@fireanimal
Absolutely beautiful job on that EBG dummy load creation! From what I understand, when you start getting into measuring amps with ultra low distortion, the non inductive properties of the resistors and/or resistor bank become very important so that they are not dominating your distortion measurements. This is in addition to the thermal demands imposed on the resistor/resistor banks during high power testing.
Great work,
Anand.
Absolutely beautiful job on that EBG dummy load creation! From what I understand, when you start getting into measuring amps with ultra low distortion, the non inductive properties of the resistors and/or resistor bank become very important so that they are not dominating your distortion measurements. This is in addition to the thermal demands imposed on the resistor/resistor banks during high power testing.
Great work,
Anand.
This is truly impressive engineering, both in the Wolverine and in the measurement. You guys are setting the state-of-the-art. 
sp33ls - I was not part of the Wolverine development, but I can answer your questions. EF3 is necessary to avoid loading the voltage amplifier. The voltage amplifier output is a high-impedance point. All high-performance amplifiers have three current gain stages after the voltage amplifier.
The distortion spectrum does not matter once the total distortion is low. It is much better to have low THD than to have any particular spectrum.
As an observer to the THD wars, I feel that the Wolverine needs a competitor. The BC-1 fans should rise to the occasion. This could be as entertaining as "Godzilla vs King Kong" (I have not seen the movie).
Ed
sp33ls - I was not part of the Wolverine development, but I can answer your questions. EF3 is necessary to avoid loading the voltage amplifier. The voltage amplifier output is a high-impedance point. All high-performance amplifiers have three current gain stages after the voltage amplifier.
The distortion spectrum does not matter once the total distortion is low. It is much better to have low THD than to have any particular spectrum.
As an observer to the THD wars, I feel that the Wolverine needs a competitor. The BC-1 fans should rise to the occasion. This could be as entertaining as "Godzilla vs King Kong" (I have not seen the movie).
Ed
@fireanimal do you suspect the Sanken outputs to be a contributing factor to such a stellar result? Or, would the other output devices be right there alongside it?
Also, that's an awesome dummy load setup you have there.
@fireanimal
Excellent THD and THD+N measurement results are achieved. You certainly have excellent measurement equipment.
Will you also be measuring the IMD which will confirm the great properties of the Wolverine ??
Please excuse my English (translator).
Excellent THD and THD+N measurement results are achieved. You certainly have excellent measurement equipment.
Will you also be measuring the IMD which will confirm the great properties of the Wolverine ??
Please excuse my English (translator).
I Pulled apart my dead CJ MF 2200 (200 watt solid state amp) last night and realized the EF3-4 boards will fit! As it was a 200 watt amp, I think I'll risk it. My last big expenditure is power supply. I was going to do 2 500va 45v trannies, but it occurs to me that in addition to the tight fit (can't stack them in 3U), a 1kva 45v transformer can give much more current as needed. Does anyone have advice based on listening? Any input is appreciated!
Not really, but why would you. You will win by sharing a larger cap bank on each rail across both channels.
You can do the multiple bridges per secondary if you want to create separate DC sections for each channel. It won't provide the same isolation as two transformers, as there is some coupling through the common secondaries. Still, somewhat better isolation than single caps and rectifiers. On the other hand, the single DC supply with the same total capacitance can supply more power to one channel or the other as the program requires. Just wire each channel from the caps separately.
I doubt it makes a whole lot of difference to the channel separation. BTW, some toroidal transformer manufacturers state that you should not mount two transformers on a common axis (stacked).
I doubt it makes a whole lot of difference to the channel separation. BTW, some toroidal transformer manufacturers state that you should not mount two transformers on a common axis (stacked).
Thanks, but that load bank is not my creation I cannot claim it is. I put it together with suggestions from Stuart and Daniel. But you are right you have to have non inductive resistors and clean wiring, that is a must.
On the outputs, the Sanken's are great but this amplifier performs equally well with all transistors on the BOM, I have tested pretty much all of them, and would run anyone of them in my personal build. I prefer the big Sanken's myself though, they are just so damn sexy that huge MT-200 package.
Thank you it has been a work in progress for sure! I have measured the IMD on multiple builds and it measures just as good as the rest. What specific IMD test and level would you like to see? The English from the translator is perfect by the way.
And if anyone wants to see any specific test or different output level let me know.
I have heard the opposite.
I've heard that stacking them gives you the opportunity to rotate and flip them to reduce/cancel the noise and EMI
produced.
Twin Toroids
@wkloppen Please take care when installing components you don't want to box yourself in so you can't apply some solder to the top side of the board.
You also risk branding your sensitive components with your soldering iron.
Install large components last.
I have been working on some additions to the build guide I hope to be finished soon.
These notes may help you for now.
Don't forget you can also refer to my build album.
You also risk branding your sensitive components with your soldering iron.
Install large components last.
I have been working on some additions to the build guide I hope to be finished soon.
These notes may help you for now.
Don't forget you can also refer to my build album.
Wolverine IPS board – Suggested component installation order.
Notes:
Installing components left to right, top to bottom, and smallest to largest, can help ensure that have sufficient access to allow your soldering iron room to reach the top of each component pad.
Try and install components with their component values facing up or in a position where the component value can be read once all components are installed.
You may need to refer to other sections in the build guide when it’s time to install one of the components listed below.
You may want to use the suggested component installation order as a checklist, crossing off each component as you go.
When it comes time to solder in the TO-92 small signal transistor. Care must be taken to install them at a height where good access to the top of the pad is available if you install them too low you may burn them with your soldering iron.
C10, C12, R00, R0, R22, R23, R1, D4, D5, D6, D7, D14, D13, R10, R27, R3, R4, R2, R9, R24, R12, D1, D2, Rlift, R21A, R6, R7, R8,
RHelp, R26, R21B, R20, R19, R18, R13, R14, R5, R17, R16, D9, D8.
Take a break here and clean the board.
Q1, Q2, Q5, Q6, Q3, Q4, C4, C5, Chelp.
CCS Heatsink and Q11, Q13.
Q12, Q19, Q14, C3, D10, D11, C6, C7, Q7, Q8, D3, D12, Q9, C3, R11, R25, Clift, C2, TP0, C8, C0, Input Terminal block, C9, C1
Take a break here and clean the board once again
Precision Output Stage Board – Suggested component installation order for the EF3-3 & EF3-4.
Notes:
Installing components left to right, top to bottom, and smallest to largest, can help ensure that you have sufficient access to allow your soldering iron room to reach the top of each component pad.
Try and install components with their component values facing up or in a position where the component value can be read once all components are installed.
You may want to use the suggested component installation order as a checklist, crossing off each component as you go.
You may need to refer to other sections in the build guide when it’s time to install one of the components listed below.
The installation order shown below is for the EF3-4 Precision output stage board. It can still be used as a guide for the EF3-3.
EF3-3 specific components will be noted with an *.
EF3-4 specific components will be noted with an #.
Rled1, Rled2, D111, D112, R102, R103, D106A, D105A, R108, RCC, R105, R106, R107, R110, R129, D116, R128, D115, R127, *R127A, *R127B, R112, R113, R126A, TR104, R126B, TO101, #R120, #R126A/B, #R121, #R127A/B, R114, R120A/B, D103, R117, R111A, R123A/B, D104, R115, R111B, R121A, R121B, R118, R124A/B, R116, R122A/B, R119, R125A/B, TP102.
Take a break here and clean the board once again.
C112, Q101, Q102, D113, D114, D107, D108, C101, C105, C102, C106
C118, C119, Q104 remote lead if applicable, Pre-Driver Heatsink mounted a minimum of 3mm off the PCB to ensure ease of assembly and disassembly if required along with Q105, Q,106 and the G2 ground connection.
C104, C109, C108, C103, C107, C109, #C121, #C122, #C123, #C124, C113.
Take a break here and clean the board once again.
Next install the terminal mounts for PSU GND, V+, V-, SPK GND, and Output.
D109, D110, F1, F2, L1, C114, C116, C115, C117, TP103, TP100
Don’t forget to test your board here. Please follow the instructions shown under the heading “Setup for initial testing”
Once tested, install.
#Q115, #Q116, Q109, Q112, Q110, Q113, Q111, Q114.
Wash and inspect the boards
Now is a good time to clean the boards to remove the flux and inspect your work. Depending on the solder you’re using, there can be a considerable amount of residual material that requires 2-3 scrubbings with alcohol and a brush to get it clean. It’s best to give it a first cleaning before installing the taller, more delicate components, making the job much easier when it comes time to give it a final cleaning.
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Usefull notes!....thx....Was already following them as much as I could think of at the time but this certainly helps. The left to right / top to bottom sequence is usefull for me as I didn't pay attention to that. Topside soldering went well although I didn't do the mica's. I forgot to the do the sipheader first but I can still access it.
