My MOSFET amplifier designed for music

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That's strange :) If you go to the bottom of the page and click on 'Terms and rules' there is a button for attachments. Zip is in there.

View attachment 1099097



Well I am really pleased and happy you are enjoying it :)
Hi Mooly

I have not had problems with the dimensions of the files to be attached : diyaudio does not accept the files done as BMP and DOCX, but they accept the DOC files ... So I had to convert them in files diyaudio accept. I did not look at all to what is written in terms and rules, there is to much to read here and there. Thank you for your help.

I must write that I did make an error in writing that my speakers are able to pass 18Hz at -3dB : my memory is now bad. It is really 26Hz at -3dB and 22Hz at -6dB. These are the measurements done by Stereoplay in Germany about my Canton's speakers. This morning I have checked that because I was in doubt with what I did write. Sorry, I am old and my memory is no more the one I had some (many) years ago.

Mooly : your amplifier provides better quality sound than what I had. It is very equilibrated. More detailed high frequencies, more bass frequencies that generates the need to lower the volume in order to get a better and more equilibrated sound. I don't know what you did do in order to get that good result, as it has always been a pain to me to get good bass in the music. So naturally I had to use a higher volume than necessary, and it was a bit high (some, not very much) for the high frequencies. Thank you Mooly.

Have a nice and very good day as I have, this hearing good music with your wonderful power amp.

Best regards

rephil
 
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Hi Mooly

I have not had problems with the dimensions of the files to be attached : diyaudio does not accept the files done as BMP and DOCX, but they accept the DOC files ... So I had to convert them in files diyaudio accept. I did not look at all to what is written in terms and rules, there is to much to read here and there. Thank you for your help.

I must write that I did make an error in writing that my speakers are able to pass 18Hz at -3dB : my memory is now bad. It is really 26Hz at -3dB and 22Hz at -6dB. These are the measurements done by Stereoplay in Germany about my Canton's speakers. This morning I have checked that because I was in doubt with what I did write. Sorry, I am old and my memory is no more the one I had some (many) years ago.

Mooly : your amplifier provides better quality sound than what I had. It is very equilibrated. More detailed high frequencies, more bass frequencies that generates the need to lower the volume in order to get a better and more equilibrated sound. I don't know what you did do in order to get that good result, as it has always been a pain to me to get good bass in the music. So naturally I had to use a higher volume than necessary, and it was a bit high (some, not very much) for the high frequencies. Thank you Mooly.

Have a nice and very good day as I have, this hearing good music with your wonderful power amp.

Best regards

rephil
My friend,reading all these, whets my appetite for another one amplifier..
 
Hi Thimios

Have a very good idea : build one Mooly's amp. You will be satisfied to get outstanding music to hear from your speakers ... It is time to be very happy my friend ;), do it.

Best regards

rephil
Ok let's do it.
 

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Ready for fire!
Without smoke..I hope.

Always use a bulb tester. It just saves any grief if anything should be amiss.

Let me know how it goes, have never figured out why I am getting oscillations on one of my boards and still looking for a faulty part every time I see someone else's build that works flawlessly. Good Luck and No Smoke!

Difficult to diagnose at a distance although some weird interaction caused by the wiring layout might be possible. The amp itself has always proved very stable indeed.
 
Always use a bulb tester. It just saves any grief if anything should be amiss.



Difficult to diagnose at a distance although some weird interaction caused by the wiring layout might be possible. The amp itself has always proved very stable indeed.
Yes,I will use the bulb tester plus two 18ohm 10w resistors instead of fuses.
Exicons is a bit strange and love the oscillation.....
Mooly did you seen this?https://www.diyaudio.com/community/threads/revisiting-lateral-mosfet-stability.381147/
Although it involves more than one pair.
 
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Strangest parts is I used 30+ year old original Laterals from a half-burned up 5-channel B&K amplifier. So I know they are original and they were from same channel and were matched quite close. Igave up after months of trying and have since built 3-4 other amps (I get bored often), but still have the boards sitting all together. Another strange thing is that I got the same problem in and out of a chassis and the chassis and wiring has worked on 3 other amps without any interference. I'm at a loss, but wishing you nothing but good luck. The one channel I have that's working sounded really good.
 
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Ok let's do it.
Hi Thimios

This is a very good idea.

Getting the volume high enough, this amp is able and will do your windows rattling as the bass frequencies are easily fully reproduced. I mean so you could destroy your windows … Pay attention and be cautious as wives never appreciate destructive music at home ! The paradise and the hell are both near to you !

Let us know how it sounds when ready my friend.

Best regards

rephil
 
Hi Thimios

This is a very good idea.

Getting the volume high enough, this amp is able and will do your windows rattling as the bass frequencies are easily fully reproduced. I mean so you could destroy your windows … Pay attention and be cautious as wives never appreciate destructive music at home ! The paradise and the hell are both near to you !

Let us know how it sounds when ready my friend.

Best regards

rephil
Hi rephil,hi bullittstang.
Thanks for the wishes!
Resume all....
Rephil had a smoked zobel resistor during the first test.
You still have an unstable one although you have used 2SJ162-2SK1058.
I'm starting to worry. I've already had a bad experience with these mosfets trying to feed them into one of duddo's amplifiers. I hope it doesn't happen again.
 
My first attempt... successful!
For this first test I use two bench power supply.
One for positive,one for negative rail.
No smoke no smell.
Next step +/- 35v and finally+/-45v.
I hope again no smoke.
 

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My first attempt... successful!
For this first test I use two bench power supply.
One for positive,one for negative rail.
No smoke no smell.
Next step +/- 35v and finally+/-45v.
I hope again no smoke.
Hi Thimios,

Thank you for this so good news from you ! You have a new very good amplifier home. This same amplifier is now my new main amplifier here, and it drives my best speakers. As you understand I would never use an amplifier that is not fully stable and without the slightest doubt it could destroy my best speakers !

Maybe you could also provide us with the so good measurements you perform from time to time to amplifiers, also some THD at some frequency of interest.

Enjoy soon hearing your new amplifier with good music my friend.

Best regards

rephil
 
Hi Thimios,

Thank you for this so good news from you ! You have a new very good amplifier home. This same amplifier is now my new main amplifier here, and it drives my best speakers. As you understand I would never use an amplifier that is not fully stable and without the slightest doubt it could destroy my best speakers !

Maybe you could also provide us with the so good measurements you perform from time to time to amplifiers, also some THD at some frequency of interest.

Enjoy soon hearing your new amplifier with good music my friend.

Best regards

rephil
Sure my friend,I will provide a full test latter.
Scope and fft measurements as soon as I will successfully test this using the main power supply.
Regardless if amplifier is stable or not please use a protection circuit especially if you use good and expensive speakers
 
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Sure my friend,I will provide a full test latter.
Scope and fft measurements as soon as I will successfully test this using the main power supply.
Regardless if amplifier is stable or not please use a protection circuit especially if you use good and expensive speakers
Hi Thimios

Thanks for this friendly advice. Don't worry, I use a protection speaker circuit that provides a test of Vdc present. If the DC is above around 1V dc, it will not connect or it will disconnect the speakers. It provides also a delay time of some seconds before connecting the speakers.

Best regards

rephil
 
Hi Thimios

Thanks for this friendly advice. Don't worry, I use a protection speaker circuit that provides a test of Vdc present. If the DC is above around 1V dc, it will not connect or it will disconnect the speakers. It provides also a delay time of some seconds before connecting the speakers.

Best regards

rephil
Good to know that your experience speakers are safe as I never had such a thing 😉