I have built 4 different el 84 pp the last 30years. The Tubelab SPP are the best! I built mine p2p soldering. Hammond transformers
This thread has lots of good examples of different tube amplifier designs.
Some are good EL84 designs.
And that reminds me of how easily I was satisfied in 1959.
I built a simple 12 Watt Knight Kit push pull EL84 mono-block, and an Electro Voice Wolverine 12 inch full range, in an EV Marquis kit enclosure, plus EV crossover to an EV T35 tweeter; and just mono until I built the second amplifier.
Before the second speaker came along, it was stereo with LPs on a Garrard changer with a Pickering cartridge, and a Roberts Headphone.
Music was very enjoyable on that simple system.
I think we often get away from simple and effective designs, because we are searching for a more "perfect" system.
And that can reduce our enjoyment of what we already have.
Some are good EL84 designs.
And that reminds me of how easily I was satisfied in 1959.
I built a simple 12 Watt Knight Kit push pull EL84 mono-block, and an Electro Voice Wolverine 12 inch full range, in an EV Marquis kit enclosure, plus EV crossover to an EV T35 tweeter; and just mono until I built the second amplifier.
Before the second speaker came along, it was stereo with LPs on a Garrard changer with a Pickering cartridge, and a Roberts Headphone.
Music was very enjoyable on that simple system.
I think we often get away from simple and effective designs, because we are searching for a more "perfect" system.
And that can reduce our enjoyment of what we already have.
@6A3sUMMER: you old codger!
Wow, in 1959 I was 6, in kindergarden.... James J. Sullivan Elementary.
Decorating a wooden spring-type clothespin with colored pencils and my name, so that our class could clip our galoshes together, after I trudged 5 blocks to school in 8 inches of snow. - Alone of course, there was no need for a parent to walk with us back then.
But by 1968, I was 15, and learning to put together a 3-tube amp with 50L6, 35Z5, 12SQ7.
My older neighbor also gave me a Quam 8" speaker and a Garrard RC88 and I installed a Sonotone cartridge on it.
I remember it sounded pretty good with a simple plywood box for the speaker.
Your "I think we often get away from simple and effective designs, because we are searching for a more "perfect" system.
And that can reduce our enjoyment of what we already have."
is quite true, and obvious these days.
It seems that the nitpicking has gone to people's heads in an unusual way.
Wow, in 1959 I was 6, in kindergarden.... James J. Sullivan Elementary.
Decorating a wooden spring-type clothespin with colored pencils and my name, so that our class could clip our galoshes together, after I trudged 5 blocks to school in 8 inches of snow. - Alone of course, there was no need for a parent to walk with us back then.
But by 1968, I was 15, and learning to put together a 3-tube amp with 50L6, 35Z5, 12SQ7.
My older neighbor also gave me a Quam 8" speaker and a Garrard RC88 and I installed a Sonotone cartridge on it.
I remember it sounded pretty good with a simple plywood box for the speaker.
Your "I think we often get away from simple and effective designs, because we are searching for a more "perfect" system.
And that can reduce our enjoyment of what we already have."
is quite true, and obvious these days.
It seems that the nitpicking has gone to people's heads in an unusual way.
Another good choice would be adapt any of the above mentioned EL84 designs for the EL86. The EL86 can do 25 watts out, for the same given supply voltage to the plates, and will do so at a reduced 4k plate-to-plate load. This is all right from the GE datasheet too, no spec busting or abuse. Any decent driver can cope with the needed swing, and it will merely take some bias adjustments, smaller load resistance, and a smaller screen voltage supply, which is minimal added complexity.
Good NOS quality EL86 (6CW5 too, same tube) are cheaper than the EL84- and this means you can pick up more for the money to match them up to your liking. I like the old "Polam" brand a great deal.
Good NOS quality EL86 (6CW5 too, same tube) are cheaper than the EL84- and this means you can pick up more for the money to match them up to your liking. I like the old "Polam" brand a great deal.
With EL84 you can try Pentode, UL, or triode. With the EL86 (or PL84 or UL84) and that B+ it is going to be pentode only, or a more complicated power supply for UL and Triode. Maybe a bit restrictive?
Which is better?
According to what criteria?
Cost
Low Frequency
Weight
Efficiency
Impedance
Etc.
Beauty is in the eye of the beholder
According to what criteria?
Cost
Low Frequency
Weight
Efficiency
Impedance
Etc.
Beauty is in the eye of the beholder
2A3 PP in Class AB1 can provide 15W.
EL84 or 6V6 PP will likely be less expensive, but subjectively inferior (IME) and not neccessarily any easier to build. 2A3 will require more voltage gain but this is just a matter of selecting different input/driver tubes. There is added flexibility in that it can also be biased it into Class A for 6-7W.
See if you can find one to listen to before settling on EL84 or 6V6.
EL84 or 6V6 PP will likely be less expensive, but subjectively inferior (IME) and not neccessarily any easier to build. 2A3 will require more voltage gain but this is just a matter of selecting different input/driver tubes. There is added flexibility in that it can also be biased it into Class A for 6-7W.
See if you can find one to listen to before settling on EL84 or 6V6.
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