2 picoDumbs
he look like great !!!
no match irfp150 , but how many watt for two irfp150 per chanel ?
Do you think I could use my transformers 2x35v?
he look like great !!!
no match irfp150 , but how many watt for two irfp150 per chanel ?
Do you think I could use my transformers 2x35v?
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Pretty sure Zen Mod has output boards to allow for multiple pairs of output devices. You can basically build any powered version you want.
Send him a pm.
Hello and sorry Zen Mod, I had not looked at my message.
actually evolved to the technoligie 5 and aleph is little to be more topical. I realized some years ago a hybrid amplifier class A based on irf 150, so I know the sound. I like the babelfish and his mount is tried and healthy.
I read the thread and I'm very interested. I do not have all my answers but I'll order a package.
A very fast for later
actually evolved to the technoligie 5 and aleph is little to be more topical. I realized some years ago a hybrid amplifier class A based on irf 150, so I know the sound. I like the babelfish and his mount is tried and healthy.
I read the thread and I'm very interested. I do not have all my answers but I'll order a package.
A very fast for later
And finally to complete my original idea, I realized the aleph 5. In 2016 the ZEN Mod !!!
PicoDumbs here are a few detected, measures for sets of irf 240, between 661 mV and 587 mV across resistors 1 ohm, 1.8A by rail. Speaker out 0,018 volts without load.
Do you think useful to install protection for speaker?
(some photos shortly) 🙂
Come and join the ABFAB community. No need to install speaker protection.
You could test for voltage spikes/thumps across an 8 Ohm resistor at power on and power off before connecting you're precious speakers for the first time if you are worried.
Now take some pictures.
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Hi there,
I've been struggling with one channel of my A-5.
Can't get is stable at a acceptable offset level.
Left channel 7 mV, so good. But right channel gives me headaches....
Can it be that the power supply voltage is too high (36,5V on PCB) ?
I've been struggling with one channel of my A-5.
Can't get is stable at a acceptable offset level.
Left channel 7 mV, so good. But right channel gives me headaches....
Can it be that the power supply voltage is too high (36,5V on PCB) ?
Not high ( just lost power by heat ) .
Need check all values (R, voltage Zene ,..) make sure correct and matching mosfet again.
Are you using a 500-1K pot above the diff pair current source to adjust this offset?
Because i had it at 35mV, i guess values are okay.
After testing i resoldered the components (at same location), and offset went up to 250 mV 😱
Now checking for bad contacts. ( tapping on PCB gave some fluctuations).
This saga continues.....
Because of one good channel, i'm confident it should work.
I should recheck/rematch the active components.
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Can it be a faulty transistor ?
I have less voltage on the top ZTX450, compared to the good channel.
Not enough gain on this device ?
I have less voltage on the top ZTX450, compared to the good channel.
Not enough gain on this device ?
Headaches, just before Xmas....
Here are some measurements, replacing Q5 didn't help.... (Pass schematic part numbers)
First voltage is the good channel, second the bad one (200mV offset)
R11 : 5,35V & 5,39V
R14 : 4,73V & 4,67V
R17 : 24,8V & 25,0V
R18 : 7,9V & 7,8V
R19 : 11,7V & 11,7V
Q5(base) : 0,65V & 0,41V <=== ???
Q6(source) : 0.61V & 0.38V
Any suggstions what to check ?
I've replaced Q5 with types with different hFE, but that didn't help anything. 😕
Here are some measurements, replacing Q5 didn't help.... (Pass schematic part numbers)
First voltage is the good channel, second the bad one (200mV offset)
R11 : 5,35V & 5,39V
R14 : 4,73V & 4,67V
R17 : 24,8V & 25,0V
R18 : 7,9V & 7,8V
R19 : 11,7V & 11,7V
Q5(base) : 0,65V & 0,41V <=== ???
Q6(source) : 0.61V & 0.38V
Any suggstions what to check ?
I've replaced Q5 with types with different hFE, but that didn't help anything. 😕
Before desoldering Q6 to Q8, i changed R20 (with a wire) from Q6 to Q7 and later to Q8.
No effect, therefore i asume that Q6 to Q8 are not defect ?
Offset stays -200mV.
The question remains : why is the base of Q5 only 0,4volt. (Instead of 0,65 volt) ???
Please help....😕
No effect, therefore i asume that Q6 to Q8 are not defect ?
Offset stays -200mV.
The question remains : why is the base of Q5 only 0,4volt. (Instead of 0,65 volt) ???
Please help....😕
What pictures do you want ?
Btw : Boards are kk, the partnames i used are from the Pass schematics.
Btw : Boards are kk, the partnames i used are from the Pass schematics.
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