[IronLion]

A brief story of the evolution of my MPXXX3. I bought my MPX3 with Solen 3, black gates, teflon caps and NOS 6SN7's from Mikhail about 3 months ago. After the first month or so of listening to the amp, I liked the sound but there was something missing to it, it just seemed to be veiled and lacking dynamics. After sending it back into Mikhail, he told me that the big Solen 3 cap had burned in incorrectly, which had made the amp sound at about 50% of what it should have been. He replaced the Solen 3, and, after the NYC Headfi meet (my first) I decided to have him upgrade it to the SLAM configuration. I thought about it a while more and decided that I also wanted to add something else to the amp, but I wasn't sure what; I knew that Mikhail had plenty of tricks up his sleeve though so I told him what I really wanted my amp to sound like and we went from there. I sent him a long email about the sound I wanted, but in short I basically told him that I wanted as impactful and dynamic a sound as he could create with the MPX3 without losing too much soundstage on it. The goal in my mind was to recreate a live concert.

On top of the SLAM upgrade, I had him add a Supra power transformer to my MPX3 to increase impact and dynamics. I thought he would stop there, but apparently I had stirred the development bug in him and he went the extra mile with my amp. I received it today, and it is truely an incredible sounding amp; he says it is one of the best sounding amps out there, and definitely the best sounding MPX3 Singlepower has made in the 5687 configuration. So, what did I get in the box this morning? My MPX3 with the big Supra transformer (which is noticably larger than the stock one), a bag full of NOS 6SN7's, 5687's, and, most incredibly, a crazy tube configuration that Mikhail had come up with using 6BL7's. I've never heard of these tubes, but apparently Mikhail really likes them and is looking to buy more of them, to do sort of a special edition run of them on some amps. In any case, they plug right into the stock 6SN7 adapters (at least, on my amp they do- not sure if they would work on stock MPX3's?) and have incredible power output.

The setup I'm currently using is the one Mikhail said he liked best, its a NOS Tungsol 5687 in the driver, with the two GE 6BL7's in the outputs. It sounds pretty incredible, and this is using new interconnects and with all my equipment just being plugged back in today after 2 months of being off. I can't wait to hear how eveyrthing sounds when its all broken in. Anyways, I will post pics later (I am in finals right now and am very busy but will post them when I have some free time) and some focused listening impressions as well, currently I am just enjoying the music. Oh, and if you're wondering why I called my amp the MPXXX3, its because in each of the three tube slots I can use the 5687's (which came with 6SN7-5687 adapters Mikhail makes), 6SN7's, and 6BL7's in any of the three positions, hence the XXX represents the sheer number of different tube configurations I can have in this amp, with each X representing a tube socket. Also, I thought it makes sense because this amp is just obscenely good sounding...

 

[PsychoZX]

Congrats on the amp purchase. Sounds like a really killer amp.

 

[tom hankins]

Awesome amp!! I see many late nights in your future rolling different tube combos. Would love to hear the difference between your current tubes used and one of the 6sn7 tubes in front of a pr. of 5687s. Have fun.

 

[NightWoundsTime]

Sounds amazing. I love Mikhail's free-form design techniques. He truly is an artist with this stuff.

 

[IronLion]

Quote:

Originally Posted by tom hankins Awesome amp!! I see many late nights in your future rolling different tube combos. Would love to hear the difference between your current tubes used and one of the 6sn7 tubes in front of a pr. of 5687s. Have fun.

That was the original plan, to just have it be the Ken Rad driver with two 5687 outputs, but as I 'm currently enjoying the 5687 driver with the 6BL7's so much I haven't gotten around to trying any other tube combination yet. I want to get a good feel for what this setup sounds like before I start rolling tubes.

 

[sacd lover]

http://i32.photobucket.com/albums/d3...Picture294.jpg

http://i32.photobucket.com/albums/d3...Picture296.jpg


Here are some pics of the 6BL7GT and the 6BX7GT. The 6BL7GT is the black plate tube in the old chassis Supra-X. The 6BX7GT tube is the gray plate tube in the new chassis MPX3. Look at the size of the plates in these tubes .... massive.

The 6BL7GT is 3-4 x more powerful than a 6sn7. Furthermore, what appears to be a very tall tube in the gain slot..... thats another loctal base mystery tube

coupled to the amp with an octal to loctal tube socket adapter.

 

[warubozu]

Wow, congrats on receiving your MPXXX3. Look foward to seeing some pics and more impressions.

 

[sacd lover]

http://i32.photobucket.com/albums/d3...Picture307.jpg
http://i32.photobucket.com/albums/d3...Picture306.jpg
http://i32.photobucket.com/albums/d3...Picture305.jpg
http://i32.photobucket.com/albums/d3...Picture304.jpg
http://i32.photobucket.com/albums/d3...Picture302.jpg
http://i32.photobucket.com/albums/d3...Picture301.jpg
http://i32.photobucket.com/albums/d3...Picture300.jpg
http://i32.photobucket.com/albums/d3...Picture303.jpg

Here are some more pics of my amps using various tube socket adapters.

With the octal to loctal base adapter I can use 7n7 and 14n7 tubes .... plus the 6 and 12 volt version of another mystery tube.

With the octal to 9 pin mini adapter I can use the 6cg7 and its 12 volt version ..... the 12fq7.

When my 5687 adapters arrive I will be putting 5687's in atleast two of my amps. The 5687 tubes can run at 6 or 12 volts but the adapter will be specific to just one voltage.

Pics 306/307 show an mpx3 with a 14n7 gain tube with two 12fq7's used for the output tubes.

Pics 304/305 show an old chassis mpx3 using three 7n7's.

Pics 301/302/303 show two mpx3's using 6BL7GT black plate output tubes and 6BX7GT gray plate output tubes ..... with pic 303 a close up of the gray plate 6BX7GT.

Pic 300 shows my stock old chassis Supra using two 6BL7GT black plate output tubes.

 

[jimmyjames8]

IronLion, what does an MPXXX3 cost as configured? If you don't mind me asking.

 

[IronLion]

Quote:

Originally Posted by jimmyjames8 IronLion, what does an MPXXX3 cost as configured? If you don't mind me asking.

Depends on the tubes you get with it, but as mine is configured I would guess somewhere between $2000 and $2400. I can't give you an exact number because Mikhail hasn't sent me the invoice yet for the work he has done since I got it 3 months ago with the Solen 3, black gates, teflon caps, neutrik jack and spiked feet and NOS 6SN7's. In short though, it is definitely a significant hit to anybody's wallet...

 

[Mikey01]

Well, I think Mikhail had lotsa help in the tube design/sound inspiration department, to help his creative juices flow. Feed the brain SL. I hope the MPX3 is an increditable experience for you. Congrats.

 

[aerius]

MPXXX3. That name is just begging for some adult humour...

Congrats on the amp!

 

[Rob N]

Earl,which are the best brands of 6BL7's or 6BX7's to try?

 

[markmaxx]

Quote:

Originally Posted by IronLion Depends on the tubes you get with it, but as mine is configured I would guess somewhere between $2000 and $2400. I can't give you an exact number because Mikhail hasn't sent me the invoice yet for the work he has done since I got it 3 months ago with the Solen 3, black gates, teflon caps, neutrik jack and spiked feet and NOS 6SN7's. In short though, it is definitely a significant hit to anybody's wallet...

So do you know how much for the tube adapters? I wish Mikhail had figured out the adapters before he switched my MPX3 over to a slam internaly.

So now it looks like we switched the wrong sockets

I have a 6SN7 for gain and 5687 for output and you say (and Mikhail) the 5687 gain and 6SN7 output is the best sounding MPX3 ever. What do you think?

I to have no idea how much it has cost me to make my amp a slam? but I hope I don't have to pay for the slam conversion then buy the adapters to switch back to the original configuration. When all I needed was one adapter for the gain tube. That could put a big dent in my budget for my Singlepower home stereo amp.

But this is great news for anyone with an PPX3 or MPX3 and wants to make it a slam the shipping alone is a big savings $50.00 each way for my amp + like $250.00 for the conversion. Thats why I want to know how much the adapters were.

 

[Glod]

Congrats IronLion!

It is always such a pleasure to see what others come up with as upgrades, improvements or sheer craziness. Yours makes absolutely sense though

I too will be very interested in getting to read your impressions after the amp has burned and settled in. I suppose that might take a bit longer than a standard MPX3, due to other components used. That said, I wonder what Mikhail made for changes in yours. You sound a bit cryptic

, whether that is due to absence of knowledge or the prerogative of the chef, not having to disclose what's going on in the kitchen

, I don't know.

Let me try to summarize what the main features seem to be.

1. Upgraded transformer to Supra specs.
2. Possibility to fully (sometimes with adapters) utilize the potentials of the electrically different 6SN7GT, 6BL7GT, 6BX7GT and 5687 tubes in all positions (obviously the outputs must be of the same sort and model).
3. Major topology changes in the circuit(?)

Would this be an accurate short-list of deviations from a standard MPX3, not counting standard, selectable, options, like different capacitors?

What I am fishing for here is whether this MPX3 would be special enough to be called a different model, or a simply a “maxed out” MPX3. As a comparison, I think that the modified Supra, called Supra-X, which currently has a home at Earl’s place, does warrant the definition “model”. The reason is that it is simply just not a Supra with standard selectable options, but has it also significant other modifications, among other things a larger transformer…