gainclone questions i just cant find ansers for!

[demogorgon]

hello!

Reading through the forums trying to look up the impossible, a cheap, small sized and nice sounding amplefier, it appears i have found it in this so called GainClone.

Unnfortunetly, there isn't any really deicive info to find about it, at least not as i have found(witch probably means there are plenty), so I'l spam the forum and hope to get some answers.

1: as i understand, the GC is an IC amp: are there one specific IC im supposed to use, or can use many different? and what IC(s) can\should i use?

2:I'v certanly seen enough finnished products, but noe under construction pics and explanations of just what is involved in making this thing.
Is there a page with a step-by-step tutorial for this amp?

I know these are stupid questions, but non the less, they need answering.

Thankfull regards
marius

ps: please exuse my english.. it's quite late..

[Peter Daniel]

http://www.decdun.fsnet.co.uk/gainclone.html

[peranders]

Mr Demo, why don't you poke around here?
http://c.webring.com/hub?ring=gaincloneamplifi

Check also these files as reference

http://www.national.com/pf/LM/LM3875.html
http://www.national.com/pf/LM/LM3886.html
http://www.national.com/an/AN/AN-1192.pdf <= very good!
http://www.national.com/appinfo/audi...gn_Guide13.xls
http://www.national.com/appinfo/audi...sign_Guide.pdf

Check also this

[matjans]

In reply to Q1:

afaik, the original gaincard (from which the term gainclone is derived) uses the lm3875. So, if you want to make a 'true' gc, use the lm3875.

But, what's in a name? most gainclones at present are no longer copies of the gaincard anymore. Some people use buffers, regulated supplies and what not.

It's up to you, really. Read all about it on Nuuk's homepage. Great reading for newbies (like me).

M.

[demogorgon]

thanks for helping out.

i really wasn't shure about the principle of the amp, but now i pretty much know what they are, so im building a couple.

how does a 5.1 gaming\film amp for my pc sound? in my ears it sounds sweet, and with the price of those things, im hooked..


im thinking of using the LM3886 68w for all channels exept the sub, where im thinking a LM4651\4652 combo.

or is it enough to use TDA 2050's? can they do the trick?
as i have altso read, the tda 2039 has seen it better days?
im altso looking at the LM4700.. it seems a good aternative..

after a year at ground cource electro i have lots of nice transformers and cooling ribs lying arround. besides i have a lot of computer ribs and fans as i'm deep into pc moddifying. worst case scenario, i'l watercool them as i'm doing my pc :P


As i altso see, the key to meke these things sound good is to keep the signal paths short?
hardwiering an entire surround amp might be a little ambissious?
i might need to etch myself some pcb's when school starts again.

any thoughts on my chose of ic's and plans?
anything i need to have in the back of my mind or any tips and hints?

thankfull regards
marius

[squadra]

Originally posted by demogorgon
thanks for helping out.

i really wasn't shure about the principle of the amp, but now i pretty much know what they are, so im building a couple.

how does a 5.1 gaming\film amp for my pc sound? in my ears it sounds sweet, and with the price of those things, im hooked..


im thinking of using the LM3886 68w for all channels exept the sub, where im thinking a LM4651\4652 combo.

or is it enough to use TDA 2050's? can they do the trick?
as i have altso read, the tda 2039 has seen it better days?
im altso looking at the LM4700.. it seems a good aternative..

after a year at ground cource electro i have lots of nice transformers and cooling ribs lying arround. besides i have a lot of computer ribs and fans as i'm deep into pc moddifying. worst case scenario, i'l watercool them as i'm doing my pc :P


As i altso see, the key to meke these things sound good is to keep the signal paths short?
hardwiering an entire surround amp might be a little ambissious?
i might need to etch myself some pcb's when school starts again.

any thoughts on my chose of ic's and plans?
anything i need to have in the back of my mind or any tips and hints?

thankfull regards
marius

If you love cooling then you might want to take a look at the various class A amplifiers that are available

From what I understood Class D amps require a lot of luck and/or pcb layout skills, so that might not be the best option to start with.
2 GC's in parallel might be sufficient (or 4 or 6 etc.)

[demogorgon]

Originally posted by squadra


If you love cooling then you might want to take a look at the various class A amplifiers that are available

From what I understood Class D amps require a lot of luck and/or pcb layout skills, so that might not be the best option to start with.
2 GC's in parallel might be sufficient (or 4 or 6 etc.)

i understand.

i'l have to look fore some pcd layouts, but if ther arent any, then i guess i'l have to do as you say. bridge them, but then i'l have to come up with a smart vay to make a active crossover. i dont want anything abowe 160hz in my sub.

[demogorgon]

as it turns out, the nice guys over at national are willing to send me some LT3886, if i can only pay those lousy ten bucks they want..

curse visa for not letting me pay online..

any tips on how to aproatch this minor setback?

[demogorgon]

well, back now, a bit more experienced with diy audio since the beginning of this post, but i do have a few more questiones..

i got the main parts in front of me now.. 25A rectefier bridges, two lm 3886, cooling ribs, capacitators and unetched printcards..

what i'm ondering about is if anyone have a printcard layout with measurements? as in how many mm between every hole and the size og every "copper area" so to say..

i really dont know how to say this otherwise, but i hope i at least made myself understood..

regards
marius

[falcott]

Have a look at the simple board designs on these pages:

http://www.mhennessy.f9.co.uk/gainclone/experiments.htm

http://www.geocities.com/rjm003.geo/...io/diy_gc.html