Simple Killer Amp Constructor Thread

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#422
GB150D Renders

Hello everyone,

So, here's some renders of my potential GB150D case design.

I'd love to hear any feedback on potential improvements, suggestions, etc.

Notes:
- No wires were rendered. I did all the 3D work this evening, and wanted to do just broad strokes. Fine cosmetic details later.
- The heatsink is cut in the middle, to make two monoblocks
- The amp module is upside down, mounted to the flange of the heatsink, with the MOSFETs pushed between the flange/body join point (most efficient location)
- Input is under the heat sink, RIGHT in front of the amp input area (shortest possible length (under 3 cm)
- Speaker output will be on each side of the amp body, right next to amp module (shortest possible length - 4.5 cm)
- The upsidedown amp module allows:
- Super short PSU supply wiring (2 cm)
- Optimum MOSFET location on HS
- Shortest possible input length
- Shortest possible speaker output length, while maintaining max distance from input
- Maximum distance between input and PSU

- Having the input under the HS, raises the HS a little, allowing better convection/cooling

Case material is aluminum right-angle stock, cut and rivited together. Steel mesh will be cut to fit openings.

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.



Whatcha think??

Cheers,
/Adam


Project here:
http://www.robotbreeder.com/photography/v/projects/GB150/
 
#424
Hey Andrew and KLe,

I bought some of those ATI cases at the beginning of the year. Have to agree with Andrew, they are excellent for the money.

I've actually got my last one for sale here:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=91192

I'm planning on moving to the battleship one:

An externally hosted image should be here but it was not working when we last tested it.


Which will make an excellent base for a 6 channel GB150 I've got planned. They work out at just under £300 each inc shipping from Thailand which still isn't bad considering the other options.
 
#426
Its a Belkin type bought from Farnell for around £13 each.

Its illuminated but you need some sort of latching circuit in place such as those from Hypex as its only a momentary push type.

They do look great though and are worth the hassle.
 
#428
Re: ATI

Cobra2 said:
I did not fint the ATI chassi particularly cheap.
The HiFi-2000 cabinets with 10mm frontplate are ~ € 235 (3 unit)
And there are others from Taiwan/HongKong...

Arne K
Click to expand...

You do get what you pay for though with the ATI stuff. Faultless finish on all 6 of the enclosures I bought from them. I also like that they're not just rectangular boxes, they have a bit of style about them.

I considered the hifi-2000 cases and would still like to take a look at some point though.
 
#430
Hi KLe,

No new renders, but a fair bit of feedback. Greg and a few others have mentioned moving the PSU back a bit. I'm on the lookout for a local metal shop - to cut the HS and a bunch of the aluminum angle stock.

I think with aluminum edges, and black mesh metal in a stripe around the middle, plus the top and bottom panels, they should look pretty nice indeed.

I'm going to put the power LED under the front HS, so they'll have a nice glow underneath the amp when it's on. A nice warm yellow / orange one probably. Soft light.

Getting closer!!
/A
 
#431
Robotbreeder said:
... I think with aluminum edges, and black mesh metal in a stripe around the middle, plus the top and bottom panels, they should look pretty nice indeed.

I'm going to put the power LED under the front HS, so they'll have a nice glow underneath the amp when it's on. A nice warm yellow / orange one probably. Soft light
Click to expand...

Hi Adam
Sounds really neat 😎
Keep us posted and some pics 🙂

thanks
KL
 
#433
You could stack your two transformers to save some space or mount them out of the main box, but, correct me if I'm wrong, aren't you using Greg's GB300S PSU's? You need to keep the supply wiring to the modules short for best performance so the whole PSU board needs to be in the amp case.
 
#434
HiFiddle said:
You could stack your two transformers to save some space or mount them out of the main box, but, correct me if I'm wrong, aren't you using Greg's GB300S PSU's? You need to keep the supply wiring to the modules short for best performance so the whole PSU board needs to be in the amp case.
Click to expand...


yes im using the gb300s, ok, so i think that the best will be to build 2 diferent cases...

one for 2 channels (300w each one) and another for 3 channels (1x300w and 2x150w), so i can put one transformer on each case, and can turn on one case for stereo sound and the 2 cases for HT 🙂
 
#435
samsagaz said:
What about to put the Transformers+rectifiers PCBs in another case? this will help to reduce the noise?
Im thinking it because is really hard to mount all the 5 channels + 2 600va transformers + 2 PSU in the same case :?
Click to expand...

Hi samsagaz
Its fine, and a good idea, to have the tranny's outside of the box , but you should have the rectifier/PS Caps Pcbs close to the amp Pcbs. The reasons are as follows ...

  • Having the tranny's outside of the box not only provides more room in the box, but, also reduces EMF effects within the box. Running AC from the tranny to the PS pcbs is much less of an issue, when compared to DC. So, distance should not be an issue, unless it is very long. Within a metre, or even a little longer, should be fine
  • It would even be better to place a grounded cage over the PS/Caps pcbs. This will reduce EMF effects, within the box, to an even lower level
  • DC feed from the PS caps to the amp pcbs needs to be a short distance. This is necessary to ensure that the amp pcbs receive a good, clean and low impedance DC supply.

Hope this is helpful
KL
 
#437
samsagaz said:
... so i think that the best will be to build 2 diferent cases... one for 2 channels (300w each one) and another for 3 channels (1x300w and 2x150w), so i can put one transformer on each case, and can turn on one case for stereo sound and the 2 cases for HT 🙂
Click to expand...

Hi samsagaz
That's a nice idea 😎

With the 1x300w and 2x150w, as Andrew has pointed out, you would need to run them at the same voltage using 1 tranny or use 2 tranny's to run the 300D at a different voltage to the 150D's 🙂

Keep us posted with some pics, and of course, your evaluation of them, also 🙂

thanks
KL
 
#439
Soxen said:
I have just ordered a GB150D assembled and setup to run Class A. I cannot wait to get them 😀

I hope they are as good as I have read they should be.
Click to expand...
Hi Soxen
Excellent, keep us posted ...

The GB150D usually comes with IRFP9240 mosfets's.
Are you getting the version using the IRFP9140 mosfets? For the 150D the 9140's will only give you 50 watts, due to it only permitting max +/-50 DC volt rails. Ie. turn the GB150D into a GB50D 🙂

Last weekend we compared my GB300D to a friends KT88 Prima Luna, and, the 300D was clearly better. More musical, better stage, actually the 300D had more valve-like texture than the valve amp, which was interesting 🙂

thanks
KL
 
#440
Hi,
For the 150D the 9140's will only give you 50 watts, due to it only permitting max +/-50 DC volt rails.
Click to expand...
this ain't the case.

Amp guru claimed exceptional peak to peak voltage and current delivery for his amp design.
+-50V rails should get close to 100W into 8r.
Since the output stage is designed for 150W, the lower voltage supply rails allow good performance into lower impedance loads.
I think you may find that operation on +-48Vrails will allow near 150W into 6r load and this would make the amp suitable for use with 4 to 8ohm, 6ohm and 8ohm speakers.

I suspect also that the 9140 could survive high mains voltage of +6% for short periods provided the heatsink keeps the devices cool while being asked to meet peak power. This assumptton would allow operation at supply rails very close to +-50Vdc.

edit.
I have a quasi BJT amp on a single pair of 2n3773 that produces a maximum power of 110W into 8r and 200W into 4r from +-50.5Vdc supply rails (while the sink remains cool).
 
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