Monica USB: Lack of "speed" and "timing"?

[martinbls]

Hi Yeo and hi to all the DIYers out there!

About one and a half week ago my brand new Monica arrived! A german fellow named Jochen (you might know him already) purchased the usb monica for me because of his knowledge about it, so he tuned in everything for me very well.
Now my Monica has burned in for more than 150 hours, playing day and night. My setup is a IBM Notebook with USB 2.0 Card, the USB Monica, a Alps volume pot and a Naim Audio power amp. And of course, i got some nice speakers, too ;-)

Monicas PS is a SMPS by Voltcraft, a high quality one. It offers 18V oder 24V regulated DC output with 1A. I use a heatsink for the LM317, for 24V and more it?s a must! Further more, voltage is buffered with a high quality 1000uF capacitor.

I tested the Monica as it was configurated by Jochen, adjusted for 24V. Later I adjusted it for 18V to test how the sound eventually differs. Well, I think 18V sounds a bit nicer to me, there is a somehow more controlled over-all-performance, everything seems to be a bit more "allright" than with 24V. Perhaps it is because the electrical circuit can handle the 18V a bit better than 24V, but at least I don`t know... I know, it?s exactly the opposite of everybody elses oppinion here!

Well, I love most of the abilities Monica has, the analog sound character, the openness in mid and high range, the details, the transparency, and, of course, the smoothness and magic, the "sense" for the music! Great work so far!

BUT: (and now it comes...) There are two certain aspects I noticed with both, 18V and 24V supplies. It is something that may have nothing to do with the supply voltage at all. These are: Speed and timing! Timing is something very important to me, it is something what really makes the music come alive. Without the right timing of tones, notes and effects, the music doesn`t involve me the right way. Ok, as a tribiute to its analog-like sound, Monica is not the most dynamic or fast sounding device. But this is not a question of "fast" or "slow", it is just, you know, timing! There is only one certain moment for a tone to appear, not a millisecond before, not after. The issue I also mentioned is speed, but perhaps it is better discribed as "impact" of the performance. The music seems to be a bit away from me, kind of "passing by me". Better would be: "Grabbing me and throwing me into it!" Well, difficult to say... I miss the impact, the strength, in one word: the power! I?m listening to a large spectrum of music. Of course I love hand made, orginally recorded music, I love the old Genesis, Led Zeppelin, Can, Bel Canto, Bjork and so on. But sometimes it has to be kind of Goa music, or just a groovy and powerful stream of some internetradio. And I think, a real good soundcard has to offer the possibility to listen to ALL kinds of music with pure, powerful sound and the right timing, speed and sense.

Sorry Yeo, don`t get me wrong here, it?s not that Monica fails in my opinion, I like her very much because of the things Monica does well, but I wonder if there is any potential for further improvement, so that Monica get?s nothing else but "perfect" ;-) Well ok, I want stars where even the moon is difficult to get, but...

The device Monica was compared to (for more than one week now, everyday more than 4 hours cross-listening!) is a Echo Indigo I/O soundcard for Notebooks, installed via PC-Card slot. The Echo is very dynamic, fast, clean and open sounding. Even though it delivers not this "harmonic sense of sweetness" Monica delivers. It is sounding more digital and sometimes a bit artifical. Here is where Monica easily outperforms every other computer soundcard. But the timing is better with the Echo, and that`s why the music becomes more involving and alive via the Echo, it is more "touching" because of the very right moment the single sounds and tones appear. The impact of music is also better via the Echo, music has more drive, more power and makes me really "feel" the tones. Ok, here I have to make clear one thing: You might say, ok then, why not stick to the Echo and everything will be fine? But Monica, you know, I like her a lot, and at the moment I?m switching between Monica and Echo, depending of what kind of music I?m listening to. But that switching every few hours could not be the answer, could it?

Yeo, what do you think about this? Is there something I probably can improve? With the Monica itself, everything is fine. No electrical or software problems at all, no humm, no clicks, nothing, works really good! Trimpods are adjusted very carefully. Sound goes via Asio driver (asio4all) and bypasses the Windows kernalmixer completely. But as I said, neither with 24V nor with 18V, timing and power of the sound seems right, everything`s a bit far away, a bit slow and doesn`t touch me the way it probably should!

With best regards from Berlin, Germany - martin

[assendor]

Hello Martin,
The task of combining D/A Converters, output stages, Pre-amplifiers, Power-amplifiers and speakers into a fantastic sounding complete system is not easy.

I will note down some things that I think might be the reason for your special experience.

1. Output impedance is essential, monica dac's do have quite high output resistance, therefore they can sound a little dull
 ? ?or less dynamic when they have a too heavy load attached.

2. ON Class A/B amplifiers there is always an enormous amount of negative feedback, signal devices connected with
 ? ?higher output impedance can have an catastrophic effect or coloring of sound.

3. If your other DAC has an OP-AMP output, it possibly has a very low output resistance and because of this sounds better in your
 ? ?system on some music.

4. I will most certainly recommend you to try a Preamp connected between your monica and your Power amp.
 ? ?Best of all would be a Tube-Preamp, if you ask me for advice.

5. If you do not use a preamp, then shortest possible cables is absolutely desireable because of the high output resistance.

6. I do not understand why you experience lower overall performance with higher supply voltage?


   Hope some of this helps. I am pretty sure that you will have great experiences with your USB-Monica, as you resolve
   whatever it is that handicaps here from performing the way she normally does.

-Jonas

[martinbls]

Hi Jonas!

Thanks for your quick reply! I guess you`re right, it might be a problem with my poweramp. I own a "good old" Naim Audio Nap 140 in mint condition, and I love this amp! It?s a combination of a tube-like warm and colourful sound with the power and drive of a conventional solid state amp. But the Naim is not easily driven by any source, I know that. Naim itself states that no one should ever combine a Naim poweramp with other than a Naim preamp. Ok, they want to sell, but I think there is some truth in it.

Problem is, I want to stick to my beloved amp, and a Naim preamp would be quite expensive. Good diy-preamps are very rare (espacially as kits with pcb), so I guess I have to go with my Echo Indigo and resell Monica USB, even if my heart is bleeding... :-(

(Or, Yeo, what do you think about a small preamp with OP amps as an option for Monica, so she could sing together with every poweramp on the market?)

We?ll see, but now I bought everything I need for building a Monica USB in a decent black aluminum case with Alps motorpot, controlled via Alps IR remote control and a high quality smps. I think it would be the best if I build everything very carefully and then perhaps somebody might be interested. I will post some pics when the complete thing is finished.

BTW: Yesterday I switched back from 18V to 24V, adjusted the trimpots carefully back to 12V. Ok, it might be my poweramp again, but really, I like 18V better! Again, everything is a bit more controlled, especially highs are more smooth and articulated. That?s funny, but I tested both, 18V and 24V, two times and for several hours, and I stick to the 18V supply! Further more, with 18V the LM317 doesn?t get that hot, so when you planning to use a completely sealed case (as I do), there?ll be no problem with overheating of components, even if Monica is running non stop for weeks or month.

Best Regards - martin

[yeo]

hi martinbls

yes, most likely jonas is correct in the sense that you need a preamp. i'll venture to guess that your naim power amp has a low input impedance.

combined with the ss i/v's high output impedance (though not higher than naim's input impedance), this could explain the "lacklustre" sound.

my advise is... built a tube preamp. those with output transformers.

i'm using one now. even if there is no impedance issue, having such a stage helps a lot!

yeo

[martinbls]

Hello guys,

I think you?re right! It seems like I need a pre amp to make Monica really sing. I will have a look, perhaps a Naim pre would be the best choice in my case. And yes, I think my Echo soundcard has op-amps in its output stage.

What I can say for the moment is, that the more I listen to Monica the more I get addicted to its sound character, even without pre amp. Every time I listen to the Echo, I want to switch back to Monica for serious listening. She definitly has something very special!

If I can purchase a pre amp that fits to my power amp, I will update this posting.

Regards - martin

[assendor]

Hello Martin,

I just accidentally noticed this item here:
http://cgi.ebay.com/STEREO-PREAMPLIFIER-KIT-BASED-ON-NAIM-NAC-324-CIRCUIT_W0QQitemZ120246569881QQihZ002QQcategoryZ12050QQcmdZViewItemQQ_trksidZp1713.m153.l1262
Pretty fast I connected my brains notice of the item to your need for a preamp.
Since your facination is mainly Naim related products, this might be something you fancy?

->Jonas

[martinbls]

Hi Jonas!

Thank you very much for this posting! Very kind of you that you keep in mind what your DIYers need to be happy ;-)

But, well...
 1. Just yesterday I had the chance to buy a Naim NAC 62 Preamp, and I bought it! Mint condition, like new and first hand. (This is remarkable: Only two days after I realized I need a preamp that fits to my power amp, I found exactly what I needed, Nap 140 & Nac 62 is a DREAM combo!) Ok, I payed for it, and now I wait for it. I?m absolutely excited how this combo sounds with Monica!

2. You know, "based on" Naim Nac is not the same as "is" Naim Nac. The offer you found might be something very interesting and very nice, but on the other hand, I don?t know anything about this unit. I?m a bit in doubt with things like that... I need a bit more dcumentation to get convinced of a product, especially if I?m not able to listen to it first. Finally, only the circuit is based on Nac 32, the caps, resistors, diodes and so on are of completely differnt brands than Naim used.

But anyway, this comes one day too late, and that?s sad because now I spent much more money on the Nac 62 than this little baby would cost :-(
And so I will go for the original...

But again, thanks a lot! When my pre has arrived, I will post my experiences.

One question is left: I played around with different supply voltages for Monica, you know, 18V and 24V, and until now I?m not able do make a decision what sounds better to me! What supply voltage do YOU use for Monica? (I guess from time to time you listen to a USB Monica as well, don`t you?) And there is another one: What kind of volume pot is best behind Monica? 10k, 50k or 100k, or is this equal?

Regards - martin

[assendor]

Hi again,

I am no specialist in Input impedances nor volume pot values, but here's the experiences and thoughts I have about the subject:

-The pot resistance should absolutely be 100k, if you are using connected equipment that has pretty high input impedance.
If your equipment does have a rather high input impedance and you use a 10k pot, you load the DAC output unnecessarily much,
possibly causing it to perform worse than it would do with a higher resistance volume pot.

-If your power amp or any other equipment connected have rather low input impedance, like lower than 15-30k or so, it normally is recommended to have a lower resistance volume pot than 100k.
But like we have discussed before, Monica do not appreciate a very low impedance load regardless of the volume pot.

-I have seen 10k volume pot being the lowest recommended value for a 5k input impedance power-amp in a specific case.
But If it was possible to get hold of a 5k, that was suppose to be performing equal or most likely better.

If someone have some corrections or more info, please post it, so that I don't mislead anyone.

I am glad to hear that you got hold of what you wanted. Really hope you can get the best out of your system with this new Preamp
implemented. Hope you get the most of USB-Monica's qualities revealed.

-I totally agree with you that "Based on" is not even close to the "Original".
When you look at that specific board possible to get from eBay at a rather low cost, there is no doubt in my mind that many of those components on that board would have been thrown directly into the bin(recycle Of course) the second I got it.
But it could be a good "budget" experiment, that possibly could have been upgraded as you got hold of better components to put in.
Also this preamp card could hopefully at least proven if it was the Input impedance that made USB-Monica perform less fantastic than your other DAC.
Now that you have the "ultimate" combo setup, nothing is better and you don't have to waste time on less good stuff.
Going straight for the goal :) :)

When it comes to My USB-DAC, that was not at the time called USB-Monica, but is the same thing as far as I know anyway.
It has those four BG's on the output as well.
I have not played on it for quite a while, I did use 16volt on all supplies when I last did, and it performed very well.
Personally I did find at that time I preferred the USB-DAC over Monica3, but it has been a little back and forth.
When I upgraded My Digital cabling for Monica3 and some other details it changed a lot.
The Gain-stage is the same on those USB-Monica Dac's as on the Monica3, so the different voltages supplied to this unit should give similar result differences.
Last I did some experimenting I preferred Monica3, but I is difficult to decide. They do sound different, that is for sure.
It is possible that Monica3 has some more Depth and a wider sound image on some music, but USB-Monica has a little "kinder" Smoother sound. It also could be that Monica3 in some cases has more details, for some unexplained reason.

I will do a Direct Comparison later this fall, but not before earliest November.

Voltages I use now:
<27.6volts is what I use on my Gain-stage now on Monica3.
I use around <13.7volts for the two other parts of the circuit.
It is SEALED LED ACID battery power. I am undecided if it sound the best with batteries or good regulators with that superior "Clean power for Monica" unit installed. (Common Mode Filter)

I really Really REALLY would recommend you to try and run such a filter on your USB-Monica, and Preamp.
If you only get one filter, I recommend using it on both the Preamp and DAC, if it does not get overloaded by this.
A friend of mine that love those Naim design amplifiers, was pretty excited when he got this "Common mode Filter connected".
So I do not see why you shouldn't like it too.

To say this, if I have not already done so:
I am a Fan of simplest possible designs, SE connected Class-A, NO, or at least very low feedback, mostly I am a fan of Tubes.
I simply love Full-range speaker drivers, especially horn designs. Nothing can get even close, if you ask me of my opinion.
I do like Charlize2 as well, speakers connected and investment possible decides what I prefer.
Charlize2 costs less than a good Paper in snake oil cap, and performs like a true angel, if you understand what I mean.  :D

Good luck to you with your latest investment.

-Jonas

[martinbls]

Hello again!

In a post above Yeo wrote: "i'll venture to guess that your naim power amp has a low input impedance." (Which means it is quite a heavy load to drive for Monica.)
In a technical description of my Naim Nap 140 power amp is stated, it has an input impedance of 18 kohms. Now, is that "low" in comparison to other amps?

Jonas, one word (ok, some more words...) about Charlize. I love simplicity too, it?s what I try to achieve with any kind of Hifi-stuff. For example, until now I?m not in fullrange speakers, heaven?t tried one yet. Main reason therefore is simple: Their size! Most of them (excluding MLTLs or some TQWTs) are quite huge, and my listening room isn?t that big. But, my speakers are Refernce 3a MidiMasters, an early version of the now available MM DeCapo. These speakers have a 8" (20cm) carbon fibre driver with large magnet, which works without ANY crossover, directly coupled to the amplifier. Tweeter is a 1" (25mm) Vifa silk dome, which has a very smooth frequency- and inpedance response and needs nothing else than one good 4,7uF capacitor. That?s it! Enclosure is about 22 l, so it?s very compact and fits perfectly into my room. I love these speakers, thery?re able to deliver music, emotions, feelings, it?s like to be live at concert. And, this is the point, they can deliver such an enormus amount of power if they are supposed to do so, it?s just fantastic! Efficiency is about 90db, so there?s not that much power needed, but the 8 W of little darling Charlize might be slightly less than necessary. I read a lot about Charlize, the tests, how to configurate and power it, the comments in this forum and so on. And I would really like to give her a try, really!! I wonder how this little thing would sound in my system. Perhaps I could sell my Naim amp/preamp combo then and save plenty much money ;-) But then I think: When it comes to the moment when the absolut power is needed, Charlize will stop going further were the Naim stuff will go on and on and on and on... This Nap 140 has only 45 W per channel into 8 ohm load, but with some good recorded music it seems like there is no end of dynamics, no frontiers, you now, with this amp music gets not really louder, but it gets bigger, wider, greater, more and more like the artists standing just in front of you, playing just for you! You can listen to a live recorded concert, feeling like you were just there, it?s amazing! I?m absolutely sure Charlize is a perfect match for fullrange drivers in a high efficiency configuration, but in my case it will run out of power sooner or later. Sadly! ;-)

Regards - Martin

[vt4c]

 :)Hi Martin,
  FYI...There will be a more powerful version of Charlize available very soon...!

Cheers,
VT4C

[ds]

VT4C, this is intriguing, I would guess its using the Tripath TKxxxx chips ala RWA Signature 30 or 70.
awaiting more news :)
DS

[assendor]

Hello martin,

You are possibly correct in the speculations of the use of Full-range's in a horn enclosure in whatever room.
The simplicity seems to be totally maximized on the speaker side of your system, you got that right.

When it comes to charlize as is now, I do agree that she could lack of power in your system, but not necessarily.
Its going to be exciting to see what pops up with higher power in the Charlize section.
I have been playing around with those Tripath's a little bit, and they should have a great potential if everything is done
the vt4c way :)

Even if Charlize2 most certainly is using the absolute best(?) chip available from Tripath, that does not help if you lack of power.
Now Cirrus have bought Tripath Technologies, so maybe they even have come up with a different chip.(Or not  :-/ )

Since we are mentioning those full-range speaker drivers again,
To me it seems there are several types of them.... (Of course, but that's not what I mean.)
Even if I have not tried an awful lot of them full-ranges yet, to my taste, I have experienced this:
Some full-range drivers are absolutely not use-able on low output impedance power amps, like A/B amplifiers.
Some of them are made to throw the sound far far away, your listening position has to be at least six to ten meters away, to
get the correct sound image. Or else it is extremely critical how you place yourself, angle of speakers and they sound too direct for my taste.
Some of them are made only with the focus on midrange and mid/high frequencies. (where most of the music is)
Obviously some are only performing well in a horn enclosure in rather big rooms.
Also I think it is a big advantage to be able to adjust or change feedback in the circuit of your power-amp, so that you can get the correct damping factor, when using Full-range's

There is a long way before I can conclude too much in speaker systems, especially since speakers sound so differently
with different amplifiers, rooms, music and taste of course. Not to mention the same driver in different enclosures.

When I hear those full-ranges That I like, there are nothing I have ever heard that can compete.
Even if I have not heard everything there is, I am pretty sure very few things can compete no matter what.
Till now that is what I think. (I could be Wrong)
When everything is "right" then any music sound marvelous, any sound pressure level sounds amazing.
Even playing at very very low levels, still the music is 100% alive and "there"
Old music, mp3, bad mp3, bad recordings, fantastic recordings, just everything sounds fantastic.
I am not saying that bad mp3 sounds the best, but they sound better than ever, when everything is "right".

When I first felt this was the situation, I had to call some friends and ask them to come over.
The verification was essential, to confirm that I had not just been messed up in my head.

Even friends and colleagues that has no interest in sound normally, just sit and stare for quite long and don't believe their ears.
Are those the speakers? Are you kidding me? Only those speakers??
Whatever you have done here, you got something right.
Then I say "There is not much deep bass, I thought you guys liked a lot of bass?"
Answer is: Yes you could be right, there is no bass here, it's more like you can hear every little instrument to the detail.
The bass guitar is just perfect, the big drums are just here, there is no bass, but all the bass instruments are there!!
You can hear every string played on the cello, you can hear the string vibrate into eternity.....
The contrabass is just like it is playing in the room, even if you don't get those deepest octaves.
It's so alive, it's so real, you can feel the sound.
-They conclude as well, this must be the way things are supposed to be, when everything is "right" (Or close)

It would be interesting to build a BIG BIG HUGE horn design that could actually respond -3dB down to about 30Hz, but those designs are so enormously BIG.

I do not even have a true horn system. (some horn design, but not quite hedlund)
So Hedlund's are absolutely something that I want to build or buy sometime.
There are so many types of Horn designs, the different ones probably fits different speaker drivers differently as well.
And of course the room size must be taken into consideration when selecting horn system.

Here is a Crazy Design, that maybe drags the simplicity into not so simple anyway??
http://www.passdiy.com/pdf/KleinHorn.pdf

Especially I do not like that you do need a lot of passive filtering to get the frequency response right.
BUT if such a speaker sounds the best in the world' even with that filtering' what the heck.

Here is another one that is so large it is unbelievable someone actually ever thought of making it:
http://www.passdiy.com/pdf/j-low.pdf

What I think about horn designs is this:
Why would anybody care making these complex and sick designs, if they do not sound A LOT better than normal speaker systems?
I have concluded, they would not have!! Well if they found they didn't, they most certainly wouldn't tell anyone about it  ;D

By the way, It will be interesting to hear what the result is with your new preamp.
When it comes to Naim amplifiers, I have not heard any of them, so there is no way any judgment can be made by me.

I got a little carried away here, as usual that is... :) :) :)

-Jonas

[martinbls]

Hi Jonas!

Yes, Nelson Pass, the "no compromise" guy... I?ve already seen the KleinHorn by Pass a few month ago for the first time when I was googling about some fullrange stuff. As you see, I?m quite interested in this. I agree with you that this KleinHorn is probably the most sick design ever build, but perhaps it?s the best sounding speaker ever build, too. I don?t know, but I?ve read a lot about Nelson Pass and his passion, and I think he knows what he does!

Actually, some weeks ago I bought everything to start my very first fullrange project. It?ll be a very small speaker though, but it?ll be fullrange! No horn, but, I think, TQWT. Do you know about Cyburgs Needle? You can google it, and you will find some interesting pages about it. It works with a 8cm Visaton fullrange in a very small enclosure, that?s perhaps why it?s called "Needle". For this driver, no crossover is required. It will be interesting to listen to these small things, I will report about it when they?re finished. But I intend to use them in a second hifi system, not in my main system of course.

When it comes to "real" fullrange drivers for larger enclosures, I?m very uncertain what to try. There are, for example, some nice ML TLs or ML TQWTs build with famous Fostex FE-206E or FE-167E drivers. See this page: http://www.quarter-wave.com/Gallery/Gallery.html. There are some interesting designs which aren?t that big, so I thought this could be something to try, and Fostex isn?t that expensive. But I read a lot about these speakers, and some love them, but some hate them, and that?s nearly the same with so many other speakers in the fullrange sector. So, if I want to build a speaker like this, not too big, not too expensive, and not too difficult to make, which fits into my room (which has about 25qm), and, say, fits to my Naim gear or, even better, to little Charlize, so tell me, WHAT should I try then?? There are sooo many drivers and I haven?t heard any of them yet!

There is another well known brand for fullrangers, Lowther. Lowther is very expensive. It?s not very expensive when you get a really, I mean REALLY good speaker to be happy with for decades, but it?s expensive for a quick try with the result that you say: "No, not my thing, no, thanks...". Got the point? I guess so ;-)

The speaker you and some of your friends listened to, what kind of speaker is this? Jordan?? (There is, actually, another version of Cyburgs Needle which has a 8cm Jordan driver, but this one needs a RCL-circuit for a flat frequency response, and as you know, I hate crossover components, so I decided to go for the Visaton).

Regards - Martin

[martinbls]

Sorry, I was wrong! The other version of the Needle doesn?t use a Jordan but a Tangband driver!

Martin

[assendor]

I am sorry to say that the drivers we listened to are Coral Flat 8" MKII. (Many say that the Flatv6" are even more magic)
Reason I am sorry that it's Coral's, They are so hard to get hold of these day's.

yeo was the reason I ever tried Coral's, and I was so amazed. (Thanks Again yeo)
After I have heard those Coral's in those Horn cabinets it is hard to convince me to buy something else, for any other reason than to just be disappointed.

I have Jordan speaker drivers and they are quite amazing, actually the best I had ever heard until those Coral's came along.
They are now mounted in those original Sophia cabinets Diyparadise sold earlier on, and they performs very well to be in such a small cabinet.
I did try them in a different cabinet also, they can manage enormously deep bass in big cabinets. At the same time they keep
up a pretty good tonal balance. The sound pressure is rather limited, they are after all just 5".
To my ears those speakers sounded best connected to a Nelson Pass design Amplifier, one of the first and very simple ones.
On Normal Class A/B amplifiers and other amps with rather low output impedance they have a little too much midrange for my taste.

Why those Fostex are so hated by some, and then loved by others I do not understand.
It could be the same thing as with the Jordan's, that they only perform the way they are supposed to on some very few amplifiers?
(To some people's taste)
I know many people do not like Fostex at all, and I know others that just love them. It is strange?
This fall I will buy me a pair of Fostex FE206E, FE166E and maybe FE208E[ch8721]. Problem will be to get time to make the Cabinets.
It's going to be interesting to test them on my own ears. If I get disappointed, well then some can say "I told you so!!"" But that's OK. I just wanna know.

There must be some fullranges that does not cost as much as those Lowther things, they are so horribly expensive.
We have Seas here in Norway making those new series of Fullranges:
http://www.seas.no/index.php?option=com_content&task=view&id=191&Itemid=187
I bet they sound good too, but the price again, Horrible.

Like you say, if it is the best speaker driver ever made, or something like that.... Well then it is probably worth it, but it is a little
expensive just to "try". Downside with those Seas, there are no Horn design for them yet, as far as I know.

I really want the stuff to have a reasonable price as well. It is a principle that things should not cost so extremely that only the
most sick people in this world can afford it. (Or only people stupid enough to pay suck sick amount of money for it).

Since we at first discussed DAC's here...
I will soon test a 24bit/192KHz DAC. I have also ordered some different OP-Amps to test it with.
I am 99.8% sure that I will be disappointed, but I want to try it.
I will upgrade the power supply, cards, capacitors, everything I find possible.....
The Op-amps I think will be the ones I end up with is 4x OPA627:
http://www.datasheetcatalog.org/datasheet/BurrBrown/mXqxttt.pdf
They need to be set in via adapters to make them dual. (Original is NE5532, that stinks)

Still it is obvious that DAC's with a current output and a NO OP-AMP circuit, are supposed to be the best.
Of course it is also possible to upgrade to this OP-amp here:
http://www.partsconnexion.com/Index/burson.php
But then again... PRICE!!! And Complexity, Monica3 is Much less complex in total, than one of these discrete opamps.
SO since discrete is the thing, well Monica is made that way!! She's cool all the way. Not just in between.
I am sure not to win, but I want to try it :) :) :)

-Jonas