| Introduction | The amplifier design | Construction of the top plate |
| Mains transformer | Hardware on the top plate | Construction of the wood housing |
| Soldering the parts | Listening | Measurement data |
The amplifier design was found on Jan Deckers' website. He named it Blue Ears. This site is in Dutch but the schematics and the photographs contain much information.
It is a headphone amplifier. Loudspeakers cannot be used on this amplifier. The design is simple with a very limited number of parts. See the schematic diagrams of the amplifier and the power supply. The amplifier is of the single-ended triode type and is based on the ECC99 triode made by JJ. The headphone impedance should fit the output transformers. I use a 32 Ohm headphone, but this does not seem to be very critical (as discovered later). Total price of the amplifier will be around 500 euros. Since the number of parts is small, I took high-quality parts. With lower quality parts, the price will be slightly less.
Where did I buy the parts?
| Mains transformer, output transformers and chokes for 'Blue Ears' | AE |
| ECC99 triodes | AE |
| ALPS Blue potentiometer | Triodes |
| Resistors for the power supply (Kiwame) | Triodes |
| Grid resistors (VTC) | Triodes |
| Cathode resistors (RikenOhm) | Triodes |
| Cathode capacitors (Black Gate) | Triodes |
| Ceramic tube sockets with gold-plated contacts | Triodes |
| EZ80 rectifier tube | Rotte |
| Gold-plated RCA chassis parts (for connecting the interlinks) | Art Speak |
| Power supply capacitors (JJ) | AE |
| Wire, Silver wire, Teflon (PTFE) tubing | AE |
| Silver solder (WBT) | Speakerland |
All other things can be obtained from regular shops for electronics parts. Since Triodes recently changed the assortment, part of the above parts probably cannot be obtained from them anymore. Searching the internet will surely yield alternative suppliers.