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Posted

Ok cant comment on the chinese driver tubes as I ordered the unit with NOS RCA 6SJ79.This tube is black metal case bottom right on picture.This tube is very well balanced and has no obvious flaw,it was not microphonic and appears built to last forever.

The second tube I rolled was the Visseaux 6SJ7 pictured bottom left in shiny aluminium jacket.

The 6SJ7 is a high gain screened pentode that was used in early equipment and amplifier circuits.

These French Visseaux 6SJ7MGT were made for the French Military in the 1960's. Unlike the American metal 6SJ7, 6SJ7Y the French used Aluminium for the outer casing as this material does not rust. The result is that these are in pristine condition.

Visseaux Military contract valve were all superbly made with the highest quality control and with the best materials. These are amongst the best sounding metal 6SJ7 that I have ever come across.

So if you own a early Fender tweed champ or the later British amplifier made by SJB then this is the 6SJ7 to use.  

 This tube was remarkable in that it had a very extended high frequency response and high levels of detail.Yet in use it sounded very good(not tipped up)midrange and bass all extended and clear.It is not bright or fatigue inducing.

This tube is ideal for younger people or if your system sounds a bit flat.I purchased these from Watford valves for 16pounds/tube.

 

Next up is the famous Western Electric 713A.This tube was made famous by YAMAMOTO JAPAN with its use in their 45 set(funny thing I auditioned this amp and felt it sounded a bit sterile,lacking valve goodness).OK this tube has a very distinct character lets call it meat on the bones.High frequencies may be slightly curtailed but midrange and lower is full and powerful.Alas all 3 of this tube I have are highly microphonic.One was unusable as audible valve rush was heard through speakers.The other two settled in ok and will produce a bell like ring if you tap the amp case.For normal listening they are sweet and sound great.The tube is shaped like a button mushroom and bears NAVY marking in orange colour.

 

The last tube I tried was the RCA 5693 with red metallic casing.These tubes are rarer than the black rcas and command a premium.This tube is the winner it has all the valve goodness of the 713A without the microphonic problem.Just sounds magnificent really.I purchased the 3x713A and 2x5693 from DB Tubes,Canada for approx $180 all up.Shipping 5 weeks.

 

I use JJ KT88 as power tubes,they work great adding power and plenty of texture in this circuit.I tried Svetlana(non winged c)EL34 and was left underwhelmed,bit boring really.JJ destroyed it.I 

might add that no recent production EL34 I have heard sounds good to my ears.Cant understand people raving about this tube.

 

Oops I nearly forgot an interesting tale about the 713a(probably made in 1940s folks).Their factory burnt down and WE managed to save machines etc which was relocated to a Tungsol factory.Hence some 713A tubes bear the brand name Tungsol. 

 

Happy to answer questions.

mp301.jpg

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  • 1 year later...
Posted

Hi Elnido,

I just discovered this thread a few days ago. I also read your comments on the Lii F15 thread.

 

We have very similar systems. I have the mp-301 mk3 and a pair of F15 in a "Caintuck Audio" style open baffles (barrel shaped). You also use/used the Visseaux 6Sj7, which is my favorite input tube, but I see almost no one talking about it. By the way, Watford Valve doesn't have any in stock. My favorite power tube to date is the Tung-Sol El34b. I know you said you didn't like El34s in this amp, but for me it's just fantastic. It gives me lush, rich, full-bodied mids, while also giving me tons of detail, just the sound I'm after. I am using a Sony HAP-Z1ES as my source. And Duelund tin platted copper wire.

 

I really love the sound I get from this system  So much so that I chose the mp-301 over a Decware Se-840UFO that felt underpowered to me. I'm not going to say that one amp is better than the other, simply that my preference was for the mp-301.

 

The only thing I would really like to improve is clarity and "legibility" during "dense" and complicated passages. I find that, although still sounding quite nice, energetic, rich and so forth, sometimes it all doesn't hold together as much as I'd like it to. Sometimes the sound tends to get muddled and confused.

 

So, after that long introduction, I have two questions for you:

1) How do the Visseaux 6Sj7s and the RCA 5693s compare?

2) Do you have any suggestions about what I could do to keep everything I like about the sound I'm getting now while improving clarity during complex passages?

 

Thanks for any feedback. 

 

  • 4 months later...
Posted

Hey all I also have the MP-301 mk 3 for the last 5 years which I run with my Bob Crites "Cornscalas " horn 3 way speakers with 103db sensitivity. Have been so happy with it in my system after leaving solid state. Now with the tubes I went on a splurge quite quickly. Started with the Shuguang KT88 swith the General Electric 6s j7 and that was I nice introduction to tube sound. Then went on popular opinion which was Tung Sol 7581 A which were a lovely improvement. Then the RCA 6sj7wgt pre which I really enjoyed matched with the Tung sols.  Now the power tube which I have found to love are the Cosser KT88 big blue tubes which just have a great clean power across all ranges..Also picked up NOS Western Electric 717A after hearing how amazing they sounded but was let down that even after settling down after a long warm up does as writer above says and ring and in idle mode have lots of crackle and noise which is frustrating as were expensive...   Alot of users have the "fire engine" Rca pre tubes and love them..   Also I did the upgrades mentioned in the group on facebook (changing capacitors etc) and this may help Dalza as it eliminated all background noise and improved the soundscape brilliantly.  

lots of reviews on tubes and the upgrades here..

https://www.facebook.com/groups/musicalparadisemp301owners

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