cmoy or cha47 for sr-80's. on very tight budget.

Well, I have a JMT Cha47 and it sounds really good. I haven't heard a regular Cmoy. I tried to make one and ended up, well. Messing up pretty bad. Anyhow. I can attest to the quality of a Cha47. They really work well with the Grados.

The cha47 was pretty much designed with Grados in mind. I have a JMT built cha47 and it's a great little amp.

I like my cha47 for its faster sound but equally enjoy the cmoy for its clean round characteristics. IMO, it's basically a preference thing since both the original designs are so alike.

if portability is not a concern, why not a szekeres ?

edit : some people prefers it to the meta with grado, make a search on the diy forum

Yep, I'm one of them. Luuuvvv the cha47 with the Grado's. To me the sound with the Meta comes off a touch "flat".

If you like "punchy" and "lively" go with the Cha47. Otherwise, the Meta or Cmoy may be more to your liking.

I cant comapre my CMOY to the Cha47, since I don't have the latter, but the CMOY does improve the sound of the SR80s. Specifically, I get a fuller soundstage and the bass is deeper and punchier. Sounds to me that the Cha47 would prolly win in a face-off, however.

A good amp will help the sound of any good headphone like the SR80. There are some basic design differences between a basic CMOY, a CHA47 and a META. But also be aware there are differences between the components that go into any one of these amps that affect their sound. The idea behind the CHA47was to design an amp with higher output current capabilty by using two op amps instead of one. The heart of any of amps is the op amp that they all use, but there are many different types each with its own pros and cons that can vary with what type of design its used for. Different op amps have different output capability, some have over twice what others have, so doubling op amps in the CHA47 can be better but what if you use one op amp that already has twice the output current? There are other factors like supply voltage and your headphone impedance. Are all "JMT built cha47" amps alike? I doubt it, as he is a custom amp builder and can build you whatever you want. So comparisons between types of amps become less meaningful unless you know about all of the variables. If you go to the trouble to study all of the details you can learn at lot about them but it is a lot of work...something that often only the DIY'er is willing to go through.

The confusing downsides of getting a DIY amp are often offset by the fact that they usually offer more value than a commercial amp, not to mention the flexability of getting something custom made.

The Grado SR80s have an impedance of 32 ohms. One question you can ask is, What is the available power for a 32 ohm load? This is what seperates many basic CMOYs from their CHA47 counterparts. Not that you will be using that much power, but it is useful to see how much reserve is available. You could also ask, What is the output impedance of the amp? If you divide the headphone impedance (32 ohms) by the amp's output impedance, you get the damping factor. Generally a higher damping factor will give you better bass control. These are only two variables that affect the sound quality, but this gives you a start. The best, really the only way to determine which amp is best is to listen to it...unfortunately this is often not so easily done.

Yes go to the library atHeadwize and do some research. It is all there.

I did something similar with my cha47. All you need to do is connect a 9v battery clip to the output lead of the wallwart. You need be wire the new battery clip in reverse. Meaning: The neg. out of the ps goes to the pos. of the 9v battery clip, and the pos. out of the ps goes to the neg of the clip.

Thinking about it, you should be able to use more than a 9v ps. I used a 24v ps with my cha47, you should be able to do the same. Will sound better with more voltage, IMO.

Ok, I just checked the schematic of the Mint and you should be able use a 24v ps. I would also add, a RS wallwart will work, but I think a elpac or diy ps will perform better.