Advice On Tubes
|Many people ask
me for advice on which tubes they should use in their amps. Taste and
money are two very important factors for each choice, more expensive
certainly doesn't have to mean that they will sound better for you.
I find that preamp tubes can be an important part to get the best out of an amp. For example you'll see people complain about the sound of a Dual Rectifier being buzzy, flabby low end, shrill high end, weak cleans, noisy, no dynamics, etc. Now this me be caused by many things, but because many Recto's are shipped with Chinese pre- and poweramp tubes it might be the most common source of these troubles (and the fact that people turn the gain up to ten).
I now only have writting some advice on 12AX7 / ECC83 tubes. Soon I'll add a piece about 12AT7 / ECC81 and 12AU7 / ECC82 tubes too. Because in many cases these tubes offer the right solution, especially if your amp needs to have some more headroom (see article on the Triaxis) or control over the breakup of the preamp.
Current production preamp tubes
All current production preamp tubes come from these factories. So
Mesa/Boogie, Marshall, Ruby or Groove Tubes don't make preamp tubes. The
same thing accounts for power tubes as well. For one exception, which is
that Groove Tubes is now producing a 6L6 tube in the
The Chinese tube is easy to identify. On the right you see a picture of it. The highlighted part is something I've only seen in Chinese tubes. So that's the easiest way to identify them. Another thing you will see is that it has 2 insulation spacers at the top. These are two horizontal plates directly above each other, they are pressed against the glass to stay in place.
The other tubes that are used a lot come from Sovtek in Russia. They've produced different tubes over the years and have lately produced their best tubes so far, the 12AX7LPS and the 12AX7EH (sold as Electro Harmonix ). The noise is lower and the tone is much better, but they still have a bright top end that may give amps a buzzy top in their lead stages, also the clean sound isn't as toneful as most other tubes. I regard these as o.k. repair tubes and people who are on a lower budget, but there are certainly better alternatives for aprox the same price if you ask me.
The last tube I can not really recommend is the Ei/Yugo ECC83, which is too bad. The sound of these tubes is simply amazing for high gain, their top end has something special which give them an amazing good sound. But there is one major drawback, they go instantly microphonic and are thus useless for normal use in a guitar amp. That's really too bad because it's one of the best sounding tubes for high gain imo. Maybe buying some special selected Ei/Yugo's and saving them for recordings only, is a good idea, otherwise I see them as useless.
Besides the previous mentioned tube companies, there are still two factories making preamp tubes: (Tesla/)JJ and Svetlana . We can keep it short on the Svetlana as 99% of production goes directly to Marshall. According to various sources these tubes are not stable and the quality isn't as high as expected. And then we have the JJ's left. These are built in the former Tesla plant and are modelled after the Telefunken ECC83, one of the best tubes ever.. The sound of the JJ's is warmer which is great if you want to get rid of the buzzy sound in many of todays amps. They have a very deep low end and distinct mids and sound great both for high gain and clean.
Together with a friend we took out the Sovtek LPS in his Peavey 5150II and replaced them with JJ's, the clean sounded much better, more dynamic and better tone, and the lead tone was more full, less harsh. Some people complain that these tubes are too dark, which could be in some cases. But I highly recommend them for people who want more tone and less buzz from their modern high gain amps that use Sovtek, EH or Chinese preamp tubes.
ps. I read that the current
production of the preamp tubes in China have been improved. Also Ei/Yugo
have been working on new tubes, which seem to be a bit better.
Old Stock preamp tubes
If you are looking for the real Fender type twang then I highly recommend using GE 5751's, they have a bright top end and late break up. Using these in Fenders or in the clean stages of Boogies will give you a fresh and clear open sound with lots of dynamics. In high gain stages they give you more control over the break up which can be great to get that pushing/breaking up sound. The sound is pretty raw and bold, don't expect silky smooth endless sustain, so these are not what I recommend for solo's but for rhythm guitars they are great. But in high gain situations they tend to produce more noise then some others. Still these are great as main input tube and for all other applications to get a clean and clear sound with plenty of detail and lots of headroom.
For a warmer sound then I can suggest you check out tubes from Philips . They have a great warm sound, deep lows, low noise, good gain. The USA made JAN spec tubes tend to have more top end then the European (Miniwatts). I personally prefer the European ones made in Holland or imported from Mullard. They have a very warm sound that's great for cleans and smooth leads.
If you want a true rock/blues tube then RFT 's are definitely something you should check out. These East German made tubes were also sold as Telefunken, Tronal and other companies and are known to produce a sound that is very close to Mullards. They are extremely low noise, plenty of gain, deep lows and a nice warm top end. Their breakup is great and they are very reliable and low in microphonics.
But when it comes to bang-for-a-buck, nothing beats original 70's Tesla tubes. They were made by and for Telefunken on their machinery and they are identical to Telefunkens. I have a nice stash of E83CC (12ax7) tubes from Tesla, they are simply amazing. The detail is by far the best I've heard, frequency spectrum is wide and balanced, quality is high and tubes are all close when tested. Original Telefunkens will go for a lot of money, but these Tesla can be found at affordable prices. They bring the best out of any amp. I've tried it in my whole setup, in a Bogner Triple Giant and a Peavey 5150 II for example and have sold many to very happy customers. These are the ones I'll be working with the next years.
These are the tubes I recommend if you want to go NOS and don't want to spend too much cash. Of course there are many other fine NOS tubes out there that sound amazing like Telefunken, Mullard, Brimar, Siemens and Sylvania, but I haven't been able to test them all, or they are soo expensive that I can't really recommend using them unless you have Grade A gear and the money to spend.
For more information on tubes check the following links: