danne_linkinpar,
For pictures of the amp, I can reffer to post nr.1. If you click on "afbeeldingen" in this URL you can find pics of this amp.
If you realy would like to make this amp, I suggest just to start on it. Try to find first all the components before you make a PCB for this amp. The original output devices are very hard to find and extremely high in price when you should find some. this amp hasn't HIFI specs compared to newer amplifiers. These are the word's of Ton Giesberts from Elektor (the designer of amps there).
I would suggest you, just to choose an other amp to build.
Greetz
Ben
For pictures of the amp, I can reffer to post nr.1. If you click on "afbeeldingen" in this URL you can find pics of this amp.
If you realy would like to make this amp, I suggest just to start on it. Try to find first all the components before you make a PCB for this amp. The original output devices are very hard to find and extremely high in price when you should find some. this amp hasn't HIFI specs compared to newer amplifiers. These are the word's of Ton Giesberts from Elektor (the designer of amps there).
I would suggest you, just to choose an other amp to build.
Greetz
Ben
Pics:
http://groups.msn.com/BenJanssen/6kanaalsaudioversterker1.msnw?albumlist=2
Can you describe what your amps does/doesn't. Do you have some measurements? How much bias (voltage over sourceresistor 0.22Ohm)? What voltage have you over the zenerdiodes of 3.9V. If you have taken 1.3W zener's, you sould lower the resistor from 10K to 2.2K. (10% of Pd = 0.13W --> 2.2K). Even the standard 10K is a bit to much, better is 5K6.
Are you sure every solder is perfect?
Ben
http://groups.msn.com/BenJanssen/6kanaalsaudioversterker1.msnw?albumlist=2
Can you describe what your amps does/doesn't. Do you have some measurements? How much bias (voltage over sourceresistor 0.22Ohm)? What voltage have you over the zenerdiodes of 3.9V. If you have taken 1.3W zener's, you sould lower the resistor from 10K to 2.2K. (10% of Pd = 0.13W --> 2.2K). Even the standard 10K is a bit to much, better is 5K6.
Are you sure every solder is perfect?
Ben
I have built several of this amp and I like the sound, I feel it sounds good to me. Other people don't like the sound att all. I built this before the digital time, I did not have a digital camera or any camera att all, therefor I can not bring any pics. I have mailed to you danne_linkinpar about some changes you have to do, as you for example have a 100uf/10v at the rail where you have to have a 100v elyt and some other things. You can mail me again in Swedish and we can try to find more faults. I know english can be difficult but we have to respect this forums language.
In Swedish:
danne_linkinpar vi har mailats vid om dina problem med ditt crescendo bygge. Hör av dig via mail så försöker vi söka efter mer fel.
Regards,
Bengt
In Swedish:
danne_linkinpar vi har mailats vid om dina problem med ditt crescendo bygge. Hör av dig via mail så försöker vi söka efter mer fel.
Regards,
Bengt
Finally, now we can get somewhere.
All these resistors can be smoked due to a failure in the diff stage.
When the current throught the legs of the diff stage is to high (R9 + R10), this would give a high voltage over resistor R11 + R13, then this will cause a high current to flow through R15 + R16.
Make sure you use BC546 and BC556 (80V devices)
Make sure you did the assembly correctly (changed two transistors??)
Check that zener diode (3.9V), when this is broken, it could be a short. Or maybe an other voltage. This would lead to a higher current through the diff stage --> power dissipation in these transistors is to much.
Ben
All these resistors can be smoked due to a failure in the diff stage.
When the current throught the legs of the diff stage is to high (R9 + R10), this would give a high voltage over resistor R11 + R13, then this will cause a high current to flow through R15 + R16.
Make sure you use BC546 and BC556 (80V devices)
Make sure you did the assembly correctly (changed two transistors??)
Check that zener diode (3.9V), when this is broken, it could be a short. Or maybe an other voltage. This would lead to a higher current through the diff stage --> power dissipation in these transistors is to much.
Ben
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