Show your headphone amplifier
- Thread starter boza
- Start date
cratz2
Addicted Member
Here are my two headphone amps. My amp at work is a Garage1217 Project Sunrise III driving AKG x Massdrop K7XXs.
My home amp is an APPJ PA1502A with uprated coupling and cathode caps. Right now it's driving my HiFiMan HE-500s.
Wow! How gently does that design push those KT66s?
Most guitar amp designs that use two KT66s are running about 35-45 watts! Granted, they are striving for at least a bit of power tube breakup, but still!
CZ4A
Active Member
I'd say, "very gently!" The max plate voltage is only 210V. The APPJ originally came with 6P6P (Chinese military 6V6GT) power tubes and it still works best with 6V6 and similar. My favorites for power tubes in this amp are vintage T-S 6V6GTs and Mullard EL33s.
I got the Russian T-S KT66s lightly used for cheap. I bought them to prove 6L6s could be used in this amp - the T-S KT66s have the same heater current rating and similar ratings elsewhere as a 6L6. I can't use other KT66s because they draw 1.3A, which is too much for the APPJ to handle (max 1.25A for power tubes).
However, changing the coupling caps from 0.1uf to 0.47uf is the best mod you can make to the APPJ. The amount of sonic improvement, especially to detail, was impressive. It turned the APPJ from a good amp to an outstanding amp!
boza
Super Member
Luckbad
Basshead
You should try the Garage1217 Project Sunrise with a linear PSU. I can almost guarantee you'd swap that over to your home setup if you do so and use a nice clean tube (new production Electro-Harmonix 12BH7 are surprisingly impressive, but I also really love 6N6P tubes).
Going to steal your idea, I travel a lot for work and have the same case unused sitting on a shelf.
My nobsound is tube front and end single ended. One output transistor per channel. Thats not a bad idea. I'll have to try and roundup a couple very small heatsinks since they are SMD's. What adhesive did you use to attach the heat sinks?
Cool. Hope to see some pics. If you want to cut the foam as cleanly as possible look into a DIY hot wire cutter. I used a jig saw so it’s rough. Still works fine though.
boza
Super Member
I used double sided thermal tape.
I recently changed them for one bigger one.
The tape holds it pretty solid. The heatsink is one i cut down out of a old pc.
I have 600 ohm Beyer DT880's arriving on Wednesday.
I saw discussion on head-fi that receivers won't typically drive these well.
I use a Marantz 2275 in good condition but unrestored to my knowledge.
I'm not a member at hifiengine so I can't DL the specsheet and don't have an OM for it.
I sorta panicked and ordered a JDSLABS Objective2 by NwAvGuy after many hours of frustrating research.
Will my 2275 power these 600ohm cans well or is a dedicated amp truly necessary with this old 75W receiver?
I saw discussion on head-fi that receivers won't typically drive these well.
I use a Marantz 2275 in good condition but unrestored to my knowledge.
I'm not a member at hifiengine so I can't DL the specsheet and don't have an OM for it.
I sorta panicked and ordered a JDSLABS Objective2 by NwAvGuy after many hours of frustrating research.
Will my 2275 power these 600ohm cans well or is a dedicated amp truly necessary with this old 75W receiver?
Last edited:
JoeESP9
ESL's & tubes since 83
Why not become a member? It's free and they don't send you any unwanted mail. All they ask for is a user name and password.
I use my Silk Audio MS38E Tube Integrated Amplifier............
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Luckbad
Basshead
Have you ever considering trying out a tube amplifier?
