To NOS or not to NOS

[Rockin_Ron]

I got my hand's on some tubes for my LSS. One is a JJ 12AX7 and the other based on my web research appears to be a NOS RCA 7025 with the halo getter and grey plates and all that good stuff!

Plugged the 7025 into V1 and the JJ into V2 replacing the stock MESAs expecting to get my socks knocked off. I'm not hearing it. Am I missing something? I've read through many of the previous posts (even one that was quite informative, I think it was titled LSS and preamp tubes) showing a lot of love for these NOS tubes. Should I be hearing a dramatic difference in sound and tone?

What about these low gain versions of the 12AX7 ... the 5721? I'm looking to warm/thicken the amp sound up and take away some of it's brightness or brittle sounding top end

Suggestions always welcome.

 

[stokes]

How good or bad a tube sounds in a particular circuit is affected by many factors,not the least being the subjectivity factor.What sounds good to me may not be good to you.When trying new tubes for tone improvement it would be beneficial to change one tube at a time,as opposed to changing V1 and V2 as you did.It could very well be that the NOS 7025 greatly improved your tone,but the JJ you put in V2 is canceling that out,or vice versa,know what I mean?It could also be a case of the 7025 not being 100%,maybe it was used,or if it were stored for 25 years in a less than ideal environment it might not be up to the task.The low gain sub for the AX7 is the 5751,not 5721.I find it to be perfect for taking that "edge' off that you may get with an AX7.But it does lower the gain a bit.It gives,to my ears anyway,a smoother break-up,but it is not the choice for that shred/metal distortion.I use a 5751 in all my amps in the V1 position and in multiple positions in my IIC+,one in V1 and one in,I believe V3, which is like the V1 for the lead channel.

 

[Timbre Wolf]

What about these low gain versions of the 12AX7 ... the 5721? I'm looking to warm/thicken the amp sound up and take away some of it's brightness or brittle sounding top end

Suggestions always welcome.

The common NOS GE 5751 (gray-plate, 2-mica) can do what you want, and is still relatively inexpensive. There is plenty of overdrive capacity remaining with this lower-mu substitution.

As for your question about NOS substitutions... You "should" only hear what you hear; nothing else. If that one tube sub has not thrilled you, though, it is no reason to generalize a conclusion, one way or the other, about NOS or current-production tubes. If you are happy with current-production, it will save you lots of time, effort, and money to avoid NOS.

I have noticed that the more I selectively use vintage tubes, the more sensitive the circuit becomes. In other words, the more you dial it in, the more room for improvement will be revealed. It is a slippery slope, paved with your hard-earned cash. Are you willing to proceed? 8)

- Thom

 

[tramp]

I'm fully oiled and gaining momentum, now where's the brakes :shock:

 

[Old BF Shred]

Yes, the differences can be subtle. And I'd imagine it will make a bigger difference in some amps; less in others. But, having said that, you'd have to pry my vintage Telefunken's, RCA's and Amperex' from my cold dead hands. :twisted:

It's a subtle difference that I can definitely hear in my Ace and Triaxis. Not as much, it seems, in my Cal .22, but then I don't play it as much as the others. I was lucky in that I got most of those old tubes for free...they were in some old tube gear I received in payment for newer stuff I repaired.

The Telefunkens are my favorite....very smooth and balanced tone; no shrillness that I've noticed in some of the newer tubes. But, you may have to try them for a while to appreciate the difference.

The good news is the new production tubes are getting better every day......

 

[Rockin_Ron]

Thanks for your replies. I definitely hear what you are saying .... some of these prices for tubes listed on ebay are crazy expensive! I've seen these 5751's for up $250 to $350 for a pair! Not ready to spend that kind of money, I'm hoping to find some reasonable priced RCAs. From what I've read online the GEs can be had for cheaper but are a bit more high ended. Any truth to that? Is there much difference in these RCA triple mica vs. standard 5751s?

Here's what I have discovered so far after swapping out tubes multiple times:

Just playing around with V1 & V2 slots using MESA Russian, MESA Chinese, JJ, and and RCA 7025. The MESA tubes are by far the harshest with high frequency shrill. Right now I've got the RCA 7025 in V1 and the JJ in V2. While subtle, I can now hear the "thicker" tone. It tends to take the edge off of the highs to where it is more pleasant to the ear or maybe just more musical and not piercing like the MESAs with the Chinese being the worst. Small sample size, but that's my take.

I'm itching to catch a good buy on ebay for some RCAs. Unless you guys have some other recommendations. The hunt continues.

 

[Timbre Wolf]

some of these prices for tubes listed on ebay are crazy expensive! I've seen these 5751's for up $250 to $350 for a pair! Not ready to spend that kind of money, I'm hoping to find some reasonable priced RCAs. From what I've read online the GEs can be had for cheaper but are a bit more high ended. Any truth to that? Is there much difference in these RCA triple mica vs. standard 5751s?

Pricing for 5751 can vary, widely, depending on which you're after. $250-$350 per pair is crazy money, paid by people that want to look at their tubes, not play them. The older black-plate versions by Sylvania, RCA, Raytheon and GE are most expensive, but you can still get bargains if you're patient. I was suggesting starting out with the lowly JAN-GE 2-mica gray-plate 5751 (less than $25 at Doug's Tubes, for example) - it is a decent tube.

If you find out you like the gain of the least-expensive NOS 5751, then you can get fancier. State the tonal qualities you favor, and I can help guide you to a nice old black-plate 5751. But try the less expensive, first.

- Thom

 

[Rockin_Ron]

Thanks Timbre Wolf,

I guess if I had to best describe the tone I'm after .... think The Boys Are Back In Town by Thin Lizzy or All Right Now by Free. Love the "not heavily distorted" thick power chords and lead tone. Not into that frizzy metal shop stuff! Even Clapton's tone. I guess it's called that 70's stuff!
Any help in guidance toward tubes leading to that would be much appreciated. I assume the LSS would provide a good foundation in getting there.

Ron

 

[Timbre Wolf]

Thanks Timbre Wolf,

I guess if I had to best describe the tone I'm after .... think The Boys Are Back In Town by Thin Lizzy or All Right Now by Free. Love the "not heavily distorted" thick power chords and lead tone. Not into that frizzy metal shop stuff! Even Clapton's tone. I guess it's called that 70's stuff!
Any help in guidance toward tubes leading to that would be much appreciated. I assume the LSS would provide a good foundation in getting there.

Ron

Ron - what I was looking for was how you want to change your particular sounds. More or less overdrive (less?), more/less compression, accentuate or cut bass, low-mid, upper-mid, treble, etc.?

- T