Objective2 (O2) amp

[CherryBomb]

Also, I paid with paypal and am still within the period for filing a complaint. Since it has been a few days and I have not heard from Epiphany, I think I'll go ahead and take that route.

Edited January 1, 2012 by CherryBomb

[CherryBomb]

I went ahead and did the paypal thing. Even if that works, I will still lose about $75 on this since I placed an initial deposit that is outside of the period for filing a complaint. Oh well - you live, you learn.

[justin]

this reminds me to check my inbox again, make sure i dont have any stale New Years Eve emails to answer

[CherryBomb]

this reminds me to check my inbox again, make sure i dont have any stale New Years Eve emails to answer

It would be different if you were the seller since you have an established, good, reputation. This guy at Epiphany, Oliver, is a total unknown. He may be a good guy in the end - I just don't know yet.

[DefectiveAudioComponent]

I just got one of those O2 amps. I did not build much of it myself though.

In hindsight I think I should have used a different led than the red one. I does not go so well together with the blue metal box.

[grawk]

red and blue look great together if you're tripping

[DefectiveAudioComponent]

It is possible to press the extra-sensitivity button and get som really entertaining distortion of the highs through an LCD2. Some other random orthodynamic might do it as well.

It goes "click" through the headphone when I power it up. Perhaps I should take a look at the board.

[pigmode]

I like red led on port, green on starboard, and white in the back, so I can tell which way the sound is moving.

[DefectiveAudioComponent]

Actually, I think the this small amp sounds all right. And it is cheap. It even looks as cheap as it is. And I needed a cheap amp.

I can imagine that in the future we might find four of these stuffed into a really expensive fancy box that used unusual screws that could not easily be unscrewed, with a fancy name and number and silly sales text that wasn't quite written in english....

But, I could use yet another ok cheap amp. So, is there another design that is even cheaper and better?

[spritzer]

Build the 100$ amp Kerry drew up, makes the objective look like the garbage it really is. Price doesn't include the heatsinks, transformer etc. but this is one performs way past it's humble pricetag. I'm also sure you can build a Dynalo for silly little money simply by being frugal and using a simple 317/337 or 317/317 PSU (depending on the transformer used).

[cobra_kai]

If you can get your hands on a pcb one of the versions of the the wire from diyaudio might be worth looking into. Three lme49990 configured as an instrumentation amplifier on the input and then a lme49600 buffer on the output. More info here: http://www.diyaudio.com/wiki/The_Wire_Headphone_Amp_GB \

You should be able to build it for under $150 I think.

Or you could wait for KG's black hole. Construction will be more complicated I think cuz it needs external sinks

[cobra_kai]

Build the 100$ amp Kerry drew up, makes the objective look like the garbage it really is. Price doesn't include the heatsinks, transformer etc. but this is one performs way past it's humble pricetag. I'm also sure you can build a Dynalo for silly little money simply by being frugal and using a simple 317/337 or 317/317 PSU (depending on the transformer used).

Link?

[ujamerstand]

The build:

The schematics:

[cobra_kai]

^^ thx

[TruBrew]

I am glad I read through this thread. I was considering building one of these. I bought a soldering iron a while back, and have yet to use it. I don't own a portable amp, and I thought this may have been a cheap and decent project.

[limp]

I am glad I read through this thread. I was considering building one of these. I bought a soldering iron a while back, and have yet to use it. I don't own a portable amp, and I thought this may have been a cheap and decent project.

It still is a cheap and decent project.

Spritzer might be right about the Gilmore and Kerry designs being better, but the fact is that noone has ever checked.

So if you want a small battery powered amplifier with the most thorough documentation I've ever seen, you shouldn't write off the O2 quite yet.

[TruBrew]

I appreciate the opinion. I start back in school on Monday, and will be kept busy. That gives me plenty of time to look around before making a decision.