Where to start: DIY amplifier (tube, gain clone?)

[isaeagle4031]

I think I maybe ready to try my hand at building an integrated amp. I know enough to know I don't know what I want. :D

My "idea" will be to use it to drive a pair of higher sensitivity 8"2ways, 93-94db. So 20-25w at 8ohm will be more than enough I think and not be a huge investment. Lets say budget should be around $250 not including a case. That I think I can handle.

So can someone point me in the right directions?

[50 watt head]

Re: Where to start: DIY amplifier (tube, gain clone?)

Lets say budget should be around $250 not including a case.

That pretty much rules out a tube amplifier ... unless, you restore/rebuild a vintage amp, find used parts on eBay, etc.

[hongrn]

Re: Where to start: DIY amplifier (tube, gain clone?)

I wouldn't start with a tube amp either, since you talked about "building" an amp. Having had 5 amps under my belt, please allow me to give the following recommendations:

1. Pick an amp from the PE site that fits your speaker power and impedance needs. Stay away from the eBay amps for the time being, since instructions and tech support are non-existent.

2. Pick a DC power supply to power the amp. Depending on the voltage and current need, you may be able to get away with a laptop brick, or pick a PSU from the PE site. I recommend against building a power supply for your first amp.

This will give you a good start, since you have to learn to install source inputs, speaker outputs, volume control, and put everything in a case. Trust me, this is not going to be your only amp, so success with the first one is important. Hope this helps.

Hong

Good combo right here:

http://www.parts-express.com/2x50w-tda7492-class-d-amplifier-board--320-301

http://www.parts-express.com/24-vdc-6a-145w-regulated-switching-power-supply--320-314

You can use a 19.5V laptop brick to power this amp as well.

[isaeagle4031]

Re: Where to start: DIY amplifier (tube, gain clone?)

Thanks for the heads up. Much appreciated. I have no problem building a PS even for my first try at it. I do have some excellent support to draw from there.

What about a tube preamp/chip poweramp combo? Budget can go up a bit. I am basically dedicating next years speaker budget to this project.

[djg]

Re: Where to start: DIY amplifier (tube, gain clone?)

These have been around for a while, mixed reviews.

https://www.s5electronics.com/thome.html

[bdiermeier]

Re: Where to start: DIY amplifier (tube, gain clone?)

Shameless plug- I just posted my chipamp LM3886 kit up for sale, then saw this. Whether mine was for sale or not, I'd recommend this kit.

I totally agree with what Hong said- stay away from ebay amps for a first build.

The chipamp LM3886 kit is capable of 68w, far more than you need. It is a pretty simple kit to build, and will work on with a very wide range of transformer voltages (starting at 18v, but my uncle has his running at 29v!).

As for support, that is where chipamp.com really shines. One of these was my first build, and I messed up - A LOT. Allen @ chipamp.com was extremely helpful with all my questions. When I made a really stupid move and blew up a chip, he even sent me a new one, free of charge. Heck, you can even download an instruction manual for assembly!

Here's the link for chipamp.com:http://chipamp.com/product/non-inver...amplifier-kit/

Let me know if you're interested, I would probably be willing to drop the price a little if I know it's going to someone who will get some use out of it.

[thekorvers]

Re: Where to start: DIY amplifier (tube, gain clone?)

Shameless plug- I just posted my chipamp LM3886 kit up for sale, then saw this. Whether mine was for sale or not, I'd recommend this kit.

I totally agree with what Hong said- stay away from ebay amps for a first build.

The chipamp LM3886 kit is capable of 68w, far more than you need. It is a pretty simple kit to build, and will work on with a very wide range of transformer voltages (starting at 18v, but my uncle has his running at 29v!).

As for support, that is where chipamp.com really shines. One of these was my first build, and I messed up - A LOT. Allen @ chipamp.com was extremely helpful with all my questions. When I made a really stupid move and blew up a chip, he even sent me a new one, free of charge. Heck, you can even download an instruction manual for assembly!

Here's the link for chipamp.com:http://chipamp.com/product/non-inver...amplifier-kit/

Let me know if you're interested, I would probably be willing to drop the price a little if I know it's going to someone who will get some use out of it.

You have a pretty nice kit for sale and someone will probably pick it up. However it is a bare circuit board.

I don't know the O.P.'s soldering skills, but for someone who has never built an amp, I would recommend an assembled pc board for his first build.

[50 watt head]

Re: Where to start: DIY amplifier (tube, gain clone?)

If you're thinking of tube preamp, then you might want to check out the Aikido all-in-one linestage.

[bdiermeier]

Re: Where to start: DIY amplifier (tube, gain clone?)

You have a pretty nice kit for sale and someone will probably pick it up. However it is a bare circuit board.

I don't know the O.P.'s soldering skills, but for someone who has never built an amp, I would recommend an assembled pc board for his first build.

I actually have to disagree here. Regardless of what kit it is, I think that soldering a bare board makes for a much more rewarding build- especially for a first build. Most non-eBay kits (chipamp, audiosector, etc) are very clear about the placement of components, and make it almost impossible to screw up.

As for soldering, what I did to learn before my first build was picked up a cheap eBay kit- I think it was a light up star or something. It doesn't matter what it is, just the cheapest solder-together kit you can buy for good practice.

No disrespect, I just think soldering is part of the adventure. Plus it will take longer- probably a good thing if he spends his whole speaker budget for next year

[djg]

Re: Where to start: DIY amplifier (tube, gain clone?)

More challenging than the S5 kits.

https://www.tubelab.com

Might as well throw this in too.

https://www.tubes4hifi.com

[[email protected]]

Re: Where to start: DIY amplifier (tube, gain clone?)

The simplest would be something like the 2x100 http://www.parts-express.com/2x100w-...-only--320-334
With a regulated ps.. http://www.parts-express.com/36-vdc-...pply--320-3141 adjusted to 32volts. or this one http://www.parts-express.com/univers...-port--120-502 Using the 19.5 tip. One big cap could probably help with the low stuff.
Just add jacks, IEC plug and a volume pot and............rock and roll!
Very similar to what JR is doing. These have enough gain that a pre is not needed in my experience.
This will get your feet wet Chuck.
I have a similar amp but with the 2x300 that I'm going to add a Blutooth modual too soon.

Pics here http://s413.photobucket.com/user/arl...?sort=3&page=1

[tc]

Re: Where to start: DIY amplifier (tube, gain clone?)

I would second the idea of chipamp.com First, if someone really wants to get into the hobby of building equipment, having soldering skills is kind of a must (or at least makes it a LOT easier and provides TONS more options).

You will learn a lot just by building a very simple PSU. And if following the instructions for a 3886, you will learn a lot about how the chip works. Will translate a bit towards transistors. A bit towards op amps, etc, etc...

I think I have about $100 in mine (scavenged old 2-channel recievers and other things). You will love it. Plus, there are a ton of people who have built it, can lend a lot of advice, and probably hundreds of posts on it at diyaudio.

[isaeagle4031]

Re: Where to start: DIY amplifier (tube, gain clone?)

Thanks all. Lowell, I knew you would jump in here. Yours and Craigs builds are what have my interest in this project going. I have a couple of old receivers and an amp I could scavenge PSUs from. Just not sure I want to tear into something that actually does work.

[[email protected]]

Re: Where to start: DIY amplifier (tube, gain clone?)

The IRS2092 2x250 I did was a design by Craig. The second was gleaned from Hong and other builds around the net. He has the PSU down pat now if that's the way you want to go but way more power the you suggested wanting.

[isaeagle4031]

Re: Where to start: DIY amplifier (tube, gain clone?)

Oh def much more power than I need right now Lowell. I just wanted to have a bit more DIY than slapping a couple of pieces into a box. Thought I could at least tackle the PSU.