| HOEK |
Here are some pics off my jlh69
Yes i know it is a little overconstructed , but i like separate
housing for amp and psu
The volume and control is passive
groet hoek |
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| HOEK |
| Speakers klipsh heresy |
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| HOEK |
The amps use 29V/1,5A (trafo 24v)
There is absolute no hum
The input cap. o,47uF paper in oil (audionote)
Ouput 2x1000uF blackgate nx serie |
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| HOEK |
Next plan is constructing a diy zen amplifier.
Is there anybody with experience about the different types? |
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| mikeks |
| Excellent handiwork, Hoek. :nod: |
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| Malotron |
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/foru...y.php?forumid=8
ps UGLY pic of DOZ in Hafler DH200 chassis |
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| HOEK |
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. |
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| valve power |
Great work!
Are the enclosures 'SAREL' industrial electrical enclosures? |
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| HOEK |
The enclosures are indeed Rittal KL.
We have a company and i get them via the techn. wholesaler |
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