I wanted to do one final test just to make sure there is nothing wrong with the Amp modules. I removed the power supply and setup up a temporary power supply outside the chassis. I did tie the chassis to earth ground. Results: Absolutely dead quiet, (With or without the inputs shorted). Then I hooked up my preamp and media player, still dead quiet, zero hum. Music sounds fantastic.
It really tells me that the power supply has to far away from critical parts of these amp modules.
So do I take a chance and buy a chassis for $400 or do I just have an external power supply.
I'll have to think about this one.
Scott
It really tells me that the power supply has to far away from critical parts of these amp modules.
So do I take a chance and buy a chassis for $400 or do I just have an external power supply.
I'll have to think about this one.
Scott
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Keep your PS in a separate box or just the transformer. No point to spend $400 for a new amp enclosure. If keeping your toroid out of the amp's enclosure is good enough then buy a small enclosure with a switch etc just for the transformer. It will cost you much less.
cheers,
cheers,
If kept in the same enclosure, you want the transformer as far away from the input boards as you can get it. Move the amp boards towards the back as far as possible and the transformer as far forward as possible, even mounted to the front panel, if it fits.
The right board mounted perpendicular to the heatsink should be mounted flat against the heatsink like the left, that gains some precious distance.
I really like @janusz suggestion also. For an amplifier, I would leave the power supply board in the amp enclosure and make the leads from the power supply to the amp boards as short as possible.
The right board mounted perpendicular to the heatsink should be mounted flat against the heatsink like the left, that gains some precious distance.
I really like @janusz suggestion also. For an amplifier, I would leave the power supply board in the amp enclosure and make the leads from the power supply to the amp boards as short as possible.
@90scaraudio
I have two toroidal trafos 500Va pack ....
The distance between the input -output terminal -caps and trafos about 7cm....
Completely silent.....
I think your problem its bad way connection...keep the cables too short especially the 110 or 220 Vac.
As you see the box all it's hand made... nothing special.
I have two toroidal trafos 500Va pack ....
The distance between the input -output terminal -caps and trafos about 7cm....
Completely silent.....
I think your problem its bad way connection...keep the cables too short especially the 110 or 220 Vac.
As you see the box all it's hand made... nothing special.
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I would also vote to put the transformer and power supply board in a seperate enclosure. Then I would want some capacitance close to the amp boards in the amplfier enclosure. It would be nice to only have DC entering the amplifier enclosure.
If you go with an external DC power supply, you need to have additional filter caps inside the amp case for a number of reasons. Keep on experimenting.
Was counting on you to be the first with a LiFePO4 setup. 40 cells 3.2V 100Ah, good for 12.8kWh ripple free DC @ 2 x 64V.
I finally found the time to finish my Wolverine : EF3-3, NJW3281G/NJW1302G outputs, 600VA 4x38v transformer, +/-55V rails, all caps 64V, more than enough power for my Ekta mkII and my ears. The transformer is slightly elevated to leave room for the softstart and a small transformer for the speaker protection. Everything is set up as a double mono-block, and there is no hum whatsoever. Many thanks to the Wolverine team for this really nice DIY project and fantastic amplifier !
The only thing I am probably going to change is the relay speaker protection. I want to implement SSR and there are already some nice examples (felix1024) on this forum for inspiration.
The only thing I am probably going to change is the relay speaker protection. I want to implement SSR and there are already some nice examples (felix1024) on this forum for inspiration.
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Which Modushop case do folks prefer using for Wolverine & Cobra SMPS? I have a 4U monoblock that I was going to try and shove everything into, but now I’m thinking that may not be ideal haha.
Is the Mini Dissipante 4U/400 sufficient with stuffing in the Cobra? Just taking consideration for a little breathing room near the input stage. I’m trying to keep things as slim as they can be, within reason.
Appreciate any suggestions!
Is the Mini Dissipante 4U/400 sufficient with stuffing in the Cobra? Just taking consideration for a little breathing room near the input stage. I’m trying to keep things as slim as they can be, within reason.
Appreciate any suggestions!
If it is chosen to place the transformer in an external box, it will be possible to use the power supply for other amplifiers as well. A great advantage for diy.
Power supply is the most expensive unit in amplifier construction.
Thick cables, good quality plugs must be used as well as additional capacitors bank inside the amplifier.
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I'm using Mini Dissipante 4U/400 since I built my Wolverine and it's working quite well. Just one thing, I used Hypex SMPS1200A400, which is smaller than the Cobra, but I think it should be ok.
Regards,
Gaetano.
I used these - SB1100E-G, https://www.mouser.com/ProductDetail/750-SB1100E-G. I'm sure either are fine, but I used cheaper option
Can anybody tell me where to look for a problem? Doing 16.3 and everything checks out except TP104 to V-. I'm only getting 48 ohm resistance not the 10k+
You may need to make sure the capacitors C115 and C117 do not have any charge in them, since it will affect the resistance measurement.
Hope this helps, if not then you will need to check a few more things before power up. Take your time with the checks
- Dan
Hope this helps, if not then you will need to check a few more things before power up. Take your time with the checks
- Dan