Looking for beginner project

[systemerror909]

Hi, I'm new to these forums and was looking for some advice. I've become interested in "audiophile" sound over the past year and was hoping to continue upgrading my system by replacing my amp. Currently, my system includes a pair of wharfedale 8.2 diamonds (new this summer), a sony CA70ES cd player and an old pioneer VSX type reciever from the early 90's. I'm extremely pleased with this setup, but know after upgrading the speakers and the cd player that the reciever is dragging down the system's performance, mainly due to the 10 band graphic equilizer incorporated into the device.

Anyway, I was hoping someone here could help me by posting a link or set of instructions to help me attempt to build my first amp. I'm looking for something relatively simple and low cost to build, but also very clean. My requirements are not much, just a simple stereo amp with volume control. I currently do not have a preamp, but (correct me if I am mistaken) don't think there is reason to have one if I am only using my cd player as a source and don't want any type of EQ.

In terms of power, my speakers carry a resistance of 6 ohms and have an efficiency of 86db/ watt, I believe the max power input for them is 100 watts rms. My current reciever is 390 watts max (something like 100 watts rms right?) and is waaay overkill, so I'm also looking for recommendations on power output as well. I'm living at home now, but this spring I should be living in a dorm, so I don't need something terribly powerful. A friend of mine built a 6 watt amp and was quite pleased with it.

Lastly I'd just like to cover my current set of skills in putting tocether electronics. From electromagnetics class, I've got a very basic understanding of what capacitors, inductors, resistors and transistors are, but i'm really sort of lacking the experience of building complex electronic devices. I should be fine soldering and using a multimeter, but apart from that won't really be able to test anything. I've got experience using an oscilloscope, but won't have access to one.

So all in all, i'm just looking for something cheap, relatively easy to build and hopefully marginally better than my current reciever to get my feet wet in the world of diy audio. thanks in advance for your help

[bigpanda]

Try this one

http://www.redcircuits.com/Page2.htm

Easy to build, no tricky components. I had it on a 3x6" pcb (stereo) compact enough?

[jaycee]

If you're a beginner, but you could handle putting some parts together, look at the Chip Amp forum for numerous "Gainclone" kits. These provide on average 50W RMS per channel and should be more than enough for light domestic use.

[systemerror909]

Yeah, I was looking in the chip amp forums last night and found a similiar post from someone who just completed his first amp, it looked like something I could do.

Just finished my very first Amp!

It looks real good, I guess I just got a few questions about the design, etc.

I guess my first question is, when building an amp for a stereo system, you need to build two identical amps, correct? In that case, I am wondering if that would lead to having two seperate volume controls, one for each speaker. How does one make sure that both speakers are turned to the same volume?

which brings up another question of mine that may be a bit complex for my current abilities. How does one create a system for bi-amping so that the two amps have equal (or rather correct) sound levels? Maybe this is a bit too complex for me to jump into, I'm just interested in learning more about it since my speakers support bi-wire/amping. I've currently got them setup for bi-wiring and am very pleased, but just wonder how much better bi-amping would sound.

Thanks for the replies

[systemerror909]

Oh, and a few more questions I forgot to include.

Anyone know the specs for this system? My impression of chip amps is that they are miniturized versions of full size solid state amps, so do they provide a "usable" amount of power?

[jaycee]

Originally posted by systemerror909
I guess my first question is, when building an amp for a stereo system, you need to build two identical amps, correct?

Yes.. although you can build the two amplifier circuits into the same case, which is what that person has done there. I would not use a plastic case as that person has done though.

Originally posted by systemerror909
In that case, I am wondering if that would lead to having two seperate volume controls, one for each speaker. How does one make sure that both speakers are turned to the same volume?

You use a dual-gang potentiometer for the volume control.

Originally posted by systemerror909
which brings up another question of mine that may be a bit complex for my current abilities. How does one create a system for bi-amping so that the two amps have equal (or rather correct) sound levels? Maybe this is a bit too complex for me to jump into, I'm just interested in learning more about it since my speakers support bi-wire/amping. I've currently got them setup for bi-wiring and am very pleased, but just wonder how much better bi-amping would sound.

Bi-amping is rather fiddly. In this situation you would be better with power amps for low and high frequencies, and a pre-amp that controls volume, the output of which is split in two for each amp.

Really there's only any point in bi-amping if you are using speakers that allow you to disable the internal crossover, and do the crossover filtering electronically at the pre-amp stage. If not (and most speakers don't, especially if they support "buy wiring") there's not much point.

Stick to building a stereo amp for now.

Originally posted by systemerror909
Anyone know the specs for this system? My impression of chip amps is that they are miniturized versions of full size solid state amps, so do they provide a "usable" amount of power?

I think the LM3886 chip is rated up to 68W RMS output into 4 ohms. That would be about 40W at 8 ohms which is OK for domestic use. If you want to blow your eardrums, you would need to build an amp from discrete parts which is more complex.