My friends, this is the first time I post a comment, rode my aleph j. I measured the voltage at the output (speaker) and I 24vdc. I do not know what happens, measure the voltage between gnd and also (gate, drain and source), all voltages are 24vdc, can someone help me? I reviewed the circuit many times. I will be very grateful.
Greetings
Greetings
Dear AudioSan, thanks for the interest. The problem is with the two channels, the source is + - 24V symmetrical. I bought the fets in Germany (mached quad) per channel. I tested the ZTX before soldering them. The 2sj109 I have not tested. The voltage at the output of the speakers is 24vdc. The mosfets do not heat, no power consumption. There 24vdc in source and gate drain ....
Greetings
Greetings
okei. i bet your sj109's is fake. then this will happend. 90% of all on the marked to day are fake.
buy 2 matched pairs of sj74 insted. f.ex from spencer.
another reason for this can be the PSU. f.ex that there is no -24V
measure the PSU first. see if you get +/-24V.
but i think it is the sj109's.
buy 2 matched pairs of sj74 insted. f.ex from spencer.
another reason for this can be the PSU. f.ex that there is no -24V
measure the PSU first. see if you get +/-24V.
but i think it is the sj109's.
I had also Problems with my 2sj109bl
I think they are genuine (bought my a thime ago from Little Diode seems they have origin Parts).
But in the Aleph J they produced a slightly Hum.
First thougt it was the PSU but after changing the 109er hum was gone.
Later testet the 109er Idss was ok around ~8mA.
Hmm... what can be wrong with these little critters?
When i know the parts are the problem i would use them no more.
but if the problem is elsewere then i can take the 109er
Because "could be illusion" but I thought they sound a little bit better to me as a pair of 2sj74er
-but a humming amp drives my crazy
May be someone of you knows whats happend in my amp
greets Alex
I think they are genuine (bought my a thime ago from Little Diode seems they have origin Parts).
But in the Aleph J they produced a slightly Hum.
First thougt it was the PSU but after changing the 109er hum was gone.
Later testet the 109er Idss was ok around ~8mA.
Hmm... what can be wrong with these little critters?
When i know the parts are the problem i would use them no more.
but if the problem is elsewere then i can take the 109er
Because "could be illusion" but I thought they sound a little bit better to me as a pair of 2sj74er
-but a humming amp drives my crazy
May be someone of you knows whats happend in my amp
greets Alex
I had pin 4 not connected. I have the board layout from there:
AlephWiki : Aleph J
Had anybody compared the sound of a 109er with a pair of 2sj74?
(All settings the same except from the input Jfets)
And what was your experience? Do they sound similar for you or is there a difference in your ears?
Rear panel + some questions
First power amp build ever. It is taking time, but I am getting there.
The PCB's are done (expect for MOSFETs) and I am working on the PSU (hardwiring).
Not ever having done any metalwork, and not having the equipment or physical strength, I decided to out-source the rear panel. UPS delivered my beautiful rear panel on Friday from Schaeffer. I just had to put the parts in to see what it would look like.
Enclosed a (lousy) photo taken with my mobile phone.
Question:
I need to tap holes into the heatsinks and will probably out-source to a local metal shop. What size thread (M3, M4, etc) do I need for MOSFET's? And what depth? Metric answers, please
Another question:
I am using this type of connector (ring, fork and others)
SVES1-3.7 - MULTICOMP - CRIMP TERMINAL, FORK, 3.7MM, RED | Farnell Nederland
and have bought an expensive ratchet crimping plier
430021 - CK TOOLS - CRIMPING PLIER, RATCHET | Farnell Nederland
but am unable to apply enough force to crimp the connectors.
Are similar connectors (in fork, ring, etc varieties) available in a solder type? If so, what are they called and where can I buy them?
First power amp build ever. It is taking time, but I am getting there.
The PCB's are done (expect for MOSFETs) and I am working on the PSU (hardwiring).
Not ever having done any metalwork, and not having the equipment or physical strength, I decided to out-source the rear panel. UPS delivered my beautiful rear panel on Friday from Schaeffer. I just had to put the parts in to see what it would look like.
Enclosed a (lousy) photo taken with my mobile phone.
Question:
I need to tap holes into the heatsinks and will probably out-source to a local metal shop. What size thread (M3, M4, etc) do I need for MOSFET's? And what depth? Metric answers, please
Another question:
I am using this type of connector (ring, fork and others)
SVES1-3.7 - MULTICOMP - CRIMP TERMINAL, FORK, 3.7MM, RED | Farnell Nederland
and have bought an expensive ratchet crimping plier
430021 - CK TOOLS - CRIMPING PLIER, RATCHET | Farnell Nederland
but am unable to apply enough force to crimp the connectors.
Are similar connectors (in fork, ring, etc varieties) available in a solder type? If so, what are they called and where can I buy them?
