Hi Guys,
I’m excited to share a fresh development for the Wolverine family: the EF3-5 output stage board! As you know, our current lineup includes the EF3-3 (3 current gain stages, 3 output transistor pairs) and the EF3-4 (3 current gain stages, 4 output pairs).
Now, we’re taking it up a notch with the EF3-5, featuring 3 current gain stages and 5 output transistor pairs for even greater power and stability.
To top it off, I’ve mirrored the EF3-5 design—just like the EF3-3 and EF3-4 in the 5th Group Buy—offering dedicated Left and Right channel versions. This keeps the inputs at the rear and outputs low on the heatsink, maintaining that clean, symmetrical layout you’ve come to love.
The EF3-5 boards are 7 mm longer and 10 mm wider than the current EF3-4 boards. All the holes still follow the UMS, except for the two at the top where the output transistors mount—they’ve moved up 10 mm. The output transistor mounting holes have also shifted up 10 mm, so some drilling and tapping will be required if you’d like to use the EF3-5.
The EF3-5 is perfect for those pushing higher currents or lower impedances (think 2-ohm loads or beyond) with the same Wolverine Class AB finesse.
If you’ve already placed an order for an EF3-4 board and want to upgrade to the EF3-5, or if you’d like to add a pair of EF3-5 boards to your order, please email me your requirements at stuartmp@internode.on.net, and I’ll update your order sheet.
Best regards,
Stuart (stuartmp)
Wolverine Team
I’m excited to share a fresh development for the Wolverine family: the EF3-5 output stage board! As you know, our current lineup includes the EF3-3 (3 current gain stages, 3 output transistor pairs) and the EF3-4 (3 current gain stages, 4 output pairs).
Now, we’re taking it up a notch with the EF3-5, featuring 3 current gain stages and 5 output transistor pairs for even greater power and stability.
To top it off, I’ve mirrored the EF3-5 design—just like the EF3-3 and EF3-4 in the 5th Group Buy—offering dedicated Left and Right channel versions. This keeps the inputs at the rear and outputs low on the heatsink, maintaining that clean, symmetrical layout you’ve come to love.
The EF3-5 boards are 7 mm longer and 10 mm wider than the current EF3-4 boards. All the holes still follow the UMS, except for the two at the top where the output transistors mount—they’ve moved up 10 mm. The output transistor mounting holes have also shifted up 10 mm, so some drilling and tapping will be required if you’d like to use the EF3-5.
The EF3-5 is perfect for those pushing higher currents or lower impedances (think 2-ohm loads or beyond) with the same Wolverine Class AB finesse.
If you’ve already placed an order for an EF3-4 board and want to upgrade to the EF3-5, or if you’d like to add a pair of EF3-5 boards to your order, please email me your requirements at stuartmp@internode.on.net, and I’ll update your order sheet.
Best regards,
Stuart (stuartmp)
Wolverine Team
In summary Wolverine V5.0 / GB5 will offer:
3 pair, 4 pair and 5 pair output stages
The lowest THD measurable thus far
Mirrored PCBs
Refreshed and updated BOMs
Refreshed build guides
Instant upload and purchase baskets for mouser.com
All revised boards final release built and tested by the team
Dust off your old chassis and PSU's and heat up them soldering irons
3 pair, 4 pair and 5 pair output stages
The lowest THD measurable thus far
Mirrored PCBs
Refreshed and updated BOMs
Refreshed build guides
Instant upload and purchase baskets for mouser.com
All revised boards final release built and tested by the team
Dust off your old chassis and PSU's and heat up them soldering irons
MT200's will not fit the EF3-5 unfortunately.
IMO MT200's better thermal performance is best taken advantage of in lower pairs anyway.
IMO MT200's better thermal performance is best taken advantage of in lower pairs anyway.
The MT-200 can not be used on the EF3-5.
The transistors on the EF3-3 and EF3-4 are spaced at 40mm. For the EF3-5 the transistors centres are 30, 30, 30, 30, 40, 30, 30, 30, 30. The outer two transistors are in the same horizontal position as the EF3-4
Attachments
Hi guys.
For my Wolverine V4 build I designed some simple 3D-printed wire bridges to jump the output from one side of the board to the other.
If there's any interest in something like this for the people in this group buy, I can update the design to make them a bit prettier and supply them for this group buy with the help of Stuart. You'd then be able to buy them together with the boards from Stuart.
They're printed in ASA plastic, so there shouldn't be any concern regarding having them mounted on a warm heatsink. I have attached some images of my own Wolverine build and a close-up of the installation.
If there is enough interest I can print a bunch and sell them to Stuart for no profit and he will sell them for the same price. I doubt it will be more than 5$ per bridge, though I haven't done any math yet.
Please reply or DM me if you might interested! 🙂
For my Wolverine V4 build I designed some simple 3D-printed wire bridges to jump the output from one side of the board to the other.
If there's any interest in something like this for the people in this group buy, I can update the design to make them a bit prettier and supply them for this group buy with the help of Stuart. You'd then be able to buy them together with the boards from Stuart.
They're printed in ASA plastic, so there shouldn't be any concern regarding having them mounted on a warm heatsink. I have attached some images of my own Wolverine build and a close-up of the installation.
If there is enough interest I can print a bunch and sell them to Stuart for no profit and he will sell them for the same price. I doubt it will be more than 5$ per bridge, though I haven't done any math yet.
Please reply or DM me if you might interested! 🙂
Attachments
Wow, This is something! 3, 4 or 5 output pairs.
For a first build I'm sticking with the 3 pair. Can't wait to get my hands on it and get started!
For a first build I'm sticking with the 3 pair. Can't wait to get my hands on it and get started!
May I ask, for the new v5 EF-3|4 the drill template for mt-200 ef-3|4 stays the same? I am going to prepare the heatsinks modu 5U case.
There has been no changes to the hole locations for the EF3-3 V5 or EF3-4 V5 boards.
8 x 2sa1381E (4 per channel)
6 x 2sc3503e (3 per channel)
For ease of parts handling I have just been doing 8 pairs for a stereo Wolverine build.