[Uncle Erik]

Quote:

 
I'm almost feeling that if anything unorthodox or radical is suggested around here that it is immediately shot down by purist old-schoolers.

No, every person here wants you to have a working Beta22 without problems.
 
I've tried some unusual case designs, too, and have gotten bogged down.  One has been boxed under the bed for nearly two years.  A demanding work schedule didn't help, but it's only coming out of mothballs once I get the workshop set up in a few months and buy some more tools.  It was frustrating and I lost interest in it, but I will go back to it.
 
As for your question about hum, no one knows whether your design would hum.  But what if it does?  How much time are you willing to invest in troubleshooting?  Are you willing to go back to the drawingboard to rework the entire design?

 

[haveblue]

Uncle Erik, would you mind sharing those unusual case designs?

I fully relate with your sig, by the way.
 
After seeing Ti's data (I like data), I have decided to scrap this chassis and am thinking of a new chassis that would put the transformers about a foot away from the amp boards. That's the distance at which amb's own B22 seems to be set up. If it hums, at least I know it's not because of the transformer location and that it can be troubleshot. Of course, I'll troubleshoot and test before I put the boards in the chassis.
 
To be honest I am quite satisfied with the sound of my current rig. It's at least 95% there to headphone perfection. There's no financially justifiable reason why I'd need to upgrade. The last few percentage points of audio purity that would be gained from this project is not the main purpose. It is icing on the cake.
 
The main reason I want to do this is to exercise creativity, which I won't be satisfied with if I did a typical two-box design. The B22, S22, and Buffalo II kits represent the pinnacle of headphone performance, which are conveniently available for me to test my creativity around. Might this new chassis be even more impractical and ridiculous, wrought with engineering challenges? Yes, because I prefer it.
 
"Too often we are so preoccupied with the destination, we forget the journey."

 

[Nebby]

Oh but what a long journey some beta22 builds have been

 
Quote:

"Too often we are so preoccupied with the destination, we forget the journey."

 

[qusp]

 
 
 
sure you thought of it John, sure you did

 
haveblue, sorry mate, you have had everyone come in here and tell you that its a really cool idea, but that you are creating problems and overcomplicating things for yourself (especially for someone with little knowledge in the field taking on their first like project) and despite some quite good ideas for other solutions in the same vein, all you do is keep packing in more and more complexity. hell we told you it was a bad idea when it was just the amp in there, now you have added a dac, plus USB input, probably spdif receiver, MUX, source switching, IV stage. more toroids, more power supplies, water cooling, more power supplies...... seeming to relish making it more difficult just for the sake of it; even seeming to now be spurred on by it all to 'show us' you can do it. It seems to me its not about the audio at all, which is cool, but call it what it is, you could use a much cheaper dac and amp to achieve the same result if its just a spectacle/conversation piece you are after. (I actually think Giza would look much cooler, pretty easy to hide cables and there is an entire catalogue of multipin power and data connectors at digikey with thousands of items), you will need to plug it in somehow no matter what you do and I tell you what the lemo umbilical connectors are much more tech and cool looking than a simple IEC, or have it connect from underneath with the power supply hidden, whatever.... there are myriad ways around the issue
 
sorry for the 'tude, but i'm getting a bit annoyed here, you come in here with knowledge in a totally different but vaguely related field; asking for comments and advice. you obviously just wanted to show off, because constructive suggestions and warnings from people that have actually built numbers these type of projects and the designer himself; have been met with stubbornness, arrogance and naivety. you seem to think that your misguided assumptions trump real world and relevant experience because of what?? because you have built most of  a model aeroplane? i'm getting a bit annoyed with being asked to comment when it is clear that you are set on your idea and have no intention of listening to any kind of critique.
 
 
maybe it will work out well for you, who knows, but if it doesnt it will be one massive expensive and public fail. troubleshooting such a project would not be all that fun; I wish you luck, I really do, but this s the end of my participation
 
no motor with the relay attenuator remote or not (ipodPJ was right, although I did suggest remote, I dont mean motor drive), but I would actually recommend since its all one item, to use the sabres own digital volume via the volumite and dont have an analogue attenuator at all, it doesnt even need a separate power supply (although that may be a put off for you at this stage), it can piggy back off the buff's own regs, takes up less space and IMO is much more sonically transparent as well, now for remote control of that you would need some other mechanism, but should not be too hard, I dont know at what stage TP's own module is at.

 

[amb]

Quote:

Ti, on that test data above, could you roughly tell me how many inches is "near" and how many inches is "a distance apart"? Doesn't need to be exact.
 
And it is true that Toroids emit a stronger EMF toward their axes?

 
If only that question could be answered so easily...
It depends on the transformer, its size (the larger it is, the stronger the field), its construction (toroid, EI-core, etc), its orientation, the board and wiring's orientation, etc, etc.
 
For the noise floor graph I posted above, they are not β22s, but the same principle applies.  The "noisy" amp has a 25VA Amveco toroid only inches away from the main amp circuitry.  The "quiet" amp has the same transformer located in a separate PSU case, located about 2-3 feet away from the amp during measurement.  With the β22 and larger transformers, you'll need more distance for really clean noise floor.
 
Quote:

And it is true that Toroids emit a stronger EMF toward their axes?

 
Try google.

 

[qusp]

only just saw the reneg post after finally seeing sense (maybe, we'll see

I hadnt when I posted the above, but I think the above needs to stay, sorry for getting worked up, but it was getting to me. BTW IMO the ackodac is a more sophisticated (but lesser known) reference dac design than the buff II thats based o the same family of ESS chips. if you relish the challenge, would it not be better to buy a dac that allows you to build the whole thing and chose your own parts instead of buying a prebuilt module? I have both and the ackodac wins. the MCU module is also more conducive to remote control of volume and source selection with no motor, in fact he is coming out with one with an external wifi receiver.
 
I get the whole love of problem solving thing, but generally better to have previous success to build on

 

[nattonrice]

Bahahaha this thread exploded since I was last here.
 
A b22, a traffo AND a water pump in the same chassis... I can hear the hum from here!
 
The number of heat sources to be sunk and tight quaters means the pressure drop would demand a decent pump.
I have a couple of spare Iwaki's here that would make this even more ridiculous  =D

 

[qusp]

dont forget the buffalo II, IVY, placid, spdif MUX and USB board etc etc. I thought my builds were ambitious with how much I wanted to fit in.
 
dont let us stop you OP, its really great to see someone thinking 'outside the box' but my spidy senses are tingling on this one

 

[haveblue]

Quote:

dont forget the buffalo II, IVY, placid, spdif MUX and USB board etc etc. I thought my builds were ambitious with how much I wanted to fit in.
 
dont let us stop you OP, its really great to see someone thinking 'outside the box' but my spidy senses are tingling on this one

Nope, no need for multiple spdif inputs. There sure is a lot of stuff in there though. Here's the preview of new shape with clear acrylic column supports. Going to be lots of wires in one half and a lot of water tubing with blue liquid in the other half. No matter what I do I am putting that lead crystal pyramid paperweight on the top. The transformers are on the bottom and facing to the side to minimize upward field, and they're about a foot away from the boards. The pump is down there too. Should be fine.
 

 
 
This rendering feature is neat.

 

[nattonrice]

This reminds me of Evangelion   O.o

 

[Nebby]

Given the weight of the waterblocks, the water, the pump, and the radiator, what sort of supporting frame are you going to be using? Also, how are you cooling the beta22 boards? Are you getting custom waterblocks made for them?

 

[haveblue]

 
Quote:

Given the weight of the waterblocks, the water, the pump, and the radiator, what sort of supporting frame are you going to be using? Also, how are you cooling the beta22 boards? Are you getting custom waterblocks made for them?

Current plan is to stick five of these in there, which will hit the beta22 boards, the sigma22 boards, the main LED, and the two DAC PSU's.
http://www.newegg.com/Product/Product.aspx?Item=N82E16835106059&nm_mc=OTC-Froogle&cm_mmc=OTC-Froogle-_-Water+Cooling-_-Thermaltake-_-35106059
 
That's two more than the original plan, but now the PSU boards are far away and will require their own blocks.
 
The blocks weigh only 5.3oz each. I'll run aluminum angle brackets touching the mosfets. I'll then mount the waterblocks onto those.
 
All the transformers (4.2lbs) and the pump (7.3oz) are located at the very bottom so there won't be much structure needed to hold them up. External panels and supports at their current thickness are 12.2lbs. The boards are essentially weightless. Final weight should be around 25lbs.
 
I'll make a supporting structure out of standoffs, acrylic, and aluminum that is adequately strong enough to hold the whole thing upright, and then when the panels get installed, they'll act as a monocoque and brace the whole thing up. That'll make it nice and rigid.
 

 

[Nebby]

I don't believe that aluminum angle brackets will be adequate for distributing the heat to the waterblock since it has such a small surface area. I would guess that one or two of the mosfets will see some cooling with the other two significantly hotter. I'm not sure what effect the temperature difference will have on performance but I doubt it will be good. I would highly suggest building up a single board and doing thermal tests before diving into your project.

 

[haveblue]

Quote:

I don't believe that aluminum angle brackets will be adequate for distributing the heat to the waterblock since it has such a small surface area. I would guess that one or two of the mosfets will see some cooling with the other two significantly hotter. I'm not sure what effect the temperature difference will have on performance but I doubt it will be good. I would highly suggest building up a single board and doing thermal tests before diving into your project.

I just ran an example of the B22 waterblock system. Two B22 boards share one waterblock in my design. Each MOSFET is rated for 175deg F according to the data sheet. They are attached to a 3/16" angle beam attached to a 3/16" plate.
 
According to amb's site, on a typical setup the outboard amplifier MOSFETS put out 8V*0.16A and the inboard cascode MOSFETS put out 22V*0.16A (correct me if I'm wrong, Ti). This puts 4 whole B22 boards at 38.4W. That sounds about right given its 100W power supply. For simulation purposes, let's double that for a factor of safety. That's 2.56W for each outboard MOSFET and 7.04W for each inboard MOSFET.
 
At 100% load my 125W CPU cooled by a Corsair H50 (single radiator cooler) shows 133deg F at an ambient temperature of 75deg F. Let's assume somehow we'll need to also remove 125W from the entire system and that the waterblocks are at this same temperature. When a steady-state simulation is run, the maximum indicated MOSFET temperature is 142deg F, safely below the manufacturer posed limit.
 
Take note that this temperature value is for a hypothetical extreme example. In actual use, much less power will need to be dissipated and the initial waterblock temperature will be much lower. The MOSFET temperatures will probably hover around 120deg F at most.
 
Logically speaking, if those little passive bolt-on heatsinks can adequately cool the MOSFETs, an active water loop should do the job much better.

 

[HiGHFLYiN9]

Quote:

Let alone fluids and electronics are not friendly bedfellows.

I've constructed some watercooling rigs when I was younger (out of car radiators, water pumps, plexiglass reservoirs and some shrouded fans). After trying to live with it for a while, I found the maintenance was too much hassle. You can also destroy a rig very easily if you're not careful, but it's assumed you know what you're doing by even suggesting the idea. Teflon tape, tight fitting brass fittings and waterproof epoxy are your friends