You are right, according to Peter D. they are optional?!. well, it seems they are not needed because it sounds good without them.
Trust me....it will sound better with them at least 10000uf per rail.
Long time ago I build a few LM3875 from Audiosector, they come with "joke" 10uf caps for power supply. as soon as I changed them to 10000uf I could "literally" feel the bass.
Power supply caps are not optional and they are not 10uF
The power supply caps are on amp boards and those are 1500uF
Of course you can experiment with larger caps and you may even like them, but then you will be building a different amp, not the Gainclone which is the subject of this thread.
Here's the way to attach "optional" larger caps, snubber components are also recommended in such case.
Here are the links to my impressions when experimenting with different caps and larger caps:
http://www.diyaudio.com/forums/digi...gate-caps-out-production-so-2.html#post574431
http://www.diyaudio.com/forums/chip...ut-any-comments-suggestions-8.html#post581230
Here are the links to my impressions when experimenting with different caps and larger caps:
http://www.diyaudio.com/forums/digi...gate-caps-out-production-so-2.html#post574431
http://www.diyaudio.com/forums/chip...ut-any-comments-suggestions-8.html#post581230
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In an another thread someone told me that my current amp "DFA888" should be much better than the one I was building but now I know he was wrong.
The bass control with the parallel LM4780 is outstanding, all other ways of defining the sound is too subjective but it is for sure a GREAT amp and gives me a big smile on my face.
greetz,
Joery
The bass control with the parallel LM4780 is outstanding, all other ways of defining the sound is too subjective but it is for sure a GREAT amp and gives me a big smile on my face.
greetz,
Joery
I have an LM4780 premium dual mono setup with 2x 22v transformers. This setup plays fine but it lacks bass. My old standard LM3886 gives better results as does my TA2020. I though about increasing the value off the caps but as Daniel said than i am building amp...
I like to solve this problem because the amp stands in the corner now....
I like to solve this problem because the amp stands in the corner now....
Sorry to say but it seems you or made a mistake or your speakers and/or room have a problem.
The only difference is that I used a 2x25Vac 500vac transformer but i guess that should not make that big difference.
The amp I have here now plays REALLY great....
Greetz
The only difference is that I used a 2x25Vac 500vac transformer but i guess that should not make that big difference.
The amp I have here now plays REALLY great....
Greetz
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Mmmhh i checked it and all seems fine, and as I play my lm3886 and ta2020 with same speakers in the same room the bass sounds more alive and much deeper. Maybe Peter Daniel has an idea?
The overall sound is extremely pretty...a better bass would make it complete..
The overall sound is extremely pretty...a better bass would make it complete..
Then I don't know, maybe peter has an idea. to bad for you, I'm really enjoying his amp. and the previous amp I used seemed not to be the worst and peter's is way out of that's league .
The lm3886 is from chipamp.com is also dual mono and uses 2x25v transformer and the usual chipamp power supply and only the standard parts are used.
I see a lot off builders using caps on the input, could this be the answer?
I see a lot off builders using caps on the input, could this be the answer?
To bad you live far from me, if you want your very welcome to come over to listen here in Eindhoven
In that case put the similar caps in LM4780 and you should receive similar results. Previous pic shows that larger caps will fit on rectifier board.
Caps on the input are only needed when source shows DC offset, otherwise, in most cases, they will degrade the sound.
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Thanks for your replies, I will try the swap with the parts.
Eindhoven is a bit far otherwise I would have a listen but thanks anyway!
Eindhoven is a bit far otherwise I would have a listen but thanks anyway!
The pics in post1738 show the copper bar is bolted to the thick aluminium Chassis. It is not floating. That aluminium is you heatsink.
Have you inserted Thermal Paste into the joint between copper and aluminium to reduce thermal resistance. Why only 2 bolts? Three would be better, five are probably good enough.
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I said the AMP is floating, not the copper bar.
Its bolted with 3 M5 bolts to the aluminum chassis.
I did not use paste because I'm not sure the paste can cause electrolytic corrosion, Two different metals with fluid in between can cause the least noble metal (not sure you say it like that in English) to corrode away.
3 bolts are enough as the metal strips are thick and will only very slightly bend.