find my source a mate...an amp questions

[omendelovitz]

Hey all,

first of all, I've searched.

Now, picked myself up a CA Azur 840C yesterday and want an amp to match. I'm using modded Denon D5000's. I tend to prefer SS over tubes as I'm a detail/analytic freak. A rule of thumb I assume holds is that the amp doesn't cost more than the source, so that limits the playing field to $1500-ish, which is more than ridiculous for an amp mated to a $1500 source IMO. I was thinking used GCHA, but want to know what others suggest. No op-amps here preferably, unless the circuit is well designed, and designed for said op-amp.

I looked into a B22, but don't know who I can get to build one. I'd DIY it, but don't know where to find suitable kit and/or nice case for it.

Thanks all, be kind to this newbie ass-hat.

[Pars]

A B22 would certainly be a candidate. As for kits, jrossel (Glass Jar Audio) has them. Your on your own for casework however. IIRC, Thrice builds B22s occasionally/all the time?

An M3 might also suit you as well. No one is building Dynahis anymore AFAIK, but a used one (avoiding certain builders) would be good as well.

[Dusty Chalk]

Go B22 from thrice...don't know if it'd be in the $1500 region, though, depending on options.

[n_maher]

Go B22 from thrice...don't know if it'd be in the $1500 region, though, depending on options.

There's also the very real question of when he'd be able to do it. Far as I know he's still working on the last batch and hasn't opened up the ordering process again.

Also, since it seems unclear, does the OP want single-ended or balanced?

[omendelovitz]

single ended for now. the 840 has balanced outs, but I can't imagine that balanced inputs on the B22 with only a single ended output would be useful. balanced D5000's might be nice though... Holy shit, there goes my son's tuition:palm:

Sorry N - to answer the question, my cans are single ended, so I'd be looking for that for the time being. I could probably do the B22 by myself. It looks like Thrice wants $1650 for a completed B22, and i could probably DIY this thing for about $500 (nice cases in Thailand for about $200, plus $300 for the kit from glass jar audio). I'm just so nervous about milling the case and all....

EDIT: I assume I only need 3 channel or 2 channel and use the case as grounding for single ended? Is it worth balancing the inputs and single ending the HP jack?

[n_maher]

i could probably DIY this thing for about $500 (nice cases in Thailand for about $200, plus $300 for the kit from glass jar audio).

No, you couldn't, trust me on this.

EDIT: I assume I only need 3 channel or 2 channel and use the case as grounding for single ended? Is it worth balancing the inputs and single ending the HP jack?

2 or 3 is fine, I've never tried to figure out which I prefered. And no, I can't think of a good reason to use the balanced outputs unless the 840 does something crappy to create the single ended signal.

[omendelovitz]

No, you couldn't, trust me on this.

2 or 3 is fine, I've never tried to figure out which I prefered. And no, I can't think of a good reason to use the balanced outputs unless the 840 does something crappy to create the single ended signal.

How much would this cost me, you figure?

are you saying stick with RCA unless 840 degrades the single-ended signal? If so, phew!

[n_maher]

How much would this cost me, you figure?

2-channel you might, might make it at $500 if you used a single chassis and by doing so you risk trafo induced hum. 3-ch figure $700+. And those would be barebones cheapass parts builds. And figure it taking you ~40hrs or so to build it. I think thrice is crazy for doing it for as little as he charges.

are you saying stick with RCA unless 840 degrades the single-ended signal? If so, phew!

You lost me, I'll have to reread everything later.

[Pars]

<snip<

and i could probably DIY this thing for about $500 (nice cases in Thailand for about $200, plus $300 for the kit from glass jar audio). I'm just so nervous about milling the case and all....<more snip>

And who might this be? The only Thailand vendor I knew of closed down.

[omendelovitz]

2-channel you might, might make it at $500 if you used a single chassis and by doing so you risk trafo induced hum...

You lost me, I'll have to reread everything later.

trafo? see below before you reread:cool:

And who might this be? The only Thailand vendor I knew of closed down.

You mean Arthon closed down?

And no, I can't think of a good reason to use the balanced outputs unless the 840 does something crappy to create the single ended signal.

This is what I meant, Nate. Thanks again everyone.

[iceman94]

If you can't get the B22 going and/or want a commercial option, don't forget the Headamp GS-1.

[en480c4]

trafo? see below before you reread:cool:

Ummm, you still need a transformer for the PS. Which would be with the audio section in a single-chassis build. Find Nate's posts regarding PS transformer hum in his 3-channel Beta and the bitch it is to rid an amp of it. I think they're concentrated in the Headwize B22 thread.

[Pars]

You mean Arthon closed down?

ATI Research closed down... is Arthon another company? If so, I'll have to check them out...

[omendelovitz]

Ummm, you still need a transformer for the PS. Which would be with the audio section in a single-chassis build. Find Nate's posts regarding PS transformer hum in his 3-channel Beta and the bitch it is to rid an amp of it. I think they're concentrated in the Headwize B22 thread.

I thought I'd use an adjustable bench test PSU...

ATI Research closed down... is Arthon another company? If so, I'll have to check them out...

No, Arethon was the name of the manager/owner. He is ATI research, so to speak - ATI Research Company Limited

It looks like they're back in business;D

[n_maher]

It looks like they're back in business;D

I wonder if they'll actually have anything in stock this time. :|

[purk]

beta22 is my vote as well.

[omendelovitz]

Thanks everyone - I've already looked up the BOM on AMB and have started looking for parts. I think I'm going to go after the 2 channel unit, and was thinking of using this: MASTECH HY1803D DC POWER SUPPLY VARIABLE 0-18 V @ 0-3 A - eBay (item 140209000077 end time Aug-18-08 05:48:03 PDT) - it's a mastech HY1803D PSU.

Can anyone comment on the suitability of this PSU, other than the fact that it's an ugly pig of a PSU?

[Beefy]

Can anyone comment on the suitability of this PSU, other than the fact that it's an ugly pig of a PSU?

No good. The β22 needs a dual rail +/- power supply. The one you have linked is single rail + only.

Really, the σ22 is the best option for powering a β22.

[n_maher]

I say this with all sincerity, the fact that you'd select a single rail PSU does not inspire hope that you'd successfully build a beta22. Don't be fooled by the PCB, it's a complex and involved build.

[omendelovitz]

I'm sure it is, and this is honestly my bad:palm: - I'm used to building transistor based amps with DC inputs (for simplicity, I guess). I've also built a PSU (from kits), so as long as I have the instructions, I think I'm good. Nate, am I still in over my head here? I know mosfets are much less forgiving than transistors...

[n_maher]

Well, when it comes to instructions there isn't much for the beta/sigma projects. There are parts lists and very loose assembly instructions followed by some initial setup procedures. None of which are terribly difficult but very unforgiving of mistakes. Also, simply stuffing the boards is maybe half the work, the case work and wiring is not insignificant.

[n_maher]

maybe you should build him one, nate.

My face currently looks like your avatar!

[Beefy]

am I still in over my head here?

The β22 was the project that lured me towards DIY....... but I think it really should be seen as the 'ultimate' build; the destination rather than part of the journey.

I ended up starting my DIY audio career with the MMM/σ11 combo and I would be surprised if it doesn't meet your needs. Easier build, less expensive, but still packs a mighty punch. It does use OPAMPs, but they are very well implemented and used only for voltage gain - not driving the phones themselves. Something even more simple and less expensive like a CKKIII is a good option as well, and will outperform commercial amps several times its price.

So start with something a bit less demanding, and the β22 will still be waiting for you in a years time......

[omendelovitz]

cheers guys. Don't worry Nate, I don't expect you to build me one (although it would be nice...). I honestly don't have the money to pay someone to build me a unit like this - the DIY costs are daunting enough.

Beefy, thanks for the advice, but truly speaking I've already got what I believe is the max of all entry-level/mid-fi amps - the Purity Audio KICAS (yes, its my company; no this is no shameless plug (I can't imagine the unit would overly impress anyone on this forum); no i didn't design the circuit (my partner did, man he knows his shit), but I did build many of the units by myself w/o play-by-plays). I'm looking at something like the B22 b/c I can't get my hands on a headcode (affordability aside) and I'm not a fan of the tube (running for cover while changing into my flame suit); The KICAS is great tonally, but needs improvement in the dynamics area and maybe in power output (although 600 ohm DT880's are driven well by the amp according to Rob Hughes).

I may just wait awhile as I can only assume that the SOHA, C2KIII, and M^3 kind of play in the same area as the KICAS.

Would the Headwize and HF DIY boards be enough in terms of instructions, proper testing methods, etc?

Cheers.

[n_maher]

It's hard for me personally to tell you how the M3 would compare to the kicas since I have no idea what it is. Got an internal shot you can share? Also, I'd hardly call the M3 mid-fi just because some folks on head-fi got it in their deluded little brains that because it can be built for ~$400 it only performs as well as similarly priced portable amps. Before the beta22 came out the M3 and PPA were just about the bees knees in terms of circuit design (ignoring the gilmore stuff for a moment) and still are if opamps are to be used as a part of the audio circuit.

Also, what's your official company name so we can give you the appropriate title. I had no idea that you were a company or made anything. I'm a bit out of touch I guess.