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

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#583
diyralf said:
I have a question. How was that measured (1K = 0.000003%)? The value is outside of physics.
Click to expand...
Ltspice simulation. Please note that while the simulation is setup to account for many many things is not setup to account for the variations in component tolerances or transistor gain variations.

These number provided a good indication of how well the circuit performs. Please check the YouTube videos for the actual values.
 
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#584
jjs said:
The MG6331/9411's will work well go ahead and use them. These parts are still plenty fast, their Ft still manages 16-17MHz at 100mA bias. Maybe you'll have to increase C4/C5 but I doubt it. I've simmed with 4MHz Ft parts and those are fine except they don't turn off so well at high frequencies which could lead to cross conduction and destruction of the of the Output stage.

Onsemi is sneaky on their datasheet, they specify the maximum cob for both npn and pnp transistors leading you to believe they are matched. Typically the pnp cob is about 2x the npn cob.

Jeremy
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Thanks Jeremy,
I'll use MGs then. Interestingly, FT vs Ic of Motorola's MJL1302/3281 looks different than that of ONSemi devices. I wonder if there was such difference in reality or not.
cheers,
 

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#585
janusz said:
Thanks Jeremy,
I'll use MGs then. Interestingly, FT vs Ic of Motorola's MJL1302/3281 looks different than that of ONSemi devices. I wonder if there was such difference in reality or not.
cheers,
Click to expand...

It might just be how data is plotted

The old datasheet
X-axis is linear scale
Y-axis is log scale

The new datasheet (easier to read at low currents)
X-axis is log scale
Y-axis is linear scale

Jeremy
 
#586
jjs said:
It might just be how data is plotted

The old datasheet
X-axis is linear scale
Y-axis is log scale

The new datasheet (easier to read at low currents)
X-axis is log scale
Y-axis is linear scale

Jeremy
Click to expand...
This is true that different scales are used and for NPN there's not much difference but for PNP there is notable difference, especially at Vce of 10V. I checked FT for each current level up to 8A. Below 8A down to 0.5A FTs notably vary. At 0.5A motorola is about 15MHz, ONsemi 35MHz but from 1.5A up to 6A motorola has almost the same FT and then gently falls to not less than 35MHz at 8A while ONsemi is rising and then falling rapidly so at 8A motorola has FT of about 27MHz. How much would it matter in real appliction I do not know.

The interesting fact is that theoretically the same devices produced by different manufacturers are not exactly the same. Old IRFP9240 mosfet is a good example, IR is different in some respect from Fairchild IRFP9240 and other manufacturers such as Intersil, Vishay or Harris.

cheers,
 
#587
Does anyone know when the sending of PCBs ordered in the 2nd GB will start? I already have everything prepared to start building.

To avoid departure from the original design, and consequently increased distortion, I have purchased everything from Mauser, according the original BOM.
It is amazing how quickly the parcel has arrived: From Mnsfeld TX to my doorstep in Central Europe in just 60 hours.

Now, I'm just waithng for for the PCBs ordered in the 2nd GB.
 
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#588
Berlusconi said:
Does anyone know when the sending of PCBs ordered in the 2nd GB will start? I already have everything prepared to start building.

To avoid departure from the original design, and consequently increased distortion, I have purchased everything from Mauser, according the original BOM.
It is amazing how quickly the parcel has arrived: From Mnsfeld TX to my doorstep in Central Europe in just 60 hours.

Now, I'm just waithng for for the PCBs ordered in the 2nd GB.
Click to expand...
A rough time line below.

We hope to order the PCB’swithin one week from now.

One week or so to manufacture and ship.

One to two weeks to get here as they will pass through customs.

Then Jeremy and I need to sort and pack each order.

Then we need to weigh and create shipping labels.

Send out payment requests for the postage.

Wait for payment.

Then post them out.

Then they'll ship to your location.
 
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#589
Thanks Stuart,
Meanwhile, I will study all available information to prepare. This is a complex project and it would be imprudent to hurry up.
I have already seen Daniels' videos on youtube. I have found all of them rather useful, but for me, distortion measurement video was the most impressive with all these tricks and details. There is a great deal to learn there.
My objective isn't just to get extraordinary amplifier at relatively low cost. I want to learn and make a product conceived by a great group of enthusiasts.
 
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#590
SRMcGee said:
stuartmp & Co.:

Yes, actually. I spoke with my parents a couple of days ago and they were ecstatic about the improvement to their stereo! The Gainclone that I built for them in 2005 was reliable but no sonic match for the Wolverine-based integrated amp I gave them a few weeks ago. The stereo is located in a large combination art studio and reading nook measuring roughly 5.5 meters (18') by 6.5 meters (21'), with a cathedral ceiling that at its peak is probably 4.5 meters (15') high. The space is pretty reflective (lots of brick and glass surfaces and a hardwood floor) and the speakers are wall mounted, which affects their bass response. Even so, when I installed the amp its superiority over the Gainclone was abundantly clear (though I mentioned nothing to my parents). Music is much more "present" in the room now and is detailed, wonderfully resolved and rich. My parents, who typically spend 4-6 hours a day in that room, told me that they find themselves in the studio for longer periods these days because the music is so inviting. They remarked specifically about the improved clarity, depth and resolution (though not necessarily in those words) and are very happy with their gift.

Kudos, again, to the Wolverine design team!

Regards,
Scott
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Hi Scott,

So pleased to hear that your parents love the Wolverine you made for them; their reaction and impression, together with that of the other members that have so far completed their builds, makes me so happy that I decided to join the group buy and go for it (doing EF3-3, at ~50 volts, into 8 ohms).

Anyway - whilst I await the arrival in due course of the 2nd group buy boards, just a quick query please. I'm sure you mentioned in one of your earlier posts that you used a 3U/400 enclosure, together with the pre-drilled UMS heatsinks option. However, I can now only see this heatsink option available for the 4U or 5U enclosures, both on DIYAudio store and also at Modushop/HiFi2000 directly .....

So, would you mind confirming which enclosure variant you actually ended up using?

Thanks so much, and well done on your great looking build!

Thanks,
Richard
 
#591
Richard:

Yes, my parents' integrated amplifier was built in a 3U 400mm Dissipante chassis from Modushop/HiFi2000. As you are undoubtedly aware, the Wolverine pcbs have mounting holes consistent with the diyAudio UMS; however, the Wolverine design includes a few additional holes. Gianluca, from Modushop, worked with the Wolverine design team to develop a Wolverine-compliant set of drilled/threaded holes, and Modushop drilled and threaded that pattern in my 3U 400mm heatsinks.

I suggest you send an inquiry to Modushop, as the Wolverine hole pattern is probably still a special order. It's probably worth noting that Gianluca will be attending Burning Amp this coming weekend in San Francisco, so his response time to your correspondence may be affected.

And for what little it's worth, my Wolverine project also included the EF3-3 boards and ~50 V rails. The heatsinks never got very hot, even after the amp was on for hours.

Best of luck with your project!

Regards,
Scott
 
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#593
SRMcGee said:
Richard:

Yes, my parents' integrated amplifier was built in a 3U 400mm Dissipante chassis from Modushop/HiFi2000. As you are undoubtedly aware, the Wolverine pcbs have mounting holes consistent with the diyAudio UMS; however, the Wolverine design includes a few additional holes. Gianluca, from Modushop, worked with the Wolverine design team to develop a Wolverine-compliant set of drilled/threaded holes, and Modushop drilled and threaded that pattern in my 3U 400mm heatsinks.

I suggest you send an inquiry to Modushop, as the Wolverine hole pattern is probably still a special order. It's probably worth noting that Gianluca will be attending Burning Amp this coming weekend in San Francisco, so his response time to your correspondence may be affected.

And for what little it's worth, my Wolverine project also included the EF3-3 boards and ~50 V rails. The heatsinks never got very hot, even after the amp was on for hours.

Best of luck with your project!

Regards,
Scott
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Hi Scott,

Thanks for that info - in that case I'll give Gianluca a shout, can't do any harm!

Cheers,

Richard
 
#595
richbandit said:
Hi Scott,

Thanks for that info - in that case I'll give Gianluca a shout, can't do any harm!

Cheers,

Richard
Click to expand...
Hi Guy's,

I have spoken to Gianluca this morning. He tells me that the wolverine hole pattern is a made to order thing. Gianluca also told me that he will look into adding it the ordering options on his website once he returns from the burning amp festival.

So for now you will need to make it clear during your ordering process that you'd like the wolverine hole pattern for you chassis heatsinks
 
#597
Like many others I have been earnestly reading the design doc and watching the build videos of this amplifier. Looks very promising. I will be attending BAF this weekend and would love to chat with like minded enthusiasts who have built or are building this amp. Thanks to Stuart et al., for all the efforts. Given his recent timeline post, I expect the boards to be delivered in December sometime which is perfect timing for the holiday build queue. I will also converse with Gianluca this weekend. I don't know if I will go with a 5U/400 UMS or get a custom 4U/400 for my EF-4 build.

Best,
Anand.
 
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#598
diyralf said:
I am a little late at the party. Is there a place on github or somewhere where I can read all the schematics/documents etc?
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Just order the boards and join the party, this is the real fun. Until now I was gaining knowledge on simple ebay/aliexpress kits, I have also invested in meassuring equipment and now I know how to measure important parameters of audio equipment. Now, I feel confident I will be able to build this high quality amp with the little help from my friends.
So hurry-up guys, don't miss the 2nd chance. There is nothing worse than the missed opportunities.
 
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#600
Hi everyone,

I'm starting to get the parts for my EF3-4 build but have hit a bit of a wall.

This project is much bigger than any I've attempted so far so I read through the forum looking for recommendations and decided upon this combination.

Pre driver- 2sc3503e + 2sa1381e or ksc3503e + ksa1381e
Driver - 2sc4793 + 2sa1837
Output- njw3281g + njw1302g

The output drivers are on there way but all the others seem to be obsolete. I have found them but I'm not sure of there authenticity.
I guess I was hoping someone could tell me if it's worth persuing the combo above or going another route.

My speakers are 4 ohm 87 db and I planned on 59v DC.

Thanks for your time.
 
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