DK Design VS.1 Reference mkII - Optimization

This time I will remove the opamps from the amp and replace them with much better sounding ones.

After adding the WBT RCA's and Binding Posts and Cardas wiring to the Amp, the sound just took off!The service tech had a problem with the WBT RCA's, they had to be cut or drilled to fit. I used Cardas 19AWG wiring to the Binding Posts and changed or upgraded the connections to the pre-amp. The Tech did the same for connections from the Amp to the pre-amp. The higher performance level from the my upgrades were so great!The Amp's backgound runs a black you can feel, the high end is so much better. Running the DAC and Transport from the Amp now I can do my serious listening. I still love my vinyl too!

Lauritsvd,
In what country do you live? There are other options than to send it to the USA. LSA has a European Master Distributor, if you live in the European community, for example.

Larry R. Staples

Hope this tread is still alive:
To Isslewis:Yes, changing the fuses to HI-FI Tuning, is great just. But if You only changed 4, You surely are missing the one under the bottom cover of the amp. It is hidden under a plastic cover too.. And this one makes a big difference, I missed it myself , that’s why I know...

My Tweaks:
I have fittet a Vincent powercord to my MK II with great result. Clears up the soundstage in a nice way. It seems to be sensitive to powercords.
I also use a “symmetry box” on the in my powerline and it makes a lot of difference. It works well with everything I tried it on. But the company that made them has closed, I am sad to say.
I have also changed the big and heavy speaker binding posts to a banana type. I have found some with very little mass. And I use bullet plugs for my rca. Sounds more natural than the types with lots of metal.
The tubes are Siemens cca (gold pins), think they are the best sounding tubes for this amp. With lots of air In the high notes.
The amp is standing on Solid-Tech: IsoClear feet from Sweden. They have a lot of small springs and keep the amp “floating”. Even thou it stands on a very heavy Audiomagic Hepta rack, they make a lot of difference.
Another thing to try out, is fitting short-wired rca plugs to the unused rca`s . Only the input ones of cause…!!! I have used WBT ones, and it makes a big difference in my set-up.. The soundstage becomes much better defined. Some sound recordings suddenly sound a bit narrow, and others sound huge, like they are supposed to, I guess.
From day one it has had a little hissing sound from the speakers, but don’t` know how to cure it, Maybe somebody else knows this?
I am very pleased with this amp and is still looking for more tweaks and upgrades. But sending it to U.S. for major upgrades is not an option because of the shipping costs.

I have changed all the RCA connection and the binding posts on the amp. Added WBT's, this was also a great upgrade to the amp. The sound is much clearer now. The highs have a little air now.

I have changed the CAPS in my DK amp also, to Auricaps 3.0!
they sound a hell of a lot better. I my mind the highend
fuses working with the CAP upgrade takes the amp to even
higher level. I don't get the un-even sound anymore. Once
the amp is hot and ready to run, she runs! I have noted that the highs sound a lot better now after the change. They still sound a bit distance. The total job cost me about $100.00. $40.00 for the caps, $60.00 for have them
put on the boards. Beats buying a new amp!

CHANGE THE CAPS WITH HIGH QUALITY LIKE I DID ON MINE I REPLACE THOSE BIG CAPS ON TUBE BOARD WITH NICHICON GOLD SAME VALUE AND AURICAP 3.0 MF IT TRANSFORM IN THE NEXT LEVEL.

Try HIFI Tuning Fuses! Four inside you have to replace, I
did and got very good results! You can see more into the
soundstage now. Highs are better also, but this is not the
shot in the arm you maybe looking for. You need good cables
with this amp! The Power cord plays the major role here,and you can't use bright sounding cables at all here. I had planed on getting a new amp up to this point. Not anymore! I'm going to try the fuses with my Black Cube's power supply next. They did great things for my Kora tube DAC.

I received this email through audiogon recently,

"Jomoinc, My name is Tom Bery, National Sales Manager for The LSA Group. We will be offering an upgrade for the MKII amp to bring it up to the "Signature" status, as much as is possible. We are still working out the details and price. If you are interested I will provide details as they are available. Please contact me directly at tom.berry@thelsagroup.com, or 888-671-8607, if you are interested. Thanks."

Any one else taken the modification plunge? DIY or Vendor?

At the risk of beating a dead horse, John Tucker is now a part of DK/LSA Group. John maintains his interest in Exemplar Audio, but they are completely separate companies.

I had a DK MK2, but now have the new statement. If you are considering taking the plunge, do it! It's that good. Rumor has it that DK may offer an upgrade for the MK2 down the road, but I don't know.

To all,
Sorry if that comment, clarifying the nature of John Tucker's involvement in MY company ruffled Jomoinc's feathers--it's just that, with others actually modifying, therefore voiding warranties, I wanted to set the record straight.

The Amp's name will change to LSA in our next run--simply to make our marketing direction clearer. We have made significant product upgrades in the internal parts, and quality control since buying DK more than a year ago.
QC'ing all the amplifiers has been a great value add for most of our customers--since we include a certificate with each amplifier, signed by the technician performing the tests.

Our newer models, the Signature and Statement, are in the hands of reviewers as I write this, so we should have press shortly--also, Bound for Sound's Marty DeWulf reviewed the Signature some time ago--and was impressed with the sound, enough to compare it to units,(even separates) costing multiples of the price.

Thanks for the opportunity to clarify.

Best,
Larry R. Staples
President/Designer
LSA Group

OK Lrsky, that's two shots

As a manufactor's rep, if you would like to contribute to, as the description of this thread states:

"tuning, customizing, hot rodding, tweaking, what ever.. as an OWNER of DK Design VS-1 MK2 to bring out the best in this amp."

Please do. That is the concept of this thread.

It does not say if you are the owner of the company that no longer sells this product... It would be wise to be proactive & supportive to these ends rather than reactive to the very owners already financially committed to this model.

Redd Foxx Atlantic SD18157 LP You Gotta Wash Your Ass
"It is better to wash your ass than to try to cover it"
mmm....

Jomoinc,
Please read the correspondence preceeding yours.

Larry R Staples
President/Designer
LSA Group

I found a matched pair of RCA 7308 tubes and am thoroughly enjoying them. I would like to explore getting the Four Camille Cascode Constant Current Sources (C4S) to replace the stock plate load resistors ala Bottlehead topography and possibly replacing some of the stock caps with VH audio V-caps or better. Too bad DK does not presently offer past product upgrade support from Exemplar....

This is incorrect information.
John Tucker is Vice President of Operations of LSA Group.
This is not a mod, but a collaboration between John and myself for the improvement of the original design.
I don't know how rumors like this become so convoluted, John has worked for us for about a year now, and brings a remarkable technology with him.
These are stock units, that being the Reference, all QC'd by our Seattle facility, John's facility, then an upgrade to the preamp section only, the Signature Edition, with the final upgrade being to STATEMENT Version, which is a full exchange of parts in all areas, replacing inexpensive op amps, utilizing Active Tube Loads, stabilizing the tubes into the 4/6 MHZ region, generally unheard of.
This is definitely NOT a mod, but a factory recognized, and internal event.
Just so everyone understands the relationship, John IS a part of the LSA Group Team, brining his full expertise to the company. We are fortunate indeed to have him aboard.

Best,
Larry R. Staples
LSA Group
President/Designer

If you are not in a big hurry, apparently exemplaraudio.com will modify (commissioned project) these to add their "active" tube control circuit design as seen in some other tube preamps as well as other design issues (capacitor / power supply mismatching) and upgrades to parts. They are known for mods to the Denon 2900 & others to kick them up into a higher performance category. They also offer build services on the Bottlehead Valve Kits. Also rumored to be the design source for some of the DK signature version improvements....

Jon,

I was coressponding with Daniel some time ago, and in one of his emails he wrote the following:

The line-stage has variable gain. There are small potentiometers on the pre-amp board next to each tube. The potentiometer is adjustable with a screw driver and you can set the optimal gain for your system if needed.

I've tried this yesterday without any luck, the volume is still at 9-10 for notmal listening level. So, I guess I'll have to contact DK Design and see what they will advise....I let you know.

Jimtyrro,
I read that the input level is ajustable from the preamp pots but that is all I know at this time. It was in relation to dropping the gain to allow for a "hot" phono preamp input voltage. If you find out anything, please post and I will do the same. I noted the same thing on an earlier post on this thread.
Jon

I wanted to ask, how do I change the gain of the amp? I'm asking because I listen to it at no more than 9-10 o'clock and it's pretty load, or is it b/c it's so called 'class A' amp? Anyone noticed this?

Jomionc, I have come upon a tube that just seems to synergize with the DK beautifully and this is it:
http://www.tube-classics.de/TC/Tubes/Valvo%20E88CC/E88CC12.htm
It is designated a Valvo, sold to me as a Mullard, but evidently is a Phillips/Amperex according to Tube Classics. All of a sudden there is this deep structured, detailed bass response with neutral and transparent mids and highs. Look for it as a Valvo E188CC.
Here is a German site that features it:
http://www.jogis-roehrenbude.de/Roehren-Geschichtliches/ECC88-Familie/Valvo-E188CC/Val-E188.htm

The difference this tube made in my VS-1 was nothing short of amazing.

Sundance1,
I also am interested in what the Parts Connexion upgrade path could do for my unit and would love to hear about the options, process & timeframes, and of course, the results during and after break in.... I would highly encourage you to post your thoughts and progress for us other owners interested in what is possible. Thanks in advance and best of luck in your quest! It would be great to be able to bump up to higher level of performance keeping in mind the "Fun per dollar ratio" we all love about this model.
Best regards,
Jon

Thanks for the feedback on the Parts Connexion Upgrade, Nicksgem. I have dealt with Chris in the past, just not on a project of this size (literally with the DK!).

I agree with you about the (past) Audiogon climate concerning this amp. I think it got ridiculous on both ends of the extreme. What a shame to move away from insightful and balanced discussion as we are all (hopefully) music lovers and the equipment is just a means to an end.

Take care and wish me luck as I prepare to pack this beast up without any harm to my body.

I had Parts Connexion modify a DK VS1mkII a while ago. It was a great improvement over the stock amp. If I didn't have problems with changing gear every couple months I would have probably kept it & been happy. It sounded killer. I think it was money well spent. The quality of work by Parts Connexion was absolutely 1st class all the way. I wouldn't hesitate to deal with them again in the future. I have since gone back to separates and am chasing my tail again. I sold the amp on Agon and the new owner is absolutely thrilled with the sound and that was with some inexpensive tubes in the pre section. He also got my cryoed CV2492 Mullard tubes to plug in when he is ready. The DK is a nice amp that never really got a fair shake due to marketing/shill and all the crazy threads and arguments. It isn't the last word in amps/preamps but for the money it is a great value.

Hello Malbor,
You mentioned you have a friend that has done the Parts Connexion Upgrade to his DK. I have been considering having this done for quite some time and have never, until now, found someone who can give me their opinion with the outcome. Without being rude, is it possible to pass on my email to your friend? Thanks.

Oh, and just so that you know, I was one of the first to buy the DK (and I don't mean that in an Al Gore/internet kind of way) but was very pleased with its sound right away. And in the early and quiet beginnings of this amp had many conversations with Daniel. And while listening to his enthusiam about using the supplied powercord and interconnects, those items didn't make it a day beyond their break-in with my system. While this is a beautiful amp, it's not a plug and play amp and, as with any personalized audio system and component, will greatly benefit from a thread like this.

I do most of my serious listening with vinyl and did a phase test with the Shure test recording TTR-110 through the phono and input A and the phase was reversed. I flipped my speaker cables red to black, black to red,to correct this. FYI- I use Silver Sonic Q-10 speaker cable presently connected to full range dipole speakers (Hunt Janni Tombstones-DIY). I am looking for my test CD to check the input I use for CD play (mostly background music as my setup is in my living room......

Mullard CV2492 gold pin cryo tubes . Somebody talk to me who has rolled a set of these into the preamp. I presently have a set of Tungsram E88CC/6922 and did not see a substantial change from stock tubes. What cha got there...?

The removal of ferrous materials in and around circuit boards, crossovers and speakers will result in lower distortion and a more musical presentation. Providing vibration direction,focus and relief in my experience results in a much more natural, dynamic, and open sound. Brass is my material of choice in most every instance. Tom

Theaudiotweak: Brass? That's a surprise, I would have guessed rubber or wood or maybe glass or plastic. Do you also feel that the metal screen transmits electromechanical vibration and or electromagnetic induction? It seems like the metal screen would be a good electromagnetic sink or do you feel a polyester screen would be preferable?

Theaudiotweak: Brass? That's a surprise, I would have guessed rubber or wood or maybe glass or plastic. Do you also feel that the metal screen transmits electromechanical vibration and or electromagnetic induction? It seems like the metal screen would be a good electromagnetic sink or do you feel a polyester screen would be preferable?

Brass of course..And then proper mechanical grounding of all the boards, power supply caps, transformers and then the entire chassis. Vibration either self induced or of external influence can be given a positive relief to a higher mass..ground. Tom

The Eichman Power cord with Mullard Tubes. Synergistic Alpha Quad Active's at the bottom and Guerrilla Audio Silver for the top end in a bi-wire configuration. The transformation is absolutley amazing. The bass and mid-bass response is now among the best I have ever heard anywhere at any price. Does anyone have a short list of materials that would be considered acoustically and electromagnetically inert and a better choice for the cover?

If I recall correctly I used the top of the line Audience power cord with the DK. Not sure but I think so.
Art

I mean that I leave power on. Standby helps but it's not enough. I'm guessing, hoping, that the tubes have a low current and will last a long time (change annually?)
Art

Sbayne, I was thinking also about the "integrated" issue with both the preamp and the power amp being fed at the same time from the same hose, er... cable.
Hey in relation to the modified VS1MKII I wonder if the Parts Connexion could modify it to separate it up to provide for an external preamp power supply and as long as we're dreaming, how about a separate amp only input! Somebody stop me!!

Jomoinc, yes the Black Lightning is "only" recommended up to 200 watt amps but I would totally agree with Mark that its the quality of the power cable not the AWG that counts.

I have tried several power cords with my VS1MK11.
Guerrilla audio, Signal cable,Supra Lorad 2.5 VirtualDynamics power one. For my ears the VD is the clear winner. When it comes to ic's i haven't tried as many, Mas silver,Zsquared copperheads, VD audition, once again the VD was the the best for me.
I was talking with AGON member that had his VS1MK11 modded by Parts Connexion they change over 85 parts. He said it was huge upgrade from the stock amp!! even at the 1k price.

The DK amp is supplied with a regular computer power cord, such as the one that comes with most Dell PCs. I had several discussions with DK regarding this and they are simply selling the amp and circuitry at the lowest possible price with a cheap power cord and tubes which they believe are user upgradeable. Also, the previous owner, Daniel Khesin, was not a big believer in power cords, although he heavily emphasized upgradingthe tubes.

Sbayne,
I went to the Zcables website and was reading the Black Lightning info and noticed that they "do not advise the 12AWG for amps producing over 200 watts non didgital" I emailed and received a reply from Mark Hampton stating that high current amps may benefit from a larger AWG. "The more complicated answer it that sometimes amount of current is the most important thing for power amps, and sometimes quality of current is."
Do you or anyone else know what the DK provided ac cable AWG was? Anything unique about it? Also other owners...what power cable are you using with this amp to benefit its performance?

Knowing the real answer to why? may greatly increase the application of the answer. Tom

Tvad, you are absolutely right.

Electrons vibrate regardless of mass. If there was no motion their would be no sound. Giving that motion focused direction and relief is the key to better sound and greater efficiency. Tom

I dont think vibration is an issue with the DK amp. It is a very massive peace of equipment and there is no vibration to speak of. This brings me back to the EMI issue. The concept is quite simple, some of the EMI bounces off the aluminum cover and goes back into the circuitry, creating a sort of a negative feedback circuit. When a small amount of signal goes back into the circuitry it gets amplified again. This is the reason I believe the amp sounds better with the cover off.

What I hear is that the midrange becomes even more open and organic when the cover is off. There is also a bit more detail and texture in the bass.

Hey guys my thoughts were that removing the top changed the vibrational pattern and therefore the sound...for the better or for the worse. I am very comfortable with myself knowing that vibration can be given a pattern as well as direction in all things that are in motion, which is everything. Removing the case which is more likely less massive than the main chassis would probably reduce the amount of various resonance points that could be transfered back to the main chassis and electrical components to be reamplified in the mix. Most of you know my previous history and thoughts ..mass loading versus mechanical direct coupling..anyway the case removal altered the vibrational direction and flow..Proper mechanical grounding of all the boards, transformer and power supply caps to the main chassis and all of this direct coupled to a greater mass {the floor of your home} would transfer vibrational energy away from and out of your component..The result would be greater resolution and dynamic scale. So I have experienced.. Tom

Tvad, I'll take a stab at the vibration/top issue, by way of example. I have a CDP with case vibrations induced by the transformer. These vibrations are sufficient to rattle the tube innards which increases any potential they have to be microphonic. When I take the top off the CDP I'm eliminating one of the surfaces which facilitate the transmission of the vibrations. Often the audible (as well as physical) frequency (pitch if you will) and intensity of the vibration changes - usually lessens. Mass loading can have a similar effect.

If you have the best LN tubes and your unit has a low noise floor you might not actually change anything except reduce the audible transformer hum (not a bad thing at all), but if you have borderline tubes and a highish noise floor these vibrations can induce tube microphonics which can be audible. FWIW, I think there are better ways of getting 'spacious and open' than using microphonic tubes. :-)