What is the fattest, warmest, biggest-sounding CP 12AX7?

[Rex_Rocker]

What is it, IYO?

JJ ECC83S's are smooth, but they don't really have a deep low-end. It's mostly just low mids.

Is it Sovtek LP's? They've got a pretty chunky extended low-end.

Sovtek WC's are pretty warm to the point of being dull, but they're kinda weak in terms of output compared to others.

 

[GuitarStv]

Re: What is the fattest, warmest, biggest-sounding CP 12AX7?

Tung-Sol 12ax7s I've tried probably give the biggest and warmest sounding cleans . . . but it's more like a sweeter high than an extended low end. JJ's ECC83S's are my pick for warm/thick distorted tones . . . but again, I'm never really aiming for just low end. Low mids are what I want with distortion.



I like Sovtek 12ax7-LPS for balanced clean sounds. Good response from low to high, but definitely not the warmest tube. Work great with effects. What's not to like?

 

[Rex_Rocker]

Re: What is the fattest, warmest, biggest-sounding CP 12AX7?

I actually find the TS pretty bright. Not ice-picky like EH, but it does have sweet airy highs. It does have nice low-end chunk too, though, but I consider it more like a broad almost hi-fi sound.

The short plate Mullard CV4004 is also pretty big-sounding. Kinda like a warmed up Tung Sol. Not sure if it has a bigger low-end than the Sovtek LPS, though.

Reason I ask is I got a Tube Pilot pedal which is VERY bright and kinda thin. I tried the JJ, and it was warm, but it didn't do anything to fix the thinness. The Sovtek LPS has a fat low-end, but it didn't do anything to fix the harshness. The Sovtek WC has a fitting EQ curve, but it's too weak, and it made the pedal too quiet not reaching unity gain even with the output cranked. I was expecting the long plate Mullard ECC83 to be warmer than the Sovtek LPS, but it was pretty similar, just slightly weaker.

 

[Silence Kid]

Re: What is the fattest, warmest, biggest-sounding CP 12AX7?

Mentioned RFTs in another thread- they ‘fixed’ my over-bright/thin Vox. I bought a stash.

Along the way tried Russian GTs, Tung Sols, Sovtek, Chinese GTs, Slovak JJs - maybe slight differences but nothing like the RFT’s power.

 

[NegativeEase]

Re: What is the fattest, warmest, biggest-sounding CP 12AX7?

Honestly, there's incredible variability inside each brand and tube. I don't think it's as simple as brand characteristics other than sweeping generalities to get you started with.

All of the assembly line gear wears and varies through a run, like stamping vinyl -From annealing the plate metal, to blowing the glass thickness, to the lead paths and gauage, tip heat dissipation effectiveness, to the spacer dimensions, to the socket tinning, to the pressure on the vacuum pump, and filament quality etc etc

I've pulled a Mullard out of a Hammond organ that was incredibly warm and another from the same lot that wasn't.

They are ALL different in my experience.

 

[JMP/HBE]

Re: What is the fattest, warmest, biggest-sounding CP 12AX7?

Doesn't exist.

 

[Gtrjunior]

Re: What is the fattest, warmest, biggest-sounding CP 12AX7?

I feel like it really is amp dependent.
Tubes sound different in different circuits.

 

[GuitarStv]

Re: What is the fattest, warmest, biggest-sounding CP 12AX7?

Probably also depends on speakers to a great deal. Speakers that push similar frequencies to those enhanced by a tube vs speakers that compliment them could make the same tube sound like it's got heavy low end in one amp, and be mid-rangey in another.

 

[misterwhizzy]

Re: What is the fattest, warmest, biggest-sounding CP 12AX7?

For what you’re asking, I’ve had the best luck tonally with new-production Mullards.

 

[Gtrjunior]

Re: What is the fattest, warmest, biggest-sounding CP 12AX7?

Spam much?