DIY reference amp designs?

[Mbira]

I've seen the idea kicked around here a few times, but I don't remember seeing any completed projects. Do you mean to tell me that all you DIY gurus out there are using store-bought amps to run your nearfields?

:green:

Any ideas on good places to look for a decent design?

Joel

 

[gyraf]

The LM3875 Gainclone chipset pretty much took the air out of diy'ing low-and-medium-power amplifiers - it's pretty hard diy'ing amplifiers that are better, imo..

Jakob E.

 

[rodabod]

I've been wanting to write a little about this with respect to Class-D / Class - T amplifiers.

Has anybody tried the Sonic Impact T-amp?

Apparently it rivals expensive audiophile amps.

 

[featherpillow]

it's pretty hard diy'ing amplifiers that are better, imo.

I second that. It still suprises me that these little amp pack IC"s that are found in car stereos can be used to get such a good sound.
There are several people here who do gainclone stuff, including MCS and Peranders.

 

[Mendelt]

[quote author="rodabod"]I've been wanting to write a little about this with respect to Class-D / Class - T amplifiers.
[/quote]

I'm about to build an amp based on the 180W class-D modules by hypex for a friend of mine. But that hardly qualifies as DIY.

 

[analag]

I did post a pic of my DIY reference amp all 1000 watts of it. In fact I'm using it right now.

I am too lazy to put on the finishing touches. I did the trannie myself (dual secondary) and the heatsinks too.

 

[featherpillow]

180W class-D modules by hypex

I thought those were no longer available?

I did post a pic of my DIY reference amp all 1000 watts of it. In fact I'm using it right now.

I remember that.
http://www.groupdiy.com/index.php?topic=8644&highlight=reference+amp

 

[Kev]

[quote author="Mbira"] Do you mean to tell me that all you DIY gurus out there are using store-bought amps to run your nearfields?[/quote]
nuh
but here is a blast from the past
not one of mine
... and even this was a rework of an old faithful from the 70's

http://www.diyfactory.com/projects/workhorseamp/workhorseamp.htm
perhaps I'll finish the page one day

 

[Svart]

Class T?

:shock:

I have never heard of such things..

 

[Carl_Huff]

I have just ordered the parts for an active loudspeaker system. I am building up a board that has eq stuff on it that feeds a Hypex UCD400 module. The eq/amplifier assy is designed to slide into the back of the loudspeaker cabs. The loudspeakers are tall linear arrays that are the front pair in a large home theatre setup. 24 drivers per side.

Does this interest anybody?

 

[Mendelt]

[quote author="featherpillow"]

180W class-D modules by hypex

I thought those were no longer available?
[/quote]

They even have a 400 and 700 watt version now. But i heard the 180W version sounds better.

www.hypex.nl

 

[bcarso]

I haven't heard any of the Hypex stuff yet but I am inclined to suspect it is very good---the UcD (licensed from Philips) concept is beautiful. Way way better than the "pure digital" phoolery/marketing hype madness. The only drawback I can see at first glance is the difficulty of avoiding heterodyne artifacts with multiple channels in a system, unless you carefully choose the output filters' natural resonances to be spaced well apart from each other, and then customize the details of the feedback network appropriately. Or, do other games that explicitly synchronize and adjust the effective output filter resonance on the fly, which is decidedly nontrivial.

IMO the National stuff is nothing special---big power op amp approach that is o.k. but nothing to write home to mother about. Also, not very efficient and really ugly when it starts to protect. And yes, it is difficult to do better and especially when you want the result to be bulletproof---but whoever said this was supposed to be easy anyway?

 

[Mlewis]

somebody back engineered a Pass Labs amp and has posted full schematics of a 100W scaleable version of the supersymetry X series amps that everyone seems to rave about. i could be wrong but i believe the circuit is similar for larger power versions but with greater biasing and a bit more cascading for the really large ones. it's even been given a bit of a nod from Nelson Pass himself who was flattered that somebody went to so much trouble and even offered some help!!! don't see that very often!!

the massive thread is at www.diyaudio.com and near the top of the Pass Labs section. thread called "X100 backengineered here".

not sure if that's helpfull but i certainly got quite excited when i saw it.

Mark.