Topic Index

• HiFi Application Top Picks
  
• Audio Amplifiers with 5751
  
• Guitar Amp - Distortion, Distortion, Distortion
  
• Guitar Amp - Tone, Tone, Tone
  
• Recording Gear Application
  
• Limited or No Longer Available
  

HiFi Application Top Picks

TungSol 12AX7
Recently introduced, Russian made TungSol 12AX7 is balanced, detailed and smooth like Sovtek 12AX7LPS, but some of our customers like it better for its richer mids. TungSol 12AX7 has small plate design with star micas that are well supported in the glass. This makes it very low in microphony and suitable for use in high gain stages like phono.

JJ ECC803S
Based on old Tesla ECC803 design, this long plate 12AX7 gives plenty of lower-mid body. JJ ECC803S particularly excels at classical music source, so if that is you preferred source of music, this tube is definitely worth considering. Like Sovtek 12AX7LPS, long plate does make it more prone to microphony.

Audio Amplifiers with 5751

(Photo is 12AX7EH Gold installed on McIntosh tube amplifier.)

Some preamps and headphone amps use 5751. These tubes have slightly different characteristic than 12AX7.

Sovtek 5751
Based on the same construction as popular Sovtek 12AX7LPS. Sovtek 5751 utilizes different grid winding to achieve lower gain with the same benefits you get out of 12AX7LPS. Gold Pin version is also available.

5751 JAN GE NOS
This tube is NOS and in high demand so may not be in our stock all the time. It is worth mentioning since this tube does well in audio application, even as a substitute for 12AX7. It has slightly lower gain and good tonal balance which results in lower noise floor and better linearity.

Guitar Amp - Distortion, Distortion, Distortion

TungSol 12AX7
Very low microphonics, terrific amount of gain, and very quiet. Better yet, this tube has excellent tonal balance and clarity. You can set up your amp to get long, powerful sustains and good full bodied crunches. Easily compares to many expensive NOS 12AX7s out there.

Electro-Harmonix 12AX7EH
Great all rounder. Good gain, good bite and when pushed, great Rock tone. Many gear manufacturer uses this tube, so if you are looking to upgrade gear with 12AX7EH already, TungSol 12AX7 is a better choice. If you are upgrading from Chinese OEM or Sovtek 12AX7WA tubes, this is a good inexpensive upgrade.

Groove Tubes 12AX7M Mullard Re-Issue
Looks like a Mulalrd, but is it as good? Well, the jury is out. And this tube is simply superb. It has smooth drive, excellent details when overdriven, and has great tight bass to compliment it all. While it does not sound identical to NOS Mullard ECC83, Groove Tubes 12AX7M excels in its own with that magical tone not found in any other 12AX7.

Shuguang 12AX7B Silver Dragon
Very good gain. This is for those who want the highest shredding gain on the budget.

JJ ECC83S
This tube is a little less rich sounding and a bit brighter. But when pushed, it does that Marshall thang very well.

Guitar Amp - Tone, Tone, Tone

We suggest you try a few 12AX7s first if you are experimenting, but sometimes you just can not get the tone you want because you have too much gain.

For that soulful bluesy guitar tone or solid powerful crunch with clarity and definition, we suggest you try reducing gain. This is especially true with today's hot pickups where higher gain causes higher distortion and washes everything out. Whether it be Blues or Jazz, changing out the 12AX7 to one of the tube types below can help you get the most out of your gear.

You can reduce the gain by changing the first stage 12AX7 to (from higher gain to lower) 5751, 12AT7, 12AY7 and 12AU7. Here are some suggestions:

(Photo is Groove Tubes 12AX7M installed on 1950's Fender Tweed Amplifier)

5751 JAN GE NOS
Touch less gain of this tube might be all it takes to dig out that Bluesy sound from your amp.

12AT7EH
12AT7 is close in gain to 5751, but has different characteristic that makes it give different balance. Great for full bodied fat crunches.

12AY7EH
12AY7 has less than half the gain of 12AX7, but if you are looking for the clean tone even with the amp turned up all the way, this might be the ticket.

12AU7EH
All you want is that warm clean tone but still getting the distortion and feedback with your beautiful semi-acoustic? 12AU7 has one-fifth of the gain of 12AX7 and will greatly bring down the gain.

Notes:

• Whenever you change V1 to lower gain, your amp will seem quieter, and you will have to turn up the master volume further. We had a musician customer switch to 5751 JAN GE NOS, who did not like it at first. He then took the amp in to the studio and played with it for a while under real volume. Turns out, he ended up really loving the tone!

  So experiement with your amp settings as well. If you change the tube type, things will definitely be different than what you are used to.

• The description here is for your information only, and we do not warranty against any problems that may result of it. We have never had, nor heard of such problems, but you are doing this at your own risk.

Recording Gear Application

For re-tubing a studio grade gear, Sovtek 12AX7LPS or TungSol 12AX7 is excellent and will give you comparable or better results than NOS in many cases.

Limited or No Longer Available

SED 12AX7WC
Offers superb tonality, clarity and balance with extended range - a jewel of a tube and our favorite in McIntosh first stage. Unfortunately, these tubes can pick up filament hum in some circuit.

Sadly, SED no longer produces this tube. (2006)

12AX7Ei (SB or EG)
Has crisp top end, excellent details with good low mids to support it. Simply great with contemporary jazz, pop or rock material. These can be microphonic and a bit noisy, so definitely keep away from phono use.

12AX7Ei can sound awesome in guitar amps too, but it can be very microphonic and will often turn your amp into a wailing siren.

Regrettably the supply of Ei tubes have become very limited as of 2006. We do have quantities of Ei tubes, so get them while they last!