Can I get the enough clean volume(headroom) with EL84 pair?

[psychepool]

I have a purpose when everytime I make a DIY tube amp.
It is "as possible as small size/loud output".
I want to loud cleantone volume that can beat the drum sound.

I thinked at the first time, the el84 is most suitable output tube for this purpose.
Because they have very tiny size and can get 15~25W output with just two tubes.


People says the 15~20W tube amps have enough clean volume output that can beat the drum volume.
But I made and used many 15~20W full-tube amps,(vox ac, marshall 18watters, Laney lc15, blues junior and etc...) and then I realized it was not true.
They can mix with drum volume only if they breaks up or make crunch tone. When play it with pure clean tone, I can't find the existence of my guitar tone.

The 6v6s have the same result with EL84s.
With the small size it has, help me to make the amp small, but unfortunatly, the clean volume is not enough to me.
(I made Princeton reverb, Deluxe reverb, Dumble lunchbox and etc.)

The final point of compromise that I found is Hammond 35W with 5881.
When I use hammond Pro reverb replacement output transformer with 5881 pair, I can get barely enough clean volume in a small box.


Is it impossible to make loud clean volume with EL84 pair?
The EL84s that I used are all insufficient.
But I have not used mesa mini heads that has EL84 pair.
They introduced it has 25W, and people says it has very loud clean volume.
But I can't trust the EL84 pair amps because of the EL84s that I used.

Does anybody used the Mesa EL84 25watters in ensemble with cleantone? Does it has enough output?
If the output is enough, why the Mesa EL84s are different?
I want know how can get 25W output with EL84 pair.


I make a Dumble with Orange Tiny Terror sized chassis. It has 35W OT with 5881.
I can get the satisfaction with It. Very small, enough loud.
But if I can get enough loud clean headroom with EL84 pair, I want to make more small clean amp for pedalboard.



Wait for your advise.

[Stevem]

Facts for you.

20 watts of clean RMS power thru a 10" speaker will not cut it with a loud drummer.

20 watts of the same above thru a 12" speaker is border line.

20 watts of the same thru 2-12" speakers = good 85 percent of the time.

35 watts of clean RMS power thru a 12" speaker will always cut it!

35 watts of the same thru 2-10 speakers will cut it 95 percent of the time.

I am sure others will chime in on this topic!

[Littlewyan]

I personally use a 35W TW Express or 50W Marshall at band practice with 12dB attenuation. So the 2x12 Cab (with 96dB Greenbacks) is only seeing roughly 1 or 2W. This seems to easily cut it with my drummer. Live I don't turn up any louder because I get miked up.

If you don't get miked up live then yes you will need more power.

Also depends on the drummer. My drummer can play much louder if he wants to but he doesn't. Some like to play full whack all the time.

[martin manning]

If you run a pair of EL84's up around 400V I think you can get what you are looking for. there is a long thread here on TAG about a transformer replacement in a Traynor YGM-3 which operates there. You could start with that and strip out the trem and reverb.

[pdf64]

Note that amps rarely achieve their claimed / theoretical power output.
I wouldn't expect a p-p pair of EL84 in cathode bias to do much above 12 watts clean.
How 'loud' a rig is, ie the volume / SPL it can achieve, is determined by the amp power, the efficiency and number of speakers, and, to a lesser extent, the cab type.

I think that a 12 watt '18 watter' with a couple of Celestion G12H30 would give a sufficient degree of cleanish SPL to keep up with most drummers.

Moving to two speakers has a lot of advantages.

[xtian]

You can squeeze larger iron and a pair of EL34s or 6L6s into nearly the same space. Why bother with lightweight tubes?

[Scumback Speakers]

I've found two el84's or 6V6's aren't enough for what you want in clean headroom. Going to need four of them, 30w clean minimum. You can do it with a single 12, but two 12's is preferable, IMO.

[Phil_S]

These are the reasonable choices:

You can squeeze larger iron and a pair of EL34s or 6L6s into nearly the same space. Why bother with lightweight tubes?

I've found two el84's or 6V6's aren't enough for what you want in clean headroom. Going to need four of them, 30w clean minimum.

You can do it with inexpensive Russian 6p3c if you keep plate voltage below 300V. The SV-83 (6p15pi) is supposed to be a 12W tube.

Speaking of the SV-83, has anyone got experience with it?

[psychepool]

Thanks all. There's many replies than I expected!

I use 1 x 12 cabinet. May be It causes the matter.
Nevertheless, I want to make enough output on 1 x 12 cab to respond to a variety of environments.

The overall opinion is EL84 pair can't get enough output.(even at the cabinet that has more speakers)
Are the Mesa Boogie 25watters have the same result?
Is there anybody play Mesa 25W combo or head to 1 x 12 cab with band? Does it also has insuffcient clean volume?
If the Mesa 25watters have enough clean volume, what is the difference between the other EL84 pair amps?

If you run a pair of EL84's up around 400V I think you can get what you are looking for. there is a long thread here on TAG about a transformer replacement in a Traynor YGM-3 which operates there. You could start with that and strip out the trem and reverb.

Can EL84s withstand the 400v?
The highest voltage that I used in EL84 plate is about 360V.
It was ceriaton creme brulee. I make it with Hammond Blues Junior OT.
But it also has insuffcient clean volume.
Can 400v makes the goals?

You can squeeze larger iron and a pair of EL34s or 6L6s into nearly the same space. Why bother with lightweight tubes?

Oh, you thinked the small size that I wanted generously.
It exceeded the desired size to use EL34 or 6L6 itself.
For example, I made the 18watters at this chassis
http://www.hammondmfg.com/pdf/1444-16.pdf
It is impossible mission that make it with EL34/6L6 and the matched iron.


If the EL84 can't get the headroom, It seems to be compromise with my 35W 5881 pair.

[Stevem]

Keep this one fact in mind.
If a 10 watt amp does not have enough clean head room for you but you feel a amp that is twice as loud would , then you need a 100 watt to get there, or a speaker that has a 6 db greater SPL rating over what you are currently using , or using two speakers .

[M Fowler]

For small venues I used to use my home built Matchless Spitfire 18w two EL84 amp with pedal board. When I thought I needed more push I engaged a linear booster (EH LPB1). No problem cutting through.

Since then I've used 18w Rocket and 30w Rocket type amps through 2x12 cab.

I have always used 2x12 cabs for gigging. I have to carry all the PA so carrying a 2x12 verses a 1x12 isn't a big deal. I then started bringing a 4x12 stereo cab with two amps Marshall type 50w and 30w Trainwreck Rocket type so each amp gets 2x12 speakers from that 4x12 cab.

Mark

[martin manning]

Can EL84s withstand the 400v?

Check it out: https://tubeamparchive.com/viewtopic.ph ... highlight=
This amp ran for a couple of decades at over 450V. After replacing the power transformer, it has now run for a year at 430V.

[tubeswell]

Good EL84s can handle around 400ish voltage on the plate. But not all EL84s are like that.

If you have 4 x EL84 in push-pull with a 30W OT (like a Vox AC30) or 50W OT (like a PV classic 50), with 12" or 15" speaker(s), you can get something of a loudish cleanish sound.

But the range of bias voltage typical of an EL84 is lower than for a tube like a 6V6 or a 6L6. This means that a further limiting factor to achieving a clean output signal, is how big of a driving signal you can hit the output tube grid(s) with. So a 6L6 under typical conditions (say 450V on the plate with -45V of grid bias), can take a much bigger driving signal before the signal at the grid clips that an EL84 with 400V on the plates and -12V of bias.

Therefore the headroom in the output signal from the PI/driver also determines the 'cleaness'. And that is affected by the type of driver tube(s) in the pre-amp, and the type of PI, as well as the number and type of gain stages in the pre-amp, and the attenuation between each stage, and fidelity of the overall signal, and the amount of NFB, and the amount of HT voltage for each stage, and the amount of driving signal from the guitar pickups etc etc.

[Stevem]

I see no sence in pushing them that hard, nor going thru the gyrations to do so if the amp needs to counted on to gig with 2 to 4 nights a week.

If you want more than 25 watts of clean power with the same feel and responce to drive signal as the 84s have then the EL34 being the same non beam type tube is the best way to go!

A real nice 4 tube set up I did for a guy long ago was two 84s and two 6v6s
In a fully beat to Hell Superreverb, with a different OT of course!

[M Fowler]

Has anyone ever built something like the Weber six EL84 amp?