• From: Detroit
  • Registered: 2006-06-02
  • Posts: 5,807

Topic: I don't like Mullard 12AX7 preamp tubes

So, a couple of months ago, I decided to buy into the voodoo of Mullard preamp tubes.

Why not!? I mean SRV used them, and they're supposed to be... like, the best preamp tubes for clean and headroom, yada yada...
I had JJ ECC83S preamp tubes in there, and those were supposed to be high gain, so I figured I "should" be able to tell a big difference.

I tried them in two amps. A 100 watt Rivera Knucklehead, and my modded Fender Blues Junior. In the Rivera, they only sounded good in V2-V4. Put one in V1 and the gain was terrible. Can't describe it. Just cloudy sounding. I put three Mullards into the Blues Jr., and it was like putting my amp in a ziplock bag. The sound was clear, but it didn't sparkle the way it used to. It turned the amp from a hyper 12 year old, to a drug smoking 16 year old... if that makes any sense. The amp just sounded lazy, like it didn't want to try that hard to define any notes.

In the Rivera, I now I have a TungSol in V1, and Groove Tubes in V2-V5. I just want to hear a difference between them and the JJ's. We'll see. In the Blues JR, I put the JJ's back in. cool

I bought Mullards in spite of what I read here:
http://thetubestore.com/12ax7review.html#mu12ax7

Mullard 12AX7 / ECC83 Reissue - This is a nice tube but in my opinion better suited to home audio than guitar amps. The tubes have well balanced triode pairs and a very even flat response. Compared to a Tung Sol it sounds a bit flat, but so does a NOS Mullard. Microphonics are not an issue despite the larger that average plate structure. The transconductance on my sample was the same as two NOS samples I measured. Not really high gain at all, but a real good noise floor and a nice smooth tone that doesn't encourage ear fatigue the way some preamps can be. The Tung-Sol 12AX7 is my favorite preamp for guitars because it accentuates highs and lows. The Mullard adds virtually no tone coloring and is smoother sounding to my ear than a JJ ECC83S. For hi-fi gear the Mullard will likely be a winner but there are better choices for guitar amps for less money.

- Nic from Detroit... posting on JB's Forum since 6-2-2006
Ask me about my handwound Great Lakes Guitar Pickups
Since 2010, Bonamassa fans have taken advantage of my JB friend discount = my cost + shipping. cool
  • Registered: 2011-07-06
  • Posts: 17

Re: I don't like Mullard 12AX7 preamp tubes

Those are Mullard reissues and are nothing like the originals.
I tried some RI mullards ECC83s in my Jubilee and they were brittle and lacked balls.
Then I found a bunch of original mullards down my local tip - I pulled em out of some old valve radios.
Those sounded absolutely incredible. They had tons of gain, excellent balance and tested higher than any CP valves I've ever tried for output and gain on my techs tube tester machine. They were very musical sounding, just awesome. The reissues shouldn't be allowed to use the name mullard. They are nothing like the Blackburn made originals .

  • macg1
  • BONAMETAL
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  • From: St. Petersburg, FL
  • Registered: 2010-01-21
  • Posts: 1,020

Re: I don't like Mullard 12AX7 preamp tubes

Tung Sol 12AX7's are the only preamp tubes I will use!

Amp: Firebird Musical Amplifiers
Guitars:62 LP SG , 02 FB VII, JB FB I, 76 Electra Omega, 64 Firebird V, 73 LPC, 61 Custom Tele, 59 and 60 Melody Maker
Effects: Mythos Chupacabra, Strymon Deco/Flint
  • From: York, PA
  • Registered: 2010-08-27
  • Posts: 1,749

Re: I don't like Mullard 12AX7 preamp tubes

Theres a video of TheToneKing comparing preamp tubes and he uses a Mullard RI and I didn't care for the sound much either.  I used headphones to watch the video but even still...  At least it didn't set you back $$ much to try a simple mod like that.

5 Reply by DaveWammbarro (edited by DaveWammbarro 2011-07-11 17:16:31)

  • From: N.Wales, UK
  • Registered: 2009-03-06
  • Posts: 2,183

Re: I don't like Mullard 12AX7 preamp tubes

You need NOS.

Reissues of ANY valve aren't worth jack...

(I'm quite happy with my JJ 12ax7s and 6L6s as it goes)

  • From: Detroit
  • Registered: 2006-06-02
  • Posts: 5,807

Re: I don't like Mullard 12AX7 preamp tubes

I was quoted some NOS tubes for my amp:

V1-GE7025-$35
V2-Mullard-$45
V3-High gain Raytheon Black Plate-$45
V4-Sylvania Gray Plate-$35
V5-Philips made PI-$40

and I'm not sold. Here's why. V1 needs to be the quietest tube. What if the V1 that is sent to me is noisy or microphonic? I just lost $35! hmm

- Nic from Detroit... posting on JB's Forum since 6-2-2006
Ask me about my handwound Great Lakes Guitar Pickups
Since 2010, Bonamassa fans have taken advantage of my JB friend discount = my cost + shipping. cool
  • From: Ridgeland, MS
  • Registered: 2009-08-12
  • Posts: 1,248

Re: I don't like Mullard 12AX7 preamp tubes

DaveWammbarro wrote:

You need NOS.

Reissues of ANY valve aren't worth jack...

(I'm quite happy with my JJ 12ax7s and 6L6s as it goes)

+1  There is no comparison. They last longer too.

  • From: Ridgeland, MS
  • Registered: 2009-08-12
  • Posts: 1,248

Re: I don't like Mullard 12AX7 preamp tubes

NPB_EST.1979 wrote:

I was quoted some NOS tubes for my amp:

V1-GE7025-$35
V2-Mullard-$45
V3-High gain Raytheon Black Plate-$45
V4-Sylvania Gray Plate-$35
V5-Philips made PI-$40

and I'm not sold. Here's why. V1 needs to be the quietest tube. What if the V1 that is sent to me is noisy or microphonic? I just lost $35! hmm

Don't buy them from eBay. Find a reputable dealer such as http://www.audiotubes.com/6l6.htm or http://www.kcanostubes.com/
or http://mhuss.com/sgtoverdrive/ (David Lee Roth's former guitar player and a straight up dude) or  http://www.coldspringselectricalworks.com/