Schematic of Hi-End

[sonnya]

He may be right but in the same time LM3875 is an easy way to achive something. By using this IC you are take rather many shortcuts. I think it's best if you state a budget then deside what you can get for it.

State also basic specifications like power, bandwidth, distortion, complexity etc.

Sonny has nice design very much alike my QRV-08 headphone amp but a problem may be the surface mounted parts.


www.mirand.dk

Hugh (AKSA) doesn't mind surely to sell a amp kit to you. You have many options if you settle for a pcb and gather the parts by yourself. Hugh sells a kit and this may be easier.

The problem Per address is actually a big problem.

I have spoken to my wife today, and we have been talking about letting a company in denmark do all the SMD work.

She would take over handling and shipping as i do not have time for this and she is at home with the kids.

Just to help "ordinary" people build this amplifier....

 

[ThorstenL]

Konnichiwa,

Engineer from Russia said:
LM3875 is mediocre amp with quasicomplementary output stage on bipolar transistors. Russian analog device is ÓÊÓ020 in 1970-x years. It is very bad. Sorry.

Well, no offense meant "Engineer from Russia", but he knows diddly squat.

If you can accept the fundamental thermal and electrical limitations of the LM3875 (or LM3886) the results IF IMPLEMENTED CORRECTLY can be easily as good as most "High End" amplifiers.

Untill Jeff Rowland switched to "Ice-Power" switched mode amplifiers his amplifiers used LM3886 Chips, in case of the Concentra 6pcs per channel. Here some reviews of the Concentra, to give you an idea just ho "very bad" the Nat Semi LM3875/86 is:

http://www.audioenz.co.nz/2003/jeffrowland_concentra2.shtml

http://www.audio-ideas.com/reviews/integrateds/rowland_concentra.html

http://www.audiophilia.com/hardware/concentra.htm


For What It's Worth (FWIW), the "Blue Circle" Amplifiers use the Nat Semi LM12 Chip.

So at the very least the note "It is very bad." is plainly wrong.

I would suggest that your "Engineer from Russia" does not know much at all, aprt from prejudices, you may be better off building a gainclone kit than getting something that he find "very good".

In fact, while it is possible to outperform the LM3875/3886 with discrete circuits you need to go far beyond "generic" circuitry and then often parts availability becomes a problem. In fact, to comprehensively beat LM3875/3886 based Amplifiers is so much hard work that I rather build something with Valves.

Sayonara

 

[ThorstenL]

Konnichiwa,

Chipamp like LM3886, LM3875 etc. is no solution for the one who finds the real sound quality. It is easy to work with chipamps, that's why they are popular in DIY community, but sound is mediocre.

As mediocre as a Jeff Rowland Model 2 (one of the absolutely best solid state amplifiers I had the chance of hearing)?

Well, you sure are talking the talk, why not suggest something that anyone can actually BUY and that is significantly better than the "mediocre" Model 2?

Sayonara

 

[Bonsai]

Not to go off beam here, but that Gamut looks like one ugly beast inside - these things sell for about $5k. That mosfet probably comes from Ixys or IR, and I would bet my bottom dollar that its got multiple die inside - and they will probably not be matched.

Thing is, these things get rave reviews.

 

[juma]

but he knows diddly squat.

Oh, what a wonderful expression !

I like it so much that i'll put it in my acronym vocabulary - KDS (Knows Diddly Squat). It is applicable on so wide a scale - from guys that talk a lot without being able to perform all the way up to guys who start wars because "that's what my daddy did, it must be something I should do too".

Thanks once again Kuei Yang Wang, you really made my day !

Cheers all !