Your amp is coming together nicely! Yes that Variac would be perfect for testing
Work in slow progress here (not in a hurry and making the fun last). I am trial fitting all the elements in my 4U 300mm chassis. The transformer is a (modest) 600VA 4x38v on special order from Toroidy, already a big donut (I don't know how you 1k or 2x500VA guys can make it fit 🙂. Anyway, I don't need the extra power and this way I can use 64v caps.
I am considering different configurations (no wiring yet, one EF3-3 board is missing in the pictures). Anyone has any advice on which is the best or how I could do better ?
I am considering different configurations (no wiring yet, one EF3-3 board is missing in the pictures). Anyone has any advice on which is the best or how I could do better ?
Attachments
First 2 psu boards arrived yesterday. The other 2 diy v3's yet to arrive but they have pretty much the same dimensions. Dont need the diode section as I'm using 4 chassis mounted bridges. I either need to do some delicate cutting removing 2 filtercaps on both v+ and v- to narrow it down a bit. Or I could design my own boards with which Im not to comfortable yet even if the scheme is simple. Another option could be chassis mounted filtercaps with a copper gnd plate etc... Something to think about in the next couple of days...
Slice off the diode mounts and turn the cap boards on end? Depending on the height of your caps that could give you more room to mount everything.
Yeah... something like that. Dont need 8 caps per channel. 4 in the middle per channel will fit with the diode section cut off + 2 extra holes for the mounting.
Wkloppen,
If you're going to use 4 caps per channel with off board rectifiers, your proposed setup is a lot of waste, IMO. Member Prasi shared a compact psu that anyone can purchase by placing an order with PCBWay. It can be configured as a CRC or CC, can use dual rectification or center tapped. I've used them in class A and class AB builds with active rectification and will use them for Wolverine also.
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COMPACT_CRC_PSU_FOR_ITHER_DUAL_SECONDARY_OR_CENTER_TAPPED_TRANSFORMERS.html
If you're going to use 4 caps per channel with off board rectifiers, your proposed setup is a lot of waste, IMO. Member Prasi shared a compact psu that anyone can purchase by placing an order with PCBWay. It can be configured as a CRC or CC, can use dual rectification or center tapped. I've used them in class A and class AB builds with active rectification and will use them for Wolverine also.
page-41
COMPACT_CRC_PSU_FOR_ITHER_DUAL_SECONDARY_OR_CENTER_TAPPED_TRANSFORMERS.html
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Out of the woods finally. Yep..thats the boards I need!....THX....got quite a few boards now...some of them still need to arrive🙂...
edit: ordered them. Takes about 10 days
w.
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Hi Janusz,
These transformers are the best I have used unfortunately they are not cheap. But the pricing was reasonable considering the build quality.
You will need to contact them if you want pricing.
- Dan
The boards I designed are even more compact, they have both channels on the same board, that will save some space, see attached.
I designed it for CLC filtering for my Class A amp but you can use 0.22R resistors instead of inductors for class AB
For those interested PM me, I still have a few leftovers.
I designed it for CLC filtering for my Class A amp but you can use 0.22R resistors instead of inductors for class AB
For those interested PM me, I still have a few leftovers.
Hello everyone
Some photos of my Wolverine Amplifier
EF3-4 board with MJL power transistors (TO264)
Heatsinks are very heavy
Tapping was done by me
I've tested the boards without power transistors first (jumper) and then with power transistors and lab power supply with current limiting
Next step was to tested the board with the target value of 64V
To do that, an old Bryston amp with the two side amp disconnected (you must solder a jumper to use the power supply without boards)
A variac in front to get the target value and I can make some tests with the scope and generator
Bias is 100mA per pair
Offset <1mv and stable
Load is 4 ohm
It's best to use fuses of low value on the boards (in case of...) as this is the first test with 64V and heavy load
Next step is the power supply
Many thanks and congratulations to the Wolverine team for this fantastic amplifier. Build guide is also amazing (I've never seen that before...)
Square waves of 40, 1k, 10k, 50k
Bode plot
Bandwith is about 190khz (-3db)
I can get about 39 V rms (limit clipping) with 4 ohm load (380 W)
I will order transformers to have little bit more (67V)
Perhaps some resistors to adjust...
Some photos of my Wolverine Amplifier
EF3-4 board with MJL power transistors (TO264)
Heatsinks are very heavy
Tapping was done by me
I've tested the boards without power transistors first (jumper) and then with power transistors and lab power supply with current limiting
Next step was to tested the board with the target value of 64V
To do that, an old Bryston amp with the two side amp disconnected (you must solder a jumper to use the power supply without boards)
A variac in front to get the target value and I can make some tests with the scope and generator
Bias is 100mA per pair
Offset <1mv and stable
Load is 4 ohm
It's best to use fuses of low value on the boards (in case of...) as this is the first test with 64V and heavy load
Next step is the power supply
Many thanks and congratulations to the Wolverine team for this fantastic amplifier. Build guide is also amazing (I've never seen that before...)
Square waves of 40, 1k, 10k, 50k
Bode plot
Bandwith is about 190khz (-3db)
I can get about 39 V rms (limit clipping) with 4 ohm load (380 W)
I will order transformers to have little bit more (67V)
Perhaps some resistors to adjust...
Attachments
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Hello Bouli.....whats the reason you used this very nice looking but big C1 input capacitor of 70uF?
I use these cap ( Clarity Cap CSA) just because….
I had them in stock
But yes it’s a very compact and nice cap
And price (in Europe) is not high (less than 10 euros)
Input impédance is 22 k( easier for tube preamp in case of…)
