I am waiting for some parts and the PCB to build Mark's T2 head amp.
Will be comparing it against few others I've build through the years, including:
-A Mosfet amp based on Marcello's (Tortello) Zen-like design with simple, unregulated PSU
-An opamp+transistor amp (NE5534+BD139/40) with regulated PSU
-A tube design based on a variation of EARMax amp by Morgan Jones (tube rectifier PSU, AC filaments)
-Another tube design using 6DJ8 with 6AS7 as CF (also tube rectifier PSU, AC filaments)
I like the simple, all through-hole, low parts-count approach of Mark's design. Will power it with some kind of linear PSU though.
Will be comparing it against few others I've build through the years, including:
-A Mosfet amp based on Marcello's (Tortello) Zen-like design with simple, unregulated PSU
-An opamp+transistor amp (NE5534+BD139/40) with regulated PSU
-A tube design based on a variation of EARMax amp by Morgan Jones (tube rectifier PSU, AC filaments)
-Another tube design using 6DJ8 with 6AS7 as CF (also tube rectifier PSU, AC filaments)
I like the simple, all through-hole, low parts-count approach of Mark's design. Will power it with some kind of linear PSU though.
What kind of T2 amp is this?
Asking because there is the original Stax T2 and also Kevin Gilmore's vastly improved T2, sometimes referred to as the DIY T2.
I have both, but not Mark's T2.
Edit: Oh, you mean this one? Completely different class of an amp, sorry to bother. And it was also renamed and is no longer called T2.
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I designed a pocket Class A headphone amp a while back. Superb sounding single ended Class A. Should work well for earbuds as they are generally very sensitive. For regular cans, don’t go lower than 50ohms impedance.
The BF862 is harder to find and can be replaced by 2SK209 with a small resistor change. Output MOSFETs can be almost anything N channel and even IRF610 can work. I ended up using a pair of Panasonic SEPF 1000uF 16v caps in parallel for output DC block. This can drive 50ohm headphones. Rechargeable 9v batteries last almost 3hrs per charge. Don’t use alkaline except for testing unless you don’t mind going through expensive batteries like water.
I came from Vietnam. I asked in your thread about changing capacitor. I am using Whammy headamp, it drives my diy earbud awesome, so I try to find class A portable for my earbud when I want to listen music far from home. But I think portable class A can not compare with desktop amp like Whammy.
Maybe not available as a kit but the schematic is available (inspired by David Berning's MicroZotl) and it is considered by many to be the best (arguably) so i juts gave it i go and i must admit it is very clean and powerful enough to even drive a loudspeaker (dc level is possible if no coupling cap is used).
