what good DIY amps are there?

[Soymilk]

i've been looking at amps, and it seems that i can get a better value for the money (i'm thinking like $50ish?) if i build a DIY amp rather than buy one. i'm pretty sure i won't have any difficulty putting it together, i've done this stuff before, i just don't know what to look for. these will be used to drive a dt770pr80.

thanks

 

[TzeYang]

CMOY with extra modifications and tweaks.

Sijosae Class AB

Pimeta

Pint

Etc.

 

[Soymilk]

details please? i've heard of cmoys and pimetas before, but have no idea how much they cost. i've also heard of the pint, but the post said they're not being sold anymore?

thanks

 

[Filburt]

No more PINT boards left. Tangent said he'd release some sort of new design at some point but there hasn't been much update on that. I'm guessing it's because he has a life, but maybe it's something else

I do have one board left over from a cannibalised former PINT. I'm going to build der uber PINT with it.

 

[Soymilk]

is there a page of like a summary of the different DIY types, what parts are needed, and how much it costs to build one?

 

[DennyL]

Quote:

Originally Posted by Soymilk /img/forum/go_quote.gif is there a page of like a summary of the different DIY types, what parts are needed, and how much it costs to build one?

There's a lot of information here:-

http://headwize.com/projects/index.htm

 

[FallenAngel]

You're not going to have that many options with a $50 budget, but you could easily cover these:

CMOY
A47
Sijosae Class-AB (Very nice budget amp, I loved mine - probably your best bet)
PINT / PPAS (Very tight budget for these, but may be possible)

Of course this all depends on your soldering / layout skill level. If you're ok with a soldering iron and can read schematics, go for the Sijosae Class-AB, you'll like it. And if you're up to it, make it a 3-channel design and use the same opamp + diamond buffer for ground as the other channels. You can use a dual opamps for ground, first for rail splitter. I did this before and can say it sounds fantastic, but lets just hope you like working on breadboard.

 

[Soymilk]

yeah, im proficient with a soldering iron and can read schematics fine. is the sijosae class-ab better than the pint/ppas, or are you suggesting it because the pint is out of my budget / out of production / hard to find?

 

[FallenAngel]

Well, the PINT is practically impossible to find a PCB for and it might be pretty hard to get a hand on the PPAS PCB as well. Plus, the PINT was unusualy hard to build for a lot of people. Maybe due to the AD8397 being nicely appropriately called a "terrible opamp from hell". It sounds great, but hard to get stable. Mine took like a month of work to stabalize

It's a huge current opamp outputing 200+ mA so no buffer necessary. PPAS is a SMC version of the PPAv1 amp, I haven't followed that thread too much, but it looks interesting.

The Sijosae Class-AB has a discrete output buffer while the PINT has none and the PPAS is buffered by BUF634. I personally liked my PINT over the Class-AB, but it also cost twice as much.

I would also really suggest taking a look at PPL's new LISA III amp. It's very similar to what I did with Sijosae Class-AB, but Phil did serious research and designing which made a wonderful optimized version in his amp. It has a better buffer with CCS. You should be able to breadboard it before the boards come out (unknown timeframe at this point). His design calls for AD744 in compensation mode, which is supposed to sound great, but you can always use any other opamp and bias it into class-a with a 1mA ccs or just leave it unbiased.

Hopefully LISA III won't be over your budget, it looks very promising

 

[Soymilk]

hmm, i guess ill keep my eye on the sijosae class-ab and the lisa III since the pint costs twice as much as the sijosae.

 

[Soymilk]

ouch, the lisa III looks like it's going to be expensive (relative to my point of view) judging by the discussion going on in the proline 750 amp thread.

do you have a link to more information about the sijosae? i can't find anything

 

[Soymilk]

bump

 

[TzeYang]

Quote:

Originally Posted by Soymilk /img/forum/go_quote.gif ouch, the lisa III looks like it's going to be expensive (relative to my point of view) judging by the discussion going on in the proline 750 amp thread. do you have a link to more information about the sijosae? i can't find anything

normally, you would only require the picture of the schematic and layout sijosae designed. If you need extra information, you can refer to this thread:

http://www.head-fi.org/forums/showth...=182796&page=2

Though it gets tougher as FallenAngel decided to tweak and change the output stage into something better.

 

[Soymilk]

ah, so it's truly diy. i'd found the schematic, but didn't know if there was anything else or not. thanks

i'm probably not going to get around to actually doing this for a while though, since currently i dont have anything worth amplifying. just getting ready for when i do get a dt770

edit - does anyone know what the cost for parts generally is on a sijosae class-ab?
also, i'm in college right now (first year), EE major, so if i get bored next year or maybe later i may try designing a layout myself

 

[FallenAngel]

$30 or so