High-End Tube Amplifier Schematic Design -- 2
Budget: €30 – €250 EUR
Project Goal
I am looking for an electronics designer with proven experience in high-end tube amplifier design to create a complete, precise, and build-ready schematic for a stereo power amplifier in pure Class A, push-pull with EL34 tubes.
This is a real project intended for manual point-to-point assembly (no mandatory PCB). I am not looking for a theoretical simulation — the schematic must be ready for actual construction and technically sound.
⸻
Technical Specifications
• Configuration: Stereo, push-pull, pure Class A
• Output tubes: 2× EL34 per channel (total 4 EL34)
• Driver stage: ECC81 or suggested alternative (e.g., 6SN7, ECC88)
• Output power target: ~15–20 W/ch into 8 Ω
• Input: Stereo RCA
• Speaker output: 8 Ω via quality output transformer
• Volume control: Stereo potentiometer, bypassable via switch (or relay)
• Optional: Switchable negative feedback
• Optional: Triode / Ultra-Linear mode switch
⸻
Power Supply
• Mains: 230 V AC
• Main switch: ON/OFF with fuse
• Rectification: Tube (e.g., GZ34) or solid-state (designer’s suggestion)
• Heater supply: AC or DC (designer’s suggestion)
• B+ target voltage: 400–420 VDC
• Soft-start: Recommended
• Mute-on-delay: Appreciated
⸻
Deliverables
• Complete schematic – PDF + source file (KiCad, EasyEDA, or similar)
• BoM with real, available components (with supplier references)
• Transformer recommendations with real model codes (or winding specs)
• Chassis layout suggestion – positioning of transformers, sockets, controls
• (Optional) Simple PCB only for auxiliary circuits (soft-start, delay, etc.)
• Notes for assembly to avoid hum and interference
⸻
Payment & Milestones
Milestone 1 – 30%
Released only after delivery of a complete preliminary project including:
• Draft schematic matching the agreed specifications
• Defined circuit topology & main component values
• Power supply concept & transformer specs
Milestone 2 – 40%
Released only after delivery of the final build-ready schematic, in PDF and editable format, fully verified and technically consistent.
Milestone 3 – 30%
Released only after delivery of:
• Complete BoM with real, purchasable parts
• Chassis layout with physical component placement
• Transformer recommendations with supplier details
• (Optional) Auxiliary circuit PCB files (if included)
⸻
About me
I’m an audio enthusiast with good manual skills and experience in soldering and discrete electronics. I want a solid, real, and technically correct project — not something cosmetic or unfinished.
⸻
Languages
English or Italian
⸻
Budget
150 euro
⸻
Final Note
If you love vacuum tube audio and want to contribute to a serious, enjoyable DIY project, this will be rewarding for both sides.
I am looking for an electronics designer with proven experience in high-end tube amplifier design to create a complete, precise, and build-ready schematic for a stereo power amplifier in pure Class A, push-pull with EL34 tubes.
This is a real project intended for manual point-to-point assembly (no mandatory PCB). I am not looking for a theoretical simulation — the schematic must be ready for actual construction and technically sound.
⸻
Technical Specifications
• Configuration: Stereo, push-pull, pure Class A
• Output tubes: 2× EL34 per channel (total 4 EL34)
• Driver stage: ECC81 or suggested alternative (e.g., 6SN7, ECC88)
• Output power target: ~15–20 W/ch into 8 Ω
• Input: Stereo RCA
• Speaker output: 8 Ω via quality output transformer
• Volume control: Stereo potentiometer, bypassable via switch (or relay)
• Optional: Switchable negative feedback
• Optional: Triode / Ultra-Linear mode switch
⸻
Power Supply
• Mains: 230 V AC
• Main switch: ON/OFF with fuse
• Rectification: Tube (e.g., GZ34) or solid-state (designer’s suggestion)
• Heater supply: AC or DC (designer’s suggestion)
• B+ target voltage: 400–420 VDC
• Soft-start: Recommended
• Mute-on-delay: Appreciated
⸻
Deliverables
• Complete schematic – PDF + source file (KiCad, EasyEDA, or similar)
• BoM with real, available components (with supplier references)
• Transformer recommendations with real model codes (or winding specs)
• Chassis layout suggestion – positioning of transformers, sockets, controls
• (Optional) Simple PCB only for auxiliary circuits (soft-start, delay, etc.)
• Notes for assembly to avoid hum and interference
⸻
Payment & Milestones
Milestone 1 – 30%
Released only after delivery of a complete preliminary project including:
• Draft schematic matching the agreed specifications
• Defined circuit topology & main component values
• Power supply concept & transformer specs
Milestone 2 – 40%
Released only after delivery of the final build-ready schematic, in PDF and editable format, fully verified and technically consistent.
Milestone 3 – 30%
Released only after delivery of:
• Complete BoM with real, purchasable parts
• Chassis layout with physical component placement
• Transformer recommendations with supplier details
• (Optional) Auxiliary circuit PCB files (if included)
⸻
About me
I’m an audio enthusiast with good manual skills and experience in soldering and discrete electronics. I want a solid, real, and technically correct project — not something cosmetic or unfinished.
⸻
Languages
English or Italian
⸻
Budget
150 euro
⸻
Final Note
If you love vacuum tube audio and want to contribute to a serious, enjoyable DIY project, this will be rewarding for both sides.