Re: Interesting Choice
Thanks for the response.
Wish I could but that will add at less another $300(new speakers)to my tube project.
The reason I wanted 6L6wxt push pull was to get 40 watts and keep the cost at $300. I have some of the parts. I need the tubes,sockets and 2 output transformers.
I repaired an old paralleled 6bq5 stereo amp that came out of a console. I paid $10 for it,so I was going to fix it than give it away.
Now I think I will buy two output transformers and run it push pull for 12 watts
Thanks for the response.
MIKET said:
Wish I could but that will add at less another $300(new speakers)to my tube project.
The reason I wanted 6L6wxt push pull was to get 40 watts and keep the cost at $300. I have some of the parts. I need the tubes,sockets and 2 output transformers.
I repaired an old paralleled 6bq5 stereo amp that came out of a console. I paid $10 for it,so I was going to fix it than give it away.
Now I think I will buy two output transformers and run it push pull for 12 watts
PP 6V6 or 807
You did not state power requirements. If you have 96-100dB efficient speakers, go a SET design. If not, read on.....
I like a quad of parallel PP (four tubes per channel) triode connected GE coin base 6V6GTA or same PPP design with vintage RCA 807s for more power. (Forget that notion parallel power tubes smear sonics). The 6V6s will produce 15-watts out & the 807 produces 30-watts out triode connected. A good twin tail type driver/splitter tube is a 6SN7 such as the Sylvania 6SN7WGT from the 1940s. Drive the 6SN7 with a 76 or octal base type 6P5GT and never look back.
Use quality parts such as Mills or Vishey 1% precision resistors. A LCLC type filter power supply with a tube rectifier such as Sylvania 5R4GYB performs well. Make sure quality audio output transformers are used. Unload the tubes slightly on the audio transformer primary. 6K primary for the 6V6 & 4K for the 807s. If going with 807, do not apply more than 400 volts measured from plate to cathode. Careful to not include the cathode bias voltage in that 400 volts- 400 volts plate to cathode! The amp will need more voltage added for cathode bias.
Use good coupling caps and inexpensive AuriCaps are a good start or perhaps good forever without those '$50 dollar each' capacitor upgrades.
I like an oil cap on that power supply LCLC output & 25uF for the 6V6 or 50UF for the 807s is plenty of capacitance at the last capacitor position.
Careful- Even a change like using a 12AU7 in place of the 6SN7 will ruin the sonics. The only half-*** acceptable 12AU7 is Hytron/CBS made in the 1950s. So, just use the older Sylvania 6SN7 as suggested.
The 6V6 design I built is so good, even a DIY PP 45 with high dollar custom audio output transformers only slightly outperformed the 6V6 lower cost design. The difference is mimimal. Only triode connected 6V6 or 807s are great, I would not use tetrode design or ultra-linear designs. One can use loctal based 7C5s in place of the 6V6. Same tube inside as the 6V6.
Be assured, the proposed designs above will blow most or all PP vintage tube amps out of the water- no contest! Been there, done that applies here.
You did not state power requirements. If you have 96-100dB efficient speakers, go a SET design. If not, read on.....
I like a quad of parallel PP (four tubes per channel) triode connected GE coin base 6V6GTA or same PPP design with vintage RCA 807s for more power. (Forget that notion parallel power tubes smear sonics). The 6V6s will produce 15-watts out & the 807 produces 30-watts out triode connected. A good twin tail type driver/splitter tube is a 6SN7 such as the Sylvania 6SN7WGT from the 1940s. Drive the 6SN7 with a 76 or octal base type 6P5GT and never look back.
Use quality parts such as Mills or Vishey 1% precision resistors. A LCLC type filter power supply with a tube rectifier such as Sylvania 5R4GYB performs well. Make sure quality audio output transformers are used. Unload the tubes slightly on the audio transformer primary. 6K primary for the 6V6 & 4K for the 807s. If going with 807, do not apply more than 400 volts measured from plate to cathode. Careful to not include the cathode bias voltage in that 400 volts- 400 volts plate to cathode! The amp will need more voltage added for cathode bias.
Use good coupling caps and inexpensive AuriCaps are a good start or perhaps good forever without those '$50 dollar each' capacitor upgrades.
I like an oil cap on that power supply LCLC output & 25uF for the 6V6 or 50UF for the 807s is plenty of capacitance at the last capacitor position.
Careful- Even a change like using a 12AU7 in place of the 6SN7 will ruin the sonics. The only half-*** acceptable 12AU7 is Hytron/CBS made in the 1950s. So, just use the older Sylvania 6SN7 as suggested.
The 6V6 design I built is so good, even a DIY PP 45 with high dollar custom audio output transformers only slightly outperformed the 6V6 lower cost design. The difference is mimimal. Only triode connected 6V6 or 807s are great, I would not use tetrode design or ultra-linear designs. One can use loctal based 7C5s in place of the 6V6. Same tube inside as the 6V6.
Be assured, the proposed designs above will blow most or all PP vintage tube amps out of the water- no contest! Been there, done that applies here.
Mullard 3-3 amplifier topology
Has anyone here tried the Mullard 3-3 topology with some other pentodes, such as EF95, EL95, 6V6, etc?
How about going ultra-linear with the output pentode?
BTW here is a nice Mullard 3-3 page: Mullard 3-3 Three Watt Amplifier
Has anyone here tried the Mullard 3-3 topology with some other pentodes, such as EF95, EL95, 6V6, etc?
How about going ultra-linear with the output pentode?
BTW here is a nice Mullard 3-3 page: Mullard 3-3 Three Watt Amplifier
Mullard 3-3 three watt amplifier schematic drawing
Here is a schematic drawing of the simplified version (without bass boost control etc.)
Here is a schematic drawing of the simplified version (without bass boost control etc.)
An externally hosted image should be here but it was not working when we last tested it.
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