el84 in triode

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JoshBernstein
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el84 in triode

Post by JoshBernstein »

Im trying to reduce the output of my 2061x style build, and im wondering how much power would be lost if the push pull pair of el84's were run in triode configuration.
I've searched around on google and have come up empty handed.
Thanks
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TUBEDUDE
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Re: el84 in triode

Post by TUBEDUDE »

You will drop about 2/3rds of your power. Volumewise it won't seem as much, but the tone and response changes may make it seem greater. At least that has been my experience with a small non Marshall 2 EL84 amp. If you firewall your amp, the difference may not seem as great.
Tube junkie that aspires to become a tri-state bidirectional buss driver.
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JazzGuitarGimp
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Re: el84 in triode

Post by JazzGuitarGimp »

Firewall?
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JazzGuitarGimp
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Re: el84 in triode

Post by JazzGuitarGimp »

Firewall? The "double post" is doubly good! :-)
Last edited by JazzGuitarGimp on Sat Mar 19, 2016 6:50 pm, edited 1 time in total.
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JoshBernstein
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Re: el84 in triode

Post by JoshBernstein »

the reason im asking is that i need an amp to bring with me to college, and it needs to be relatively quiet. I dont think i have the budget right now to build another amp, but im thinking about trying the jj el844, which is supposedly a 9 watt tube, in combination with the triode mode.
is there any other tubes i could use that have much lower output?
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JazzGuitarGimp
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Re: el84 in triode

Post by JazzGuitarGimp »

This link may prove helpful. Scroll down to the EL84 Application Data section. Two of the eight examples are push pull, triode operation. Assuming your B+ is close (one example is at 250V, the other at 300V) and your OT is close (10K in both examples) you will have an idea of what you'd be looking at.

http://tdsl.duncanamps.com/show.php?des=EL84

Edit: You might also consider VVR and PPIMV

Still curious about what is meant by "firewall your amp"... :-)
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martin manning
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Re: el84 in triode

Post by martin manning »

Lou, to "Firewall" it (the throttle) is aviation slang for push it to the limit. The firewall is the bulkhead between the pilot and the engine.

Josh, if you want to quiet your 2061 why not a PPIMV?
John_P_WI
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Re: el84 in triode

Post by John_P_WI »

My experince is that triode muddies the tone and feel of the amp. I've built a handful of 1/2 watt and 1 watt solid state amps that can still be too loud through efficient speakers. IMO, your best bet would be a good master and power scaling combination. Before going to triode, I'd suggest simply lowering the screen voltage, the little bottles would appreciate too.

Just be aware, no matter what method you employ, at low spl s, it isn't going to sound the same.
katopan
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Re: el84 in triode

Post by katopan »

I built my 18 Watt with a pentode/triode switch. Waste of time. Ended up removing it. Triode mode didn't reduce the volume by that much and sounded very bland. VVR ended up being the way to go.
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Kagliostro
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Re: el84 in triode

Post by Kagliostro »

Wrong Post

Please delete

K
Last edited by Kagliostro on Mon Mar 21, 2016 11:47 am, edited 1 time in total.
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Kagliostro
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Re: el84 in triode

Post by Kagliostro »

Some of the possibily solutions:

. PPIMV

. VVR

and, if you don't push to the max for long time the amp

. L PAD Attenuator (very simply to use)

http://www.ebay.it/itm/like/181944862555?lpid=96&chn=ps

[img:225:225]http://thumbs.ebaystatic.com/images/g/9 ... s-l225.jpg[/img]

Ciao

K
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