Schematic diagram


2005-06-09 5:10 pm
Does anyone out there has a schematic diagram for a simple power amplifier. I'm new to this forum and also to this kind of audio gadget, but i'm very interested in it, so i hope that you guys can help to build my new power amp, but first, I need a good and simple power amp schematic diagram.


2005-07-20 7:41 pm
Matthewong said:
Does anyone out there has a schematic diagram for a simple power amplifier. I'm new to this forum and also to this kind of audio gadget, but i'm very interested in it, so i hope that you guys can help to build my new power amp, but first, I need a good and simple power amp schematic diagram.
Well, let's see, there's simple and then there's simple...
I once knew a fellow who rebuilt engines for fun. He claimed it was simple. From my point of view, there were way too many parts to keep track of. If I had a Chiltons or something, I might be able to do it, but he did it with no reference at hand.
It's the same with electronics. Once man's simple is another man's confusion.
Now, the first thing to ask is: How much power were you thinking of?
1000 watts? That's a little ambitious. Not in the simple category. Even if the circuit is simple enough conceptually, it's going to involve a lot of money and the consequences of a bad solder joint could be spectacular in the fireworks sense of the word. Crushing disappointment and financial ruin are not good memories to take from your first project.
If it's a first project, then a more modest 10 or 20W amp would be a good bet. The relationship between watts and volume is not linear, so although it won't crack the plaster in the ceiling, it will play louder than you might expect, especially if your speakers are efficient.
There are numerous small amps here and there on the web, but the pedigree of some of the mutts is questionable.
In the running for Simplest Amp Possible is the Son of Zen. Two transistors and a few resistors. Can't beat that for simplicity. runs seriously hot (by design) and requires a power supply the size of a Volkswagon. Okay, I'm exaggerating, but it's not necessarily the best choice for a first project. One notch up the complexity scale is the Zen. A few more parts, but a lot more versatile in terms of matching with speakers. Not a bad choice.
Where to find?
There have been something on the order of about seventy trillion Zens built and a large percentage of the builders are available right here to answer questions if you get stuck.
Build a Zen and see how you like it. Afterwards, you may feel like making a run at something more elaborate.

Call it Rollins after Pass. The Mini-A was a quick take on shrinking a real Aleph into a smaller package. Nelson did all the hard parts. I just kinda refigured a few things.
A Mini-A is somewhat like a Zen with a front end. The parts count is a little higher. It's a little more efficient. The specs are presumably a little better than a Zen, but do not make the mistake of assuming that means it necessarily sounds better than a Zen--there's more to this than the numbers would have you believe.
It was just a toy that I threw together in order to have a building block to use whilst pursuing the Aleph-X project.

I got a little story to add to this.. I some times wonder why people need more than 40watts.. right now im running briangt's rev 1.0 Smd Mini a's 20V rails i assume about 15watts maybe less. to be honest why do people even need more than 15watts. Im pretty sure that my speakers that i have now are not efficiant. They play pretty well for what they are and sound good. Loud you ask. Well there is lots of bass and it does go loud. I wish i knew how to read my db meter ( the old radio shack anolouge one's )

On another note. illbe running 4 so i can do bi-amping. Im wondering alos there are 2 versions of the mini a's one from grey and one that briangt has .. grey's have less part's i wonder how his sound.. Maybe i should do up a board and compair.. :d
I second jleaman's comments. The mini-a is a worthy and simple project. Even if it doesn't find it's way as your main amp in your main system, you will certainly find a nice home for it. It's a great place to start, and it actually does sound just fine on somewhat inefficient speaks. Build one, and then move on up if you see fit. If you're running a pair of Forte's or something, it would probably be all you'll need!

Another thing to consider when looking at a schematic is whether or not you can get support for when you get into trouble. The small Pass stuff has more support here than you will ever need :cool:. There's some guy floating around here that has built thousands of them.
Actually I just looking a schematic diagram that the output power is around 40-60watts are enough. No need to reach untill 1000watts. That's way too much of power to me and since I'm still new to this gadget. And from my opinion, a good low power amp will sound better than a high power amp. But when you push up the volume, the sound will lose control. If the power of the amplifier is too high, the sound will be congested. Nothing is perfect especially in audio. Some people like warm sound, some people like sweet sounding, it is all depending to personal taste. And get back to the thread that I posted earlier, does anyone has simple schematic diagram for power amp with I think 30-60 watts would enough for me.
<tangent thought>

Wow, did Harry H. sneak back in with a new moniker?!? Almost like reading the Aleph-X thread again...

<end tangent>

Matthew, since you posted your question in the "Pass Labs" forum, I'd spend some time at Pass Diy . There are many fine amps there (all Class A- designed by Nelson himself) that will suit a variety of needs. Grey did a nice job providing a road map through the various designs..

You might also want to check out the Solid State Forum for a variety of Class B designs. Lots of nice folks around in either forum to help with questions.


2005-07-20 7:41 pm
Re: Help

MikeW said:
Grey was just trying to help. Calm down. There are a lot of good low power amps. Don't knock pass labs amps until you try one. If you want high power try some of Anthony Holton's designs.

Wow thats a behemoth of an amp...

Well I heard one once upon a time and I dont have a love affair with any particular brand as of last count I think I own like 17 amps now... and crown is my fav.... In fact I am going to get another for my home... I have become pretty good at picking equipment from specs and having my expectations met when I receive it, that and I have many years of experience...

I dont build amps anymore... they are too good and too cheap to bother with them... back when I had more time than money I did that sort of thing... So I am quite qualified to knock pretty much anything out here....