[Skylab]

Congrats Miguel! I'm sure that is just awesome

 

[Skylab]

Well, as it happens, I have decided to try an MPX3. Mine is the 6SN7 version, and it arrives today. Can't wait

It will be fun to compare it to the Extreme, which I really love.

 

[mrarroyo]

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif Well, as it happens, I have decided to try an MPX3. Mine is the 6SN7 version, and it arrives today. Can't wait It will be fun to compare it to the Extreme, which I really love.

Well enjoy it! After you have had it for a while let me know if you would like to try slam adapters (2), or 6CG7 adapter, or the one for the 5670.

 

[guzziguy]

Quote:

Originally Posted by mrarroyo /img/forum/go_quote.gif Quote: Originally Posted by Skylab /img/forum/go_quote.gif Well, as it happens, I have decided to try an MPX3. Mine is the 6SN7 version, and it arrives today. Can't wait It will be fun to compare it to the Extreme, which I really love. Well enjoy it! After you have had it for a while let me know if you would like to try slam adapters (2), or 6CG7 adapter, or the one for the 5670.

The 5670 needs the 2c51 adapter. I really like the 2c51 as a gain tube but haven't heard a 5670. Yet! Earl recently wrote this in a PM to me: "For sound quality, I still like the TS 5670 just as well ..... and the Sylvania or GE 5670 almost as well." If you really want to splurge, you can try the extremely rare Bendix 6385, which also uses the 2c51 adapter. That's the tube that Earl was comparing the 5670 tubes to. I just bought one and really like its sound. Whether it was worth the high price is questionable however.

I also suggest getting a 7n7 adapter so you can use 7n7 tubes. They are much cheaper than 6sn7 and it only takes buying a few 6sn7 to pay for the adapter and several 7n7 tubes. I recommend the Sylvania tall bottles. Earl suggested these to me when I got my PPX3 Slam and I like it better than any 6sn7 tube I've tried.

Note that you can use all these tubes in both of your amps as a gain tube.

 

[mrarroyo]

guzziguy send me a PM w/ your mailing address and I will send you a
5670! Where can I get a 7N7 adapter? Have tubes but no adapter.

 

[Skylab]

Actually, one of the main reasons for my getting an MPX is to make use of some more of the about 50 6SN7-type tubes I have. I do not *want* to use other tubes. I am trying it with some basic tubes now that it's here, but since it seems to work fine, it will be getting an ECC32 driver tube and some Brimar CV1988/6SN7GTY's for the power tubes

 

[guzziguy]

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif Actually, one of the main reasons for my getting an MPX is to make use of some more of the about 50 6SN7-type tubes I have. I do not *want* to use other tubes. I am trying it with some basic tubes now that it's here, but since it seems to work fine, it will be getting an ECC32 driver tube and some Brimar CV1988/6SN7GTY's for the power tubes

I understand. I'll warn you though that 6SN7 as output tubes won't satisfactorily drive your K340s. You'll need the Slam "upgrade" to do that.

 

[Skylab]

That's OK - they are driving mu JVC DX1000's VERY nicely

I'm pretty enthralled with the sound. Much warmer than the Extreme, but still nicely detailed. With this tube complement it's a slightly "tubier" sound than the Extreme, but VERY enjoyable. Problem is, looks like I will need to keep both

 

[guzziguy]

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif That's OK - they are driving mu JVC DX1000's VERY nicely I'm pretty enthralled with the sound. Much warmer than the Extreme, but still nicely detailed. With this tube complement it's a slightly "tubier" sound than the Extreme, but VERY enjoyable. Problem is, looks like I will need to keep both

I listened to a maxed out MPX3 at the NorCal meet. That's pretty much my impression too. The MPX3 has a more delicate and finer sound than the Extreme. The one I was listening to had a 2c51 gain tube, so it wasn't as tubey as having three 6sn7 tubes. The Extreme does PRAT and dynamics better than the MPX3.

I'll be keeping my Extreme but it would be great to have both. I'm envious of you.

 

[Beav]

Quote:

The one I was listening to had a 2c51 gain tube, so it wasn't as tubey as having three 6sn7 tubes

It also used 6BL7 tubes for power

I've tried a number of 6sn7's on this unit, and they all produced quality sound; ended up with Mullards and Sylvania's before the Denon 5000 became my reference can; with the 5000 a bit more punch was needed so Mikhail recommended the 6BL7/2C51 combo, and that's where I've settled.

 

[guzziguy]

Quote:

Originally Posted by Beav /img/forum/go_quote.gif It also used 6BL7 tubes for power I've tried a number of 6sn7's on this unit, and they all produced quality sound; ended up with Mullards and Sylvania's before the Denon 5000 became my reference can; with the 5000 a bit more punch was needed so Mikhail recommended the 6BL7/2C51 combo, and that's where I've settled.

I couldn't remember whether if the output (power) tubes were 6SN7s or not. Thanks for clearing it up. To me, the gain tube affects the tonality of an SP amp much more than the power tubes. Is that what you heard? Of course, if the power tubes won't drive the headphone well, it will make a large difference. It would be interesting try other gain tubes with the 6BL7s and see how things change.

 

[mrarroyo]

Any reason why a properly stored 2C51 adapter would go bad? Before I sent my MPX3 to Mikhail the adapter worked with any of the 10 or so 5670 tubes I have.

Since I received my MPX3 w/ the lates mods I have been burning it in using 6SN7-GTB tubes. Yesterday I tried using the 2C51 adapter and all I got was HUM. I then tried 3 other 5670's with the same results. I doubt 4 different tubes would have gone bad, just like I am doubting that the 2C51 adapter went bad althogh I will try to borrow another 2C51 adapter to test that posibility.

This leave only the option that with the last set of mods the use of the 2C51 was dissabled by Mikhail. Does this make sense? I have tried the 6CG7 in the driver w/ its corresponding adapter and I have had no problems. Thanks.

 

[Skylab]

Gee Miguel, that is really weird...

So some more time with the MPX3 today and I have to say, I see what all the fuss is about. REALLY great sounding amp. Kinda hard to stop listening to it. It does an awful lot right. Gorgeous mids, nicely extended and detailed highs, powerful bass, fantastic soundstage, nice resolution, no detectable noise or hum at all...very nice.

I wonder if it would sound even better with 3x ECC32 instead of what I am doing now, ECC32 driver tube and the Brimar CV1988's as the power tubes. Anyone use it with 3 ECC32's?

 

[mrarroyo]

Skylab, I got a response from Mikhail. He will be sending me a replacement 2C51 adapter.

I wish we could test side by side your stock MPX3 and my modded one to see what are the differences in sound.

By the way the ECC32 is one expensive tube, have you checked if you have the 0.95 amp vs. the 0.6 required by the 6SN7?

 

[Skylab]

Mikhail has told me that the ECC32 is a terrific tube to use (at least as the driver tube) in his amps, so not worried about that. Yes, the ECC32 is an expensive tube, but it sure sounds good to me.