Aleph 3 Upgrade

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thanks ZMa ( ZenMasterAleph) :D

and less speaker dampening too i presume so i will keep the 0,47 .
i also re-put the AC current resistor as the bass seems also more controlled with it.
very fun amp to tweak :)

let ' say i'm a crasy frogy is there a way to put a Sony 2SK82 in place of the mosfet ? 21V 1,2amp seems good for it ?
 
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more OLG , in same circuit , means more feedback , thus greater damping factor

speaking of tiny differences .......

2SK82 is depletion mode device , while mosfets in your amp are enhancement mode (google, ya kwayzee froggy :rofl: )

so , that'll be completely reworked Frankenstein ......

leave it (now) as is , enjoy ..... and build something else and experiment with it
 
KAboum ! :bomb: put the 0.33 resistor and foget to resold the Bias resistor result 10V on the O,33 source resistor and one IR244 dies :rolleyes:

so even if the Pass design are idiot proof there is some exception ( call it french touch )
by chance as now i run it as Mini Aleph J i have 3 Mosfet Left..

after some rework , i finished with 1.8AMP 22V on each IR244 and an Heatsink at 50° C

that's all folks :D
 
sissiest of all

AlephJschematic.gif


is it possible to replace the semisouth JFET with a Lovoltech LU1014D without any change ?

wants to try the queen of the siissie's aleph :)
 
oops i did it again..

some strange idea comes to me this week i have change the irp244 on my aleph Mini with a Sony SIT 2SK82.
i just dial the upper CCS to 1.5amp and put a negative supply on the Vfet betwwen 21V negative rail and vfet gate to get 1.5amp bias
swap the input jfet and attack directly the Vfet input with a capacitor.
and put a 10000uf capacitor on the speaker output for safety :D
so let say it's a L'amp CCS with bipolar supply.

but you know what it doesn't work , can't have 0V offset on the output ( always
-16V ) there is sound anyway not so bad ? is there a reason i can't have no offset here ?

i also wire it as normal l'amp CCS and it works fine at 19V 1.5amp so i have no problem with a chip somewhere..

i can't wait the ZM sentence :D
 
Hello colleagues! I built an amplifier based on Chinese boards. It works, but in one of the channels there is a slight noise of 50 hertz. The power supply is one for two channels. Everything is symmetrically connected. Can not understand! Any thoughts? Where to look?
Thanks!
Oleg
 
Give us more details... What type of power supply do you use? What are the values of caps and resistors/coils (depending of which is used)? Draw us a topologic schematic of your grounding scheme...

***IMG_3143.JPG | Files.fm.
Now I dismantled the RCA connectors from the case. And the whole case is not grounded. However, I tried to connect a single wire from the power supply to the case. Nothing changed.
Look at the photo montage! Any ideas may come up. I have little experience building such devices.
 
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