Do I want a different 12au7?

I'm really happy with my system except for one small thing. I wish vocals were just a tad more present and detailed. With every improvement; be it cables, component, cartridge or isolation I'm always satisfied with the results except for this one thing. I'm not even looking for a dramatic change. With pretty much every lp or CD I just wish I could ask the singer to move towards the mic another inch or two.

Will swapping the 12au7 in the preamp spot of my integrated amp help me? I'm using a new production Gold Lion 12au7.

Again, I'm very satisfied with my system-it's listed in my profile-except this one little thing.

Thanks in advance.

 

I'm not familiar with the Gold Lions 12AU7s (never used them). Rogues generally do respond quite well to tube rolling (I have a Stereo 100 and an RP7, and have tried many combinations). If you are looking to bring the vocals perceived levels more upfront, try a Mazda 12au7, of which I've tried the long plates. Mazda seem to have upfront vocals as of their traits (and are downright pleasant in that regard) The only you have to lose is money. : ) That said, if you are really lacking in vocal presence, not sure if tube rolling will solve that, could be your speakers or room.

 

I have a Rogue RP5 Pre and have rolled the tubes in it a few times. I have ended my search with the Brimar from Upscale Audio. The RP5 takes four and I replaced them all. I think this tube sells for around $90. It did make a substantial difference in my system. I can't speak to your specific issue with the vocals but I have an LP with a good test track for any and all upgrades. It's the first song on Harvest Moon by Neil Young - Unknown Legend. The chorus on that track ("Somewhere on a desert highway, she rides a Harley Davidson...")breaks up unless everything is right. Everything I buy gets tested against this one track. The Brimar tubes made the biggest difference to date. At this includes some significant equipment purchases. I don't know how many tubes your Cronus takes but this may be the cheapest upgrade you will ever make. Try it. You can always sell them.

 

The preamp tubes are the first tubes to roll. You need a transparent tube with good midrange presence. Amperex Holland has air on top with forward, liquid mids. They do well with vocals. They also have wide and deep soundstaging. Their premium tubes are expensive, but the Bugle Boys are affordable.

Brimars are some of my favorite tubes, I own many. I don't think they have the clarity for great vocals.
Telefunken is the ultimate transparent and dynamic tube, but pricey.
Sylvania makes very clean sounding, transparent tubes with very good detail. Not sure which one to recommend, but they're known for being very very revealing.

 

It's hard to beat good Amperex! In my RP7 I have long plate 7316 as primary, less expensive Bugle Boys as followers. Liquid is a great way to describe them, vocals are forward, sound stage is big, but not diffuse, and there's plenty of punch in mid bass. Treble is spot on, with natural decay. I was using a quad of Mazda long plates before that, which surprised me in their warmth (I didn't expect them to be that way!) and honestly I would've kept them there, but they were just a bit too rolled off in the treble. BEfore that I tried many combination, Brimars, Mullards, many different American tubes (some of which are awesome!). Amperex have it all to my ears. I'm listened to Ernie Hines Electrifed on vinyl right now and am loving it. Smooth vocal city. : )

 

Two good sounding 12AU7s. Brimar 12AU7 long plate. CBS Hytron 5814.

 

So, what you all are saying is "Yes, rolling that tube will solve your problem."

 

You're looking for more clarity in the upper mids and rolling the preamp tubes is where you should start. Next would be the input tubes to the amp.
My question to you is, are you using any isolation devices on the amp? Aftermarket footers, platforms will help increase the detail and dynamics of your amp.

 

Thank you.

I am not using any isolation on the amp. Any suggestions?

 

This can be a long and complex answer with personal preferences involved. Try and find threads and Google audio component isolation. You'll need to research this.
First question is what kind of furniture or rack are your components on? The goal is to isolate the amp from the shelf, you dont want vibrations affecting your components.
A good place to start is to look at Herbies Tenderfeet. I like the Big Tall Tenderfeet for an amp.
Component Isolation

 

This. I was going to recommend a Brimar 12AU7 or a GE 5814. Never tried a Hydron.

 

yes, possibly more. a more foward, open sound was my preference too. if you are using the stock jj tubes in the 12AX7 front positions and 12AU7 in the rear two positions changing them will help your cause in addition to the 12AU7 preamp tube.
i tried lots of tubes in my cmii
brimars were too bassy
rca 5814s back row were my long term as well as rca 5963
preamp tube definitely amperex or amperex off label like mazda. no others came close.
telefunken sounded too forward and kind of mid fi.
front row 12ax7 i liked the amperex too but expensive and hard to find. the stock jjs were passable but lost too much transparency.
try rca or sylvania 5751 if you cant get amperex.

 

I've got a stash of 12au7's just sitting around. You pay shipping and a few $$ more I'll send them right away.

Baldwins, Conn, Sylvania. 4 of each. Probably have more if I dig.

Found a pair of RCA's.

 

Have you tried a 12at7 yet ? Might be surprised !

 

No, someone did recommend this to me once.

 

No offense, but I'd prefer to buy something like this from a retailer. Thanks for the offer though.

 

12AU7 Tubes in Stock read his thoughts about the triple mica ECC82/12AU7 Siemens tubes ... then look at the prices, ouch. I use the '12AT7' version (from Tubemonger) as driver tubes in my 300B amps, they imparted a nice sense of clarity which I also was looking for. I have no idea if they'll do the same in your amp though, but it seems like the Siemens (maybe 'only' the triple micas?) do lean in that direction.

(PS: I do not know if a '12AT7' type of tube would work (well?) in your amp in place of the 12AU7 ... but IF SO and you can verify it, I would venture a guess that the Tubemonger tubes would do what you want. YMMV of course, etc..)

I don't know if there's a Siemens (triple mica?) version of the 12AX7 or what those tube positions 'do' in your amp. I know there's been threads about tube rolling in your amp ... maybe do a search.

I see 'out of stock' on the Tubemonger tubes, I got another backup pair of these a couple months ago, he said he had a large stash at his European warehouse/partner, so might be worth a call to see when more of these are available here.

 

12AU7[/QUOTE]

Good idea to search for tube rolling in your amp.

You'll need to ask the manufacturer about substituting a different tube type. 12AU7 has a gain factor of only 20, while the AT7 is 60. Quite a difference if these are for the preamp gain stage. A 12AX7's gain is 100 mu.

 

In some circuits substituting a 12AT7 for a 12AU7 (or visa-versa) can actually release the smoke. So this is not good advice as a general rule of thumb.

 

AHA, maybe I'll also recommend Analysis Plus cables ... which I've used for a long time now. Started with Oval 9 speaker cables (when they were $400 for a 12' pair, now $800 or more, ouch again). I use the Oval 9s on the Silver 8 speakers, and bought Oval 12 for my Triangle Titus monitors. I really like their ICs and power cords now as well, having outfitted my system with them. I do have some Shunyata Venom power cords on my SS gear, but AP power cords and ICs on my 300B amps seemed to give me more clarity and resolution.

AHA as well ... maybe splurge on some Oval 12 speaker cables? to replace (generic?) 12 ga cables. I can't say what to try first though.

Analysis Plus Pro Power Oval Mk II Power Cord – The Cable Company
Analysis Plus Oval One Interconnect (Pair) – The Cable Company
Analysis Plus Black Oval 12 Speaker Cable (Pair) – The Cable Company

are what I have in my tube amp chain. Venom power cord to Parasound P 7 preamp, then all AP cables to the 300B amps and Triangle Titus speakers. Highly recommended!

 

Here’s the thing: You can research about different characteristics of specific tube brands, but unless someone has rolled those tubes in your amp and you trust their ears, you’re still just making an educated guess on what difference that tube will make in your amp, with your speakers, your ears, etc.

You buy some well regarded tube for retail $ and if it works and achieves your goal, great. But if it doesn’t make the difference you want, changes the flavor in some other way that doesn’t hit your sweet spot, or maybe makes no noticeable difference at all, you now have an expensive tube at retail cost that you’ll either keep and may or may not use down the road, or you sell it on for a loss. And then you either are back where you started, or you repeat the process with more possible losses in selling off tubes you bought at retail. And your amp has 3 12AU7 slots - not sure what the other two 12AU7’s do to affect sound, but at some point you may want to roll and find out.

My opinion is you should get a variety of vintage tubes for as little as you can, $-wise, and then just try them out at your own pace. Don’t research ahead of time what each brand is supposed to sound like, just roll them in and listen and see if they get you closer to what you want. Write down your impressions for how they differ from your current Gold Lion. Then you can research a bit and see if the reputation of each tube matches the change you observed. If so, then you can place a little more trust in the characteristics/reputations. If not, then you’ve learned that you can’t just go by online generalizations and really need to try them in your own setup.

If they did sound different but nothing matched what you want, you can keep searching with more inexpensive tubes. If none of them sounded very different at all, then maybe your preamp/amp isn’t very sensitive to different tube brands.

If you do find something that meets your goal, you can later seek out NOS or lightly used tubes from a retailer of your choice because at that point, you’ll know what you like and then it’s fine to pay retail if you trust that channel more. If nothing in that initial bunch floats your boat, you’re out little $.

My point is that it may be a process. And if someone offers you a bunch of tubes of different brands for the cost of shipping plus a few more $, think a bit and don’t dismiss the possible benefits of that option - it can be a great way to get started and learn something.

And back to those two other 12AU7 slots - if they are for some feature you’re not using (like for an integrated phono stage which you’re not using), then you can ignore them. But if they have the potential to affect sound, you’ll want to check out the effect of tube rolling there too. And doing so with pricier tubes you purchased at full price from a tube retailer will again be expensive when you can check at least the initial effect of those slots with a stash of used tubes you get cheaply.

You’ll just want to be sure whatever you use tests good and don’t have shorts.

 

How you experimented with different amounts of toe-in with you speakers? I wonder if this may solve the problem?

 

I've done that. It has a helped a little but it's still not quite where I want it.

 

Ive compared "RCA clear top" (from Brent Jessee) to Gold Lion 12Au7 in Rogue Sphinx V2. I think you would prefer the RCA.

 

You mentioned above that you have already experimented with toe-in and it helped some. Have you experimented with how far into the room your speakers are? In my system, tube rolling made the most difference in the tonal aspects of instruments and vocals (midrange, bass, air on top) but when it came to the depth of the soundstage, moving my speakers either further from the front wall or closer to the front wall had the most effect on vocal presence. My dilemma was the exact opposite of yours, I felt that vocals were a tad to forward for my liking. I started moving my speakers out further away from the front wall until I was satisfied with the vocals.
I would try this first and then roll some tubes to your flavor.