[giovanni]

Hi,
I am trying to experiment with some tubes on my MPX3.

I understand that the first tube from the front is the "gain" and the other two are the left and right channel something. I don't quite know what any of that means.

My question is: what should I expect by changing the front tube v.s. changing the other two (which I understand have to be the same) ? In other words, is it the case that the gain tube affects certain things and the others other things ?

by the way, am I making any sense ?

I have changed all of three but I will say later from what to what as I don't remember and what the impression where, I am still listening

and enjoying of course !!!

gio

 

[drarthurwells]

The front is the input or power tube while the others are output or driver tubes.

All are important - the input tube may be more important in sound quality.

I find it is not better when all tubes are the same - I use a different brand/type of tube up front than in the rear - but the rear output tubes should be the same and even matched and balanced. Matched means that the two tubes are close to equal to each other and balanced means that internally the two sides of a single tube are close to equal.

SACD Lover is the expert with your concerns and will likely see your post soon.

 

[PFKMan23]

Well the first question I would ask is, what tubes have you tried? Have you tried different types of 6sn7s? While it maybe be true that the driver tube might be more important, you will find that there are alot of notable output tubes that are discussed, especially in consideration with the Singlepower amps. Also, alot of it has to deal with your equipment and how it interacts (the synergy thing). A component of this is the upgrades that you might have on your MPX3, as there are some tube combinations that sound, better/good which cna vary based upon what upgrades you hgave in your amp?

Before we go on, what tubes have you tried? Also are there any specific goals you'd like to acheive by tube rolling (like making it more open, brighter, more impactful, etc..) What types of music do you listen to? Now in your profile you've mentioned specifically opera and classical (and others except for country...) with the Senn 580s as your can of choice. If I was looking to explore different tube types I'd probably look into getting some 6BL7GTs, 6BX7GTs/ With the advent of tube adapters, you can try other tubes like the 5687s (which are powerful tubes, essentially making it a SLAM), 6CG7s, 6463, 6350, etc...

I think if I was looking for as more open/imapctful sound I might go to he 6BL7GT or the 6BX7GT, first, as those are octal tubes (the same type of tube socket as your amp pressumably, assuming you have octal sockets). If you are willing to go with tube adapters, the 5687s are highly regraded with stuff like rock, etc... which are quite impactful (the SLAM, etc..) or even something like 6350 or a 6463 which is another type of tube...

 

[giovanni]

Thanks guys.

I will post later tonight when I get home with more details. particularly addressing some of your (expected) questions.

gio

 

[cheechoz]

Calling Earl the SACD Lover, come in Earl!!

 

[sacd lover]

Quote:

Originally Posted by cheechoz Calling Earl the SACD Lover, come in Earl!!

Hey .... Art and PFKMan23 already did a good job answering his questions. There isnt a whole lot I could add without more details. I will just say, generally, I like the 6sn7 or an equivalent like the 7af7 or 7n7 for the gain tube. I like the 5687's or 6bl7gt/6bx7gt's best for the output tubes.

Once we have more info I can be more specific.

 

[Glod]

Just a small detail. The output tubes on a MPX3 do not necessarily have to be perfectly matched, like perhaps in other brands of amps. SinglePower states this - and IIRC, so has a few owners also concluded. Happy rolling!

If I was to add something to what has already been said, I would say that one has to be careful not using a too character-full tube as input. IME, it is better to have a "neutral" driver and to do the fine adjustments by rolling the output tubes. This in order not to create bottle-necks, down-stream, for the output tubes, hampering them in showing their qualities. An early Hytron 6/12SN7GT has always been a favourite of mine for this job: Very transparent. A Ken-Rad 6SN7GT is also very good.

 

[PFKMan23]

While the tubes don't need to be matched, persay, I still wouldn't really advise having 2 tubes that test vastly different on the amp, (talking a about the output tubes here). But no they don't need to be matched at all.

On the issue of having a neutral driver, I don't necessarily agree with that. Without going too deep into the debate/discussion about neutrality, good tube combos are good tube combos, and it really is a matter of personal preference whether you wnat to build around output tubes or driver tubes. Personally I'd do a bit of both and I've experimented and found good tube combos by building around certain driver tubes and certain output tubes as some tubes invariably act better as driver tubes and some as outputs. You're really shortchanging yourself. if you confine yourself by using a singular methodology about it. For example, I found that a RCA 7n7 with a GE 6BX7GT s was a little too bland for my tastes, I then put in a RCA 12sn7GT for a driver, which was very good, and which I liked alot, but that I found a bit too dark at times., Then I proceeded to put in a Sylvania 12sn7GTA, which was not quite a bright as the Sylvania 12sn7GT, but not nearly as dark as the RCA 12sn7GT. If I wanted something with more body I could put on some of the 6BL7GTs that I have.

That said, I suppose you could build aroun the driver, but IMO by limiting yourself by building around just the driver or just the outputs, you can be missing alot of great combos.

Also, I wouldn't really call a Ken Rad 6sn7GT VT231 anywhere near neutral, atleast not the ones I have and have heard. Unless you were just talkngi about using that as the focal point of tube rolling although heh, speaking of that particular tube, the one issue that I have with it, is that it has alot of bass. Sometimes a bit too much, which rolling the outputs won't really address.

Howver all of that said, you really just need to get some tubes and try them for yourself. We can talk about theory and impressions of different combos forever, but the best teacher is personal experience. You need to find what works for you and the only way that will happen is to just try stuff.

 

[Glod]

Quote:

Originally Posted by PFKMan23 ..."On the issue of having a neutral driver, I don't necessarily agree with that. Without going too deep into the debate/discussion about neutrality, good tube combos are good tube combos, and it really is a matter of personal preference whether you wnat to build around output tubes or driver tubes. Personally I'd do a bit of both and I've experimented and found good tube combos by building around certain driver tubes and certain output tubes as some tubes invariably act better as driver tubes and some as outputs. You're really shortchanging yourself. if you confine yourself by using a singular methodology about it. For example, I found that a RCA 7n7 with a GE 6BX7GT s was a little too bland for my tastes, I then put in a RCA 12sn7GT for a driver, which was very good, and which I liked alot, but that I found a bit too dark at times., Then I proceeded to put in a Sylvania 12sn7GTA, which was not quite a bright as the Sylvania 12sn7GT, but not nearly as dark as the RCA 12sn7GT. If I wanted something with more body I could put on some of the 6BL7GTs that I have. That said, I suppose you could build aroun the driver, but IMO by limiting yourself by building around just the driver or just the outputs, you can be missing alot of great combos. Also, I wouldn't really call a Ken Rad 6sn7GT VT231 anywhere near neutral, atleast not the ones I have and have heard. Unless you were just talkngi about using that as the focal point of tube rolling although heh, speaking of that particular tube, the one issue that I have with it, is that it has alot of bass. Sometimes a bit too much, which rolling the outputs won't really address. Howver all of that said, you really just need to get some tubes and try them for yourself. We can talk about theory and impressions of different combos forever, but the best teacher is personal experience. You need to find what works for you and the only way that will happen is to just try stuff."

I am not opposed to use driver tubes with outspoken characters, on the contrary, I regularly use RCA VT-231, early 6SN7GTA, Marconi B 36, Sylvania "Bad-Boy" among others to great pleasure. My point is merely that it is easier to get to learn the tube characteristics b listening to them as outputs, with a "neutral" driver. Only your imagination sets the limit to what you can create after that

Whether the Ken-Rad VT-231 is "neutral" or not. Well, let’s say it is a benchmark driver to many tube rollers - like you perhaps implied.

 

[giovanni]

hey guys, lots of info already here !

And of course I forgot to check last night.

For now though what I can say is that the MPX3 came from SP with the stock output tubes and a Hytron in front.

Then I purchased the Ken-Rod for input and 2 other output tubes which wre recommended by SP but these I have to looks to see what they are called.

Anyhow, I also have a USB Tubedac on its way, will probably improve somewhat the overall resolution.

But I still can't really formalize the difference experimented so far, but first I need to let you know what those output tubes are anyhow.

best,
gio

 

[PFKMan23]

Just out of curiosity, what options/upgrades did you get on your amp? The reason being, the type of upgrades that your amp has and how it's tuned, can affect what tube choices work well with your amp, as I've recently discovered.

Also if you could get onto addressing our questions about what music yhou listen to, the equipment you have (cans/source/etc//) and the tubes you have on hand.

 

[falcogreg]

Regarding the tube adapters, where can you buy those? Also, who or where is a good source for either the 6sn7 and/or 5687's or 6bl7gt/6bx7gt's output tubes?

Thanks,
Greg

 

[giovanni]

Quote:

Originally Posted by PFKMan23 Just out of curiosity, what options/upgrades did you get on your amp? The reason being, the type of upgrades that your amp has and how it's tuned, can affect what tube choices work well with your amp, as I've recently discovered. Also if you could get onto addressing our questions about what music yhou listen to, the equipment you have (cans/source/etc//) and the tubes you have on hand.

PFK, sorry, you are absolutely right and you had asked me that info already. Actually I can tell you that right away (since I have SP's bill here at work, again I simply followed his recommendation, because I have no idea what each means, excpt for the attenuator, which I actually really like):

Black Gate Capacitors
Jensen Capacitors
Goldpoint Attenuator
Solen Stage I

Let me say, I really really enjoy the sound so far with no tube changes (that is with the Hytron and stock tubes). Now, having said that, I sometimes wonder whether I might be missing a bit of life in the higher frequencies, that is, when I would expect it in a particular piece. But note, as I know you are wondering, I listen mostly, but not only, to classical and opera and classical includes symphonic as well as everything else. And I have the hd580. And my source is mostly my Mac and mostly lossless files. So lots of not optimal settings here.

Ok, I guess while I am at it, I will through in a couple of very superficial (premature?) comments on the tube change. I felt the lower end lost some definition/precision, slightly more boomy. That is just my very first impression, other than that so far I could not hear big differences. If I had to chose though I would reverse back to "as shipped". Again, I do have to do some more listening and try different combination.

Another factor you more expert dudes might consider is that this amp is probably not even close to be broken in. I might have ...10 hours on it overall.

That was and is the original intent of the post. Try to see whether there are some obvious paths for tube rolling that others have found made more sense, since I begin to have a number of permutations available for tubes. Anyhow, more later.
gio

 

[PFKMan23]

Quote:

Originally Posted by falcogreg Regarding the tube adapters, where can you buy those? Also, who or where is a good source for either the 6sn7 and/or 5687's or 6bl7gt/6bx7gt's output tubes? Thanks, Greg

You buy the tube adapters from Mikhail of Singlepower. The tube adapters for 5687s, 6cg7s, 6350/6463, 7n7/7af7 are $99 per adapter.

As far as sources for tubes, check the following sticky:

http://www6.head-fi.org/forums/showthread.php?t=20676

You can also do some google searches and such.

........

Going back to the tube though. I'm really curious as to what type of Hytron he gave you as AFAIK, his standard fair for tubes are 3 x EH 6sn7. I'd also like to know what the other 2 tubes are besides the Ken Rad....

Howver, yes you need to let your amp burn in, as that's going to clear up alot of the muddiness and open things up a fair bit. Some tubes that I would try are probably the Sylvania 6sn7, some 6BL7GTs or some 6BX7GTs... If you're willing to go with adapters the 5687s are definitely a tube to check out, especially if you're into harder stuff like rock.

 

[DevilDog]

This brings up some questions I've been having. Exactly which type of tubes are interchangeable? Can you put a 6BL7GT or a 12sn7GT in an MPX3? If you can, what is the downside? Are the voltages too hot or something?
As you can tell, I know nothing about this. I can tell a huge difference when I change tubes, but I just don't know how far I can go. Is there a good guide somewhere as to which tubes will fit or something?