A Few Niggling Questions About Amps in General?

Bellycaster

You pick up knowledge on here, but sometimes you realise you haven't learned everything when curve balls come at you.

So, Valves? You get used to 2xEL34 producing around 50 watts, then you see it is possible to get some 20 Watt Amps with the same.

I get 50 Watts from 2X6L6 in my Mesa Express 5:50, but 5 Watts from 1 X 6L6. Sometimes you only get 35 Watts from 2X6L6 in other amps.

Another genuine question.....Do all EL84 Amps generally sound the same? I'm sure they don't obviously. I love my Maz, but seeing as I'm looking to grab another Amp in the 20 Watt region, if I got another amp running EL84's I'd want something a little different, hard task maybe since the Maz 18 covers quite a bit of ground.

Don't Know, just edumacate me further please.

Thanks.

uncledick

IMHO, the output valves have less of an influence than the preamp design or the speaker/cabinet.

Bellycaster

uncledick said:

IMHO, the output valves have less of an influence than the preamp design or the speaker/cabinet.

True @uncledick ;

But what sourcery is it that reduces the Wattage from what is normally 50 watts to 20 watts with 2xEL34, is it the Transformer Design, Voltage, this is where my knowledge ends.

ICBM

You can run a valve at at power level below the maximum it's capable of simply by changing the voltages it's supplied with, and other circuit parameters - bias arrangement, transformer ratios, screen voltage, etc. There are also differences in the way output power is measured and claimed, which further confuses things.

The output valve type has very little effect on the sound of an amp, but there are *some* characteristics of the valve which influence it. But if you were to list EL84 amps, you could have things as radically different-sounding as the Vox AC30, Fender Blues Junior, Peavey Classic 50 and Mesa DC-3, none of which sound remotely like each other… but once you're familiar with them, you may be able to hear a type of midrange 'ring' to them when pushed hard, which is quite different from (say) a 6L6 amp.

Bellycaster

Thanks @ICBM ;

I had nearly a lucky guess with "Voltages", obviously with the other circuit changes you mentioned, it's good to learn although there is much to learn.

As to the other stuff, yep, have learned on here and elsewhere about "characteristics" of Valve types and certain tones and a lot of the amp sound coming also from the pre-amp/circuit design etc.

Definitely find that the Maz slices through the mix with that chime or mid characteristic. The Mesa was quite good too, but not the same, more defined high end and tight but boomy low end, not as much mid spike, 6L6 trait I assume.

The Maz 18 is insanely loud, we rehearse in a School Hall (Bassist is a Caretaker) which is 40ft x 60ft and a high ceiling, against a Drummer, another Guitarist, Vocals and Bass, the Maz 18 Master was just below 10 O'Clock and the Volume(Gain) around 9 O'Clock or smidge above.

pintspiller

I A/B'd my Sound Cty 50+ (EL34) and Peavey Royal (EL84) playing them max volume through an attenuator. I expected them to sound different as I assumed the wee Peavey would be Vox-like.

They sounded identical.

ennspek

Anecdotally I think the tone stack makes more difference to the tone than the valves.
I have absolutely no expertise in this area though so I may be talkong rot.

Drew_TNBD

I'm not sure that the output valve doesn't have an impact on the sound. With my two Laney's at least, the EL34 sounded very different to the 6L6 loaded one. Squishier and less high-gain metal sounding. Could be down to preamp tubes I suppose.

hywelg

I went to buy a Redplate Astro Dust from Coda a long while ago. I had previously demod one and liked it. I went back a month or so later with the cash to buy one. Only the one in stock had 6L6's in it, the one I demo'd had EL34's (I know 'cos I looked in the back), They sounded quite different and I walked away without buying it.

I think I can also detect an EL84 based on the sound. There's something about the valve that is discernible, but it maybe that I've only ever played cathode biased versions and its that that I'm hearing. I did put EL84's in my Dumble clone using the THD Yellow Jackets and I could hear it there.

ICBM

Drew_TNBD said:

I'm not sure that the output valve doesn't have an impact on the sound. With my two Laney's at least, the EL34 sounded very different to the 6L6 loaded one. Squishier and less high-gain metal sounding. Could be down to preamp tubes I suppose.

They do definitely make a difference - just less than is commonly thought, and less than the overall amp circuit design.

ie you can hear the difference, but you can't turn a Marshall into a Fender or vice versa just by swapping to the other type of output valves.

My Mesa will run both 6L6s and EL34s, and comparing them was interesting - when the amp was set for a sort of 'neutral' sound, there wasn't a huge difference, but when it was deliberately dialled in to be more 'Fendery', the 6L6s sounded much better, and when dialled in to be more 'Marshally', the EL34s did. So they seem to reinforce the voicing of the amp rather than dictate it, to me.

Bellycaster

Good to see some more replies. I've been looking at Friedman Amps and wondering what the difference is between a Pink Taco and Dirty Shirley, both have almost exact descriptions on some Guitar stores, but learned since that the D.S is more "Vintage" voiced.

I have to say, since buying the Maz, I am blown away by it's tone, it can shift dramatically. I think I'm nerding out regarding OT Valves, but it's just cos I want something that sits inbetween my Bogner GF45 and Maz 18.

I do have the hots for a Dirty Shirley Mini at the moment.

Chester

ICBM said:

Drew_TNBD said:

I'm not sure that the output valve doesn't have an impact on the sound. With my two Laney's at least, the EL34 sounded very different to the 6L6 loaded one. Squishier and less high-gain metal sounding. Could be down to preamp tubes I suppose.

They do definitely make a difference - just less than is commonly thought, and less than the overall amp circuit design.



I agree. Preamp differences aside (which are significant), if a circuit is designed around a 6L6, it will shine there. An EL34 switch will sound different, and could be perfect for specific applications, but within a more limited range of settings. IME, it's a compromise that usually led me back to the original "core" spec 

I now have specific EL34, 6L6, and 6V6 amp heads that do what they do without compromise, which works best for me. 

 

BowynMadley

I once owned a blackstar ht-20. I liked it when I had it and thought it sounded good. Now I know different but that's another story. That ran two el34s in standard bias which meant that because the voltages they ran at was so low you never really had any form of power amp distortion leading it to sound very digital and almost like a solid state. My current amp runs two kt66s in cathode bias which produces 29 watts. 

Dave_Mc

^ Are you sure it wasn't the fact that the preamp in it (and probably the PI too) is half solid state? I thought lower voltages actually increased the amount of power tube distortion (or at least lowered the volume you need to hit to get it, which granted is totally not the same thing at all... ).

ICBM

I don't think it's even to do with that, although it is true that it's a hybrid amp. To me they have a very 'tight' response, which is what makes them sound like that - not the solid-state parts or the bias arrangement.

My theory is that in the quest to reduce noise, they've overly-filtered the power supply among other things, and killed the dynamics. The reason I think it's this is that to me, even the all-valve, high-voltage amps they make sound like that.

I think the things that make a valve amp sound like a valve amp are largely the flaws in the technology, from a hi-fi point of view - not just the distortion but the power supply sag, the low damping factor and even the background noise. All these add 'life' to the sound in my opinion. (Yes, even the noise.)

slacker

I had a Cornell romany Plus for a few years, lovely amp but I wanted it to sound a bit more British. So I swapped the 6L6 for an EL34, it got louder, I swapped that for a 6650 it ot louder still. Changing the Jensen to a V30 to a Tone Tubby made the biggest difference. Eventually I sold it and bought an amp I was happy with (and then bought another).

The loudness thing is partially the type of valve (a GE6L6 was not as loud as the stock Sovtek) the class A thing (not going there) the speaker (huge variance)  and the manufacturer marketing (aka lies) . THe Mesa F30 cannot be 30w.

ICBM

slacker said:

The loudness thing is partially the type of valve (a GE6L6 was not as loud as the stock Sovtek) the class A thing (not going there) the speaker (huge variance)  and the manufacturer marketing (aka lies) . THe Mesa F30 cannot be 30w.

Not unless it was Class B, which would sound dreadful for audio. It's actually 22W, as you would expect from their previous 2-EL84 amps. (I measured it, of course .)

slacker

ICBM said:

slacker said:

The loudness thing is partially the type of valve (a GE6L6 was not as loud as the stock Sovtek) the class A thing (not going there) the speaker (huge variance)  and the manufacturer marketing (aka lies) . THe Mesa F30 cannot be 30w.

Not unless it was Class B, which would sound dreadful for audio. It's actually 22W, as you would expect from their previous 2-EL84 amps. (I measured it, of course .)

And to be fair it was marketed as Dyna Watts (whatever they were) just in case Mesa want to take issue with me.

Dave_Mc

ICBM said:

I don't think it's even to do with that, although it is true that it's a hybrid amp. To me they have a very 'tight' response, which is what makes them sound like that - not the solid-state parts or the bias arrangement.

My theory is that in the quest to reduce noise, they've overly-filtered the power supply among other things, and killed the dynamics. The reason I think it's this is that to me, even the all-valve, high-voltage amps they make sound like that.

I think the things that make a valve amp sound like a valve amp are largely the flaws in the technology, from a hi-fi point of view - not just the distortion but the power supply sag, the low damping factor and even the background noise. All these add 'life' to the sound in my opinion. (Yes, even the noise.)

Yeah that may well be so. I just thought it was funny that he'd think it was the voltage that was causing it.