I studying yours photos and I think that nap500 it’s BTL nap300 and nap500 have more voltage lines on power supply
I can’t see anything special in your NAP500 block diagram. I’m not sure how they split the input signal into inverting and non-inverting; maybe a function of that x1 input buffer. Each amp has 4 “DR” blocks; high power for the output stage and low power for the rest.
What else do you think there might be?
I think Naim's own forum for their customers and prospective ones is enough for them. They've had years of criticism and comments from this clone building and DIY repair forum and a few others other the years and probably don't need any more adverse feedback or aggravation from us DIYs who, almost by definition, won't be buying new Naim product anyway.
I think good criticism is better for studying another ways for production of new designs
I have little cases (criticism of “audio guru” ) of my product Head Amp and I try change my design after that sound is better. If you have of designer experience you need every time get of new ideas
) this is better for audioThe simple block diagram is my guess work. The official diagrams are from Naim white papers...
I remember that the 500 can deliver full power into almost a short, happily drives 2R and has extremely clean 0V returns because of the topology (see also here and here).
If it's just a BTL the PDIP8 could be the inverting circuit or phase splitter and the additional smaller PCB the protection circuit (or vice versa). If it's that simple, the attached diagram should work...? Or do we need to connect the feedback resistor to the opposite amp as shown in fig.1 here?
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This kind of circuit was known already in the 70s, so how could they claim property? After all everything I posted here I found elsewhere on the net. But it seems to make an amp sound really like a Naim it needs more than just the correct circuits with the correct parts. So I guess they are not too afraid of us diyers
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Your experience of tinkering with existing products and clones in order to make what you believe are improvements, is similar to what a lot of DIY folk here find and that's how we become inspired to learn and find out what we are really doing in objective terms by subjective measures. Commonly, it's just increasing even harmonic distortion to create more sweetness and warmth in the sound. Vereker's original parts and tweaks to Naim amplifiers created his distinctive PRAT sound effect that gave a snappy, rhythmic feel to music that might otherwise have sounded subued.
Naim's forum is actually for retail customers sharing their listening experiences, encouraging sales and offering user advice to people who are planning on buying their new products. The last thing they will want to hear is technical queries or criticism of these products at the same website their customers are browsing. I think anyone who buys or trades goods from retail traders will understand what to expect if you only want to discuss and learn technical details of their products for your own purposes.
For technical issues, arguments and sharing Naim ideas, stay here at DIYAudio or Pinkfishmedia forum who have members that have at least been involved with Naim service at some time. However, there is no institute of audio design out there to help you become an audio guru or engineer yourself. You need to study for an engineering degree in electronics for that or least reach technician level at a suitable technical college. You don't find engineers discussing anything deeper than how to get the most from using their Uniti player, Atom, discontinued model amp etc. at Naim's forum. See for yourself: https://community.naimaudio.com/
Naim's forum is actually for retail customers sharing their listening experiences, encouraging sales and offering user advice to people who are planning on buying their new products. The last thing they will want to hear is technical queries or criticism of these products at the same website their customers are browsing. I think anyone who buys or trades goods from retail traders will understand what to expect if you only want to discuss and learn technical details of their products for your own purposes.
For technical issues, arguments and sharing Naim ideas, stay here at DIYAudio or Pinkfishmedia forum who have members that have at least been involved with Naim service at some time. However, there is no institute of audio design out there to help you become an audio guru or engineer yourself. You need to study for an engineering degree in electronics for that or least reach technician level at a suitable technical college. You don't find engineers discussing anything deeper than how to get the most from using their Uniti player, Atom, discontinued model amp etc. at Naim's forum. See for yourself: https://community.naimaudio.com/
I would not do the ESL method for bridging. It’s one of those ideas that looks great to a toddler but has practical difficulties.
I would be surprised if the NAP500 works like this (unless Sells designed it <brutal, sorry>). Feeding one amp from the output of the other - let’s throw stability out of the window.
I would be surprised if the NAP500 works like this (unless Sells designed it <brutal, sorry>). Feeding one amp from the output of the other - let’s throw stability out of the window.
It may even be a disadvantage to have degree level engineering education. It can make a person arrogantly myopic. I speak from personal experience
I think NAP500 build for very power acoustics
And if you don’t use parallel output transistors you need BTL schematic some like automotive monolith amps
)) My old friend Alex explain this “Oleg if you get power transistor current for audio signal you watch that many of many transistors give current about 10 A and nothing more but in docs for this transistors current power about 15-20 A…”
Correct!!! Please look to New Naim … excellent design by hi electronic education but not have sound ..It may even be a disadvantage to have degree level engineering education. It can make a person arrogantly myopic. I speak from personal experience
I think JV was still there when they designed the 500...
Is it possible to take the inverted signal from the input LTP?
I guess it’s possible but not without difficulties. Easier to make an input buffer/phase splitter I would think, which feeds two identical amps.
I’ve never had to bridge two amps; someone else here will have a solution.
about 22 years ago I building BTL amps on TDA7294 and this working
)) 200 wats amp without box )) oh young years ))Attachments
I knew some guys who really liked the sound of the NAP110.
https://www.diyaudio.com/community/threads/nap-140-clone-amp-kit-on-ebay.112453/post-5741750
https://www.diyaudio.com/community/threads/nap-140-clone-amp-kit-on-ebay.112453/post-5741750
Same idea as shown in the link to Rod Elliots BTL I posted earlier...about 22 years ago I building BTL amps on TDA7294 and this working
Transistors amplifier is better
))But future is come in and all components are made in SMD and sound not good
)