DIY Class A/B Amp The "Wolverine" build thread

Hi Mainframe,

thanks for your very rapid and professional response. I appreciate the links to the appropriate posts and the fact that your answer is based on experience. I am very satisfied with the information received, but would appreciate your response to my question about recommendations for main filter capacitors. I am looking for good capacitor types for 54 V rail voltage with reasonable prices. Proposals by other members are also welcome.

Regarding my question 1, I found that when using separate rectifier bridges for each rail voltage, the transformer secondary wingings are galvanically connected only during the capacitor charging pulses, i.e. during a small part of each cycle depending on power supply loading. In case of a single rectifier bridge common for both rails the transformer wingings are continuously solidly connected to the common ground. In addition the transformer winding voltages behave differently. In the case of separate bridges, the voltages of the windings follow each other with a continuous difference, which is the rectified peak voltage. In case of a common bridge, the voltages of the winding ends connected to the rectifier bridge vary in opposite directions between the positive and negative rectified peak voltage. These two facts might cause some difference in performance, which is difficult to reveal by simulations.

Regards
Martant
 
If its difficult to see in a sim, its probably impossible to see in the final product. If you've got the coin and the room, go dual bridges. Otherwise don't, its not really gonna affect much. You certainly wont hear it. But if you're already in thought this deep, its gonna bug you either way you go 😛

Rail caps depends on how you want to fit out your chassis. If you go snap in, you'll need a PCB. here's a nice compact solution, but there are thousands out there; https://www.diyaudio.com/community/threads/lt4320-based-active-rectifier.336572/post-6233338. If you dont want a PCB and prefer point to point wiring, you'll need screw caps or similar. I think most people go PCB's with snap-in caps, and in that case the best value cap is this guy here https://www.mouser.com/ProductDetail/Chemi-Con/ESMH800VSN103MA50S?qs=xI6Y96ivSIyl3%2BiMJta85A==
 
V5 is alive!

The first EF3-4 V5 mirrored stereo set has received full voltage and biased up like a dream. Excuse the workshop dust, cat hair and solder flux on the output transistors it was getting late!

Passed all initial power up and warm up tests no issues at all. Huge thanks to the team for putting together, and meticulous QA, of the schematic and PCB and BOM @stuartmp @danieljw @Harry3 @jjs so that when I powered it up (very cautiously) it didn't splode or smoke. EF3-3 and EF3-5 builds to follow.

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Hi Mainframe and danieljw,

thanks again for good and valuable advice. Anyway I have noted the importance of avoiding the disturbance caused by charging current peaks. I believe that correct details of the power supply topology is the most important thing for this. In my previous amplifiers I have not faced any problems related to this issue.

Regards
Martant
 
I'm determined to have every Wolverine in a MonoBlock 4U 400 10mm chassi.
@stuartmp In what timeframe will you have the boards ready to ship
Regarding the timeframe for the 5th Group Buy boards, we’re almost there. The final step is verifying the EF3-5 boards, which should arrive with @danieljw around Wednesday next week.

From there, Daniel will build and test the Left and Right channel versions in his own time and report any minor issues in component placement, silkscreen etc.

Once we get the green light from Daniel, I’ll place the bulk order for all boards. Fabrication typically takes about one week, followed by 3-4 days for shipping.

So, barring any unexpected delays, we’re looking at a few weeks until the boards are ready to ship.

A huge thank you to everyone for your patience—this community’s support is what makes the Wolverine project shine. I’m confident the wait will be worth it, especially with the new mirrored boards and the EF3-5’s power boost!

Stay tuned for updates.

Best regards,
Stuart (stuartmp)
Wolverine Team
 
Dual mono or stereo? How many transformers and what size have you put in? Any auxiliary boards?
Stereo. I used an Hypex SMPS to go 33cm width and reduce weight. I added Stuart's loudspeaker protection, t-shaped ground board and ground lift board.
not sure if I need 4U or 5U...
I think it could depend on the PSU voltage you'll decide to use...

Gae.
 
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Hi Guys,

I finally finished my EF3-4 (V. 4) boards. I am ready to test. Question: I see the note in the Build Guide that Q103 does not need a heat sink when powering up without the output transistors installed. My boards will be parallel to the heat sinks and Q103 is positioned under EF3-4 and between Q107 and Q108. Do these three transistors need to be tied to the heat sink when using this configuration during initial power up w/o output transistors installed?

Thanks,

John
 
Hi Guys,

We’ve got some fantastic news for the Wolverine 5th Group Buy! A huge shoutout to Gianluca from ModuShop for stepping up to support our project in a big way. Not only is ModuShop offering a 5% discount on all 3U, 4U, 5U Dissipante and Mini Dissipante chassis, but Gianluca is also providing custom heatsink drilling for the following Wolverine board patterns at no extra cost:

  • EF3-3: TO3P, TO264
  • EF3-4: TO3P, TO264, MT200
  • EF3-5: TO3P, TO264
This means you can get a perfectly tailored chassis for your Wolverine build—whether you’re rocking the new EF3-5, or classic EF3-3/EF3-4 setups—with holes drilled to match your chosen output transistors.

To grab this deal:
  1. Visit the ModuShop Chassis Collection.
  2. Use the discount code DIYWOLVHF2K at checkout to enjoy the 5% savings.
  3. Specify your desired drilling pattern on the website (EF3-3, EF3-4, or EF3-5, with TO3P/TO264/MT200 as needed).
This is an incredible opportunity to elevate your build with a top-notch chassis at a discount, all while supporting a company that’s backing our Wolverine community. Let’s give a big thank you to Gianluca and ModuShop for making this happen!

If you have questions or need help with your chassis order, drop them in this thread or reach out to me at stuartmp@internode.on.net. The 5th Group Buy is shaping up to be our best yet—thanks for your enthusiasm!

Best regards,
Stuart (stuartmp)
Wolverine Team
 
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And for anyone with existing "standard" diyaudio UMS heatsinks:

For 1 Channel. All boards have some common holes that line up with UMS so getting started with the PCB as a template is easy.

300mm deep:

EF3-3 with TO-3P outputs - no drilling required
EF3-3 with TO-264 outputs - 6 additional holes (outputs)

400mm+ deep:

EF3-3 with TO-3P outputs - no drilling required
EF3-3 with TO-264 outputs - 6 additional holes (outputs)
EF3-4 with TO-3P outputs - 6 additional holes (pcb and drivers)
EF3-4 with TO-264 outputs - 14 additional mounts required (pcb, drivers and outputs)
EF3-4 with MT-200 outputs - 22 additional mounts required (pcb, drivers and outputs)
EF3-5 with TO-3P outputs - 16 additional mounts required (pcb, drivers and outputs)
EF3-5 with TO-264 outputs - 16 additional mounts required (pcb, drivers and outputs)