18Watt.com

I like the clear tone of the EI EL84 .
When I tried the selected Tad EL84 I realized that the EI lacks a lot of mid punch by comparison.
Therefore I'm trying to improve the missing mids of the EI EL84 with warm sounding preamp tubes.
So far I've been using GE 5751 - not knowing that these are favored among the guitar crowd and also by SRV - and I like them especially when they are slightly distorting while the power amp is fired up .
However they aren't that punchy and not the most brilliant tubes out there.
I'm wondering if you guys are using the EI El 84 in your amp? Some suggestions for preamp tubes?

I'm thinking about putting the EI 12ax7, JJ 12ax7 or Tube Town 7025 in my amp or even mix them together!?

Or would it make more sence to use the selected Tad EL84 and put some bright preamp tubes in the amp to get more brilliance out of those Tad's?

I've been trying different preamp tubes to improve the mid punch of the EI EL84 but I come to the conclusion that a EI EL84 cant't sound as powerfull as a TAD EL84!
Therefore I gonna look for other EL84 like JJ and Sovtek!

Do you guys have recommendations on EL84's that sound more powerfull than EI's but still have accentuated highs?

Ei el 84 is excellent tube,one of the best.
But you can`t just swap tubes without biasing and go...this one`s better.
It is also a good point to know what amp/bias style we talking about...

I'm using a single ended class A power stage (waiting for the 18Watt output transformer) with bias resistor at 220Ohm which makes a constant current of 0.040A for the EI and 0.0398A for the TAD (quite the same). The preamp stage as well isn't 18Watt style since there's no phase inverter:

V1: GE 5751 (/12AX7-C)
V2: 12AX7-C (yugoslavia) (/EI 12AT7/GE 5751/)
(No tone or equalizer circuit)

For tests I gonna install a bias pot for the EL84 (250Ohm).
Maybe a different bias is gonna change the sound of the EI EL84 (at least when playing loud)!?

leslie wrote:Ei el 84 is excellent tube,one of the best.

Did you recognize reduced punch/power using the EI EL84?
What kind of circuit/amp are you using?

If you want a bright 12AX7, try the Ruby Silver Series, prominet in the upper registers without drilling your ears out.

With all the time and money it takes to find a useable combination of new production tubes, you could just buy a set of good NOS ones, have great tone and be done with it, don't mean to be rude, just sharing my experiences.

Franky wrote:I'm using a single ended class A power stage (waiting for the 18Watt output transformer) with bias resistor at 220Ohm which makes a constant current of 0.040A for the EI and 0.0398A for the TAD (quite the same). The preamp stage as well isn't 18Watt style since there's no phase inverter:

V1: GE 5751 (/12AX7-C)
V2: 12AX7-C (yugoslavia) (/EI 12AT7/GE 5751/)
(No tone or equalizer circuit)

For tests I gonna install a bias pot for the EL84 (250Ohm).
Maybe a different bias is gonna change the sound of the EI EL84 (at least when playing loud)!?

leslie wrote:Ei el 84 is excellent tube,one of the best.

Did you recognize reduced punch/power using the EI EL84?
What kind of circuit/amp are you using?

I did not recognize any power reducing with EI(I have 80`s production Ei),fresh ones should be as same as philips El84(Holland),because the productin line in Serbia(ex Yu)was originally set up by philips.
I use them in 60`s ac 30 and 70`s Guyatone (which is transformed to )2xEl 84/SS rect./custom wounded OT by myself/60`s greenback/fixed bias/.
I have Mullard and Brimar and it`s a hard to tell big difference(they are subtle).
I had oportunity to try out Telefunken (Berlin/germany)in Guyatone...at first hand (just swaped) nothing special,but when I tuned it around 30mA(1 0hm resistor method)...ooooh boy! What a musical distortion/clean harmonics...
One more tube is very interesting.. ****(Japan) El84, fantastic with big F!
When I Heard it in my amp was so amazed ...I found that **** factory was set up by Mullard.

Regards

Wait, what tubes are ****???

Matsush*ta?

Alexo wrote:Wait, what tubes are ****???

Matsush*ta?

Yes.


**** happens ?

I found in a old tube radio the Telefunken EL84, so i gonna try out that 30mA trick soon.
Hopefully I can get these japanese EL84 somewhere.

leslie wrote: I have Mullard and Brimar and it`s a hard to tell big difference(they are subtle).

My Telefunken EL84 concerning it's overall sound is pretty much like the EI EL84, however the Telefunken adds (in some conditions) sweatness to the tone and is smoother than the EI EL84.

The TAD EL84 sounds like you would use a bass-mid-boost in your circuit - the change in sound really isn't suble anymore!
I wonder if someone has made the same experience with TAD's or is mine differing from the "normal" EL84 production !?

I've heard the same thing about their 6V6's, fwiw.

Franky wrote:I found in a old tube radio the Telefunken EL84, so i gonna try out that 30mA trick soon.
Hopefully I can get these japanese EL84 somewhere.

No this is not trick ,that was sweet spot for my amp with given trafo/speaker configuration/PI/Circuit...yours could be whole different.
Experiment with bias ....( recomended bias for tube in datasheet +/-).

http://tone-lizard.com/Biasing.htm

I've been using EI EL84's in my AC30 since I got it new in 1993. I'm still going through my pre-war EI's though so I haven't used any recent manufacture yet in it. I've tried NOS Mullards, Telefunkens, Amperex, GE, in addition to modern JJ, Chinese, and New Sensor (Sovtek, EH, etc) and except for the Amperex and GE's, the EI's really sound the best. I haven't had any issues with microphonics either. I keep a nice quad of GE's to use for recording purposes, and other than that, I use the EI's in this amp.

I can see where depending on the amp you might think their tone is a little mid-shy, but the highs are very nice on the EI's and the overdrive tone is much better on them than most others. Hi-fi guys really like the EI stuff too...

I'm relieved that I'm already using s pretty good tube (EI EL84) in my amp; thanks for the input.
Searching for the right output tube seems to belong more into the category of finetuning. So the TAD EL84 probably is an exception. I'll maybe try a good NOS in future to make up my mind about these tubes.

I believe that the weak mids and bass can be traced back to the output transformer that I'm currently using (still waiting for the authentic Marshall 18Watt transformer).

To Leslie:

You wound your transformer yourself, right? Where did you get the information about that (core, ...)? Do I have to care about DC resistance besides the AC resistance?

Franky wrote:
To Leslie:

You wound your transformer yourself, right? Where did you get the information about that (core, ...)? Do I have to care about DC resistance besides the AC resistance?

1.You must take care of everything when you build transformer.
2.If not ,either you are dead or your amp is .
Formulas,ratios,math,wire diameter,good winding skills,...or results are poor-
Or see - 2.
Good output transformers are affordable these days,so don`t gamble with your 2.

Unless you know what you are doing,but according to way you put (last)question to me...dont`t do it.

I must be rude here,sorry!(Poorly homemade transformer is Pandora`s box.)