7 pro changes

[Low Down Brown]

Ordered

Always been a fan of Tung-Sols myself. Curious to hear what you think about them vs. the others

 

[JeezyMcNuggles]

So, I'm thinking that this may just be the best way to do a shoot out. The 7 pro is a one tube preamp. There is nothing else in the chain. It's just one 12ax7, and the amp. This is gonna be great! I'll have it up in a couple days, when they come in. I'll do a mic test, and a di. Keep a lookout.

 

[JeezyMcNuggles]

Time to get to work

 

[JimmyM]

Time to get to workView attachment 4319334

I did a little fooling around in my old 7 Pro with tubes once, even used one of those Tung Sols you got. It's pretty darn responsive to tubes for a single tube preamp. I have a handful of NOS tubes and a handful of newer tubes in it and stuck with the JJ because that to me is the sound I chase. Interested to hear which one's brighter and tighter for you between the Mesa and the Tung Sol, because wow, that Tung Sol is really bright and tight, too.

 

[JeezyMcNuggles]

Tung Sol is the winner.

 

[JeezyMcNuggles]

Not by far though.

I got a lot of footage to cut up. But, tung sol is tight, clear, punchy, and has great bottom. Highs are very present, but smooth at the same time. To me, it's just the most natural and plays how I want it to. Mesa has the most high end, but to me it lacks in the low end. Sounds killer with the gain maxed out though. But, it's a little too "hi fi" for me. Highs and high mid oriented. Electro was a close second. Same overall feel as the tung sol, but it seems to just be lacking a little luster compared. The stock JJ is more low end oriented. Bass and low mid. But it also seems to have a top top bite compared. But, lows and low mids are the stars. It's got kind of a looser sort of "blurred" feel. I guess you could say that it's the most "tubey." Alright, stay tuned.

When I'm done chopping it up, I'll post the vid.

 

[agedhorse]

The noise floor and microphonics of the SPA tube is quite different from an average tube. These are roughly the top 5% of the tube lot screened for these parameters. The heat shrink affects the resonance of the glass envelope and does not significantly affect the life of the tube.

 

[JimmyM]

The noise floor and microphonics of the SPA tube is quite different from an average tube. These are roughly the top 5% of the tube lot screened for these parameters. The heat shrink affects the resonance of the glass envelope and does not significantly affect the life of the tube.

Never saw that before. Is it to just cut down on microphonics or would there be a significant change in sound if you took it off?

 

[agedhorse]

Never saw that before. Is it to just cut down on microphonics or would there be a significant change in sound if you took it off?

It reduces the “ting” resonances of the envelope. It’s more effective for guitar frequency energy from the speaker in a guitar combo vibrating the glass .

 

[JeezyMcNuggles]

The noise floor and microphonics of the SPA tube is quite different from an average tube. These are roughly the top 5% of the tube lot screened for these parameters. The heat shrink affects the resonance of the glass envelope and does not significantly affect the life of the tube.

Yeah, I didn't think so.

But yes, I feel that this tube would be cream of the crop for a guitar amp. Just, not quite my deal in a bass amp. Maybe to shine in a metal band. Tighten up, and add some tone to drop tuning or something. I could get that. But I do feel that it stayed together the best out of all of them with the gain maxed. Stayed clear. Well, as clear as full on distortion gets at least.

 

[JimmyM]

It reduces the “ting” resonances of the envelope. It’s more effective for guitar frequency energy from the speaker in a guitar combo vibrating the glass .

That makes sense now that guitarists seem to be mostly using lower powered combos in the field these days.

 

[Jim C]

So, I made an interesting discovery the other day. I popped in one of these bad boysView attachment 4314148
And it turned my 7 pro into a crisp, clear, gainy, tight bottomed, rock machine

Popped the JJ back in today, and the fat, warm, massive 7 pro was right back at home.

Went back and forth a couple times, and then I realized, with this one little 25 dollar Mesa tube, I've just created an entirely new amplifier. One that's fat, warm, and round. And one that's tight, crisp, and clear with a more usuable breakup structure.

The stock JJ has more bass, and seems to be focused on the bottom end of the mid spectrum.

The Mesa has a tighter overall sound, with crisper highs, and seems to be very broad in the midrange.


With the turn of 10 screws (or so), I now have two completely different 1000w amplifiers.

Pretty nifty

Does the JJ meet spec? Curious if that was the difference.
I rolled a number of tubes through my old 7Pro and found the differences to be really minimal. This batch included original Telefunkens, Amperex, and Mullards. I found the same to be true with V1 and tone control tubes in my old 3Pro, single 12 AX7's in SWR's etc.

As a general rule, I have not found hardly any differences when changing the single tube in bass amps (12AX7 in the V1 position) unless the tube was out of spec.

The only exception in a bass amp that really had a noticeable change was a Mesa WA in both the pre amp and driver tube.

 

[JeezyMcNuggles]

Does the JJ meet spec? Curious if that was the difference.
I rolled a number of tubes through my old 7Pro and found the differences to be really minimal. This batch included original Telefunkens, Amperex, and Mullards. I found the same to be true with V1 and tone control tubes in my old 3Pro, single 12 AX7's in SWR's etc.

As a general rule, I have not found hardly any differences when changing the single tube in bass amps (12AX7 in the V1 position) unless the tube was out of spec.

The only exception in a bass amp that really had a noticeable change was a Mesa WA in both the pre amp and driver tube.

I'm sure it does. It sounds just like my other 7 pro did. I noticed differences with each tube I tried.