What are we getting from a 36W EL84 build, over an 18?

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cstenger5
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What are we getting from a 36W EL84 build, over an 18?

Post by cstenger5 »

I know the obvious "an extra 18 watts", but with little perceptible volume difference, are we just getting headroom at the power tubes? Some other character difference? As I map out my next build (I have a matchless/vox build ahead of my next build from here - but after that), I'm wondering if I might as well do a 4 EL84 build, yanking 2 of the tubes for half power. But if there's negligible difference between the two, what am I really gaining?
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Re: What are we getting from a 36W EL84 build, over an 18?

Post by JMPGuitars »

For me, I build my 36W amps with a pair of EL34 tubes. EL34s are my favorite. I like EL84 also, just not as much. The extra headroom is okay if that's something you need, but I wouldn't expect to see much more than that, especially if you're still using EL84s.
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Re: What are we getting from a 36W EL84 build, over an 18?

Post by cstenger5 »

Thanks man - much appreciated
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Re: What are we getting from a 36W EL84 build, over an 18?

Post by Bieworm »

I think the 36W is substantially louder than the 18W. The 18W I can crank at home in my workshop. The 36W just hurts doing the same thing...
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Re: What are we getting from a 36W EL84 build, over an 18?

Post by zaphod_phil »

Bieworm wrote:
Mon 09/20/21 1:03 pm
I think the 36W is substantially louder than the 18W. The 18W I can crank at home in my workshop. The 36W just hurts doing the same thing...
I'm afraid I must disagree with that view. Keep in mind the way the loudness of sound works on the decibel scale. To get a doubling of volume level, you would need to increase power output by a factor of 10 times (assuming the same speakers) and doubling of power output will only give a fractional increase in the sound volume you hear. I'm not sure what laws of physics operate in your workshop :) I find a regular 18W with good speakers (around 100dB/W @1m) makes my ears ring if I'm anywhere in the same room. And I have often been told to turn down my 13W ECL86-based LiteIIb version, when playing on stage. 8O

What you will find however is an increase in clean headroom before the 36Wamp starts to breakup, relative to an 18W. Likewise, when you move from 50 W to 100W Plexis. This has been quite widely reported on various tube amp forums.
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Re: What are we getting from a 36W EL84 build, over an 18?

Post by Bieworm »

zaphod_phil wrote:
Mon 09/20/21 3:14 pm
Bieworm wrote:
Mon 09/20/21 1:03 pm
I think the 36W is substantially louder than the 18W. The 18W I can crank at home in my workshop. The 36W just hurts doing the same thing...
I'm afraid I must disagree with that view. Keep in mind the way the loudness of sound works on the decibel scale. To get a doubling of volume level, you would need to increase power output by a factor of 10 times (assuming the same speakers) and doubling of power output will only give a slight increase in the sound volume you hear. I'm not sure what laws of physics operate in your workshop :) I find a regular 18W with good speakers (around 100dB/W @1m) makes my ears ring if I'm in the same room 8O

What you will find however is an increase in clean headroom before the amp starts to breakup. Likewise, when you move from 50 W to 100W Plexis. This has been quite widely reported on various tube amp forums.
Zp.. I'm not saying double... but still substantial. There is a noticeable difference...it's louder
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Re: What are we getting from a 36W EL84 build, over an 18?

Post by zaphod_phil »

cstenger5 wrote:
Mon 09/20/21 8:07 am
(have a matchless/vox build ahead of my next build from here -
Holy icepicks! 8O
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Re: What are we getting from a 36W EL84 build, over an 18?

Post by zaphod_phil »

Zp.. I'm not saying double... but still substantial. There is a noticeable difference...it's louder
I think it might be placebo loudness :lol:
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Re: What are we getting from a 36W EL84 build, over an 18?

Post by cstenger5 »

zaphod_phil wrote:
Mon 09/20/21 3:29 pm
cstenger5 wrote:
Mon 09/20/21 8:07 am
(have a matchless/vox build ahead of my next build from here -
Holy icepicks! 8O
Haha, I'll have a top cut. I was a huge fan of the DC30, just waaaaay too loud. This'll be a 15 watt. All part of my plan to build all the amps I either sold and regret, can't afford to buy, or loved except for this one fatal flaw.
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Re: What are we getting from a 36W EL84 build, over an 18?

Post by zaphod_phil »

cstenger5 wrote:
Mon 09/20/21 6:52 pm
zaphod_phil wrote:
Mon 09/20/21 3:29 pm
cstenger5 wrote:
Mon 09/20/21 8:07 am
(have a matchless/vox build ahead of my next build from here -
Holy icepicks! 8O
I was a huge fan of the DC30, just waaaaay too loud. This'll be a 15 watt.
In that case you might like to check out Trinity's TC15 -https://www.trinityamps.com/product/trinity-tc15-kit
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Re: What are we getting from a 36W EL84 build, over an 18?

Post by cstenger5 »

zaphod_phil wrote:
Mon 09/20/21 3:29 pm

In that case you might like to check out Trinity's TC15 -https://www.trinityamps.com/product/trinity-tc15-kit
I'll have to look at that one. Before I discovered this site, I built my bill of materials and placed my order. I based it on the Poweramp from the Mojo tone nc3015, the top boost channel from a AC30, and the ef86 channel from a DC30. I'll check out the Trinity one and see how far from that my build was going to be. I'd actually much rather use someone's tried and true schematic, as opposed to one I SWAGged together.
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Re: What are we getting from a 36W EL84 build, over an 18?

Post by JMPGuitars »

cstenger5 wrote:
Wed 09/22/21 5:16 pm
I based it on the Poweramp from the Mojo tone nc3015
Mojo has a lot of good products, but don't trust any of their schematics. Reference something else to compare it to, or you'll be troubleshooting their docs for them.

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