[Vargtass]

I've been thinking about building 2 small amps for Ety 4s and Grado sr80.

I have no experience with electronics, but an experienced friend of mine is happy to help me out. 150 - 200$ total for both amps would be preferable.
Is it worth doing this quality considered? Or are there other amps in this price range that work particularly well with these phones?
If a DIY soultion is a good idea, could you recommend me parts?

Vargtass

 

[Jazper]

The A47 is supposed to work well with grados but it'd probably be ok for etymotics too, considering they're low impendance. check out the design here:

http://headwize.com/projects/showpro...heared_prj.htm

and here:

http://www.feistworks.com/ben/a47/default.asp

you'd probably be able to build this for close to $50 with reasonable quality components. You can always go overboard on components and build it up.

At the other end of the quality scale you can look at PIMETAs and PPAs.

http://www.tangentsoft.net/audio/ for references.

Why do you want two seperate amps? I realise the etys are different from the grados but to an amp they'll look similar.

In terms of parts, both the etys and grados are bright, so TI/Burr brown Opamps would be recommended opa 627, 637, 132, 134, 227, 228, 2134(I think), 2227 and such.. hard to recommend without a specific design in mind.

 

[bg4533]

I would look at the Mint on Tangents site linked above. The Pimeta is a bit nicer if you can go a little bigger.

Quote:

Originally Posted by Jazper In terms of parts, both the etys and grados are bright, so TI/Burr brown Opamps would be recommended opa 627, 637, 132, 134, 227, 228, 2134(I think), 2227 and such.. hard to recommend without a specific design in mind.

The OPA627 and OPA637 are great opamps but aren't really battery friendly. The OPA228 and OPA637 require a gain of 5 or higher (more like 8) to be stable. That is probably way too high for Etys and Grados.

 

[Vargtass]

Thanks for the advice. I appreciate it.


Quote:

Why do you want two seperate amps? I realise the etys are different from the grados but to an amp they'll look similar.

One of the amps will be made for a friend of mine. Not getting two different amps for myself.

Vargtass

 

[Jazper]

Quote:

Originally Posted by bg4533 The OPA627 and OPA637 are great opamps but aren't really battery friendly. The OPA228 and OPA637 require a gain of 5 or higher (more like 8) to be stable. That is probably way too high for Etys and Grados.

I agree that it's high, but I'm running a gain of 11 in my amp and for my Ms-1s it's fine, sure I don't use the full sweep of the pot but 50-60% is used depending on how loud I want to listen and there's plenty of resolution in that band.

 

[digi01]

3ch cmoy,
http://headwize.com/ubb/showpage.php?fnum=3&tid=5020

cmoy with classAB buffer,
http://headwize.com/ubb/showpage.php?fnum=3&tid=5340

enjoys
Zang

 

[digi01]

the real amps.
the right photo is 3ch cmoy,the left is cmoy with classAB buffer.