Hi just make minimal changes to R14. The problem is that the IRF9610 are not matched enough. I did it with the aleph X (R23/R25), and now the output is 0,011 V
Succes
Succes
Tips to make your amp a better amp.
Change the bias if you have a low speaker impedance (more power). I your power supply ca hold it. (I 'have 100 Watt at 4,2 ohm). calculation sheet !
Place a 1UF cap over Z5 (better sound)
Place a speaker protection unit in the amp (kan je je speaker kosten als je het niet doet)
Groeten Berry
Change the bias if you have a low speaker impedance (more power). I your power supply ca hold it. (I 'have 100 Watt at 4,2 ohm). calculation sheet !
Place a 1UF cap over Z5 (better sound)
Place a speaker protection unit in the amp (kan je je speaker kosten als je het niet doet)
Groeten Berry
He thanks Berry!
Do you mean R14 on the pass schematics or on kristians board?
I had now music playing for one our. One channel is going between 020 and 035mv and the other is going between 095 and 115 mv. He's getting very hot now, I only can touch him with my hand flat on the opposite of the heatsink for about 5 seconds.
But the sound is wonderful.
Teake.
Do you mean R14 on the pass schematics or on kristians board?
I had now music playing for one our. One channel is going between 020 and 035mv and the other is going between 095 and 115 mv. He's getting very hot now, I only can touch him with my hand flat on the opposite of the heatsink for about 5 seconds.
But the sound is wonderful.
Teake.
Hi there!
Another question!
On kristijans aleph 5 board there is a R25 to connect a led, it does not do anything only to check if everythings working. from the board with 030mv output I did not mount these. Only on the board with 120mv I left the resistor 100K without the led, maybe it has some influance on the output, I don't know? Somebody does?
Greetings Teake! I also have 3 new matched irf9620, Will this solve my problem?
Another question!
On kristijans aleph 5 board there is a R25 to connect a led, it does not do anything only to check if everythings working. from the board with 030mv output I did not mount these. Only on the board with 120mv I left the resistor 100K without the led, maybe it has some influance on the output, I don't know? Somebody does?
Greetings Teake! I also have 3 new matched irf9620, Will this solve my problem?
It make no difference with the led. Better matched fets will work 🙂
After 100 hours playing you will hear a better amplifier. The DC at the output is lower when the aplifier is warmed up (1 hour).
How big are the heatsinks ?
Partnumber fisher ?
After 100 hours playing you will hear a better amplifier. The DC at the output is lower when the aplifier is warmed up (1 hour).
How big are the heatsinks ?
Partnumber fisher ?
He Leeuwarden!
Nothing is getting better. I just got new matched irf9610 in the board and instead of getting lower MV i.am getting more I had 125mv now I.am getting 400. So I measured the irf's on both boards and they are almost the same.
Between G-S T1 left 3,9V, right 4,0V,
T2 on both sides 3,9V,
T3 on both sides 3,9V.
Between D-S T1 left 24,5V, right 24,7V,
T2 left 37,4V, right 37,5V,
T3 left 32,7V, right 32,8V.
Between G-D T1 20,5V, right 20,6V,
T2 both 33,6V and
T3 both 28,6V
I did put the 100K resistor of the led out of the board.
So what did I wrong. I, don"t like to put a speaker on it now!
I don,t know what's happening then.
At first when I did the power on there was 556mv, for the second time when I did there was 416, and the mosfets are still getting hot with 4,2 volt between G-S on both sides, so that's good.
Should I put the amplifier on for some longer time?Can I just play some music?
I hope it's getting good.
Teake
Nothing is getting better. I just got new matched irf9610 in the board and instead of getting lower MV i.am getting more I had 125mv now I.am getting 400. So I measured the irf's on both boards and they are almost the same.
Between G-S T1 left 3,9V, right 4,0V,
T2 on both sides 3,9V,
T3 on both sides 3,9V.
Between D-S T1 left 24,5V, right 24,7V,
T2 left 37,4V, right 37,5V,
T3 left 32,7V, right 32,8V.
Between G-D T1 20,5V, right 20,6V,
T2 both 33,6V and
T3 both 28,6V
I did put the 100K resistor of the led out of the board.
So what did I wrong. I, don"t like to put a speaker on it now!
I don,t know what's happening then.
At first when I did the power on there was 556mv, for the second time when I did there was 416, and the mosfets are still getting hot with 4,2 volt between G-S on both sides, so that's good.
Should I put the amplifier on for some longer time?Can I just play some music?
I hope it's getting good.
Teake
No more than 100mv DC to the speakers ! Do you have the pre amp connected while you measure the output DC ?.
Before you connect the input, measure the DC at the input (0mV), without the speakers connected !!!!.
If there is no DC at the input, connect the pre amp, wait a while (1/2 hour). Measure the output again, this has to be between 10 to 100 mV.
If the DC is only more than 100 mV at startup, use a DC protection circuit. The cap over Z5 has nothing to do with the DC, it is only for a better sound.
Before you connect the input, measure the DC at the input (0mV), without the speakers connected !!!!.
If there is no DC at the input, connect the pre amp, wait a while (1/2 hour). Measure the output again, this has to be between 10 to 100 mV.
If the DC is only more than 100 mV at startup, use a DC protection circuit. The cap over Z5 has nothing to do with the DC, it is only for a better sound.
He berry!
Is it possible that I got a losse cap 220UF C3 on Kristijans board ?because when I moved it a little the mv went between 450 and 250. when I pushed a little on it the mv went lower, but when I did not touch it anymore it went straight between 250 and 350mv, and it felt a little loose, I could move it with hand. But is is very fluctuating and I got nothing on the output nor input, only a meter.
Should it bin broken, else I will replace it.
They are philips 40v 220uf. Can I replace it with 35v? I got 34,4v on the rails.
Thanks teake.
Is it possible that I got a losse cap 220UF C3 on Kristijans board ?because when I moved it a little the mv went between 450 and 250. when I pushed a little on it the mv went lower, but when I did not touch it anymore it went straight between 250 and 350mv, and it felt a little loose, I could move it with hand. But is is very fluctuating and I got nothing on the output nor input, only a meter.
Should it bin broken, else I will replace it.
They are philips 40v 220uf. Can I replace it with 35v? I got 34,4v on the rails.
Thanks teake.
again!
I mean with fluctuating, that the mv is going up and down up and down, up and down! Does it not has to be stable at one point?
I mean with fluctuating, that the mv is going up and down up and down, up and down! Does it not has to be stable at one point?
Hi,
you can use 35V capacitors
the dc should be stable and not change when you press a cap. The problem could be somewhere else on the board though, check all earth connections.
did you really match the input fets to 0,01Volt?
William
you can use 35V capacitors
the dc should be stable and not change when you press a cap. The problem could be somewhere else on the board though, check all earth connections.
did you really match the input fets to 0,01Volt?
William
I use Elna silmic caps, and in my other aleph 5 black gate caps. I can't hear the difference 🙂 But the elna's are cheaper.
35V is ok. Look at the back of the print if you have a broken pad or wire.
35V is ok. Look at the back of the print if you have a broken pad or wire.
He thanks guys!
I will take a close study at the board and his components and connections. Teake
I will take a close study at the board and his components and connections. Teake
Hi William!
Yes the fets are realy matched bij de audiofabriek. Teake. And the heatsinks are FISHER SK 156 Berry. Teake
I measured the board and the voltages are all oke! 9.1V on Z5, 4,9v on Q4 and Q5, on R11 4,9v and on R14 4,9 V.
Yes the fets are realy matched bij de audiofabriek. Teake. And the heatsinks are FISHER SK 156 Berry. Teake
I measured the board and the voltages are all oke! 9.1V on Z5, 4,9v on Q4 and Q5, on R11 4,9v and on R14 4,9 V.
he guys!
You never believe this! I changed the three 220uf's and checked the board and now I.am getting between 20-30mv on the other also between 20 and 30mv. So I think it's allright now. But why is it going up and down between 20 and 30? Does it not have to be one steady point? Now I am a happy man again! Thanks evrybody, also Nelson Pass for opening his knowlidge to the world, Kristijan and his very good boards, Berry, Harry, Netlist and William and the others for there advice.
If its oke with you guys i am going for a Pass Pre Amplifier, but at first anjoy the music. Hoera Hoera Hoera! Greetings Teake.
You never believe this! I changed the three 220uf's and checked the board and now I.am getting between 20-30mv on the other also between 20 and 30mv. So I think it's allright now. But why is it going up and down between 20 and 30? Does it not have to be one steady point? Now I am a happy man again! Thanks evrybody, also Nelson Pass for opening his knowlidge to the world, Kristijan and his very good boards, Berry, Harry, Netlist and William and the others for there advice.
If its oke with you guys i am going for a Pass Pre Amplifier, but at first anjoy the music. Hoera Hoera Hoera! Greetings Teake.
A little wobbling of the millivolts is perfectly normal.
That's what millivolts are for.
Seriously, I think your amp is fine. Enjoy it.
Don't forget to send some pictures to the passdiy gallery.
/Hugo 🙂
That's what millivolts are for.
Seriously, I think your amp is fine. Enjoy it.
Don't forget to send some pictures to the passdiy gallery.
/Hugo 🙂
Hi again!
I listened again and it was great, and it kept stable, both channels between 15mv and 25mv, I am very happy, but oh what is he getting hot. I listened for more than an our. There is still a plop when I put the amplifier on, is this dangerous? I've got him now playin on 4 ohm loudspeakers, how will it be on my own 8 ohm loudspeakers, we'll see! Have a good night Teake.
I listened again and it was great, and it kept stable, both channels between 15mv and 25mv, I am very happy, but oh what is he getting hot. I listened for more than an our. There is still a plop when I put the amplifier on, is this dangerous? I've got him now playin on 4 ohm loudspeakers, how will it be on my own 8 ohm loudspeakers, we'll see! Have a good night Teake.
He Hugo!
I will send some pictures to Pass Diy, but I have to wait, I don't have a digital camera, so I don't know when, but it will happen.
Thanks Hugo. Greetings teake.
I will send some pictures to Pass Diy, but I have to wait, I don't have a digital camera, so I don't know when, but it will happen.
Thanks Hugo. Greetings teake.
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