Yes Nick 150 ohm will be OK with the VDV-8010 transformer. In fact this is the screen resistor value used by Menno van der Veen in is book on vacuum tube amplifier for an amplifier with two EL84 and a VDV-8020 OT
The screen resistor is like a protection resistor and any value between 100 ohm and 1k can be used, in my amplifier I use 270 ohms 2W resistors.
Just a reminder : on the schematic the heater voltage is 6.3V, this is for ECL86 tubes, of course if you are using PCL86 like me you need about 12 to 13V for the heater (about 300 mA).
Best regards,
Marc
The screen resistor is like a protection resistor and any value between 100 ohm and 1k can be used, in my amplifier I use 270 ohms 2W resistors.
Just a reminder : on the schematic the heater voltage is 6.3V, this is for ECL86 tubes, of course if you are using PCL86 like me you need about 12 to 13V for the heater (about 300 mA).
Best regards,
Marc
PCB
Dear Rootz!
Thank you for the help! I copied the design foto into a form. I called it in next the Sprint-Layout and drew. The pcb turned out like this in the barn.
Yet the a component was modified I have to discover a position. PCB 105 micron.
http://kepkuldes.com/images/1a75259414d51f910c06b2754986462c.jpg
Dear Rootz!
Thank you for the help! I copied the design foto into a form. I called it in next the Sprint-Layout and drew. The pcb turned out like this in the barn.
Yet the a component was modified I have to discover a position. PCB 105 micron.
http://kepkuldes.com/images/1a75259414d51f910c06b2754986462c.jpg
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Dear Rootz!
Thank you for the help! I copied the design foto into a form. I called it in next the Sprint-Layout and drew. The pcb turned out like this in the barn.
Yet the a component was modified I have to discover a position. PCB 105 micron.
http://kepkuldes.com/images/1a75259414d51f910c06b2754986462c.jpg
Holy cow, that looks fantastic!
Please do note I made a small mod to the original schematic. You can derive the HT/feedback to the plates of the driver tube from the plates or screen grids of the output pair. Adjust the 47k resistor to the drivers to taste (probably around 15k for roughly the same amount of feedback).
Onto new one the thanks!
The pcb, a buffer will be capacitors on the adverse page almost ready. I have to prepare the transformers going out in the future. Network transformers 100VA his piece, 250V AC on the way out. There is much work with him yet.
http://kepkuldes.com/images/ae5bf4748266d015b0f4d742d39e9d68.jpg
Wow, I read the whole thread, spanning over a decade. I was completely determined to build one of these when I started reading, but have since been giving a pair of ESLs that suck up over 100W for normal listen levels, still hope to build one of these sometime soon.
Many of the links are broken. Including the wiki that has been linked to over and over, was it moved? Or just gone forever?
Thanks to Gingertube, Yvesm, and everyone else for all the free education along the way.
Cory
Many of the links are broken. Including the wiki that has been linked to over and over, was it moved? Or just gone forever?
Thanks to Gingertube, Yvesm, and everyone else for all the free education along the way.
Cory
I'm currently putting together a BOM and schematic for this amp, I was wondering 4 things:
1: Does anybody already have a BOM so once I finish mine I can cross-reference it?
2: in the schematic, what to TP1, TP2, and TPCOM stand for?
3: Has anybody made the schematic in KiCAD, who can give me advice on how to place the transformers?
4: PCB vs. Point to Point.
1: Does anybody already have a BOM so once I finish mine I can cross-reference it?
2: in the schematic, what to TP1, TP2, and TPCOM stand for?
3: Has anybody made the schematic in KiCAD, who can give me advice on how to place the transformers?
4: PCB vs. Point to Point.
A BOM for the PCL86 Baby Huey is attached
I have been quite busy recently but finally I have designed a first layout for the EL34 PCB and I have also included the recommendation of Ian for several resistors in the schematics... They are also attached in this message. If you see anythings wrong don't hesitate to tell me. I may send the PCB in production when I will be sure everything is OK.
Best regards,
Marc
I have been quite busy recently but finally I have designed a first layout for the EL34 PCB and I have also included the recommendation of Ian for several resistors in the schematics... They are also attached in this message. If you see anythings wrong don't hesitate to tell me. I may send the PCB in production when I will be sure everything is OK.
Best regards,
Marc
The EL34 is my third project based on the Baby Huey concept
I started with the ECL86/PCL86 version, after I build an EL84 version (both presented in previous pages) and I was so happy with the sound that now I am trying to make a more powerful version with the EL34, I read once that it is like an EL84 on steroid
I have used Ian Music Angel modifications as a starting place for this version!
I was also looking for a quad EL84 but that required more work, including an auto-bias circuit which was not on the amplifier PCB but on a separate PCB which included also the power supply regulation and as I was too busy with other things, I put it on hold for some time.
Marc
I started with the ECL86/PCL86 version, after I build an EL84 version (both presented in previous pages) and I was so happy with the sound that now I am trying to make a more powerful version with the EL34, I read once that it is like an EL84 on steroid
I have used Ian Music Angel modifications as a starting place for this version!
I was also looking for a quad EL84 but that required more work, including an auto-bias circuit which was not on the amplifier PCB but on a separate PCB which included also the power supply regulation and as I was too busy with other things, I put it on hold for some time.
Marc
Alright, I've been working on drawing the schematics from the low 600's, and one quick question. I'd be building the Power supplies and signal stages separately, and tying them together with an umbilical. I'm thinking of running one wire for 0V, a pair for the EL84 heaters and 12ax7 heaters each, a -48V line, and a +56V line. I'm assuming I shouldn't run seperate lines for 0V and ground, and just connect my star ground/ground plane over to the 0V line and the chassis, but just wanted to confirm.
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Just be aware that EL34s need a lot more grid drive than EL84s. Maybe your Ian Music Angel mods will take care of that.so happy with the sound that now I am trying to make a more powerful version with the EL34, I read once that it is like an EL84 on steroid
Sent from my phone. Please excuse any typpos.
Onto new one the thanks!
The pcb, a buffer will be capacitors on the adverse page almost ready. I have to prepare the transformers going out in the future. Network transformers 100VA his piece, 250V AC on the way out. There is much work with him yet.
http://kepkuldes.com/images/ae5bf4748266d015b0f4d742d39e9d68.jpg
Hi Appme, am I right that your layout is a direct copy of mine? If so, keep in mind that I designed the pcb with the tubes in the solder side of the pub and NOT on the component side.
Maybe I'm missing the point. In normal and intended use the output tubes won't require any drive current. That's for typical AB1. The source followers make it possible to drive the grids positive though; AB2. Not that you gain much, but it's possible. What you gain is no more blocking distortion and a light load on the plates of the ecc83.
My guess is that AquaTarkus meant the driving voltage. The driver should provide approx triple the drive voltage before grid conduction when compared to El84's. I think that should be entirely possible, but you might need to adjust the feedback (lower shunt resistor and/or increase feedback resistor).
My guess is that AquaTarkus meant the driving voltage. The driver should provide approx triple the drive voltage before grid conduction when compared to El84's. I think that should be entirely possible, but you might need to adjust the feedback (lower shunt resistor and/or increase feedback resistor).
Hey, finally finished my schematic in kiCad, probably going to end up building it P2P, but right now working on sourcing all the parts. Could you guys look over this and make sure everything looks good before I finish sourcing and actually order the parts? Attached are the schematics and the KiCAD project.
Hi!
Since the pcb is not metal bores, the components got to the side of the tubes so. The buffer filters they no. The tubes are in a good position.
The rest of the components low, warmth flies away above them.