Does anyone know if there has been a build using RFT EF86’s instead of the 12AX7 tubes?
I searched this thread but did not find any information on them.
Just in case folks are wondering on how I plan on setting up my system, it would be as shown below.
Rega Planar 3 -> Wayne’s BA 2018 line stage -> Pass Pearl 2 -> BH -> Speakers
Still debating on which power tubes I plan on running with.
Thanks, James
I searched this thread but did not find any information on them.
Just in case folks are wondering on how I plan on setting up my system, it would be as shown below.
Rega Planar 3 -> Wayne’s BA 2018 line stage -> Pass Pearl 2 -> BH -> Speakers
Still debating on which power tubes I plan on running with.
Thanks, James
I would need to research that tube a lot more before I could say.
It was a tube I ran across while looking at one’s I need. I also need tubes for some guitar amps that are in line to be built so I need some NOS Tung-Sol 6550’s and Mullard XF2 duel halos for them.
So I need the above tubes and then a quad set and a pair for this build.
James
It was a tube I ran across while looking at one’s I need. I also need tubes for some guitar amps that are in line to be built so I need some NOS Tung-Sol 6550’s and Mullard XF2 duel halos for them.
So I need the above tubes and then a quad set and a pair for this build.
James
There is no BH built with EF86 instead of 12AX7 yet. 6SL7 had been used by gingertube driving 6V6 power tubes.
If properly designed, I supposed one could use any tube with adequate gain to construct an amp with the Baby Huey topology. That is our friend zintolo’s quest to build a more powerful, lower distortion amp using this topology. But if you are using Marc’s PCB, without major redesign of the circuit, you are limited to 12ax7, or 6N2P (Russian: 6Н2П). Marc’s PCB was designed to accommodate those with the 12v/6V jumper.
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After my very first thread on the "Puberty Huey", where now I see all the limits I wasn't seeing, my purpose to redesign the BH to correctly drive more powerful tubes passed through an hybrid cascoded version of the BH (that is on paper and LTSpice but yet to be tested) and then to another topology that I need to AB but seems even superior (this is the PP version: Shunt Cascode Driver meets UNSET for Push-Pull and this is the SE version: Single Ended: the pentode retaliation ).
By now I've built three my own versions of the BH EL84 (I want to sell two of them to reinvest in new amps) that I like both for their "character" and for the softness they go into saturation, and one with 6V6 (that I could sell too).
I hope to be able to build the cascoded and the new version to have an AB comparison and see what performs best.
Some earlier designs (which I have, and are related to the very beginning of this thread) have PSU onboard and can only accept ECC88/12AX7.
The loaded version. 56k is fine, you'll get around 2.1 mA that is within 5% the target value.
You are welcome. Generally speaking, for that resistor you can keep E12 values without issues. The more critical value is CCS current, not led current.
Indeed, a "led mod in the led mod" could be to have two leds in series to ground instead of just one. This allows to have more control on the CCS current, so on the working point of the PI. I will try it and report.
Indeed, a "led mod in the led mod" could be to have two leds in series to ground instead of just one. This allows to have more control on the CCS current, so on the working point of the PI. I will try it and report.
Snapper,
Looking at your attachment, have you seen anyone getting around 55 watts on the tubes you highlighted?
Thanks, James
I have a vintage echolette M150 at home, 80W sine, 110W music !
the table comes from this project:
KT 88, KT120 PP amp with the ATMega 48 on Board PCB + ATmega 48 | eBay
version without autobias:
El, 34 6L6, 6550, KT 66, KT 88, KT 99, KT 100, El 509, 5881-PP AMP PCB | eBay
the table comes from this project:
KT 88, KT120 PP amp with the ATMega 48 on Board PCB + ATmega 48 | eBay
version without autobias:
El, 34 6L6, 6550, KT 66, KT 88, KT 99, KT 100, El 509, 5881-PP AMP PCB | eBay
Attachments
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Translated versions of the Tubeland descriptions for the KT88 DIY kits
KT 88, EL 34, KT 120, oder Röhren mit Gleicher Pinbeleg
KT88 PP Mega LP
Pay attention to the different required OPT impedance depending on the tube and plate voltage used !
KT 88, EL 34, KT 120, oder Röhren mit Gleicher Pinbeleg
KT88 PP Mega LP
Pay attention to the different required OPT impedance depending on the tube and plate voltage used !
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I remember the BH TENA presented here, which was unfortunately not developed to the end and, unfortunately, there was no pcb to buy
