dviswa said:
I have no idea, that's why I was asking. As I understand from your answer that's not likely - sounds reasonable as I read in several places that GC are not suitable for car amps.
It makes me think tough how car class-D amps are made but that's a question for another thread.
P-A,
There was a nylon washer with a neck. Infact the neck was so long I had to trim its length before it would sit right.
The Berquist insulator seems to be made of some kind of fabric and the threads start peeling under stress, specially when you have to adjust its position in the presence of thermal grease.
Regards,
Dinesh
There was a nylon washer with a neck. Infact the neck was so long I had to trim its length before it would sit right.
The Berquist insulator seems to be made of some kind of fabric and the threads start peeling under stress, specially when you have to adjust its position in the presence of thermal grease.
Regards,
Dinesh
PA, Pavel,
I got my replacement parts, this time I made sure everything is shielded from the heat sink. But, I am seeing too much voltage at both TP3 & TP4 almost 11 V as measured in DC ranges on my DMM. I do not have an oscilloscope, so I cannot tell what it is. I get sound, but it is really awful, kind of badly clipped. Between TP 1 & 2 there seems to be a difference of about 100mV. What might be the reason?
One other thing I did, was that I had the mute relay mounted and when the mute was jumpered between 9-10 or 11-12 the mute relay did not open forcing the LM4780 to be in mute, so I cut the traces on the board isolating the relay and jumpered JP4, because desoldering the relay was too much pain.
Please help,
Dinesh
I got my replacement parts, this time I made sure everything is shielded from the heat sink. But, I am seeing too much voltage at both TP3 & TP4 almost 11 V as measured in DC ranges on my DMM. I do not have an oscilloscope, so I cannot tell what it is. I get sound, but it is really awful, kind of badly clipped. Between TP 1 & 2 there seems to be a difference of about 100mV. What might be the reason?
One other thing I did, was that I had the mute relay mounted and when the mute was jumpered between 9-10 or 11-12 the mute relay did not open forcing the LM4780 to be in mute, so I cut the traces on the board isolating the relay and jumpered JP4, because desoldering the relay was too much pain.
Please help,
Dinesh
PA,
I was not aware of this. That is good to know.
Anyway, I am populating my second board, hope to have better results this time.
Thanks,
Dinesh
I was not aware of this. That is good to know.
Anyway, I am populating my second board, hope to have better results this time.
Thanks,
Dinesh
Upupa Epops said:
I do have pavel,wave2:
as we know, this module can be a bridged amp by series the R_chanel and L_chanel inputs, but have you notice the different gain then?
'cos the L_chanel is "no_inverted" got a gain of 2*23, while the R_chanel is "inverted" and got a gain of -1*23.
I think this kind of bridge can cause distortion, what do you think ?
xu:
Upupa Epops said:
yes, pavel
having think about it carefullly, there's no distortion at the end of speaker.
thanks pavel
🙂
I'm curious about your results in assembling of this amp - do you have some photos, guys ? Joy my old eyes... 😎
BTW, I give you good steer for amplifier case - look at http://www.modushop.biz/ecommerce/cat079_l2.php?n=1 - performance and price are superb... 😎
Very proffesional looking enclosure Pavel.
And big enough for the power amp with a pre amp (the one that you intent to design for this power amp 😀 ).
I posted my pictures of the amp earlyer in this thread.
And big enough for the power amp with a pre amp (the one that you intent to design for this power amp 😀 ).
I posted my pictures of the amp earlyer in this thread.
Dear Pavel, P A, Ex007,
I am one happy camper now .
😀
I have one board working well, producing some really nice music.
Special thanks to Pavel for your generosity and nice design.
Special thanks to PA for making it all happen, also thank you for the GB.
Ex007, thanks a lot for the GB.
Just some thoughts, I did not like LM4562. I have not tried OPA134, but right now it is running on AD8610 and it sounds really nice. Actually I bought OPA134, but cannot seem to find it now, my children perhaps has something to do with this.
The chain is:
laptop>Foobar (FLAC)>MAudio Transit>Zhaolu 2.5C DAC>PA03>DIY Speakers (JX92 in a 48" MLTL).
DIY ICs, speaker cables and connectors I have used can be improved. I will try and play with the reservoir caps on the supply to see if it can be improved. I have a few others experiments, I would like to try.
There is a tiny bit of fatigue, that should go away when I replace the output stage on the Zhaolu 2.5 DAC which is driving the amp.
Thanks a lot again. It is not cased up, I just have the PCB on metal spacers, so I prefer not to take pics.
Regards,
Dinesh
I am one happy camper now .
😀 I have one board working well, producing some really nice music.
Special thanks to Pavel for your generosity and nice design.
Special thanks to PA for making it all happen, also thank you for the GB.
Ex007, thanks a lot for the GB.
Just some thoughts, I did not like LM4562. I have not tried OPA134, but right now it is running on AD8610 and it sounds really nice. Actually I bought OPA134, but cannot seem to find it now, my children perhaps has something to do with this.
The chain is:
laptop>Foobar (FLAC)>MAudio Transit>Zhaolu 2.5C DAC>PA03>DIY Speakers (JX92 in a 48" MLTL).
DIY ICs, speaker cables and connectors I have used can be improved. I will try and play with the reservoir caps on the supply to see if it can be improved. I have a few others experiments, I would like to try.
There is a tiny bit of fatigue, that should go away when I replace the output stage on the Zhaolu 2.5 DAC which is driving the amp.
Thanks a lot again. It is not cased up, I just have the PCB on metal spacers, so I prefer not to take pics.
Regards,
Dinesh
peranders said:It's good to hear that you have succeed.
Thank you very much once again. I have been showing it off to my friends and family and getting some rave reviews. They are largely blown by the clarity, absence of hiss/noise and how nice the music is.
Every parts of chain can ratify sound, Dinesh, so we can't to tell you, which it cause .... You must to use elimination method, i.e. to try change in turn every parts of chain...