• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

What EL84 tubes do you like?

Hey

I am looking for some EL84 tubes, or any other type that is compatible.

What tubes do you like and why?

I am not too fond of overly warm sounding tubes and neither with very bright treble.

Can you recommend something or just share your experiences?

Telefunken, Russian 6P14P-EV, Sylvanias Black Plates have peaked my interest so far.


Cheers
 
Last edited:
You're getting close to pure conjecture in the response you expect when asking a question like this, but I'll say my favorites are the POLAM brand Polish made ones, very consistent in my experience and act as they should. Close second would be old Sylvania, followed by Russian surplus 6p14p and their EV version.
 
You're getting close to pure conjecture in the response you expect when asking a question like this, but I'll say my favorites are the POLAM brand Polish made ones, very consistent in my experience and act as they should. Close second would be old Sylvania, followed by Russian surplus 6p14p and their EV version.
How do they differ from each other? I assume the Sylvania has a more fat and warm sound, but just a blind guess

6P14. Either Russian P, P-EV, or the plain Chinese one.
What's P,-P-EV?
 
6P14 - umbrella name for tube - Chinese versions usually don't have a suffix, but there is a 6P14-J I think which would be a rugged version.
6P14P Standard 6P14 from the Soviet Union.
6P14P-EV Rugged version from the Soviet Union.
 
I haven't found much subjective difference in good tubes that are well matched, comparing plain 6P14P (Russia 70s-90s) to Philips (Amperex in US) Holland, not much in it. Also tried some vintage Mullard and Tele, not enough difference to make it worth burning up vintage tubes.
Amp is a lightly tweaked Tubelab SPP with 7600ohm 25watt Hammond O/P iron (1650FA).
Disconnecting the UL taps and using MOSFET and zener string for stabilised screen supply made much more difference than tube rolling IMHO.
 
I found one tube shop https://ussr-tubes.com/vacuum-tubes-type/pentodes and the 1970 version is -K 1980 is -EV, 1990 is -ER

this is confusing... originally it was written in cyrillic like this 6П14П-ЕВ we somehow translated the "-EB" to "-EV" no idea why, some still spell it "-EB". But I thought that 6П14П-ЕВ is the only Russian EL84/6BQ5 military version.

Idk how people come up with "-K" and "-ER"
the "K" version does exist, and is supposedly for high vibration, very uncommon to find it seems, I have one single one that came in a bulk lot of other 6p14p that I picked up on ebay a couple years ago from a seller in Ukraine. I'm not very good at remembering how the letters transcribe over to eachother.

How do they differ from each other? I assume the Sylvania has a more fat and warm sound, but just a blind guess
They sound about the same to be honest, but I found them more consistent than the Sovtek and basic 6p14p surplus. Easier to find a set that bias up closely to eachother in situations that needed close idle current for a given bias voltage.
 
I haven't found much subjective difference in good tubes that are well matched, comparing plain 6P14P (Russia 70s-90s) to Philips (Amperex in US) Holland, not much in it. Also tried some vintage Mullard and Tele, not enough difference to make it worth burning up vintage tubes.
Amp is a lightly tweaked Tubelab SPP with 7600ohm 25watt Hammond O/P iron (1650FA).
Disconnecting the UL taps and using MOSFET and zener string for stabilised screen supply made much more difference than tube rolling IMHO.
Do you have a schematic for this screen supply?
 
What is the amplifier that these EL84 tubes will go into?
I suspect possible differences in the sound of various manufacturer's EL84 tubes, versus:

Guitar Amplifiers
Hi Fi Amplifiers

Single Ended with:
Pentode mode, UL mode (and UL tap %), Triode mode

Push Pull with:
Pentode mode, UL mode (and UL tap %), Triode mode

Amplifier topology, local negative feedback, global negative feedback, output transformer, etc.

1. Plate voltage and plate current.
2. Screen voltage
3. Cathode current
Grid Bias Voltage necessary to get 1, 2, and 3 as desired.

Some EL84 tube "substitutes" (SV83 for example) may have major problems in many amplifiers (Maximum allowable screen voltage).

Negative feedback can "hide" some sound characteristics, and "bring out" other sound characteristics.
No negative feedback can "hide" some sound characteristics, and "bring out" other sound characteristics.

Context please.
Just needs to be tested as they will be used.

If you do not have UL taps, then UL operation is out unless you want to add lots of circuitry. Such a shame, UL with OPTs that have UL taps is easy, not easy without any UL taps.

Just my opinions.
 
Last edited:
I haven't found much subjective difference in good tubes that are well matched, comparing plain 6P14P (Russia 70s-90s) to Philips (Amperex in US) Holland, not much in it. Also tried some vintage Mullard and Tele, not enough difference to make it worth burning up vintage tubes.
Amp is a lightly tweaked Tubelab SPP with 7600ohm 25watt Hammond O/P iron (1650FA).
Disconnecting the UL taps and using MOSFET and zener string for stabilised screen supply made much more difference than tube rolling IMHO.
Very interesting! Am I understanding correctly the difference was positive - that you prefer the sound of your Tubelab SPP with “stabilized screen voltage” in Pentode connection over the Ultralinear connection?
 
Last edited:
Some EL84 tube "substitutes" (SV83 for example) may have major problems in many amplifiers (Maximum allowable screen voltage).

In these times of scarcity of good 6P14Ps I believe these under-appreciated “substitutes“ deserve another good look.The datasheet for 6P15P below, clearly shows a ug2 max of 330V, but with 1,5 vs 2 watt dissipation (for the EL84). Suddenly, when Svetlana started their US sales operation they relabled the same tube as SV83 with a datasheet that is wrong regarding ug2. I don’t know if this was an honest mistake, or a deliberate sales decision.

1649801382508.png