stood out as being majorly different.The guy who owned the shop was very impressed with the Lampi but still was more surprised with how the Minimax stacked up against it at the price it sells for.Needless to say i left the store a very happy man knowing just how good a dac this is for the $1100 i paid plus $360 in mods.These dexa's take the Minimax Plus to a whole new level do yourself a favor spend the money and enjoy an outstanding dac |
The results with the original Minimax DAC in the office rig are as expected, beyond expectations. I have rolled in the Dexa duals into the U1/U2 positions and the Burson singles into the U6/U7 spots and the performance uniformly elevated across the frequency spectrum.
Particularly notable is the extra weight and definition with the bass. I have smallish subs in the rig but the Bursons, as with the reference rig, add quite a bit of robustness and presence without sacrificing definition. Tonality continues to improve as well.
Once again, note that one should roll both pairs of the original IC Opamps. Using discrete Opamps in all four locations dramatically improves performance, despite the fact that one could leave the stock IC Opamps controlling tube output untouched. Just as it may sound illogical to remove the tube, so also it seems illogical that replacing the IC Opamps for tube output would affect the overall performance, but it does, and in no small fashion.
This may prove to be among the most affordable answers to the "Class D Amp Problem", that being a white-ish, thinner sound. I am very much enjoying the performance of the Peachtree Audio Nova with the EE Minimax DAC now along with the Eminent Technology LFT-VI speakers. This is the best magnetic planars in an affordable rig have sounded in a long time. And I'm not even using Redbook, but Sonos with a NAS.
(I have reviewed products from these brands for Dagogo.com) |
Thanks to Bill for hooking me up with the DEXA's! They do exactly what I want in the sound, more relaxed AND more resolution. In essence they reveal more nuanced details, but do so in a way that makes extended listening even easier. I'll be doing some comparisons with my BMC DAC1, and while I don't expect the EE to come out on top, I do expect it will be very close in many ways. |
I've been running the Dexas in my DAC + for about 6 weeks and there is no question that the discrete opamps produce a sound that is much more analog like than any of the IC opamps I've tried. Based on Doug's review I have also ordered the Burson discrete opamps and will do a comparision between the two when they arrive.
I will say that at least in my system (Shindo amp and preamp, Tonian Labs (12" PHY) speakers) some of the IC opamp combinations seem to have more absolute resolution than the Dexas but the Dexas just sound more natural with less listening fatigue.
I still prefer listening to my analog gear over digital but the DAC +/Dexa combo has greatly improved my digital listening experience. For under $2K, the sound has exceeded my expectations and represents an excellent value.
Will report back later when the Burson's come in... |
Following up on my threat (actually, a promise) to put the discrete Opamps in my office rig, the sound is good enough that for all but the most ardent perfectionists it would be quite acceptable.
My office rig: Sonos with a Buffalo .5G NAS for my CD collection ripped; Cambridge Audio Azur 840C, Peachtree Audio Nova, Eminent Technology LFT-VI with pair of SHU STF-1 subs. Wireworld cabling throughout. This is not what I would call an extreme system, but a competent one. However, the discrete Opamps installed into the EE DAC (this is the older version, not the Plus version as I wrote about in the article; the Plus version is much better holistically) elevates the system vastly. It sounds closer to what I accomplish in the review system than previously. Particularly the magnetic planar speakers are sounding much better than prior, more tight and distinct.
BTW, the tube mode of the Nova obscures the pristine nature of the EE DAC; I run the Nova with SS mode and the tube removed from the EE DAC. |
I have been waiting impatiently for my Discrete Opamp Rolling article to be published at Dagogo.com; now it's up for the world to see.
It is my latest foray into Opamp rolling, this time with the lovely discrete Opamps.
A couple of notes:
There was one mental faux pas where in comparison of prices I said, "ten digit" but meant ten thousand or five digit. Should get corrected today.
I focused on redbook playback in the article, but the same results apply to the DAC being used with file playback, streaming audio, etc.
I did not get into the option of shortening the long leads of the Burson Opamps, but I have indeed spoken to Burson/Dexa to obtain additional sets for my office rig. I'm looking forward to that upgrade! |
In the U1/U2 position, how do the Bursons compare to the Dexas in sound quality? |
@Bavmike, never thought of this. Great idea. |
Okay, then I'll list what I bought then from Parts COnnexion!
2 Dexa Discrete Opamp Dual DEXA-73728 $84.95 $169.90
1 BURSON Dual Discrete Op Amp Modules, pair, (DIP Header) BURSON-74454 $179.95 $179.95
2 Dexa Discrete Opamp Single DEXA-73729 $49.95 $99.90
1 BURSON Single Discrete Op Amp Modules, pair, (DIP Header) BURSON-74456 $114.95 $114.95 |
Can you guys list the p/n's of the Dexa and Burson opmps and sources? Are some of you using single and dual dexa's and single and dual Bursons? nd some of you are using singles of one and duals of the other? |
I have been enjoying my minimax plus with dual Burson's in U1\U2 and the Dexa's in U6\U7 for a few months now and couldn't be happier. I find the sound to be stunning. Although with some recordings I like the sound of the Burson's with a Amperex orange NOS tube from pearl cryo better. You sacrifice some of the vivid resolution with the tube as well as output level, but you get a nicer, softer sound when listening to harsher recordings. I bought the flying lead version of the Burson's and trimmed them down to about 3\16" and carefully lined them up to the socket holes and wiggled them in. It was a delicate procedure, but they are in firmly now, and they clear the lid. I later thought of a better way of doing it which I'll cut and paste from another forum to save the typing.
for those who wish to roll with the Burson opamps without the hassle of having to buy the flying lead version, and deal with the shady process of trimming and worrying about the leads bending and potentially snapping off. The original reason I didn't go with the much sturdier dip lead version was because of the clearance issues with the lid. I've thought of a solution. All you need to do is buy some sheets of a product such as:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=268-030
to use as a spacer\gasket. Stick it to the inside of the lid (not sure how many layers it will take, could just be 1 but buy 4 they are cheap enough), cut a little square out where the bursons line up with the lid, and also a square where the vent holes for the tube cooling are. You will also need to find some longer machine screws to attach the lid and make some little holes in the material where they need to go through. This method will effectively allow enough clearance for the dip version, plus you will reap the benefits of a sound deadened lid! Why didn't I think of this before? |
Bill
Can you describe the sound with the Dexa's in, on another site the user said it gave body to instruments, something that may be lacking with stock op amps
Regards
Bruce |
Having lived with the DEXA Discrete op-amps for about 3 weeks now, they really do seem to be the one's to beat. I highly recommend for the tube output the Philips E80CC pinched waist D getter version as a substitute for the 12au7. Although this tubes is twice the length and you won't be able to put the tube shield in place anymore , and being that this isn't a direct substitute for the 12AU7 as it draws twice as much heater current, Alex Yeung the designer says it is ok to use. This tube with the Dexa's is fantastic! |
@Morningstaraudio, you're right the DIP versions do not fit with the lid on. However, the flylead version fits but you need to bend the legs.
I think the sound difference is worth it :) |
The Burson's do not fit under the top cover of the DAC. I do not recommend using as they also draw a lot of current.
Very much so the op-amps make a difference. I still like the OPA2604 duals and the OPA827 singles. |
Does this opamp rolling make the EE any more musical, or engaging
I just Don't feel drawn into the music with this Dac
Thanks |
Is there a difference between the Dexa opamps and the burson's? if so...how much? |
Roy,Mrtennis
I can't explain it any better then what I told you over the phone yesterday. |
if you put the dexa op amps in the original minimax, not the plus, what is the difference in sound between the minimax, and the plus, assuming both have the dexa op amps ?
i am assuming that part of the cost of the plus is the replacement of the stock opamps from the original dac. |
Yes, they do fit under the cover.
You have to make sure just to put them in correctly with the half moon circle cut out on the base of the Dexa'a always on the right hand side while looking at the front of the DAC PLUS. |
Do the Dexa's fit under the factory lid without having to make jumpers? Meaning, they plug right into the opamp socket and stand upright without hitting anything? |
No, an opamp is an electronic part on the circuit board of the DAC. Many DAC's have the opamps soldered to the board which makes it extremely difficult to swap out. The EE opamps are not soldered so swapping them out is very easy. Many people (I'm one) find that changing opamps (like changing tubes) can influence the sound. What's very nice about the EE is that between tubes and opamps you can fiddle to your heart's content and tailor the sound to what you like. The only caveat on swapping opamps is that this usually violates the manufacturers warranty if anything goes wrong. |
.
From the context of all the posts here, I have to assume that an opamp is the same thing as a tube or a valve. Is that correct?
. |
Yep, the smooth presentation of the Dexa's along with a NOS tube has won me over and I'm keeping this as my default set-up for now. It does not have the last degree of detail as the 2604/827 combo but it has enough detail and resolution for me while helping to reduce any digital harshness. Cost is only downside. It's $250-$300 for a full complement of Dexa's which may be a lot for people to invest on a $1100 unit. Never the less, I just love the flexibility of the EE unit. |
Only been playing them for a day, but immediately noticed going thru the SS output with tube removed and the dual OPA2604's still in the U1/U2 dual position with the single Dexa's in the U6/U7. Lovely smooth presentation, totally agree with Sibelius on the analog tone to this combo.
This morning installed the dual Dexa's in U1/U2 position and running that at the moment with a Siemens silver-plate thru the tube output.Really haven't had time to critical listen as now just doing some background music to burn in a bit.
Thanks to all of you who recommended these.
Later,
Bill |
Update time. Have spent time with an all Dexa Discrete opamp system in both U1/U2 and U6/U7. Impression is that the sound is softer and rounder than the 2604/827 combo. It does a good job of taking the edge off harsh or bright recordings but does not have the same degree of detail or resolution of the 2604/827 combo.
If you want the most detail and resolution I would go with the original recommendation - swap out stock opamps with 2604/827 and remove the tube. It will cost you about $80 and is a noticeable difference.
If you want to tame some digital harshness, replace the stock EH tube with a good NOS tube like Mullard, Amperex or Brimar. If you want some more resolution, you can then swap out the stock U1/U2 opamps with 2604's.
I'm of two minds on the Dexa's. On one hand they are probably the most analog sounding opamps I've tried in the DAC but at about $250-$300 they are not great value. |
Hi Mike:
Dexa can be purchased from Partsconnexion in Canada or directly from the Mfg in Denmark (NewClassD). There may be other places out there but these are the ones that came up with a quick google search.
I really like the S30. I also have a bunch of SET's but the S30 is the least colored of anything I have. I tend to switch things up a bit but can't envision a situation where I would not have an OTL. It's like having the accuracy of a top notch SS amp with the liquidity of tubes.
I agree with you on vinyl. While the Minimax has greatly improved my digital experience I still prefer analog. The convenience of digital is nice, though. I've been dipping my toes into computer audio and can appreciate the reasons why many shy away from analog. |
Hi Sibelius,
I noticed you have the Atma-Sphere S-30.
How do you like yours with the Mini-Max2?
I also have one.
Trying to tweak the most out of my system but still prefer Vinyl.
Where did you purchase the Dexa Discrete opamps?
Thanks,
Mike |
I have been using the Mullard CV4003 Milspec 12AU7 for the last 2 months.
I could not listen to the MiniMax 2 without this.
I have a 10 year old Marantz CD4000, which I had modified to use two 12AU7s in a new analog output stage.
It has external power supply and tube rectification.
It is extremely musical and preferable to most of the DACs I have heard.
Bill just modded my Minimax 2 and I hope I get it back in time to be able to listen to it this weekend.
His service was awesome.....instant turnaround!
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Hi Mr. Tennis:
Moving from the stock opamps to 2604's and 827's gave me a sharper and larger soundstage. It was very noticeable. Not a subtle change. Since then I have swapped out the 827's with Dexa Discrete opamps. This move was more subtle. A little bit more air around the instruments but not as dramatic a move as changing out the stock parts.
My tube is a standard plate mullard rebranded as Daystrom from the early 1960's I believe. Now that I know that NOS tubes makes a difference, I will probably try some additional NOS tubes. Pricing is pretty good when you only need a single.
Changing out opamps is not that expensive. With Brown Dog adapters (which makes installation a snap) I believe I spent about $85 or so including shipping. Well worth the effort IMO. |
hi sibelius:
what do you gain by replacing the stock op amps ?
my take on the stock 12au7 is the opposite of yours, namely, bright, thin and lean.
which mullard did you use, the long or short plate ?
thanks |
Here's an update on some of my tinkering.
As I mentioned before, the setup I've settled in to this point is 2604 opamps in U1/U2, Dexa Discret opamps in U6/U7 (just a smidge better than the 827s) in SS mode with tube removed.
I'm on record as stating I did not like the Dac+ in tube mode with the stock EH tube. I felt the sound was veiled and muddied. However, I have read where several people liked tube mode with a better tube. So in the spirit of giving tube mode one more shot, I ordered a mullard NOS 12au7. Well, after some more extended listening I need to ammend my original statement. While the SS mode still has more detail, the mullard tube is much less veiled than the EH tube and scored points by smoothing out rough patches in bright recordings.
At this point, which mode is better really becomes a function of the recording in my system. If a recording is bright or hard, I prefer the mullard tube mode. In exceptionally well recorded music, I find I enjoy the additional detail of SS mode. I guess the take away is don't ignore tube mode until you first try it with a better tube.
My next experiment will be to replace 2604's in U1/U2 with Dexa Discrete opamps. Will see how an all Dexa opamp unit sounds.
The good news is that regardless of your personal views, the Dac + allows for tremendous flexibility and experimentation. I'm sure almost everyone can find a setting which will be optimal in your system. |
Thank you Bill
Very proffesional from your side
Rgds |
I've been experimenting some more with opamps and have to say that the only combination I like a tad bit better than what Doug recommended (2604 in U1/U2 and 827 in U6/U7 with tube removed in SS mode)is to replace the 827's with Dexa discrete opamps. I'm finding the discrete opamp seems to add a bit more air around the instruments while making things a tiny bit warmer. However, the cost of the discrete opamps is rather high and the difference is not night and day. I think the 2604/827 combo is probably the best mod for the $.
I'm going to try two more experiments. The first is to go back to tube mode with a NOS mullard 12AU7. The second is to add Dexa discrete opamps in U1/U2 and see how an all Dexa system works.
More to come ... |
Skomak,
I was concerned also and wrote Alex again just to double check. His reply;
Hi Bill,
The DAC Plus has enough current supply for four Burson opamps.
Hope the above helps.
Thanks.
Best regards,
Alex |
Same* result here, SS output is much improved with tube removed...however, with the right tube (system compatibility) I prefer the 'fleshier' output of the tube stage.
I found no real measurable (by ear)improvement to the tube output with the removal of the SS opamps. My guess would be that the tube stage draws more juice from the p/s vs the SS output opamps. |
I've not heard anything definitive from EE, but one theory is that the power supply would see less of an overall load and perhaps lower noise level on power rails to opamp.
Whatever the reason, I've tried the tweak and do find it an improvement. |
although, indirect;y related to tyhis thread, there have been commemnts regarding the superiority of listening to the minimax, bypassing the tube stage and removing the tube.
considering that there are some "good" 12au7s available, in what way does the removal of the tube improve the sound ?? |
Thank you Bill
I will report my findings when I got the opamp. I was concern regarding the voltage compatibility. |
I wrote Alex a week or so ago regarding the use of the Burson's.
Here is his reply.
Hi Bill,
Sorry for my tardy reply, I was away. I checked the Burson web site, it said clearly
that their dual one can replace the NE 5532 and the single one can replace the NE
5534. So they will work just fine with the DAC and The Plus.
Thanks.
Best regards,
Alex |
EE DAC plus and Burson opamp
I am happy user of EE DAC plus for 1 month. Using the DAC without tube( great tweak). I have good expirience with audio-gd discete opa for my Asus ST + H6 board and I ordered( probably stupid before chacking first) pair od burson dual and single HD opa maunted on proper adapter.Now my concern is do this opa can be used in DAC plus .
bursonaudio.com
There specification is
Working voltage: +/-12-25v DC
Current Draw: 19mA (each module)
I will be very thankful for Bill's opinion.
Thank you |
