I say just plug in something and enjoy the music.
Remember thet there is no such thing as perfection.
Good enough is good enough.
The downfall of man is too many choices.

I understand how this may have conveyed a negative impression.  
But following a structured procedure to ensure better tube-rolling outcomes should not mean becoming obsessive.

I get the message, but I still need some pointers regarding best tube types' testing sequence.  Thanks for the advice.

Quote:


FB,

The thing is to get a sense of each tube's sound over time. Even then, it will sound different depending on what it is with, sometimes being sublime, and others not even so good. So don't rule anything out until you have them all burned in and have played with synergy. Even a least favorite can be a great tuning tool if its character fits the set you have in.

And burn in can be a big deal, or more subtle depending on the tube...but if these are all true NOS tubes, they will all  take time to burn in. So Donnie's thought is not bad advice. You could just play around, one tube at a time...get a sense of it, and have fun.

But you have a lot of options all the sudden, and you have to be able to enjoy the sound.....waiting out burnin can be a drag if your sound is not what you like. So I might be a little more systematic at first, compensating for slight issues with one tube by adjusting with other tube(s).

If your Amperex OA3 is like mine, it will change a fair bit over the first 50 or more hours, slowly opening up. Even some OC2s can take time. Usually the obvious parts of the break in will go from dense with unresolved low-mid/bass to opener and more spacious for darker tubes, and from brittle and hard to smoother/ richer for brighter tubes. Actually, they will all act out both of these, but the more obvious stuff could be useful to know. My power tubes, EL34 tend to take the longest in my amp, especially the warmer ones. Seems like rectifiers and inputs are a little variable, but most of your non-power tubes might be somewhat ironed out in 50 or so hours...unless you are lucky and they are a little used!!!

Where to start...Obviously you need to get some rectifiers in there. So I would start with your favorite of those. Try one with your normal tubes, letting it get good and warmed up before evaluting, and then try the other. Then leave the fav in for a while to burn in...

I almost always end up playing with bass and treble on the torii with tube changes...sometimes a fair bit....that last refinement that could make a tube that sounds not-so good, sound great.

The 12AT7 likely will be a bigger change than any if you were using 12AU7s. It will punch things up. So it might be worth checking out next.

The Russian OA3s are typically very clear sounding....If this is true with the OC2, this will give another sound option for brightening/clarifying if this is appropriate to what you want with the other tubes.

This might be a good option when you check out the power tubes....if you like one or the other, but it is too heavy, play with the OC2s, OA3s, or rectifiers to open it up. Or just hang with your current power tubes for a while...

The main thing is to get to know your tubes and in time, you may well use all of them in different arrangements. And if yo are like me, this will be an organic process. I have no idea of my favorite tue sets...It is just the one that is in there. And I think it is fun to change things up discovering new synergy I did not know i had!

By the way...I have been pretty close to the holy grail by my tastes for quite a while...the cool thing is that I can vary it with tubes, caps and/or cable changes! The grail is flexible in my system/room.

Will and Lon,

Just to clarify: The Amperex regulator is an OD3 not an OA3 (the stock regulator in the Mini is an OA3.)  Also, all these intended tubes are current production, not NOS.

In addition, I have never implied (nor imagined it existed), a perfect tube-rolling system or an absolute perfect set of tubes.  I was just aiming at some systematic approach to accomplish the objective in the best possible manner given the high level of combined uncertainties involved.  This is called a 'procedure,' and we apply this notion tacitly to most activities in our lives to help us cope with interactive or complex tasks.

I understand your points, and the key obviously is 'time.' The best approach would be to try one at a time, for long periods of time, or something along those lines.  Will, I agree with you, in the end some trial-and-error will help me find my own way around this rolling process.

Yes, the rectifiers need go first, and I will try them with the stock tubes, first the RFT EZ81 (same specs as stock) then the lower current RFT EZ80.  Next would be the Brimar 12aT7 with the stock tubes and RFT EZ81, then with the RFT EZ80.

Eventually, I will try the output tubes, one at a time, following this same routine, and finally the voltage regulators.  Considering the in-series break-in periods involved, this will take forever and a day (to quote Les  :) ), but should be fun and worth it.

Lon, you're right: Anchoring with drivers makes sense to me too.  I just need to start with rectifiers, for obvious reasons, but those are next, as described earlier.  I also intuitively follow your sequence hierarchies by tube type.

I think now I get the big picture.  It was a little fuzzy for me before this discussion.  I thank you both for the orientation.  

Sorry Lord...crossed in the ethers...

FB, Every tube effects the whole sound. You might enjoy looking at how this works. If I have it right it is like this:

The Rectifier is first, turning the transformer power to DC to power the rest of the tubes. Big player.

The OC2 regulates and effects the sound of the input tube, both by voltage and filtering through the VR.

The input tube then goes through coupling caps to the power tubes...setting up the sound the power tubes have to work with.

The OA3/OB3/OC3/OD3 regulate/filter the Power tubes, again effecting the sound of the power tubes...giving different power to the power tubes and filtering the electricity with their own signature.

Then the power tubes receive input from all of the above, AND impart their own sound signature as well.

So it is a matrix of directional interactions...

No tube is in isolation from the others. Playing with this is how subtle magnificence can be found with just the right synergy for your tastes.

You can see that changing any tube will change the whole....then the "anchor" we arrive at (if we arrive at one) we formulate for ourselves based on own comfort level, desires and personal exploration.

For me, I seem to leave the Power tubes alone mostly, and I almost never change the OC2s..but that is about it. I have a number of inputs I really love for different reasons, and they all can have beautiful synergy, so there is no "anchor" there for me. Then...changing the input, since they all have different characters and tonal balance, almost always sets up the desire for playing with the power VR or the rectifier, or both...tuning the bass/density/brightness/warmth/texture to bring out the best of the input...

So I am glad you have and OD3 to play with...It is likely to lean down the sound a fair bit over the OA3 and give you a good sense of what can be done with the OB3 and OC3 who's voltage is between these two. The slight variation in your Rectifiers might be a great tool too for tuning a tube set....one perhaps a bit bigger and pushier and one a little more low key all else being equal (unlikely).

As Lon says...you will find your own way. I just hope it is fun!

Wow, I did not know Brinmar, RFT or Amperex were still making tubes....

David,

In your shoes I would definitely consider rolling a 12AU7 tube. In every Decware component where I could use a 12AT7, I've never preferred its signature and sound to a 12AU7 in the same component. Could be just a personal thing, but it could be a shared thing too.

Lon,

Right.  For some reason, Steve included the 6N1P-Ev (this last connotation refers to the heavy-duty military version of the 6N1P), as a stock driver in my Mini Torii, instead of the original 12AU7.

I've read literature about differences, and they are not even that close, at least not interchangeable, normally (funny).  For one thing, the 6N1P draws more heater current than the 12AU7.

I also came across this reference post from another forum (audiocircle) about the 12AU7:

"I don't mean to be combatitive, but the 12au7 is one of the highest distortion tubes in extant (and not just pleasing low order, but substantial high order distortion as well), at least amongst those used in audio, while the 6N1P is quite linear (low distortion).   All the reports I've read about the Chinese 6N1Ps haven't been kind in terms of reliability while the soviet era 6N1P-ev's are suppose to be bullet proof"

Now this may be an extreme position, but maybe there's some reason behind Steve's decision of replacing the 12AU7 in the Mini.  I was surprised when I realized my Mini had the 6N1P (upon receiving it) instead of the 12AU7, since Steve had suggested to first try the 12AU7 in the Mini due to its lower gains.

The reason why I'll be trying the 12AT7 this time around is because Les Lammers has had a good experience in his Mini with the NOS Brimars.  On the other hand, you may be right, as these things are so subjective.

I may eventually also try the 12AU7, but not for now.  There are many possible combinations and such limited resources.    Thanks for the tip, I'll keep it in mind.

Because prints can hard to read-disappeared I number all of my tubes with a small square of sticky label, then enter details into a tube log.
I give tubes a decent run, maybe a couple of weeks ,2-3 hours, a day, and it`s not until that thought occurs that I decide with my own logic to have a swop round, even though tubes may not be fully burned in, or I am enjoying what I`m hearing.
Not the most scientic approach I agree,..but fun and the knoledge that you still have "that tube/s" in your locker.
 Syd.

The web site says that 12AU7 is the designed tube. It's very interesting that you have a 6N1P (love that tube type as well) as I haven't found them to be interchangeable in any circuit I've had. So I wonder if your amp is wired differently to accommodate the 6N1P. Curious! I hope the 12AT7 will work.

I personally haven't encountered distortion problems with the 12AU7. In the places I currently use them (DEC685 and ZBox) the 12AT7 has far too much gain and the sound is far too bright and forward for my tastes.

Will,

Yeah, I'm looking forward to the experience.  Who nows how those input Brimars are going to behave with the rest of my rig, but at least there are consistent positive reports on them, and one in particular (Les's) as it is on the same amp's context.

The Brimars I'm getting are also from 50's-60's England.  I'll let you guys know how I like them.

Sure, brand and build can make a difference, but if they're in spec, gain is gain. Anyway, like you I'd be interested to hear Steve's take on this. I know 12AT7 would work if 12AU7 is the tube the circuit was designed for. . . but 6N1P? Would seem too much gain.  I know the reverse is true, if a circuit is designed for 6N1P types, 12A types don't work.

Will, I hope you're right.  That's part of what I'm looking for with this rolling thing:  Openness, more air (les density) and transparency, to compensate for a current sound a bit on the warm side.

I'd probably have to find the best (among the available tubes on hand, that is) rectifier partner for these Brimars.  Then, I can still play with the OD3 output regulator tubes, which are supposed to also open up a bit.

Finally, I expect to give those Svetlana's and Tung Sol's a chance to show what they can do in this stew.  I'm assuming I won't be challenging the existing circuit design with the various slight deviations in specs involved, especially with the Brimars (gain) and the EZ80's (90 mA vs 150 mA).

Seems not unlike a cooking recipe or chemical formula, just stash in the ingredients, let them cook and give it a taste to correct excesses.  If it does not work, change the recipe and start over ...  ;)

"Finally, I expect to give those Svetlana's and Tung Sol's a chance to show what they can do in this stew.  I'm assuming I won't be challenging the existing circuit design with the various slight deviations in specs involved, especially with the Brimars (gain) and the EZ80's (90 mA vs 150 mA).

Seems not unlike a cooking recipe or chemical formula, just stash in the ingredients, let them cook and give it a taste to correct excesses.  If it does not work, change the recipe and start over ...  ;)"

David,

I would burn in the Brimars with the Russian 6V6's, OA2's and the OD3. Do not listen critically...think low volume elevator music. Give them 50 hours. Swap the EZ80's and EZ81's occasionally during the above. Once the Brimars open up...experiment with the rest of the tubes and tell us what you think.

Have fun,

Les

Dave,

I would leave the amp on when you are home and turn it off when you leave or go to bed.

Les

Les,

I agree, also because it's plain safer, isn't it? So long as it doesn't harm anything, I'll keep it working for long periods at a time.  Thanks!

Will,

I see your points.  I was resigned to not being able to listen to 'real' music until break-in, but as you say, there may be ways to circumvent this.  The point is, though, I need to pair the new drivers to the new rectifiers from the start, and apparently (as pointed by Les), those Brimars are hard to 'cook.'

So, at least for the first week to ten days, I won't be able to enjoy the music.  After that, it will depend on how fast the new russian output tubes team up with the new rectifiers and regulators, to maybe make music somewhat more tolerable in spite of the still raw Brimars .  We'll see.

Thanks to both of you for the valid input and interest.

I have to stress that the Brimars will sound awful until they settle in. Be patient. The Russian 6V6's have a few hours on them and they may not be fully settled in but they should be when the Brimars start to make music.