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72.128.93.6
Phil from Cimmaron Technology sent me a list of approved Opamps for
respective positions on the board of the EE Minimax DAC Plus; prices
include the Brown Dog Adapters provided by Cimmaron. I have been using
in the U1/U2 position the OPA2604 and in the U6/U7 position the OPA827.
I have not Opamp rolled this unit much, as I have been busied with other
components for review. I attest that the DAC Plus in SS output with the
tube removed and these opamps is sensational.
(NOTE CAREFULLY the warning at the bottom NOT to use the AD 8620 in the U1/U2 positions!) Also note that the positioning of the opamps/adapter is always with the small square solder point on the topside of the Opamp at the upper right hand when the unit is facing the installer. Finally, it is recommended that an opamp extraction tool and an anti-static device be used when removing/installing Opamps.
Is it "worth it"? Yes, emphatically, YES! :)
RECOMMENDATIONS OF OPAMPS FROM CIMMARON TECHNOLOGY:
For U1/U2
Single-channel op-amps mounted on the 020302 SO8-to-DIP8 single-to-dual
channel adapter:
qty 2 each required
020302-OPA627 $48.00 x 2 = $96.00
020302-OPA827 $38.00 x 2 = $76.00
020302-AD797B $48.00 x 2 = $96.00
. . . also for U1/U2
Dual-channel op-amps mounted on the 970601A SO8-to-DIP8 adapter
qty 2 each required
970601A-AD8620 $23.00 x 2 = $46.00
970601A-OPA2604 $13.00 x 2 = $26.00
970601A-OPA2134 $10.00 x 2 = $20.00
For U6/U7
Single-channel op-amps mounted on the 970601A SO8-to-DIP8 adapter
qty 2 each required
970601A-OPA627 $28.00 x 2 = $56.00
970601A-OPA827 $23.00 x 2 = $46.00
970601A-AD797B $23.00 x 2 = $46.00
The AD 8620 should not be used in the DAC PLUS.
"On some forum there was a suggestion to use the AD8620. for positions U1
and U2. While this is a dual op-amp, it is only rated to use up to
plus/minus 13 volts. The circuit in the EE Mini Max DAC and DAC Plus is
plus/minus 15 volts."
The greatest impediment to advancing an audiophile system is the audiophile.
Follow Ups:
I owned the EE DAC before and am using the new EE DAC Plus now.
I tried OPA627 on U6/U7 & AD8599 on U1/U2 with significant improvement in every aspects.
The Newclassd discrete opamps are even better.
The size fit perfectly in DAC Plus.
The background is blacker, resolution higher, frequency extensions wider yet equally musical.
They KO the tube output despite I am using a very good NOS Valvo 'pinched waist' E80CC.
I will try pulling out the tube soon.
(Give Lars Clausen of Newclassd an email. He's very friendly & probably will give you a discount if you tell him you are referred by Peter of Hong Kong.)
I am sure you are correct. The Dexas would beat any normal op amp. However, the circuit it way too long. If you knew what you are doing you could use just one Dexa single per channel with a coupling cap soldered directly to the ouput jack. This would sound worlds better. I use a single output device with no coupling cap for even more pure sound. Also, all the parts used in the output stage (even if very simple) still need to be upgraded to give the best sound that fits the player. Also the regulators are ordinary in the minimax. I use cascoded current sourced discrete shunt regs on my circuit. Better regs equal better sound. The potential of the EE DAC is tremendous......of course, you would want better regs on the DAC and clock and a better clock, etc.
Edits: 01/28/12
Hi Ric,
Many thanks for your suggestion!
I have similar tweaking plan : better IEC socket/coaxial jack/clock/capacitors/regulators...etc. Stepwise upgrade & tweaking is fun.
May you show us some photos of your fully tweaked DAC Plus? Have you compared yours with other DAC and what's the result?
Thank you again.
Peter
I have never modded an EE DAC. I know what can be done and how the sound will be because I have modded the Oppo 95 that uses the same DAC chip. I have been interested in modding the EE and just tonight put the info on my website with pricing. The mods will be basically the same as what I am doing in the Oppo 95 (not quite as totally involved, but that may change). I just now posted a pic of the underside of the modded Oppo 95 board on my site, so one can see the hand made wild stuff I do. First person gets 20% off.
Edits: 01/28/12
Peter,
Are you using the Newclassd discrete op-amps in the dual, and single position?
regards
Bob
Yes, two dual-Newclassds and two single-Newclassds.
They fit perfectly inside the DAC Plus chassis/circuit board.
The photo
Hi Peter,
That is good they fit under the cover. :) What about when you use the tube,sound wise? Still much better than the 627 + tube? I think they also do not draw as much current as the Burrsons.
regards
Bob
Hi Bob,
Previously I used OPA627BP at U6/U7 (for SS output only) and AD8599 at U1/U2 (for both SS & tube output).
The all-Newclassd configuration is better the AD8599+tube configuration in all aspects except that the latter sounds a bit sweeter.
Top grade opamps such as OPA627SM or OPA128SM are very expensive. They are also difficult to find with many used ones or faked ones in Hong Kong.
I purchased the Newclassd together with a few audiophile friends so as to share the shipping cost. My set of 4 Newclassds costs < USD200. IMHO the Newclassd discrete opamp is better & has much better C/P ratio than all other integrated circuit opamp upgrade. Strongly recommended!
Cheers,
Peter
Hi Peter,
Just curious, have you ever tried all OPA627s? Why did you use the AD8599s? I have not tried them.
I really enjoy the OPA627s in both single and dual positions.
regards
Bob
nt
Some of these discrete Op-Amps suck up current up to multiples of usual op-amp being replaced. I have read posts where putting in something like Burson discrete in the wrong position makes EE DAC Plus sound like "AM Radio" (from recollection).
Yes, Burson's discrete opamps suck up a lot of current so I choose Newclassd's instead.
The 4 Newclassds are running faultlessly in my EE DAC Plus for about 50 hours already and the sound is still improving.
Swapping op amps is like swapping caps or resistors or tubes or whatever.....it certainly can give a better sound but only takes you so far. The next step up from normal op amps would be discrete op amps like the Burson and Dexa...these things can be purchased from Parts Connexion and can be plugged directly in and give you a much better sound than any integrated circuit op amp. Beyond discrete op amps is changing the output stage so it needs way less parts. You could use just one discrete op amp and then a coupling cap and right out. Or you could use a zero feedback buffer and cap.....or a transformer by itself or even better a zero feedback buffer on each phase and then a transformer, single discrete I-V converter or the simple circuit I use. All of these options would be way better than the complicated circuitry in the stock EE DAC....all of these options would give you much better sound.
The easiest thing to do is op amp swapping, then discrete op amps using the same circuitry and after that you really have to know what you are doing or have a serious professional do the work.
The ESS DAC is capable of incredible sound. Complex ordinary op amp circuits are not going to give you the amazing sound......no way.
"discrete op amps like the Burson and Dexa.."
Rick,
What are your thoughts on one vs the other?
Bob
"Phil from Cimmaron Technology sent me a list of approved Opamps for
respective positions on the board of the EE Minimax DAC Plus; prices "
Doug,
You are using the word approved. Approved by who? Do you actually mean the op-amps that Cimmaron has for sale that are compatible? Might be a better choice of words.
regards
Bob
for the first review of the Minimax DAC to find alternative Opamps, and seeing as how he communicated/informed Morningstar Audio and myself in conjunction with the Audio Blast article on Opamp rolling, yes, they were approved.
Though I did not write up a separate article this time in conjunction with the Minimax DAC Plus, I followed the same protocol in emailing Phil and Bill O'Connel to assure Morningstar and Cimmaron were in communication. So, yes, these Opamps are approved through the same process except for a final article.
Thus, the word "approved" is the better choice over "compatible."
The greatest impediment to advancing an audiophile system is the audiophile.
By following this sage I do not believe Bill has any idea what will or not work other than reading or following the posts just like everyone else. Even Alex the designer has not tried some of the different available compatible op-amps.
Why are the 499990s not listed?
What about for the duals, the opa2406 DIP or the opa2107 DIP which are even better than the 2406. These can be purchased for approximately $6? AD797 for singles can also be purchased in DIP a few dollars. IMO the OPA2107 AD797 are a good less costly mix and they can be sourced inexpensively. If you want the Burr-Brown sound for singles, pick up some OPA627 DIP. With a good tube one can enjoy both the tube or SS output with the 2107-AD797 combo IMO. Op amps can also be easily sourced on Ebay, even the surface mount chips mounted on DIP adapters.
regards
Bob
I do wonder what the "final word" on LME49990 is. There are old posts saying they may "harm the DAC," but without stating why exactly. Then there are many people using LME49990 without problem for weeks now.
Jon,
They are fine to use in the original and the DAC PLUS. They have been ok'd by Alex .
for the info on LME49990. Curiosity had gotten the better of me, and DAC Plus and LME49990's are in the mail currently. I do have what seems like a bazillion op-amps as well as a crate of 12AU7's from my rolling days, so it should be fun.
I have used them in both positions w/o any problems. They are very detailed but can be a bit bright and thin sounding. In the right system I would think they would be fine. Right now I have the LME49990 in the U6/U7 slots and OPA2604 in the U1/U2 slots.
Hi David,
That is a nice sounding combination IMO.
regards
Bob
Hi Jon,
IMO there is no way it can harm the DAC. Well unless someone uses a chainsaw to open the DAC to install them. :) It would be interesting where the info for the "Danger Will Robinson" warning actually came from.
I cannot see how using a properly rated dual in the dual sockets and single in the single sockets could cause a problem. Does anyone have else have an opinion on this?
People do have to realize if they trash their DAC it is their fault, but swapping an op-amp is similar to upgrading computer memory.
It will also be interesting to know where the recommendation for the incorrect voltage op-amps came from?
regards
Bob
Bob,
I think what happens is somebody tries it, then post's about the sonic quality without knowing the circuit design and the next guy figures why not give these a try.
"Why are the 499990s not listed?"
Because you are long in your nines...
I was tempted to comment on the inanity of this thread but was brought up short as it just caused me to learn that TI had acquired NSC last Fall. The end of the Fairchild era, sigh...
So why do you guys buy gear designed by others when you're so damn smart that you know how to do it better? Just curious.
Rick
"So why do you guys buy gear designed by others when you're so damn smart that you know how to do it better? Just curious."
How do you know that they aren't just putting back parts equivalent to what the original designers selected before "value engineering" was applied by non-engineers in the purchasing department? I know for a fact that this used to go on in audio equipment in the 60's or 70's as an associate of mine's father was in charge of purchasing at a large kit manufacturer. (Of course when the resulting product worked poorly the company's ass was covered, because they could blame the problem on the customer who made an assembly mistake.) Similar things went on in the computer industry where I worked and it was necessary to develop a relationship of two-way trust between engineering and manufacturing to assure both happy customers and happy stockholders.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
"How do you know that they aren't just putting back parts equivalent to what the original designers selected before "value engineering" was applied by non-engineers in the purchasing department?"
Hi Tony,
In the case of the MiniMax this is pretty fair assessment. The 5534 and 5532 are pretty much the standard good sounding basic op-amp that many manufactures use. Even a $6500 Levinson uses what would be deemed a pretty inexpensive op-amp.
"I know for a fact that this used to go on in audio equipment in the 60's or 70's as an associate of mine's father was in charge of purchasing at a large kit manufacturer. "
Very interesting. If I may ask, what company?
regards
Bob
Because of the circumstances under which I received this information I'm not going to mention the company. I don't think it's particularly relevant.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Tony,
Just curious. Many of the kit stuff of the era used less that the best parts, but some of the stuff sounded amazing, and are classics... Just look at an Eico HF-81.
regards
Bob
"a large kit manufacturer"...
Heathkit I suppose, Eico and Knight were much smaller. I miss the days when a lot of audio stuff were kits. I still have the last one I did, an HK Citation 12.
I learned about "value engineering" early on when I worked for an outfit that almost "Muntz'ed" the designs. It was a good experience that served me well the rest of my career. It's really just a philosophical thing and the only hope was to get to where you could justify every part if asked. Pretty quick it just became ingrained. And it never went away, if an engineer can't say why a part is present and why the particular one used makes the most sense then he doesn't really have a handle on the design.
The key is that the product specifications need to be relevant. If they aren't you get the sort of problems that get a lot of press here on AA: The device meets Specs. but doesn't sound very good unless modified. Just throwing hyper-expensive parts at an extant design is hardly an optimum answer for production but may be for a user since his volume is next door to zero. If we had "good" Specs. in the first place then the design engineer would hopefully have implemented it providing the requisite performance while minimizing expensive parts. In general the best designs are those that deliver the goods while minimizing component sensitivity and cost as far as possible, but not...
Rick
Heath kits were pretty amazing. Had to be completely built, no pre-made circuit boards. You could even build your own color TV! :)
Bob
It wasn't Heathkit. Perhaps I should not have said "large". The company had a large enough range that I had experience with some of their products, though. There was just one conversation I had with the alleged miscreant's son dozens of years after the alleged event, but as I recall it was actual component values or possibly tolerances.
Specs are written by engineers. There are bad specifications because of bad engineers. And good specifications can be misinterpreted by bad engineers. I ran a group responsible for writing computer network protocol specifications and ensuring that multiple products supposedly written to these specifications actually worked together. I saw all the possible variations of success and failure of specifications. One of the things that I learned was that diligence and attention to detail were ultimately more important than intellectual brilliance, especially where the genius types came with a big ego and used their intelligence to make their systems unnecessarily complex.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
"So why do you guys buy gear designed by others when you're so damn smart that you know how to do it better? Just curious. "
I really do not think anyone is redesigning anything. People have been upgrading the stuff for years. OPA627s in a NOJE TOBE, or Music Hall CD player just to mention two. I guess you never have never?
regards
Bob
"I guess you never have never? [modified purchased gear]"
Seldom, I guess I'm just not very inclined that way. I try hard to buy stuff I like. I did fix a marginally stable amplifier stage in my preamp but that was more of a repair...
I've never given it much thought but perhaps I've avoided it because designing stuff was my day job so fixing other people's problems on the weekend had little appeal. Now that I am retired (mostly) maybe I should reconsider...
Regards, Rick
"I've never given it much thought but perhaps I've avoided it because designing stuff was my day job so fixing other people's problems on the weekend had little appeal."
I can appropriate that. :)
"Now that I am retired (mostly) maybe I should reconsider..."
Well might keep you from getting into trouble. :)
In the case of the MiniMax DAC it is a very nice sounding DAC which uses one of the most common good sounding op-amps. By swapping them for better ones it becomes an even better sounding unit. Same goes for the stock tube. Well worth the small effort.
regards
Bob
idea of what you are talking about. Go take some lessons first.
OMG you hach to crap everywhere or you would not be happy.
Please back you statement up with some actual facts!!!
and when people have issues with all the unknowns, i.e. differing prefixes on part numbers of supposedly identical opamps, from all the different vendors, they can come to you.That's what happened to me last time when the helpful folks here at AA suggested this and that opamp; people went to the Elcheapo Vendors and then found very confusing information. SURPRISE! They couldn't get answers from Elcheapo Vendors as to why there were two seemingly identical opamps with different prefixes. Would it make a difference? Elcheapo Vendor had no clue!
So, then they email me to see if I know. No, I didn't know. Do I want to spend my time researching opamps which I did not recommend. No...
The reason I worked with Cimmaron was the same reason why people go to an audio dealer, to get expertise. I don't then go and announce knock offs to piss on the service and product of the man who helped make it happen.
The greatest impediment to advancing an audiophile system is the audiophile.
Edits: 01/25/12
Also just be be clear, you list for the plus DAC is much shorter than your original article for the first MiniMax DAC.
Just curious why?
regards
Bob
Please Doug,
"the unknowns, i.e. differing prefixes on part numbers of supposedly identical opamps, from all the different vendors, they can come to you. "
Please do not make things up that are totally false. There is no such thing as different prefixes of identical op amps from different vendors.
There can be different suffixes which denote format soic, dip etc and other things which are clearly listed on manufactures data sheets. So there are no other legit venders? That is not nice! Please don't pull a chicken little... It is nice that Phil helped you but I know that even he would not try to miss-inform people for a sale.
So if we are not allowed to discuss please tell us now... Thank you...
The greatest impediment to advancing an audiophile system is a less than forthwith audio journalist...
at the insinuation of my making things up. But I'm going to try to respond in a level-headed fashion.
I was reconstructing the experience from memory; people came to me with problems sourcing inexpensive Opamps; I did not go back to revisit the sites to recall if it was a prefix/suffix to the part numbers. Thanks for the correction.
However, it seems you have a fundamental distrust me, like I have some grand scheme for trying to ensure people can't get inexpensive Opamps. I don't give a shit where people buy opamps! If someone wants to post where to get them cheaply, great. More power to them. When I began looking into Opamp rolling I was recommended by an industry DIYer/Manufacturer to speak with Cimmaron for their custom Opamps, and that is the direction I took the article, as I've stated prior.
I have no intent on being the industry/community secretary and running down every occurrence of cheap opamps. When I had people coming to me privately seeking answers from the parts sources because they couldn't get the answers themselves as to which Opamps were correct they wanted me to get answers. I tried to help them out.
I deeply resent your not so veiled suggestions that I'm lying to help people get sales. My ONLY point of the previous post was that informationally if someone goes on their own to secure Opamps they can encounter problems picking the correct ones, and as happened with people who came to me with their unresolved questions; the supplier doesn't always have the answers for them, and the audiophiles who came with the questions obviously didn't have expertise to make such decisions.
If you want to disbelieve me, so be it. Do I have the answer why the LME 499990 isn't in the list? NO. Does it have something to do with supply, cost relative to Cimmaron's internal decision making? I don't know. Do I know all of the opamps for the unit? NO. Do I have a responsibility to the community to hunt down every last shred of evidence/information on opamp rolling? NO. I'm not writing an article; I'm pursuing this extra discussion on my own because I have vastly enjoyed the experience of opamp rolling.
It's ironic; the times I have gone above and beyond in trying to inform, add extra insight, give a little extra are the times when it becomes a PITA and it makes me feel like saying, "Forget it; I won't bother sharing the what I've learned." Why don't you show me where I have stated anywhere that other sources of Opamps are not to be trusted, as though one cannot get them elsewhere. What I DID state clearly, and have all along is that other sources may not have the answers that the audiophile needs. If you still think I'm making it up that people came to me with questions on it, then so be it.
I am not an expert in Opamps, so I rely upon someone who can devote time to discussion and education on the topic, like Phil. The reason I am not giving exhaustive lists of compatible opamps is because I am not an authority on it. I build and assess audio systems, and opamp rolling I find to be highly efficacious, therefore I mention it. I don't have any problem at all with the free market and price competition. I also do not simply promote high priced gear as the only solution to building supremely good rigs, or else I wouldn't be using the Minimax DAC in the first place.
So, kindly either become a friend and let's work together, or I'm done talking to you.
The greatest impediment to advancing an audiophile system is the audiophile.
"at the insinuation of my making things up. But I'm going to try to respond in a level-headed fashion."
Thank you for being level headed. Well if not making things up, then maybe just not thinking clearly when posting. One would think as a follow-up to your insightful original articles you would be able to provide more and better flushed out recommendations.
How about upward and onward!!
Even in response to your original articles people mentioned some chips can be sourced in DIP format. Just trying to keep things in perspective.
"I was reconstructing the experience from memory; people came to me with problems sourcing inexpensive Opamps; "
Why do you keep bring up, cheap, inexpensive,bargain etc??? Do you thing people here are on welfare? Eating Govt Cheese? lol... Myself, and many others have op-amps much more expensive than the ones you listed?
"I'm pursuing this extra discussion on my own because I have vastly enjoyed the experience of opamp rolling"
As do I and many others. It is something that people have done with many products for years. You have pushed the MiniMax to new levels, THANK YOU, but by backtracking as much as you have, IMO you are actually doing a disservice to your original excellent endeavor.
regards
Bob
Why don't you develop an exhaustive list of opamps for the Minimax DAC Plus?
The greatest impediment to advancing an audiophile system is the audiophile.
Well,
Actually I know nothing!!!
But,
I was taken aback somewhat by your backtracking, I guess a bit of a misunderstanding.
I would say everything you have mentioned in your articles, except the one with the lower max voltage rating.
People have to be sure of proper orientation as you have mentioned and that duals only go into dual sockets, and singles in single. Some chips are available in DIP and can be just plugged in. Single dips like 627s can be plugged into dual DIP adapters for the dual positions. Others that are only available in surface mount have to be mounted on a proper adapter. This can be done yourself with the proper adapters. But only if you are good at soldering. I am not!!! Just don't use an arc welder! :) If not, go to someone reliable. You already made an excellent recommendation, Cimarron.
My listening experiences are similar to yours, many combos can sound very good. I can enjoy listing both the tube and SS output with the right (NOS)tube and op-amp combo. I prefer the Burr-Brown op-amps in the duals
which I believe is the I/V Filter position. I also like Burr Browns the in the single, (output) location.
I did not care for the ADs or LMs as much in the dual position. On a very revealing system AD or LMs have very good detail but came across a bit, thinner / brighter. I can listen to the ADs or LMs in the single (output) location. But this is very system dependent. Just seems voiced better to me with Burr-Browns in the dual position. IMO the Burr Browns go up in class 2406 2107 827 627. YMMV... A nice op-amp which I hope to try soon is the ADA4627-1BRZ. Supposedly it is very good. I guess the next step is discreet op-amps that have been mentioned. The Dexxa look like a plan because they can fit under the cover without modification, and do not draw too much current.
regards
Bob
Hi Bob,
By chance have you tried either of these as Tom Tutay from Transition Audio Design recommended I try these?
For the singles the LME49710NA
For the duals LM4562NA
I ordered some from Digi-Key on Friday so I'll let you know how they work out if you haven't already tried.
Thanks,
Bill
"By chance have you tried either of these as Tom Tutay from Transition Audio Design recommended I try these?
For the singles the LME49710NAFor the duals LM4562NA
I ordered some from Digi-Key on Friday so I'll let you know how they work out if you haven't already tried."
Hi Bill,
No I have not yet. Did he have any opinion on their sonic qualities? Looking forward to your results.
regards
Bob
Edits: 01/29/12
All Tom said was very fast,super quiet and the latest in Hi-Tech as some of the ones I had mentioned to him have been around for 30 years or so.He thought these would be the best of today's modern ops.
nt
This a very clever idea. You have a bright mind. That means you're lucky.
"Please do not make things up that are totally false"
Why stop now?
Oz
Don't worry about avoiding temptation. As you grow older, it will avoid you.
- Winston Churchill
"What about for the duals, the opa2406 DIP or the opa2107 DIP which are even better than the 2406." ?
Now I am confused. Did you mean better than 2604?
In any case I just ordered some 970601A-OPA 2604 and some 970601A-OPA827 from Phil at Cimmaron
to check out op-amp rolling.
Later,
Bill
Hi Bill,Yes IMO the 2107 is a bit better than the 2604. Not as dark, a little more open, still with the BB flavor. So far I like the BB sound best in the dual positions. In my system I found some of the other brands of op-amps a bit brighter in the dual positions, but good in the single position. The 2107 is dual fet op amp with the Burr-Brown sound. It gets closer to the 627s 827s in a less expensive op-amp.
It is really a very nice DAC and I am enjoying it immensely. :)
I think you will like the sound allot when you get the new op-amps! :)
regards
Bob
Edits: 01/25/12
Bob,
Is there an op-amp numbered 2406? or was there a mix up in your post and you meant to say 2604. Just trying to make certain.
Thanks,
Bill
Sorry a typo,
OPA2604
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