Beautiful JLH you have there. There are a few things you can explore on your 1969JLH. Try faster Output Transistors. I found a significant improvement going from mj21194s (onsemi) to 2sc5200s (toshiba). You can also tweak the harmonics (distortion) by varying the gain of Tr1 vs Tr2: http://www.passdiy.com/pdf/PLH_amplifier.pdf explains this in more depth than Hood did. I am using 160hfe MJL4281As for Tr1 and 110hfe 2SC5200s for Tr2 ( ~2/3 gain of Tr2/Tr1.) has a warm sweet top end with NS10/rodgers ls3/5a and SL10/ProAc 1sc.
Next plan is constructing a diy zen amplifier.
Is there anybody with experience about the different types?
The Zen variations articles is a good place to start if you have not read them yet.
http://www.passdiy.com/amps.htm
and after that, the Pass forum
http://www.diyaudio.com/forums/forumdisplay.php?forumid=8
ps UGLY pic of DOZ in Hafler DH200 chassis
Next plan is constructing a diy zen amplifier.
Is there anybody with experience about the different types?
The Zen variations articles is a good place to start if you have not read them yet.
http://www.passdiy.com/amps.htm
and after that, the Pass forum
http://www.diyaudio.com/forums/forumdisplay.php?forumid=8
ps UGLY pic of DOZ in Hafler DH200 chassis
Attachments
Mikeks,Malotron,
Thanks for your respons.
The input transistor is a 2SA970,
driver is a 2SC3421
The output transitors are MJ15003
Very important is the output capacitor,first i tried a philps
4700uf 100V LL (Qserie) but the sound was a little harsch
and agressing in the hights.
Replacing with 2x1000uf BG,s givea a big improvement ,the sound is now more flowing and naturual.
Thanks for your respons.
The input transistor is a 2SA970,
driver is a 2SC3421
The output transitors are MJ15003
Very important is the output capacitor,first i tried a philps
4700uf 100V LL (Qserie) but the sound was a little harsch
and agressing in the hights.
Replacing with 2x1000uf BG,s givea a big improvement ,the sound is now more flowing and naturual.
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