Because I’ve had a lot of experience with lots of different amps, invariably people ask me for advice – especially on what power tubes to go with. They ask, “Should I get EL34? 6L6? 6V6? EL84, etc.” My answer to that question is: Yes. 🙂 On a more serious note, I do tell them that they have to play several amps to find out what appeals to their sense of tone the most. After all, it’s what is pleasing to your ear that matters.
I used to drink the cool-aid and say something like this: “If you want real chimey clean tones, then you’ll get that with 6L6’s,” or some other rubbish like that. That’s all a bunch of crap because I’ve got EL84-based amps that have that kind of chimey clean tone as well. It’s all about how the builder voiced the EQ circuitry AND what guitar you play through the amp!
What I do see a difference between the different tubes is in how they distort once overdriven. This is NOT hard and fast, but in general, I’ve found that the ELx varieties tend to compress their signal a bit more when saturated as compared to their 6×6 brethren. The 6L6 and 6V6 amps that I’ve played usually have a more open and dynamic overdrive tone. But again, that is also affected by how the amp is wired. For instance, designs based upon Fender amps have fairly open distortion, while the Marshall-style amps have a more compressed, in-your-face distortion. And I’ll say it again: There are NO hard and fast rules here. So how do you decide?
Well, while power tubes do affect the tone, you shouldn’t make an amp decision based upon just that; though I shared a very general rule of thumb, wiring topology can strike that generalization down fairly quickly. What you probably should consider is the power rating and your application of the amp. EL84 and 6V6 tubes are generally used in lower wattage amps, anywhere from 5 Watts to 45 Watts. Generally, you’ll see numbers such as 5, 6, 10, 15, 22, 30, 36, and 40. For the top three, four tubes are usually used to achieve those wattage ratings.
On the other hand, 6L6 and EL34 power tubes are used for high-wattage applications from 40 Watts up to 200 Watts (40, 45, 50, 60, 75, 100, 150, 200), again with the top three employing four power tubes to achieve that wattage rating.
The rule-of-thumb with respect to wattage is that the higher the wattage, the more clean headroom you will have; that is, the amp will be totally clean at increasing volume levels (in decibels) before the amp goes into overdrive. For instance, taking a 5 Watt amp to the edge of breakup will be at a much lower volume level than a 100 Watt amp taken to the edge of breakup.
Another thing that I’ve found is that with high wattage amps, when they break up, their tone seems to be so much more “beefy” than their low-wattage brethren. When doing A/B tests at equivalent volumes with let’s say a 6L6-based amp versus a 6V6 amp, there is so much more sonic content through the EQ range with the higher-wattage amp versus the low wattage amp. For instance, my 22 Watt 6V6-based Aracom VRX22 sounds “bigger” than my 6 watt Fender Champ when played through the same speaker at the same volume. Conversely, that same 22 Watt amp sounds “smaller” at the same volume level than my Fender Hot Rod Deluxe at the same volume level. A lot of this has to do with the higher wattage amp producing more bottom-end by nature. This is especially evident when pushing the amps into power tube saturation.
Some may have caught the phrase, “equivalent volumes” in the previous paragraphs, and wondered how I could get equivalent volumes with a low-wattage and high-wattage amp breaking up. The only way you can get that is by using a power attenuator, of which there are many on the market, though I use the Aracom PRX150-Pro.
Finally, what advice do I have? It’s actually fairly simple:
- First, evaluate the average usage (i.e., the application). Will you need lots of clean headroom? Do you play large venues? Then a higher-wattage amp might make sense. On the other hand, if you play mostly small venues, in the studio, or in your room, a lower-wattage amp may make more sense. BUT, if you have a great attenuator like the PRX150-Pro (or DAG), my personal preference would be to go to the higher-wattage amp. While I love the tones that I get with my low-wattage amps, with the PRX, I don’t have the volume considerations to take in to account any longer that had me go with low wattage amps in the first place.
- Once you’ve determined your power needs, then you have to test amps – lots of ’em – there’s no way around it.
Then once you’ve done the evaluation, you might throw that all out the window and go for what sounds good to you, regardless of your power needs. 🙂
Hey! No one said it was easy…