I mean, this is the entire reason I was going to keep them completely out of the chassis.
Seems I'm getting conflicting advice now.
I feel like stacking toroids is a bad idea. Rule of thumb I was taught for round, magnetic field producing objects, is to not be able to see one through another
I did a test once with inductors. Played music through on inductor while measuring another right near it in different orientations with a LCR meter.
With the inductors stacked, the measured inductor was thrown off by as much as 30% when the bass hit!!! Even having them in the same plane, like in my picture, isn't great.
These are the shielded ones from toroidy. Still think they need to move?
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You seem to employing confirmation bias to arrive at the conclusion that a separate chassis is needed for this design. You are cherry-picking isolated cases to make your case and ignoring the overwhelming advice that it's not needed.
You clearly want to use a separate chassis for the transformers. Just head down this route if that's what you've already decided is right for your build. Having said this, if you go down this route, I would think it would make more sense to have the entire PSU in a separate chassis; transformers, rectifiers and caps. I believe you want to keep the lead length from the secondaries to the rectifiers short if possible.
You clearly want to use a separate chassis for the transformers. Just head down this route if that's what you've already decided is right for your build. Having said this, if you go down this route, I would think it would make more sense to have the entire PSU in a separate chassis; transformers, rectifiers and caps. I believe you want to keep the lead length from the secondaries to the rectifiers short if possible.
Really? Because I am not married to that idea. Hence me JUST POSTING a full model of the transformers inside of the chassis.
If there's no harm in stacking them then I'll go that route.
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Sorry - not meant to be disrespectful. We do things all the time in the hobby for aesthetics that have no impact on the sonics. Especially with "attractive" PCBs that will spend most of their life covered.
Twin chassis does have a cool factor if well executed.
Twin chassis does have a cool factor if well executed.
I would like this unit tk be pure function. From my understanding of noise entering signal level components, putting them outside makes the most sense.
However, if shielded toroids inside don't affect the performance, then of course I'd rather just have it as a single unit.
I am getting confused by conflicting advice is all
Hi Dan, if you do stack the transformers do you need to separate them like you did with that cool little shelf you made? Or can you literally place them one on top of the other with no problem?
If you mount them on "L" brackets can they be oriented parallel to one another. Or should one bracket be rotated so that they are perpendicular to one another?
John
Dear all: Thanks to everyone that made this thread possible.
My apologies for not reading through all 292 pages. I just want to see if this is a build for me before I do a deep dive.
I have a “random” kit I built a few years ago that uses +/-91v rails with 8 pairs of MJL21193/4 as outputs and njw0321/0281 as drivers. It work’s fine, clips close to 400w into 8 ohms/770w into 4, so its stable, but given the glowing reviews of the Wolverine, I am tempted to switch out the front end of that build with a Wolverine front end. ( ie input to predrivers will be Wolverine)
Ie. I’d be using the input through the VAS and predriver sections of the wolverine with the already built drivers and output stage I have.
The first Question I have:
Will the wolverine design be able to handle +/- 91v rails?
If no, are there a couple of simple mods that will allow this or do I need separate power supply for it?
If yes, what kit should I order? ( my drivers and outputs are already installed on a heatsink. So the EF-3-3 should work the same as EF3-5 for me right?
Thanks so much in advance.
My apologies for not reading through all 292 pages. I just want to see if this is a build for me before I do a deep dive.
I have a “random” kit I built a few years ago that uses +/-91v rails with 8 pairs of MJL21193/4 as outputs and njw0321/0281 as drivers. It work’s fine, clips close to 400w into 8 ohms/770w into 4, so its stable, but given the glowing reviews of the Wolverine, I am tempted to switch out the front end of that build with a Wolverine front end. ( ie input to predrivers will be Wolverine)
Ie. I’d be using the input through the VAS and predriver sections of the wolverine with the already built drivers and output stage I have.
The first Question I have:
Will the wolverine design be able to handle +/- 91v rails?
If no, are there a couple of simple mods that will allow this or do I need separate power supply for it?
If yes, what kit should I order? ( my drivers and outputs are already installed on a heatsink. So the EF-3-3 should work the same as EF3-5 for me right?
Thanks so much in advance.
mjl21193/94 are not recommended as output transistors for this amp.
Your power supply is too much even for the 5 pairs version.
Your power supply is too much even for the 5 pairs version.
Tks boss. I have 8 pairs, and can change outputs.
That still leaves my one question unanswered,
Can the “front end” Vas take 91v?
That still leaves my one question unanswered,
Can the “front end” Vas take 91v?
The Toroidys if they are sheilded and have the interwinding screen are the best I have used personally.
I doubt either layout will be a real problem.
Why I am suggesting this is to fit everything in. You can also stack the transformers one up one down so what is left of the magnetic fields may have some cancellation.
Also the amount of mass in that area reduces any mechanical vibration of which the toroidys have very very little due to their construction.
PS: I dont work for toroidy 🙂
- Dan
@Bmsluite,
I’m assuming you’re ordering a Toroidy Supreme transformer?
If that’s the case, order a custom unit with eight secondaries, (maybe a ninth for low voltage housekeeping duty) then you don’t need two transformers, just a single unit. This will enable you mount the trafo towards the front of the chassis away from the signal in/outs and free up some real estate.
I’m assuming you’re ordering a Toroidy Supreme transformer?
If that’s the case, order a custom unit with eight secondaries, (maybe a ninth for low voltage housekeeping duty) then you don’t need two transformers, just a single unit. This will enable you mount the trafo towards the front of the chassis away from the signal in/outs and free up some real estate.
Hi
So I am planning to build Dual mono setup using EF3-5 Boards, So someone kindly validate the bom listed below with regards to PCB / heat shield.
2 x Precision EF3-5 (V5.0) Boards
2 x IPS Boards:
2 x Ground lift Boards
2 x T-Ground Boards
2 x Rectifier Boards
2 x Speaker Protection Boards
4 pairs of 2SA1381E / 2SC3503E Transistors
4 Heat-sinks (as mentioned here EF3-4 or EF3-5 (IPS & Pre-Driver)(Amp Board, Parallel Mount to Main Heatsink): $22.50 USD (4 Heatsinks Total))
Please let me know if this looks correct, or if anything seems off.
Thanks in advance
So I am planning to build Dual mono setup using EF3-5 Boards, So someone kindly validate the bom listed below with regards to PCB / heat shield.
2 x Precision EF3-5 (V5.0) Boards
2 x IPS Boards:
2 x Ground lift Boards
2 x T-Ground Boards
2 x Rectifier Boards
2 x Speaker Protection Boards
4 pairs of 2SA1381E / 2SC3503E Transistors
4 Heat-sinks (as mentioned here EF3-4 or EF3-5 (IPS & Pre-Driver)(Amp Board, Parallel Mount to Main Heatsink): $22.50 USD (4 Heatsinks Total))
Please let me know if this looks correct, or if anything seems off.
Thanks in advance
I think unlike inductors with only one winding, with (toroidal) transformers this effect is negligible, due to the magnetic field relationship with the primary being inside of the secondary around a common core. I would've thought external magnetic forces would have to be really massive to bother the transformer doing its job. Stacking is no problem. 😊 Plenty people done it. Just don't close a steel loop through the center of one them or you end up with a ring of fire (third shorted winding, eliminated if potted anyway).
I think the external PSU thing is interesting. Yes - it's probably cost and space prohibitive for most if you can achieve a quiet amp using traditional single chassis layouts, as I have demonstrated albeit with only a single transformer and tucking the rectifiers as far away from the input stage as possible. Squeezing two large transformers into the same chassis with the amps might mean some compromises are made with regards to rectifier positioning (the biggest noise culprit) so I can't imagine getting the same result I got quite so easily. But the external PSU also splits the weight, improving portability, especially with two traffos etc. Surely, you'd be fine keeping the interlink cable to 0.5-0.6m max, use 14+awg, the right connectors, and add some local bypass capacitors (2x~4700) as close as possible to the amp rail inputs. Theres a little extra R and L between the supply and amp Caps, making the supply even quieter, I would've thought. You can also power different amps with the same power supply to try different flavors in the future. I'm looking into it...
Enjoy the process 😎
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Oooooo, I did not think of this. This is a clever solution.
Yes, that is what I'm considering right now
I didn't know they would do this. So basically a dual but in a single unit. Interesting. I'll have to get a quote from for this.
I am going to have to mull this over. Question: is there any point in shielded toroids if I have an entirely external PSU section?
Yes, best option is shielded, potted, interwinding screen and base plate.
There is significantly less mechanical noise with shielded and potted, the shield is the enclosure for potting purposes.
- Dan