Tubes for your K&K Maxxed Out Phono?

Hi guys:

I took possesion of a new, full on preamp from Kevin about a week ago. I've been running LPs through it non-stop, maybe 15 hours so far.

I wonder about break-in aspects & do understand that this puppy needs a good amount of time, before those big Cardas parafeed caps open up in particular. That said, it is already capable of fantastic resolution & imparts some nice speed to my system in almost all tube rolling configurations. It's an awesome piece of kit, I can tell that already. Mine also has the 1931 trafos.. so a maxxed out, Maxxed Out, if you will. :)

My other gear is what i'd say is pretty neutral, with a "bouncy" front end: Art Audio HC Jota (AVVT 325Bs), Gill Audio Alana preamp, an OMA Lenco/Schick arm, with a SS retipped Denon 103R.

My issue is this: I just tried rolling some Siemens ECC88s in both the K&K and then I shifted them to my Linestage (I put some 60's Mullards in to the phono stage in their place). I'm surprised that even with some late 60's short plate Mullards in the K&K and the German tubes in the linestage. While the pacing is fantastic, it just seems a bit to hot for my ears.

It was even quicker & a little preferable overall with Valvos in my linestage & the Siemens in the K&K. I've gone through my cart setup a few times, i'm sure it could be better, but i detect no mistracking and my cart orientation (VTA/RTA) is just barely tail down.

I wonder if these Siemens are just a little "too much of a good thing" in the high end department for use with the K&K due to it being so nicely extended to begin with? May I ask what other Maxxed Out owners use in their preamps?

I'll fiddle with my cartridge a touch more before giving up on the Siemens entirely for phono stage duty. Maybe I should wait for some more run in time on the unit before drawing any such conclusions on valves? It is only a few hours into service.

I can eventually figure something out and roll some other types of tubes in to it; thinking something in the Amperex school now. Just a bit of a buzzkill, cause I love the pace the Siemens give everything. They really make an all tubed, glorified, high current 300b based SET amp system get up & boogie. Fatiguing if fatuiging though.

I didn't pay a ton for the valves.. by all identifers I can see, they seem like the real article, A3 issue Siemens E88CCs from the mid 60's. I thought they'd be detailed but a little sweet as per what i'd heard about them. I guess it's system dependent & semantics (like everything else).

My speakers are Ars Aures F1 floorstanders btw. Nice, musical & err on the sweet side. Not insanely detailed by reputation or in my room.

Thanks for any & all insights Maxxed Out owners. I've had some magic already with this unit & it ain't going anywhere. I'm just looking for that little extra, perceived pace, without the ear bleeding.

Regards, Marc
I have a premium maxed-out k&k phonostage. It is an excellent unit. Give it at least 200 hrs. to burn in. Those caps are pretty big, they need some time to open up.
I made Kevin put the Mondorf s/g/o caps in mine. I am really enjoying the sound.
I have a much different set-up then you, but the Amperex 6922 PQ white label made in the US tubes are excellent (pricey). The Holland made Ampere are very good also.
I am very happy with the unit.
Good luck!
I'd say you need a good 300 hours for break-in time (there's a lot of transformer wire that needs time...perhaps even more so than the big Cardas caps). One mistake gear junkies make with the K&K is to dismiss it too quickly. Your patience will be rewarded.

I've tried rolling dozens of variations of the 6DJ8/6922/7308/E88CC/E188CC families, and I've always come back to the stock tubes, the mid 70's vintage Russian 6H23P-EB. The way I figure it, this is the tube Kevin designed the unit around and sonically (as well as parametrically), it's simply a perfect match to my ears. YMMV and all that. Good luck, and let us know what you settle on.
Isn't the unit already supplied with what's considered the best tube in that family? Mine came with some '80's Voskhod 6N23P. I also tried some '70's version and heard no difference. Maybe you should use the trim pots and dial it back a bit if you think things are too hot?
Like Palasr, when I owned a premium Maxxed Out, I rolled a lot of high-buck tubes through it (e.g. early '60s Valvo Red Labels, 1964 USN-CEP Amperex 7308, Seimens 7308, some others) but ultimately returned to the stock tubes. Kevin did a good job tuning it for those tubes.

As others have said, it takes a few hundred hours to break in fully. Enjoy!
Thanks a lot for your responses guys. Right after I made my initial post, I thought: "how can you really evaluate a tube swap, now, when this unit is so new"?

So I do think I should wait a bit and re-post my experiences when I have a little more burn in on the stage.

I'm also sure I made a few dopey, "rookie mistakes" by both swapping out the stock tubes (Russian 6N23Ps), which i'm sure are quite nice and I would agree, what the designer, implemented around & for an extra boobie prize, I went and messed a bit with my cartridge setup.

This unit, is just a good bit more resolved than anything i've ever run in my setup before.. so when I was annoyed by what I thought was some mistracking, i went right into "redo" mode right away.

For the brief time I had the stock tubes going, they were more than fine. I popped some mid 60's Mullards I had lying around from a linestage purchase though and I liked just about everything better after the swap. The Siemens did offer some speed.. which was totally intriguing.

Thanks again gang! I'm gonna find my own way for a good bit during the run in process and post back with any fun revalations, tube recs, etc.

Peace, Marc

p.s. As far as adjusting any "trim pots", I could certainly change the loading & see what kind've effect that has. I wouldn't touch the internal dip switch, individual gain controls in the unit with my cart. The low output of the 103R (.25mV), puts me firmly in the need for the high gain settings staying that way, i think.
Thanks Wrm57.

You moved on from this bad boy though huh? may i ask, whatcha runnin' now?

Hi Marc,

I really liked the Maxxed Out. Especially at its price-point, I think it's a terrific piece. But I made the mistake of auditioning a Steelhead II and couldn't go back, so a good friend is now loving my K&K.

Marchomeslice - I was referring to the trim pots for adjusting the "voicing" as Kevin calls it, by changing the bias current of the output stage. This is probably the hotness you speak of, which Kevin calls "incisive" in the manual and says you should experiment to get the sound that is best for your system.
Wow, thanks Vortex. Very interesting.. and possibly, super useful.

Good to know that this kind've customization is possible.. that, on top of a serious array of controls onboard already.

I'll shoot the good KC an email about it shortly.

Regards, Marc
do you have the manual for your unit? it shows how to read and set this. my manual is for the kit though, so I'm not sure if yours is different since it was pre-built.
Funny, my cartridge only outputs at .25 mVs (Denon 103r, sorry if I mentioned that already).

Kevin factory sets the unit at high output for the MC section which is appropriate to the 103r, but has the gain switches at their lower setting for the preamp as a whole.

I'm home now listening.. and I just switched the preamp's overall gain to the high setting. Which to me, is a little high, so I think I need to find out how to turn those pots down a touch.

Might be a stretch, but I also think this may be why those Siemens tubes sounded so hot. There was likely, a little too much gain compensation I was applying, through my linestage. Like a Valvo/Siemens double team. :)

So while i'm probably oversimplifying this.. but the Mullards I currently have in the K&K, sound more "like Mullards" now. A little less airy overall and more thick than they sounded with the K&K set to the low setting.

I have the current manual for the Maxxed Out Phono, but I don't think it has where to adjust those little biasing pots in it. I'll check again.. i'm almost positive that would help. Otherwise, I preferred it the way it worked in the low setting for the preamp. The way it is with both MC & the pre set both to high.. I have very little control with my linestage attenuators. It's a little too much gain & full from jump street right now.

Thanks Vortex! Marc
in my manual it is in the "break-in" section. it's adjusted for each channel using R115/R215 while monitoring the voltage at TP2/TP4 relative to TP1 (ground). Kevin notes the original value as 1.6VDC, but says it is adjustable between 1.0VDC to 2.4VDC (higher number is more "incisive"). he notes to do this after the unit is fully broken in.

* I should note I have the last Maxxed-Out, but the MM only standard version. I believe this should be the same with yours though, since it is the same board, etc.
p.s. I think I know which trim pots they are, but I can wait to speak with the designer.. thanks again for the heads up Vortex.
Ha, I have spent a great deal of time, effort, and funds tube rolling in my integrated amps but never even gave the tubes in my K&K a thought because it always has sounded so phenomenal, transparent, etc. I guess it would be worth a try.
Mine is not the maxed out version, perhaps you would call it Mark II. I have had it for about 8 yrs. now and still love it.

I would say you still haven't broken it in yet. Wait until you get about 50-60 hours on it before you seriously tube shop.

Just heard back from Kevin. He said to leave the trim pots alone on my unit. Said he ran it in HIGH in the MC section and LOW for the preamp's overall output; which is how he shipped mine.

It did sound best this way.

It's still incredibly tunable.. there may just be some valves I don't love in this baby. I can live with that.

Plus, I still have to just let her break in first, before I can view anything too critically, me thinks.

Thanks! Marc
Marc: I also have a K&K Maxed out unit that I built and recently upgraded with Kevin. And again I am running a JOTA HC with the 300BXL's. After doing the upgrade I also thought that my unit was to hot and was quit concerned after being so happy with the unit prior to upgrading. I am sure Kevin didn't want you adjusting the Trims until it is thoroughly broken in but it did the trick for me and they actually had drifted a little from the starting point. My suggestion would be to keep the stock tubes and be patient with the breakin, I felt that it took a good 200 -300 hundred hrs or more before it really settled in. If you aren't happy at that point I would revisit setting the trims with Kevin as they are very sensative and just the slightest change will affect the sound.I can't say enough good things about K&K, Kevin, and or my unit. I am sure it will come around and you will be very pleased.
best of Luck
Thank you Shakey (or is it Neil? In which case, may I say, what a big fan I am :) & Capeman.

Nice to hear that someone running the same amp that I am loves it. I have the stock tubes back in and am facilitating break in (most enjoyably) as I type.

Gosh, if all the personalities we deal with in this hobby were as wonderful as Kevin's: There'd be agreement on SS/Tubes, Analog/Digital, maybe.. Michael Fremer & most likely world peace. Guy is ingenuity, value, professionalism & competence with a smile.