recommend a DIY amp for HD650

The Beta22 is very much alive. If your father can pull it off, the price is very much in your budget. Great amp and it'll drive your HD-650 with authority.

You might want to check the several tube projects over at Headwize. There are some nice ones, all within your budget.

I quite like my Pimeta with my HD650, although I'm in the process of building a EHHA rev A.

 

If you are looking for plug&play PCBs many (most?) of the older amps can be tough to find... OTOH, if you dont mind point to point and perfboard the world is your oyster. 

 

There are many neat older amps that dont get built very frequently because there are no PCBs available for them. Its a shame: some of these older amps sound really nice. Some others have been upgraded and newer and better versions replaced the older ones. In these cases there is little reason to build the old thing.

For HD650, if sound quality is more important than budget and you want something that is favored to produce the best quality I would definitely recommend:

 

β22: One of the most popular high-end DIY headphone amplifiers around. It can be built 2 channel, 3 channel (active ground), or 4 channel ("balanced"). You are correct, the 2 and 3 board versions can be made for $400 - $600+, but 4 channel balanced version should probably use 2 σ22 boards and will likely cost around $800-$1000 depending on your choice of chassis and extra options. I built a balanced version and it sounded amazing (used it with HD650 too). It is not outdated by any means and can stand up next to almost every other headphone amplifier out there.

 

EHHA: A very nice hybrid amplifier by Cavalli audio. I do not have any experience with it, but I have read that it can also be built "balanced" and sounds very nice. The EHHA Rev. A has a built in power supply (this version isn't released yet), but the original EHHA is traditionally powered by AMB's σ22.

 

This doesn't even scratch the surface of options, they are just the most popular and most highly regarded from what I have heard. Others to possibly consider are the Dynahi, bottlehead kits, and bijou. There is a wealth of information here, the AMB support forum, and elsewhere!

Also, don't discount the Dynalo and Dynamid (balanced build of the Dynalo) - great bang for buck there. I'm building a Dynamid at the moment so of course I'm biased but I have to say it's been an easy build so far (I have moderate to good soldering skills) and parts weren't too difficult to find with the majority of scarce components coming from AMB's store.

 

PM me if you want pics and good luck with your amp, whichever you pick.

what's the difference between a balanced and normal amp? each signal channel has its own active ground channel? and what's the benefit? if my first assumption is true, i'm guessing reduced crosstalk between channels? is there anything else going on?

Do some research on this topic, it’s a mine field...

Indeed. The basic difference is that instead of two active signals (L+, R+) you have four (L+, L-, R+ and R-) which should reduce crosstalk and noise pickup along the cable. You'll hear a lot of people claiming that it increases slew rate and thus the 'speed' of the headphone, and an equal number claiming no difference.

Me? Well my headphones are balanced terminated so I plan to build a balanced amp and find out for myself. Even if there's no difference whatsoever then I still gain a shiny new amp and a load of DIY experience along the way.

Lavry DA11 is a DAC+headamp.

 

Are u looking to build a headamp or DAC with headamp?

I've never heard the 650, but I do own a HD600, so I'll give it a shot.

 

Of the three amps I have built, the Hagerman Castanet is my favorite: the bass is strong and well defined, there's good air, good instrument separation and soundstage and it is very dynamic. It is a relativly easy PCB build, with only one hole to drill, if you buy the front and back panels from Panel Express. You also get a low impedance headphone out for when you are ready to upgrade to Grados (joking, since I just received my HF-2). It has no problem driving the HD600, however it has a gain of 3: it is barely able to run the HE-5LE, and I have to push it quite far for my 600 ohm Beyers.

 

Bang for the buck, I can recommend the Bottlehead Crack, as long as you use high impedance headphones. It is remarkably close, but it does not sound as good as the Castanet: the bass, while it maintains a good level, lacks definition, and it sounds a bit bright, but without the air of the Castanet. It does look very nice, especially with a coke bottle 6AS7G, but it also runs quite hot, even with the tubes completely outside. Something to watch is the voltage rush on startup: it once popped the right channel on my Shure SRH840. I was stupid and basically switched it off and on very fast, leaving the headphones plugged in. The diaphragm was bloated, but I managed to push it back and (since I had them for only two weeks), didn't take any chance and replaced them. Anyway, I now NEVER leave headphones plugged in the Crack, and wait one minute after startup. I have no such qualm with my other amps.

 

Oh and being OTL, the higher the headphone impedance, the better the Crack will work with them.

 

As for the MiniMax: it's small, it looks good, it's low voltage, but it doesn't sound as good as the first two.

 

On a side note, I have heard great things on the EHHA, and I plan to build one for my present and future orthos, once Revision A is out. I'm also keeping an eye out for the Beezar kit version of L'Espressivo.

Yes. DA11 is a DAC with headphone out. 

 

Do u have hands on experience on making amp? beta22 is not recommend to DIY beginner as i have read from this forum.

If u were looking to build something similar to DA11 but with lower cost, i advise you to have a second thought.

I personally don't think your demand is going to meet.

quest5692 , if your after market cable means the symphonica cable.

then i will suggest you to at least talk to me/  jaben malaysia first.

it is kinda different from usual characteristic matching of HD650 imho.

as i had mentioned, that expensive amp doesn't actually make it sounds better.

but Hippo amp  / Govibe PPK / Lavry DA-11 both drive it to reasonable performance. compared to pico / centrance DACPort / hifi man amp/ yamamoto amp.

 

instead of getting expensive amp. might the performance not even as good as driving from govibe ppk amp. that amp has a good synergy with HD650 symphonica system.