I'm creating a thread for an upcoming DIY project I am working on, a tube headphone amplifier called the Aegis (pronounced EE-jis). This is a true DIY project, anyone taking on this project would assume full responsibility for acquiring parts, building, and testing the amplifier, although I will be available for questions and guidance if need be. I've placed a very high priority on making this design easy to build with a large portion of the circuitry on a PCB.
At a high level, the power supply is tube rectified, CLCRCRC filtered. The circuit features a choke-loaded 6SL7 input stage, capacitor-coupled to a triode-strapped pentode output stage. The output topology is a transformer-coupled cathode follower, which at this time is the only headphone amplifier of this topology that I am aware of. There is no silicon in this circuit, it is an "old school" tube amplifier design featuring Lundahl transformers and chokes. The amplifier includes a high and low output impedance switch for the purpose of matching high and low impedance headphones.
Tubes for the amp:
-Rectifier - 5V / 2A types; GZ34/5AR4, 5V4/GZ32, 5R4, 274B. 5Y3 can also be used with lower current output tubes like 6V6.
-Inputs - pair 6SL7
-Output - pair power pentodes; 6V6, 6L6, EL34, EL37, KT66, KT77, KT88, 6550. Others as well, compatibility list in progress.
I am currently putting together materials for the project which will include the following:
-Full build of materials (BOM) document with part numbers, prices, and where to source
-Information on ordering the chassis
-PCB gerber files and information on how to order (for those located in the CONUS, I may hold a stock of these PCBs and ship them to individuals on request, more to come on that)
-Project build document that will include amplifier schematics, information on sourcing parts, step-by-step build instructions, testing procedures
This is a relatively expensive design! Pricing of all of the parts is approximately $2,000 USD. However, this is meant to be a TOTL tube headphone amplifier, an equivalent design on the commercial market would be at least 3x the price. Regardless, the project should not be taken on by those who are not willing to commit the time and cost. This amplifier was recently at CanJam SoCal in the ZMF room and there are some forthcoming reviews. Hopefully Head-Fiers will then be able to determine if this is something they'd like to pursue.
At the time of my writing this, I am waiting to receive a second chassis and set of Lundahl components to build a second Aegis for the sake of creating the build document. I anticipate I will have the project posted in its entirety by the end of January at the latest. I will update here as the project develops, it is likely the major documentation and files will be hosted on a thread at diyAudio.com, which will be linked here.
At a high level, the power supply is tube rectified, CLCRCRC filtered. The circuit features a choke-loaded 6SL7 input stage, capacitor-coupled to a triode-strapped pentode output stage. The output topology is a transformer-coupled cathode follower, which at this time is the only headphone amplifier of this topology that I am aware of. There is no silicon in this circuit, it is an "old school" tube amplifier design featuring Lundahl transformers and chokes. The amplifier includes a high and low output impedance switch for the purpose of matching high and low impedance headphones.
Tubes for the amp:
-Rectifier - 5V / 2A types; GZ34/5AR4, 5V4/GZ32, 5R4, 274B. 5Y3 can also be used with lower current output tubes like 6V6.
-Inputs - pair 6SL7
-Output - pair power pentodes; 6V6, 6L6, EL34, EL37, KT66, KT77, KT88, 6550. Others as well, compatibility list in progress.
I am currently putting together materials for the project which will include the following:
-Full build of materials (BOM) document with part numbers, prices, and where to source
-Information on ordering the chassis
-PCB gerber files and information on how to order (for those located in the CONUS, I may hold a stock of these PCBs and ship them to individuals on request, more to come on that)
-Project build document that will include amplifier schematics, information on sourcing parts, step-by-step build instructions, testing procedures
This is a relatively expensive design! Pricing of all of the parts is approximately $2,000 USD. However, this is meant to be a TOTL tube headphone amplifier, an equivalent design on the commercial market would be at least 3x the price. Regardless, the project should not be taken on by those who are not willing to commit the time and cost. This amplifier was recently at CanJam SoCal in the ZMF room and there are some forthcoming reviews. Hopefully Head-Fiers will then be able to determine if this is something they'd like to pursue.
At the time of my writing this, I am waiting to receive a second chassis and set of Lundahl components to build a second Aegis for the sake of creating the build document. I anticipate I will have the project posted in its entirety by the end of January at the latest. I will update here as the project develops, it is likely the major documentation and files will be hosted on a thread at diyAudio.com, which will be linked here.
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