@ernesternest,
from the first pair SS looks the trace as vor using them, the second pair is inside the J2..
@Dennis Hui,
yes I changed also the power supply to another one and shorten the input pins. After minutes or hours the crackling / breezing comes and goes (sound like a fire). Yesterday was a day without any issues.
from the first pair SS looks the trace as vor using them, the second pair is inside the J2..
@Dennis Hui,
yes I changed also the power supply to another one and shorten the input pins. After minutes or hours the crackling / breezing comes and goes (sound like a fire). Yesterday was a day without any issues.
do you have thermometer, contact type (temp. sensor is NTC, little metal blob) ?
Thanks!
Soundhappy,
Pcbs are clean, i dont like them uncleand and i had some „nice“ efects with uncleaned Boards with smd Parts.
ZM,
Yes, will make temp measurement, next days.
Soundhappy,
Pcbs are clean, i dont like them uncleand and i had some „nice“ efects with uncleaned Boards with smd Parts.
ZM,
Yes, will make temp measurement, next days.
take measurement at heatsink ditto near SS, then on SS case if possible and - most interesting - on mid (drain) pin of SS
put some thermal grease on sensor, it helps
put some thermal grease on sensor, it helps
Replacing Caps
I just got a used J2 and noticed it has a couple of bulging caps. I'd like to replace them with identical replacements but I can't tell what brand they are, anyone know? They're 25V 15000uF.
Also where can I find info for setting the bias on this particular amp?
Sounds gorgeous BTW
I just got a used J2 and noticed it has a couple of bulging caps. I'd like to replace them with identical replacements but I can't tell what brand they are, anyone know? They're 25V 15000uF.
Also where can I find info for setting the bias on this particular amp?
Sounds gorgeous BTW
Attachments
if you don't have hum, caps are most probably still good, even if their caps are bulged
Pana or CDE, 25mm Dia snap-in
measure DC offset, measure voltage across 1R/3W Pana resistors, write here
Pana or CDE, 25mm Dia snap-in
measure DC offset, measure voltage across 1R/3W Pana resistors, write here
CDE SLPX 22mm if it's a 12-cap PSU. I think there was an 8-cap PSU as well but I don't know if that uses the same caps.
Thanks ZM. Looks like mine are Pana M's which I can't find but Mouser has these CDEs available SLP153M025C4P
It buzzes for one second as it powers up is that normal?
I'm not sure if I should replace them or just ride it out. Am I risking any other components if one of those caps spontaneously combusts?
It buzzes for one second as it powers up is that normal?
I'm not sure if I should replace them or just ride it out. Am I risking any other components if one of those caps spontaneously combusts?
I think all Panasonic caps have an "M" on them for Matsushita. There should be other letters/numbers on them.
It's old enough to be using the 8-cap board (assuming there was a method to the madness) and dual jfets (2SJ109BL). I think another member showed a picture of their J2 which had 109BL on one side and J74 on the other channel.
Your caps might actually be 25mm but if you're going to replace one, may as well replace them all as long as you can desolder the old caps properly. Sure looks dusty in there!
Is there a date code printed on the top of the caps?
Your caps might actually be 25mm but if you're going to replace one, may as well replace them all as long as you can desolder the old caps properly. Sure looks dusty in there!
Is there a date code printed on the top of the caps?
I've told you everything - if there is no hum in speakers, just chill
give me other data I asked for, so I could tell you is it still set as from Pa's
The bulge is just the shrinking plastic making the top plastic disk warp. Usually it means that the amp has been run in a warm environment or poorly ventilated. If you pop the plastic top you will see that the aluminum can is still flat. Routinely the caps are good, so not a reason for sleepless nights.
Ok, just chillen over here. On the left channel the output measures about 25mV. The resistors are .709V
On the other left channel the output is about 28mV and the resistors .705V
On the other left channel the output is about 28mV and the resistors .705V
Thanks Pa! I just pushed on the tops with my finger and sure enough it was just the plastic on top. I am gonna clean it though since the previous owner was apparently the world's ashiest man
so, you're perfectly good
now enjoy
btw. that pic doesn't count - no Porn, no Glory
🙂
btw. - it's funny how you have two left channels, and none right
Pa is so clever!!
how I didn't came with idea to make an amp with two same channels ..........
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