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

As you can see it has had 41 revisions 😱, so its consistently being updated thanks to build team and community input.

There will be a big V5.0 revision with the V5 rollout. The previous build guide will be sunset for all PCB's before V5.0

Are there preffered transistors over others for audio? I coemf from the world of automation, test and measurements, and embedded design where a transistor is just a transistor as long as it meets the specs. I see audio has a different view of components.

Indeed, there are transistors better for audio use - primarily flat hFE over a wide current range. The BOM has all of this covered, no need for studying.
 
You all have convinced me. I'm in.


Do you plan to build a stereo, dual mono or monoblocks?

Once you have the transofrmer(s) selected, I can point you to a PSU kit that I'm going to use....
Good question. I am leaning towards just a stereo build. The price of two small toroids are about the same price as a one big toroid. From what I can tell the benefit of the monoblocks is better separation of channels for imaging reasons. The advantage of a single transformer is either channel can pull from a larger bank of power since either channel can pull off of a toroid which is double its size compared to a monoblock. Am I on the right track here?
This should help you size the PSU:

View attachment 1462249

Do you plan to build a stereo, dual mono or monoblocks?

Once you have the transofrmer(s) selected, I can point you to a PSU kit that I'm going to use....
I am someone who likes to do something once so I am leaning towards running a single 1000VA transformer. Does the 64V+ DC rails require that I then have to use high voltage capable capcitors? I know they tend to jump in price once you go past 63V rated caps. I see that V5 has its own table.
We would like to announce another option for the Wolverine Version 5.

If you are planning on getting in on the PCB group buy, the V5 EF3-5 option which has 5 pairs of ouput devices is capable of running higher supply rail voltage for some more serious output power options 🥳

Due to the voltages involved this is for experienced builders only....

Please see table attached with the various rail voltage options and a scope capture with a 4 Ohm load.

IMG-20250519-WA0000.jpg
When do you expect to have V5 out? If this is a new version, I will want to build that. Voltages do not worry me. I currently have a 320V DC power supply on my desk right now. I do see this table has lower rail voltages per power supply than the older table.

I like bass heavy music so I think the 1000 VA, 45/64V with 200 amp in 8 ohm will be right up my alley. From my experience, larger toroid and cap bank supplies handle the bass dynamics better.

A few additional questions I have about parts:
  • Where are you all sourcing your toroids? I saw Antek mentioned a lot here. Is that the best price to performance vendor that is know?
  • I see people are selling some specific parts. If you are one of these people and have some parts I will need that are not easily sourced, please shoot me a DM and I will purchase them from you.
  • I will probably just buy an amplifier enclosure off of aliexpress. For $170 I can get a 400mmx320mmx410mm chassis. Metal is metal as far as I am concerned.
  • The build guide is one of the finest build guides ever written. Most of what you are asking for is in the 1st post of this thread. I am not sure if anybody reads 1st posts anymore but it’s where I look whenever I am pondering a future build. The last attachment (a pdf file) of the 1st post of this thread has the build guide. When you purchase boards, you’ll get links to the latest build guide (and loads of other stuff) but regardless as member @Mainframe has said and member @Vunce has alluded to, this isn’t your weekend build. I have built ~ 100 amps [not bragging!] in the last 5 years (not all of them made it to chassis!) and this build is one of those that I am taking my time on!

    Enjoy the journey.

    When you do find and read that build guide, I hope you can appreciate the level of diligence it took to get this design this far. The Youtube build guide video which member @danieljw has kindly uploaded and is attached to every one of his posts is also quite thorough.

    Best,
    Anand.
    This is what has convinced me. I am in. Lets do this.
 
For the sound imaging question, I'm the one of those who can't hear the difference and would probably fail every AB test so...

That's the setup I'm building, just 2 x 500 VA dual mono. For 64V DC rails yes, 80V caps should do.

I sourced my toroids from toroidy.pl because Antek did not have audio grade 500VA, 2 x 45V ones. If you go lower, they should have some.

For enclosures, I suggest you to check out the modushop.biz website, they have a Deluxe line of chassis where you can specify what version of Wolverine you are building, and they will drill the exact mounting pattern for all the boards and transistors specific package you gonna use on heatsinks. For this specific build, I went with 5U, 400mm depth.

For the PSU and rectifier/snubber boards, there is a nice "all in one" kit you can source from here:

https://tinyurl.com/yp3a9c4h

The only caveat is that the soft start board is not suitable for this build. For that I sourced Hypex soft start board suggested here on the forum, but you can go with many different variations.
 
I sourced my toroids from toroidy.pl because Antek did not have audio grade 500VA, 2 x 45V ones. If you go lower, they should have some.
What specs make a toroid audio grade vs not?
they will drill the exact mounting pattern
I am fortunate enough to be a fabricator and have an entire electrical engineering firm's fab shop at my disposal (I am the manufacturing engineer/manager of the shop)
For the PSU and rectifier/snubber boards, there is a nice "all in one" kit you can source from here:
This one here?
Is there a BOM/Schematic for these boards somewhere?
1747753283680.png

Any real difference from the above to buying something off the shelf like this? Other than being able to purchase some nicer caps of course
1747753374170.png

The only caveat is that the soft start board is not suitable for this build. For that I sourced Hypex soft start board suggested here on the forum, but you can go with many different variations.
I was thinking of just using this as the soft start. Thoughts?
1747753442641.png
 
I was thinking of just using this as the soft start. Thoughts?
1747753442641.png
Two very different items. You have shown a speaker protection board that protects your speakers from at least DC voltage going to them. A soft start board limits current flow in the primaries of the transformer when power is first switched on for about .25 to .5 seconds, sometimes more. This protects the transformer, diodes, power switch, and filter caps from extremely high current spikes for very short periods of time. When the power is switched on.
 
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Two very different items. You have shown a speaker protection board that protects your speakers from at least DC voltage going to them. A soft start board limits current flow in the primaries of the transformer when power is first switched on for about .25 to .5 seconds, sometimes more. This protects the transformer, diodes, power switch, and filter caps from extremely high current spikes for very short periods of time. When the power is switched on.
Understood. So would need something like this? Reading through the thread I see posts saying the wolverine kit comes with a soft start.
1747755968033.png

Seems at least some people have used some off the shelf boards
1747756294321.png

From your questions, I would not suggest the EF3-5 for your first build. It's not so much the voltages, it's the tremendous amount of current that it can put out. It could literally weld.
Again, I have a 320V DC power supply sitting on my desk for a photodiode tester project. I am not one to build a lot of little stuff that I won't use to build up to the good one. I just want the good one. My first loudspeaker design was a 3 way and turned out fantastic. I saw no need to build up to one. A lot of people helped me and I learned everything I needed to know. Same thing building race cars. No one person builds a race car. The entire community builds a race car. One person working while everyone else answers their questions. One guy is an engine guy, another a suspension guy, and another the aerodynamics guy (this is me, I'm the aero guy)

As long as people are willing to answer my questions, I don't see why I wouldn't be able to build this. I answer technicians' questions all day long at work. Only if I refused to answer would this shop not be able to produce projects and make a living for everyone here.
 
I'm leaning towards dual mono in either 220 or 220 power. Decision will be made based on toroid availability. Toroidy doesn't even have an option to ship the US on their site currently.

I see Antek has two different types. AN which they say is for audio and then AS which has the primaries and secondaries shielded from one another. Is the noise from the lack of shield audible or really just a "nice to have"?

The AS line taps out at 400VA which plugs me into building a dual mono and an output of 160 into 8 ohm. I'd much rather build to 220 in to 8 ohm.
1747758598819.png

Antek is, by far, the lowest price so I am searching there. They have soft start modules available so I'll just grab a couple of these.
https://www.antekinc.com/ss-12-soft-start-module/
1747758654082.png


Going dual mono I either build up some of these PSU boards
1747763486964.png

Or I just buy one of these. Not specifically this one but something like it. Seems it has everything one could want and then I'm only building the amp channel PCBs
1747763554237.png

Then some soft start modules.
Then the chassis
Then the amp board and all the parts for the boards

Am I missing anything?
 

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They will build your transformer for your needs, many people from US ordered from them.
Yep, just tell them primaries and secondaries...

I have two landing in Toronto on Thursday. If you send them an email with the exact spec you need, they will tell you the price + shipping cost to US. Manufacture time is two weeks plus shipping another week or so.

I could not find any 120V - 2 x 45V audio grade that were much cheaper...
 
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Antek is, by far, the lowest price so I am searching there. They have soft start modules available so I'll just grab a couple of these.
https://www.antekinc.com/ss-12-soft-start-module/
I would suggest to look other soft start solutions if you want to have standby function with front panel power on switch, power on/standby LEDs, temperature control...

Like you said, you're building once.

For the speaker protection boards, you can include these in the amp board order. Check for the order thread, there is an XLS file you need to edit and send to get your boards reserved. It's a group buy.
 
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I would suggest to look other soft start solutions if you want to have standby function with front panel power on switch, power on/standby LEDs, temperature control...

Like you said, you're building once.
I just looked at the release of the V5

It seems he has everything on there.
Transistors, amp boards, rectifier boards, speaker protection boards, t ground board, ground lift boards.

Outside of all that I think all I need is the toroids and the caps for the rectifiers right? This explains why I see a good portion of these boards have separate, very large, caps installed inside.

What I am REALLY insterested in is the EF3-5 board which is able to run on a 2 ohm load. This would open up a plethora of design ability as far as speakers go. Ensuring a complex loudspeaker doesn't kill a 4 ohm amplifier is an art all to itself.