Lesson in Tube Rolling:: My confirmed need for "air on top" via 12au7 ECC82 5814a tubes


I thought that I would share something that I learned in my first 90 days of tube rolling. 

I knew and still know that I don't like harsh treble.  I thought NOS Mullard CV4003s would be perfect for me.  I realized, though, that the very quality I like about them I also do not like about them--they are laid back and mellow.  But, when I move to other tubes, e.g. RCAs, Ciftes, Amperex, GE, of the same tube equivalent I feel they may be a bit too forward.  

I don't really know much but what I know is that I need a touch of air on top.  The Ciftes and RCAs helped but if I went to a full bay of those it became too bright or top end extended.  And, just as with the Mullards, what I liked about the Ciftes and RCAs was exactly what came to tire me.  

I'm happy to find that mixing preamp tubes seems to do the trick.  If I run 2-4 Mullards with 2 Ciftes (6 preamp tubes total) in the front slots of my amp it adjusts the tone just right.  

This may not be a revelation for advanced tube rollers. It is, however, reassuring because I am able to get very much closer to the tone that I want in my mind's eye (or mind's ear), and I still hear value in the various NOS tubes that I bought. 

As an aside, these experiments worked so well that now I have faith in some reissue Mullard EL34s again and when I swap back in my Gold Lion KT88s, I may go 4/6 Mullard to chill things out a bit.  

I hope this helps other novice tube rollers.  

PS  I would like to try some NOS Brimars to see what kind of air and extension they put on top.  If I roll 4/6 tubes with Ciftes it starts to get to be too much.  
jbhiller
Yup. Welcome to tube rolling.  Don't assume a new issue anything is the same as its old namesakes. Tubes dont have to be NOS either. Plenty of deals on used tubes. Perhaps though, your source has issues that are being exposed by the more revealing tubes.
For your next tube roll, try using a pair of RCA Cleartops in the gain stage. These tubes have incredible air and openness, but are completely neutral, so use a warm tube as a follower. They are also very affordable.

The Brimar longplate will have similar sonics to your Mullard; warm, laid-back, with a liquid midrange.
Lowrider!  Great minds think alike!  I just bought 4 RCA Cleartops in NOS testing condition.  They arrive Monday and I had a very similar thought. I'm glad you said this because it adds confidence that I'm on the right track in my experimenting.  Read:  I trust your opinion.  I don't think you've ever led me astray. 
I use 12au7 in my Primaluna Integrated Amp. I have tried several combos with the Mullard Reissue El34’s and GL KT77 Russian. I much prefer the KT77 sonic balance over the Mullard.

What I have found is that the Mullards have too much midrange forwardness and the KT77’s are much better balanced from top to bottom. More extension top to bottom,.the midrange is clearer and not forward.

For the Preamp section I like the combo of either the (2) Cifte or Tungsram in the Gain stage and the (2) NEC/Mullard in the first Driver Stage. The second driver stage I use the stock (2)12au7 Chinese tube.
JB, careful placement of Cleartops is key. Too many may result in brightness. Use in combination with a warm tube like the Mullard.
I look forward to hearing about your results.
Aniwolfe I have the NEC/Mullard in the 1st driver stage along with the stock PL tubes in the gain stages along with the KT77 at the moment.  I am finding its too energetic in the upper mids so I am going to roll in something else in the very back or rearmost 2 slots. I agree with your assessment on the KT77s.
Lowrider57,

I installed 2 NOS Cleartops followed by 4 NOS Mullard CV4003s.  I'm using my reissue Mullard EL34s in the power stage. 

This is a pretty nice mix.  The RCA Cleartops sound pretty rich and bombastic in the bass.  I'd swear they have a ton of punch--similar to solid state in the low end.  

I think the Mullard CV4003s are too dark to run them across the entire preamp board with 6 tubes.  

The Cleartops have a good bit of energy for sure.  With this mix, I really like them.  Maybe I'll swap in 4 just to get a good look at making an assessment of the tube.  My experience with 50s RCA tubes has been positive.  They all seem to have a tight, strong sound that is forward.  

The mixing of preamp tubes seems to get me closer to where I want to be. 
Sure, try 4 Cleartops in various positions. They do have good bass slam, and air on top. It will be interesting to see what happens when using them with the Mullard EL’s. Realize that Mullard reissues are brighter and more forward than NOS Mullards.

In my Primaluna Dialogue Premium the EL34 Mullard reissue are brighter and more forward than the stock PL power tubes but lacking in bass. The Mullard CV 4003 brought back some bass but finding the CV 4003 definitely darken up the sound. Maybe I should try some RCA Cleartops. Has anyone compared them to the Amperex (Holland) 7316? The 7316 has some energy but very detailed and expensive :(


JB this is becoming an interesting experiment ($$$) and I am enjoying reading about your findings.

The Amperex (Holland) 7316 is a rare and expensive tube. Have you tried any 1950s Amperex Bugle Boys yet (Holland 12AU7)? Very musical, incredible 3D imaging, dynamic with air on top...IMO more realistic than Cleartops.
@jbhiller ,
If the Mullard CV4003 is too laid-back for you, the 12AU7 Mullard or Brimar longplate square getter is more dynamic, yet still has good warmth and sweet mids.
@samzx12    In my preamp, I had the same results as you with those tubes.  The Cleartops were too bright for my system.   I'm extremely pleased with the current production run of  Psvane 12au7-TII.  Really nice top to bottom.  ymmv.
It is an expensive experiment. So far on preamp tubes, I've collected RCA D getter black plates, RCA Cleartops, Mullard CV4003, 70s Amperex/Mullards, GE 5 stars, Baldwin, Ciftes, and a couple others.  Fortunately, this has not been wasteful because all the tubes are very good and listenable.  They will eventually get use.  And, I do think there's something to be said for buying a $5k amp and not being pennywise pound foolish. 

Lowrider57, I have not tried those Bugle Boys.  They are a bit pricey, but I'll get them on my short list.  Maybe a birthday or father's day gift.  
Hi jb,

Can I ask what Pre-Amp/Power Amp you are using? I just had an interesting experience tube rolling. Rolled in 3 Psvane 12AX7-11 into my Vincent SA-T8. Wow! What an improvement. Sounded great with both my Vincent s/s SP-998 Mono Blocks & upgraded s/s Benchmark Plexus Power Amp. Immediately ordered a quad of Psvane 12AU7-11 to replace the "no-name" Chinese 12AU7's in the SA-T8. I switched on the Benchmark Power Amp. Yuk, way, way too bright sounding. I switched back in the Vincent Mono Blacks. Voila! Absolute magic! Dynamics, depth, soundstage etc. just exploded.

So, initially putting the 3 Psvane 12AX7's in the SA-T8 and both Power Amp & Mono Blocks sound really good. Then roll in 4 Psvane 12AU7's as well, (so all 7 tubes in Pre. are now Psvane) and when connect up Power Amp sound not so good but sound when Mono Blocks connected, awesome. Difference is staggering. Must be incredible synergy and non-synergy going on. I suppose some more experienced tube rollers would be able to relate some similar expriences.
@initforthemusic 

Sure thing. I'm using a Primaluna Dialogue HP integrated. 

I have always had strong curiosity to try Vincent's products, like yours. They look so well designed and like Primaluna seem to offer great value 

Thanks jb. Always interesting to know what equipment people are using, as different tubes wiil give different results in certain equipment.

As for Vincent products I have half a dozen. All are good to great bang for buck. Their top line SA-T8 Pre. and SP-998 Mono Blocks blow many mega buck products to the shizenhausen, they are that good.

Lowrider which Mullard 12AU7 are you referring to? The new reissue or NEC/Mullard in your post to JB?


I have not tried the Amperex Bugle Boy 12AU7. Good to know they have qualities that I am looking for. How would you compare them to the Cifties?

@samzx12 ,
ECC82 /12AU7 Mullard longplates, square getter, 1950s vintage, Great Britain.
Found on Brent Jessee site...
These are all the older long narrow plate version, with the rare early SQUARE top getter, with the 1950s date code. These are incredible tubes with a fine soundstage, clean top end with a touch of midrange warmth. Rare.
The different types of Mullards and year produced results in different sonic signatures. CV491 military and CV4003 are warm, textured, and laid-back. The ECC82 square getter is a more open tube, so is the ECC82/12AU7 Mullard longplates, halo getter.

Mullard reissues have nothing in common sonically with NOS Mullards. The Mullard name and trademark have been acquired by the New Sensor Corporation (Russian factory); same comany that makes new Tung-Sol, Sovtek, Electro-Harmonix.

(I have never tried Cifties).

I have not heard all the 12au7's created. But out of the 10 or so I have tried, the Cifte/Mazda Gray Plates have become my favorite 12au7 tube. 
The Ciftes are unreal. That said (and sorry to complicate things) I can't to more than 2-4 of my 6 in the preamp stage. They aren't bright yet they seem too much if I put too many in. Sorry I cannot be more illustrative.  I love their feel in reasonable quantities.
JB I agree they would be too much of a good thing.  Right now I am sticking with the stock Primaluna in the rear 4 slots and playing around with the front 2.  Last night I put the Gold Lion KT88 back in and while they aren't quite broken in, they have some nice qualities. However, they don't draw me "into" the music like the KT77 or EL34 power tubes or at least not so far. Mood and awareness also can affect our ears so I am being patient and having fun playing around with tubes.