Mullard CV4004 Preamp Tube ?'s

[wolfpack]

I have a few Mullard CV4004 preamp tubes I'm not sure I'll use.

Does anyone know the value of these ?

Are these better for low gain or high amps ?

Thanks !!

 

[Chi]

these are supposedly equivalant to Mullard 12ax7's i believe. I've had a few and never really find them usuable...if I do it's usually in the phase inverter positon. I've bought a bunch of them from reputable dealers at different times the majority of them seem to be prone to microphonics...

 

[Rich M]

They are great tubes. They sound best in MY amps. Email me and I will tell you where to send them.

Seriously, I've heard folks argue that CV4024 are normal 12AT7's with mil markings, I simialrly assume CV4004 are just specially marked 12ax7's. When you think about it, that's not so bad. Enjoy them. They should last a good long time.

In answer to your question, without getting too opinionated, I think that a lower gain amp probably displays the exceptional nuances of a Mullard better than a high gain one. High gain heads require some level of quality to sound good, but beyond that, I don't think you'll notice.

 

[wolfpack]

Originally posted by Rich M
They are great tubes. They sound best in MY amps. Email me and I will tell you where to send them.

Seriously, I've heard folks argue that CV4024 are normal 12AT7's with mil markings, I simialrly assume CV4004 are just specially marked 12ax7's. When you think about it, that's not so bad. Enjoy them. They should last a good long time.

In answer to your question, without getting too opinionated, I think that a lower gain amp probably displays the exceptional nuances of a Mullard better than a high gain one. High gain heads require some level of quality to sound good, but beyond that, I don't think you'll notice.

Yeah, I just put these in my Guytron GT100 (which is for sale in the emporium) & they do sound nice.

 

[jda]

I find the Mullard CV4004s to sound different from Mullard 12ax7s. To my ears, the cv4004s are brighter.

I think KCA has some, so you can check the price there. Of course, KCA's are screened and tested.

 

[wolfpack]

Originally posted by jda
I find the Mullard CV4004s to sound different from Mullard 12ax7s. To my ears, the cv4004s are brighter.

I think KCA has some, so you can check the price there. Of course, KCA's are screened and tested.

KCA is where I bought these originally.
Doesn't really matter now, I'm including them in my Guytron sale.

 

[Damon]

Originally posted by Rich M

Seriously, I've heard folks argue that CV4024 are normal 12AT7's with mil markings, I simialrly assume CV4004 are just specially marked 12ax7's.

FWIW, Mullard's CV4004 is a different design from their ECC83/12AX7. If you look at the plate structure, they're box shaped. I love the sound of the ones I have! But, I love the sound of Mullard ECC83s, too... I agree, it's likely easier to hear subtleties in a lower-gain platform (or in hi-fi gear).

 

[Rich M]

The CV4024s I have are box plates as well. I assumed all mullards were like that (none to compare with). They also appear to be made of copper. I've heard it argued that this is an advantage. Does anybody have some sharp photos of a regular Mullard 12AT7?

 

[Kidcactus]

I have a lot of NOS 12AX7's (RCA, Telefunken, Brimar, RFT, Raytheon, Valvo and maybe some more) and the Mullard CV4004 is the biggest sounding preamp I've heard. That is not necessarily good and they don't work well in all amps. I had a Marshall 2061x and they were the best sounding preamp tube for that amp bar none. They were not the best in the Komet 60 I had. They were probably the best in the 30 watt Matchless I had. It depends on the amp. I like the Brimar CV4004 better than the Mullard CV4004 in my 18 watt Reinhardt. You just have to try them and see how they sound.

 

[Timbre Wolf]

Kidcactus - can you elaborate on what you mean by "biggest sounding"? Is that an extended frequency range, or spacious clarity, or prominent lower frequencies, or?? Thanks.

- T

 

[jda]

The cv4004s are often touted as having an "extended high end response". In my experience, this has been an accurate description.

 

[Blue Strat]

Originally posted by Timbre Wolf
Kidcactus - can you elaborate on what you mean by "biggest sounding"? Is that an extended frequency range, or spacious clarity, or prominent lower frequencies, or?? Thanks.

- T

Ah, tonal descriptions that never translate from one person to another....

 

[David Simpson]

They are Mullards military version of the ax7..
I have 5 or 6 of them I run in my X99 sometimes.....they sound great.

 

[David Simpson]

http://www.tubedepot.com/nos-cv4004.html

 

[stratovarius]

Originally posted by David Simpson
http://www.tubedepot.com/nos-cv4004.html

Wow! I'm glad I stocked up a few years ago.

 

[David Simpson]

Originally posted by stratovarius
Wow! I'm glad I stocked up a few years ago.

Yeah, I think I paid somewhere between 50 and 75 each when I got mine. That was about 3 or 4 years ago.

 

[wolfpack]

WOW !!

Maybe I should remove these from my Guytron & sell them seperately

 

[Blue Strat]

Originally posted by wolfpack
WOW !!

Maybe I should remove these from my Guytron & sell them seperately

That's what most people do.

 

[Timbre Wolf]

Originally posted by Blue Strat
Ah, tonal descriptions that never translate from one person to another....

I'm committed to trying, Mike. As you know, many of us guitarists are seeking genuine help on this topic. I think specific descriptions of preamp tube performance can be helpful to all, if one uses terms such as:
- compression/dynamics/feel (responsive, stiff, etc.)
- frequency balance or accentuation in low/low-mid/upper-mid/high (bright/dark, tubby/twangy, dull/harsh, etc.)
- frequency extension (higher highs and lower lows, or vice-versa)
- articulation/clarity (string-to-string definition, blurriness, etc.)
- [what else? anyone have suggestions? perhaps in another thread?]

Of course, if its all prefaced with "in my experience," that can disarm the heated arguments of what is objectively "the best." It is all subjective impressions, but the more I discuss and investigate preamp tube performance with other players, the more I see agreement on common experiences.

- T

p.s. please let me know any further impressions about that Raytheon black-plate 12AX7A