[KnightOfAwesome]

It's been sometime since I've completed my mini3, And I've spent around 100 hours listening too it (non-rechargeable battery's) with my SR125i's. I still have one more mini3 to complete for a friend, but I already want to start a new headphone amp project, this time a full sized desktop amp.
 
Sure deciding build a mini3 was an easy choice to make, because I was already going to build one for a friend and I also had plans to build a Gamma1 too. But this time around I'm having a more difficult time choosing amongst the many many many headphone amps out there.
 
What should be my next step?

 

[WyldRage]

Transistors or tubes? Budget? For driving what headphone?

 

[KnightOfAwesome]

 
Quote:

Transistors or tubes? Budget? For driving what headphone?

 
That's what I'm trying to figure out, I'm open to anything. The only experience with headphone amps is the mini3 I have made.
 
Budget is irrelevant, I'll be driving a SR125i (33ohm)

 

[WyldRage]

All right, Grados are low impedance and require little gain. Right off the bat, forget OTL: they are happy only with high impedance headphones.
 
With tubes, the possibilities for Grados are either hybrid or transformer coupled. If you feel confident, you can try the Starving Student: it's not costly, and I heard it sounds good, but the PCB is no longer available. I've seen a lot of love for the Cavalli Audio EHHA, which will prboably be my next project, and the new PCBs are fresh out of the oven. Other alternatives are the SOHA 2, and the Millett Max and MiniMax (the latter comes with a custom case, which is useful for a beginner, but isn't the beast amp I've heard).
 
If you want to go full tube, I know of two transformer-coupled amps: the Bottlehead S.E.X and the Hagerman Castanet (my favorite of the amps I built).They cost more, because of the transformers and chokes, but I simply love the sound. An advantage is that both are easy to case, and one comes in a full-kit. Another advantage is that there's none of that "transistor" nonsense

.
 
For solid-state, I'm affraid I know little. There's the B22 that's supposed to be a reference-grade amp, but that's about all I know.

 

[nate911]

You could try the Millet MOSFET-MAX--that seems to work well with low impedance loads like Grados.

 

[alphaphoenix]

 
Quote:

All right, Grados are low impedance and require little gain. Right off the bat, forget OTL: they are happy only with high impedance headphones.
 
With tubes, the possibilities for Grados are either hybrid or transformer coupled. If you feel confident, you can try the Starving Student: it's not costly, and I heard it sounds good, but the PCB is no longer available. I've seen a lot of love for the Cavalli Audio EHHA, which will prboably be my next project, and the new PCBs are fresh out of the oven. Other alternatives are the SOHA 2, and the Millett Max and MiniMax (the latter comes with a custom case, which is useful for a beginner, but isn't the beast amp I've heard).
 
If you want to go full tube, I know of two transformer-coupled amps: the Bottlehead S.E.X and the Hagerman Castanet (my favorite of the amps I built).They cost more, because of the transformers and chokes, but I simply love the sound. An advantage is that both are easy to case, and one comes in a full-kit. Another advantage is that there's none of that "transistor" nonsense

.
 
For solid-state, I'm affraid I know little. There's the B22 that's supposed to be a reference-grade amp, but that's about all I know.

Have to agree. I've owned all the above except for the Cavalli, Hagerman, and B22.  The later because you'll need some serious dough to build one and much more to buy one built ($1K+).  For SS, add the Gilmore Lite/Dynalo.  For the price, the Starving Student is very hard to beat and the P2P isn't that difficult to build.  The Head-Direct EF1 is another good amp.
 
To the OP, I've also owned the Mini3 and it's a great portable amp and does OK for a desktop replacement.  I find the sound warm, so if you prefer a more warm signature, tube hybrids are a safe bet and the MSSH is a good starting point both in performance and cost.  Expect to pay a range of $100-150 for one built.

 

[KnightOfAwesome]

 
Quote:

To the OP, I've also owned the Mini3 and it's a great portable amp and does OK for a desktop replacement.  I find the sound warm, so if you prefer a more warm signature, tube hybrids are a safe bet and the MSSH is a good starting point both in performance and cost.  Expect to pay a range of $100-150 for one built.

 
I'm partly reluctant to build the MSSH, Although it would be a great start for understanding what tubes sound like. I'm reluctant because people have reported damage when using the gamma 1 with it. I also want to stay away from circuits that have capacitors at the output.
 
On the topic of describing the sound of the mini3, I found it to be a lot colder then the headphone out on my PC, It took a little to get used too.
 
Thanks for the suggestions so far!

 

[wankski]

why not another amb creation? m3? i have one. it's pretty awesome and will drive anything short of high z monsters...
 
but with what you have up to beyer 250s it works great in stock config...

 

[KnightOfAwesome]

 
Quote:

why not another amb creation? m3? i have one. it's pretty awesome and will drive anything short of high z monsters...
 
but with what you have up to beyer 250s it works great in stock config...

I've thought about it for a while, but i came to the conclusion that my next AMB project will be a beta22. But sadly that wont be happening anytime soon, although i already have enough boards for two channels.
 

 

[alphaphoenix]

Wow. Good for you. Going for the mothership of SS.  Good luck when you start the project.

 

[mewrei]

You might take some slack from the B22 before attempting it.  Its a pretty complicated project and its good to get some more practice under your belt.  AMB/Cavalli's CKKIII is regarded as a mini-B22, but is significantly easier to build and doesn't require a lot of special casing.  Its also a LOT cheaper.
 
The Millet MOSFET Max is also another good choice.
 
Good luck with whatever you decide on.

 

[wankski]

cool, i'm all for it! i'm assuming you did the mini^3.... now i haven't built a beta22, but i really don't see how its much harder than a m3 or mini3... sure it has a higher component count, but big deal.... no smd to deal w/ cf m3 (if you go ad8610 and other soic designs) or mini or gamma projects etc.
 
through hole... and everything is marked - big deal.
 
I would be far more cautious about something like a bijou with 520v ac flying around...
 
but still even with the b22 u are playing with a mains transformer, so caution applies, make sure u really understand the wiring.
 
 
i'm planning ona  2ch beta22 myself, i also don't think it will be that much more expensive than the m3... that cost me around $220-40 (excl casing) and i had the wall wart already... I anticipate the 2ch beta to cost in the region of $320-50 including trans @ $45 (but i will be double wiring it for use with a speaker amp as well, so it wont be wasted on just one amp)...
 
I think its more of a false economy to be building amps that are more side-grades than upgrades... if you're confident, go for it!!

 

[wankski]

oh, just read these are for sr-125s..... upgrade ur headphones! the mini^3 is already doing a great job w/ them... a beta 22 wont make the 125s sound like MSpros...

 

[KnightOfAwesome]

The mini3 is not my first DIY project (Or electronics project), The mini3 just so happened to be my first experience with building a headphone amp.
 
Fortunately for my wallet, I won't be upgrading from my SR125i's for a minimum of five years, I just got these one or two months ago and still rocking out to them

 
My next headphone amp project will be meant to be a learning experience, and replace the mini3 and become the dominant desktop headphone amp, The sonic improvement will be a plus. That being said, I won't even think about building the B22 until the end of December. I just need something to last me until then.

 

[wankski]

sweet - ur good to go! i'm sure its not so much the sonic aspect that ur after, but the challenge of building another amp - i can relate! i got the bug from amb too!
 
also consider speaker amps... many of us focus on headphone and have crappy pc speakers for predominantly music! check out the chipamps - great quality kits that clone a system that went for $3k+ its a cheap kit to tide u over until then.
 
u can also share the trans as its compatible with the beta... or if you use small bookshelves u can power them w/ a 2 channel beta22 anyways... for more power u may consider the beta 24...
 
given what i assume to be your objectives - go for the beta! its will satiate your addiction for a while - u'd have to do some looking to find a better more flexible amp, if indeed it exists.
 
i'm not gunna patronise you with financial advice - i'm sure u can add numbers and compare that to your dispensable income. apart from wiring the primaries on the trans there is little risk in the beta build. the absolute worst than can happen is u fry a $100 board, and start again. only u can decide if that's a big deal or not.