[creyc]

Speakers. Yes, I know this is practically being sacrilegious asking here but you guys are the most informative, knowledgeable DIY'ers I've met. I'm sure in your quest for quality audio some of you enjoy a full speaker system.

Well I'm in the market/mood to build several power amps, mono, about 200 watts a piece. I've started exploring diyaudio with limited success but I was hoping to find a good starting place here. My goal is to find a PCB I can stuff and put into an enclosure I'm building. I don't have the skills or knowledge to design my own layout so I'd like to find a solid, quality design already.

You guys know any good starting places for me?

 

[rickcr42]

are you sure you need 200 watts ?

That is a lot of ampage !

a couple of well documented designs but at less power are these

http://www.passdiy.com/pdf/A75p1.pdf

http://www.passdiy.com/pdf/a75p2.pdf

http://users.ece.gatech.edu/~mleach/...77articles.pdf

http://users.ece.gatech.edu/~mleach/lowtim/

http://users.ece.gatech.edu/~mleach/superamp/

you can learn enough from the above to make these amps any power you need to pretty much just by increasing the output stage devices in parallel

 

[nikongod]

do you *need* 200W?

there is an 8W tube amp that is available as a kit that sounds VERY good considering price. there is a thread dedicated to it (and various mods) on this forum. i think that if you look up the string "s5" you will fiond it. alternately use "cheap tube amp"

if tubes are not an option, there are a few companies that make SS based kits. i havent built any of them myself, but they look nice.

 

[rickcr42]

http://www.wnaudio.com/amos100.pdf

 

[creyc]

Unfortunately tubes are not an option, no. These things will be put in some serious enclosures and transported around an I dont want to subject tubes to this kind of abuse.

While 200 watts is a goal of mine, I could maybe do 150W, like a Lynx, so far the only thing I've seen even close to what I'm looking for. I know 200 watts is a lot of power but at least 2 will be delegated to subwoofer duties, depending on my setup, therefore power is important.

Price isn't really an issue here guys, if that makes it any easier.

 

[pne]

I'm surprised you didn't find anything on diyaudio, have you looked into those class D amp plans at all? They are a lot more efficicient and might be more practical if you need 200watts.

 

[Garbz]

Is this hifi you are building for or PA? For Hifi you really usually want a completely different design for subwoofer amplifiers then you do for main amps. 200watts is huge. My 2x70watt amp can reach ear shattering volume before clipping becomes a problem and my speaekrs at 88spl aren't that efficient.

Building 70watt monoblocks would allow you to go for some gainclone style amps which are easy to build. For extra power though I'll recomend the passlabs designs which rick linked to above.

For a subwoofer amp you're looking more to a Class AB or Class D design rather then pure Class-A. Further more you'll need an amp which has a selectable crossover frequency and variable phase.

If on the other hand you need to power PA equipment (in which case yes you'll need 200w

) I can't help you this is no longer an area I'm familiar with.

PNE: Class D amps are great for subs but pretty nasty IMHO for speakers.

 

[rickcr42]

if DIY is not a must look for a couple of old Hafler DH-500 or Dynaco ST-400 amps.Not up to the specced 200WPC without modifying but cheaper than any build when you add in casing and heat sink cost ($$$$$$$$)

 

[creyc]

Thanks guys, I might have to seriously do some re-evaluation.

As for the Dynaco suggestion, yes exactly! I'm looking for something comparable with an SAE, GAS or Dynaco. Anyone remember the Ampzilla? I know I don't but my uncle has one and i'd like my amps to be of similar style.

These amps wont be used for crazy hi-fi i suppose, some Paradigm Studio 100's here and there as well as a few custom built speakers. (Bozak concert grand replicas maybe?

) I suppose they would be more of a PA amp but to my ears that just doesn't sound like a term I want to use at all!

Am I screwed, having been exposed to high quality audio? hehe

 

[rickcr42]

Quote:

As for the Dynaco suggestion, yes exactly! I'm looking for something comparable with an SAE, GAS or Dynaco. Anyone remember the Ampzilla?

The schematics for all of these are online.The ST-400 and Ampzilla are both Bongiorno designs,the Hafler an Erno Borbely design.

The problem with DIY versions of any is the difficulty in procuring the old transistors used,the impossibility of obtaing an original 5 opamp chip (From original P.E. "Build The Ampzilla" article) and the chassis/heat sink would likely cost more than a second hand original.

Quote:

Am I screwed, having been exposed to high quality audio

Yes.and doomed,as are we all

Here is a possible build suggestion :

Since you mentioned the amp "banging around" I assume it needs to be road worthy and that means rack mount panel and a road case.

that means building on a standard chassis with a rack panel and side reinforcements for strength

http://www.budind.com/view.php?part=acc-ssp

http://www.budind.com/view.php?part=acc-ssp2

http://www.budind.com/view.php?part=acc-tmb

http://www.budind.com/view.php?part=al-ch

or full rack chassis ($$$$$) :

http://www.budind.com/view.php?part=ch-rm

then there is the road case (you may need fans in the back) :

http://colomar.com/Shavano/rackcase.html

http://colomar.com/Shavano/cheap_box.html

So if second hand is off the list the closest in topology to the "Ampzilla" is the Leach Super Amp.The article explains how to get more power but there is also the old standby,the bridging input making a stereo amp into a mono monster :

http://colomar.com/Shavano/pa_bridge.html


should be enough to get the creative juices flowing

 

[creyc]

rickcr24, you never cease to amaze me!

Wonderful stuff, I will definitely consider building a standard sized case as these probably should be racked sooner or later.

Have you heard of the Studio 350 high power kit amp? I saw a few mentions of it on DIY, seems like a potential candidate I would think...

Currently looking into Super Leach. And looking for the Ampzilla in the garage.

 

[rickcr42]

Quote:

Have you heard of the Studio 350 high power kit amp? I saw a few mentions of it on DIY, seems like a potential candidate I would think...

Can't say I know the amp.One thing about solid state you need to be aware of is they ALL look great on the specs but not all sound good.

for subwoofer only duty not that much of a big deal if you have good power at the bottom,and that usually means a huge power supply reserve,a a good dampning factor which mostly means gobs of negative feedback-bad for mid to highs,great help for low frequency work

The Leach is proven topology and for Pro use has protection circuit capability so should make an indestructable amp unless you spill a beer into the electronics (don't laugh,have seen AND done it

)

If you find the Ampzilla it is a keeper and to be treasured.Maybe the best high power amp ever (Bryston is not too shabby !) and there is a Yahoo Group that has all the files on this amp in three or four versions.If you are extremely adventurous you can even DIY one from the original articles but that is a tough path man.

Just in case :

http://groups.yahoo.com/group/SAE_Talk/?yguid=175486106

and for Dynaco schematics/mods :

http://groups.yahoo.com/group/Dynaco/?yguid=175486106

http://groups.yahoo.com/group/audio-...guid=175486106

you need to sign up to access the file areas but great resources for these behemoth amps of old

Quote:

Currently looking into Super Leach. And looking for the Ampzilla in the garage

good luck on both.Even if you find the Ampzilla the Super Amp is a nice long term project

 

[creyc]

lol, yes when alcohol is served, be careful with the music selection. A "guest" may just come get up in your face and dump their can of beer into your amp. Sage advice from my uncle, who's now encouraging me to build these amps.

Will all these high power amps use MOSFETS, that is to say are discreet power transistors out of the question? I still need to educate myself in this area. (so much to do!)

More to follow...

 

[00940]

There's this "simple" thing too : http://sound.westhost.com/project101.htm . The good thing with it is in the PCB and support. Lots of details on diyaudio.

I'm currently sweating on a 2X30W amp, it's bad enough for me.

 

[SHLim]

Quote:

Originally Posted by creyc Well I'm in the market/mood to build several power amps, mono, about 200 watts a piece. I've started exploring diyaudio with limited success but I was hoping to find a good starting place here. My goal is to find a PCB I can stuff and put into an enclosure I'm building. I don't have the skills or knowledge to design my own layout so I'd like to find a solid, quality design already. You guys know any good starting places for me?

The recent buzz in Diyaudio is in the Solid State forum. A new kit amp call Simple Killer Amp by Greg (or amplifierguru) of Australia. He offer fully populate pcb or unbuild kit for 150W and 300W power amp at resonable price. You will find endless discussion over Diyaudio and some over audiocircle.

This is his web site.
http://members.dodo.com.au/~gregball/guru_001.htm

Have fun,
Sam