[JoshHat98]

Hey Head-Fi, 
 
I'm looking for both a fun project and a Headphone Amp, I've been looking around eBay and have seen some cheap headphone amplifiers. 
 
I found a $20 'Cmoy' Amp; http://www.ebay.com.au/itm/Under-20-00-DIY-Cmoy-Hi-Fi-STEREO-Headphone-amplifier-KIT-18volt-Guaranteed-/190903811215?pt=AU_Electronics_Audio_Amplifiers&hash=item2c72c0fc8f
 
An also a $40 Valve Amp; http://www.ebay.com.au/itm/VALVE-Cmoy-Hi-Fi-Headphone-amplifier-FULL-KIT-12AU7-HAMMOND-CASE-INCLUDED-/200973962693?pt=AU_Electronics_Audio_Amplifiers&hash=item2ecafb4dc5
 
I was wondering what you guys think, and if they would be of any quality. 
 
Thanks!

 

[Avro_Arrow]

 
Check into Fred's Amps.

He has lots of different choices at good prices.

 

[wakibaki]

I just bought one of these:- http://www.ebay.co.uk/itm/310687727738?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648
 
And one of these:- http://www.ebay.co.uk/itm/231036339008?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
 
...which for those who can't be bothered looking, are a 15 WPC TA2024 amplifier, and a 4.2 Amp Meanwell style PSU. Together they cost £11.30p (UKP), ~U$18.71.
 
I bought them to experiment with driving electrostatic headphones via transformers. I thought I'd put a dual output on the box, to use the amp to drive regular HP as well. I already have 2 (earlier versions) of these amps, they drive the speakers I use with a couple of my TVs' headphone outputs, great little things.
 
This is not to discourage anybody from buying one of Fred's amps, which I see you have already found on ebay. Note that by using the link posted by Avro_Arrow you can access slight variations, such as buying the 12AU7 model without a tube or case.
 
w

 

[inline79]

Fred does put a nice kit together, but the "CMOY" is so simple you might even be able to do it wire-to-wire and get all the parts from digikey for two amps for the same money.
 
If you really want to be cheap, try to track down an old CD player someone is throwing out and hack the headphone amp circuit out of it!

 

[bob808]

Here's a very nice looking project that I found on the web.
If you search the picture on goolge you'll find many more references but I think it's called Crystal cmoy.
http://cdn.instructables.com/FC9/URG8/H27LRHQM/FC9URG8H27LRHQM.LARGE.jpg
It's point to point, and then it get encased in transparent acrylic.