Okey, everything else seems to be same with both channels, Iq was zeroed. These measurements are bugging be, over R17 other channel shows 2,6ohm and other 2,6K, R19 100ohm vs. 21,2K.
well , be sure what's alive , what's not - before powering up
if you're monitoring across R in CRC (cap bank) , initial current jerk is normal (filling that second C) , and it's short ..... long enough to scare you for a moment
🙂
if you're monitoring across R in CRC (cap bank) , initial current jerk is normal (filling that second C) , and it's short ..... long enough to scare you for a moment
🙂
What’s the difference in sound between 1a bias and 2a? I’m just trying to decide on a case size.
Thank you very much! 🙂
I don't understand those huge reading differences across resistors, what could cause those? Well, I'll do some work and try it again.
Correction; Only R19 is now showing strange readings.. 31,2k on working amp, 100ohm on non-functional amp. And yes, they are same size resistors, took them off and measured to be sure 😀
Edit; and Q4 all legs shows shorted in multimeter on non-functional amp. Just to be clear, IQ was set to zero at first powering attempt. Took Q4 off and it's definitely broken. Now R19 makes some sense. Can I try 9240 instead?
Edit; and Q4 all legs shows shorted in multimeter on non-functional amp. Just to be clear, IQ was set to zero at first powering attempt. Took Q4 off and it's definitely broken. Now R19 makes some sense. Can I try 9240 instead?
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well , wasn't behind you when you powered it , so I really can't say what was wrong
sole thing I can say-that I never stumbled on bad brand new IRFP mosfet , never .....
yes, you can use 9240 instead , and you most probably will not hear any sound difference between 9240 and 9140
sole thing I can say-that I never stumbled on bad brand new IRFP mosfet , never .....
yes, you can use 9240 instead , and you most probably will not hear any sound difference between 9240 and 9140
it's simply sounding better
don't cheapskate with this amp , it deserves best you can manage
I didn't meant to be rude, just tired 😀 two identical channels, other one works and other won't work.
Something chanced along 9240. Now it stays stable couple on mV's about 10-15sec, then starts to climb slowly, but with increasing speed as volts go up.
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🙂
sorry for lack of smiley(s) (I'm sleepy, long day) , of course that I didn't meant that you were rude ......
and of course that I'm sad hearing that you have Dodo SIT now .....
sorry for lack of smiley(s) (I'm sleepy, long day) , of course that I didn't meant that you were rude ......
and of course that I'm sad hearing that you have Dodo SIT now .....
take good care that both SIT and mosfet are not just tightly bolted but also well isolated electrically from heatsink
check visually and with fingers for burs , check with ohmmeter after assembly
drek happens , even after years in biz .......
check visually and with fingers for burs , check with ohmmeter after assembly
drek happens , even after years in biz .......
well,completely normal , if Iq stays where needs to be
checked that you have steady 5V at 7805?
is it oriented OK ?
regarding part quality , I took care to buy so called "double gauge" , which means no nowadays thin-back regs ; and I know these are imported from reputable vendor ( range of Digikey, Mouser , Conrad , TME)
just in case , 7805 with name looking at you , pins down ; left pin is IN , mid pin is GND , right pin is OUT
regarding part quality , I took care to buy so called "double gauge" , which means no nowadays thin-back regs ; and I know these are imported from reputable vendor ( range of Digikey, Mouser , Conrad , TME)
just in case , 7805 with name looking at you , pins down ; left pin is IN , mid pin is GND , right pin is OUT
It was oriented as silkscreen marked, so pretty sure yes 🙂 is it possible that I have broke it myself somehow? I haven't actually never got my hands on new unused broken component since I also buy only from Mouser and Digikey. This time I hope that it is the case, voltage regs are those rare parts that I can buy locally!
So I checked it like 10 times visually and DMM, there was about 25v input and 0v output, so soldered it off and getting new regulator at monday.
So I checked it like 10 times visually and DMM, there was about 25v input and 0v output, so soldered it off and getting new regulator at monday.
well , I didn't made them by my self , so I can't vouch for zillion % for anything
but , as most parts which are in kit and as for regular things I'm buying for everyday's work , I'm buying same things from few local vendors at least last 20 years
never had faulty 78xx or 79xx , but there is always first time for everything 🙁
though , all you need to ruin it is one slip with probe or tweezers, sometimes even unnoticed
can't tell that I didn't made exactly that , more than once
just recently , while assembling previous SissySIT , I killed one BD critter ....
but , as most parts which are in kit and as for regular things I'm buying for everyday's work , I'm buying same things from few local vendors at least last 20 years
never had faulty 78xx or 79xx , but there is always first time for everything 🙁
though , all you need to ruin it is one slip with probe or tweezers, sometimes even unnoticed
can't tell that I didn't made exactly that , more than once
just recently , while assembling previous SissySIT , I killed one BD critter ....
just checked few things on web - these are certainly made by ST Electronics , so I resume reputable company
anyway , that's irrelevant now - what I meant to wrote is - while troubleshooting , it's probably wise to solder/mount 3A15sloblo fuses in both rails ; once when you are on safe ground , remove them out
anyway , that's irrelevant now - what I meant to wrote is - while troubleshooting , it's probably wise to solder/mount 3A15sloblo fuses in both rails ; once when you are on safe ground , remove them out
Thank you for helping with troubleshooting, temporary fuses are easy add since I have those quick connectors on PSU. More whining and crying coming at monday or tuesday when new reg is in place, stay tuned 😀
well , everything.... hoping that you'll soon rolling happy tears , like pretty much everyone who made it
(or got made by Mighty Moi
)
edit: to recapitulate .... I am here just for the money , but always happy when Greedy Boy is happy
(or got made by Mighty Moi
)edit: to recapitulate .... I am here just for the money , but always happy when Greedy Boy is happy
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