Audiosector/Chipamp LM3875 or Mauro Penasa's My Reference RevC from Twisted Pear

[blottojon]

another noob here. ive been reading up on these gainclone amplifiers and seeing witch one to go for. i want something i can build "out of the box" and which i won't need to build a pre-amp for, yet anyway.

i want somthing simple to start with and ive decided on either down to the Audiosector/Chipamp LM3875 or Mauro Penasa's My Reference RevC from Twisted Pear.

they both seem very good, but witch shoud i go for?

the lm3875 looks like the most comman chip and the audiosector looks well deisgned. i read the other newbie thread and see i will need speaker protection circuits which will make the lm3875 only slightly cheaper than the twisted pear option, so price isnt an issue.

garnett. if your reading this can you tell me why you decided on the lm3875?

the myref and the threads about it make me think its had a lot of thought put into it.

so which should a noob looking for the best sound and easiest first amp go for?

whats important to me is sound quality, volume, and ease of use.

if you can help thanks.

[Garnett]

Hi Blottojon.

I'm on the verge of going for the Audiosector kit. I've read glowing reports of the LM3875 on here, and at www.gainclone.com. (Also - this is the chip the original gaincard came with in 1999 - as that is newer than the kit I use at the moment, and sold for about 20 times more than mine when new, I figure having as close a copy to that can't be bad. )

The Twisted Pear kit sounds very impressive, but I think that might be my second build, as it seems to evolved a lot from a simple design. I want to appreciate the most basic set-up before I start to look at anything more complicated. I read as much of the thread linked from the twisted pear site as I could, and I agree - the thought and experimentation that has gone into it can only have produced good things.

Not sure about volumes. Someone else will have to tell you about those.

I am already wondering about bi-amping and (sorry if this is thread-jacking at all ) was wondering if bi-amping with one each of these two kits would be a problem...?

[safetyman]

Hi, just to chip in my thoughts. Another noob here.

Originally, I had wanted to start off with the My Ref C from Twisted Pear but was advised by a fellow diyer that since I have never built anything b4, that may not be suitable for me at my level (never even soldered b4). He suggested I built something easier instead and gave me a LM3886 board that he bought when he was in China and I started off on my first project. Completed that and fell in love with DIY and have now started on my second project and that's the LM4780 from Audiosector, and have a LM3875 board also from the same source for the next project.

Hopefully, after these I'll be ready to build something like the My RefC which I believe is awesome. At the end of it, what I hope to do is to be able to compare all the 4 completed amps, and draw my own conclusion as to which suits me the best. I am sure that they will all sound awesome from what I am hearing from my present amp right now.

Conclusion, if in doubt of your own skills, I would go for Peter's LM3875, as it has so little components to handle, and proceed to the My RefC later. But if you are confident, what the heck, why not, go straight in for the My RefC.

[Dominick22]

Blottojon,

I am still very much an amateur myself and I was in your shoes about 6 months ago.

My first amp was an LM4780 kit from Peter at audiosector.com and now I am working on a 2*LM4780 chips per channel amp. It is challenging for me!!

What I want to tell you about is not the amp however. I want to tell you about Peter and his site. To me, when I started in this intimidating hobby, I was more concerned with finding a "mentor" if you will. Someone whom I could fall back on to nudge me through the process.

For me, Peter has been that guy. And I reccomned him to all noobies when I get the chance. He is quick with the e-mails and more than willing to help. The same is true for BrianGT although I have not worked with him as much.

Anyway, I really would have been lost with a bunch of parts lying around if it wasn't for Peter.

I suggest the LM3875!

[Nordic]

For a basic GC, especialy the LM3875 ones, a kit is hardly justified, and will rob you of much learning abilities. It will be far more fulfilling sourcing the parts and doing your first amp with point to point wiring, this should cost a fraction of a kit.

The Twisted pair board is not a gainclone (even though it uses a chipamp) it a much more refined implementation... the kit parts are so well made and boards well marked you can hardly make a mistake if you spent a few minutes practising soldering.

remember, that nothing worth reaching ever is easy.

[dfdye]

Originally posted by Nordic
remember, that nothing worth reaching ever is easy.

Yea, I guess I am wierd like that. My amp NOOb DIY project is building a LM4702. That has been fun!

Almost up and running, btw.


As far as gainclones go, the Linkwitz LM3886 implimentation is pretty darn straightforward and is easy to wire point to point on some protoboard.

Edit: Guess a URL may help.

http://www.linkwitzlab.com/xo_eq.htm

It is down toward the bottm of the page, though the whole section is diy geek heaven!

[blottojon]

Thanx guys. i still cant decide. i do want the ease of a kit for my first build. nordic, i think your right. the more you put in the more you get out.

in the meantime im struggling with the way everything fits together. i want to make a website about building my amp with my absolut beginners views. what i havent seen is a website that shows a good overview of the whole process. i want to be able to go from an overview into detailed bits on every part.

ive drawn a very bassic table which i hope shows how the various stages of the music system fit together. can you look at it for me and suggest any improvements and additions.

i haven't included a phono stage, because im not a big vinyl fan but if someone can think of a good way to fit it in then please tell me.

also as i understand it each stage except the speakers need power (although im sure even here there are exceptions - there generally tend to be in this game!).

can people also suggest which are the best power supplies at each stage (or atleast list some of the options) and also put wether a power supply can be sheared by different stages.

when im done i want to be able to draw a basic diagram with all the different possibilities for every stage, with suggested values/specifications for each, breif descriptions, and reccommended sources and part numbers.

hopefully each stage can then be broken down, possibly even to the component stage but i know this will take a long time.

[Nordic]

http://myweb.tiscali.co.uk/nuukspot/...gainclone.html

start there, just take care, the 47uf capacitor is actualy 4.7uf...

[rudi]

well for value for money I would go the Ref-C route. (from twisted pear) the board is VERY simple to build. you can do it in a hour. and you would not have to upgrade to anything else for a VERY long time. connect this to a good line stage and you will be richly rewarded.

rahter practice your building skill on the Line stage. you will have a great amp to test it with

[Dominick22]

Have you made a decision yet?


Dominick