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

[NSP]

What do you all think about one 1200 VA transformer with four 50VAC secondaries instead of two 600VA trafos with two 50VAC secondaries each?
Is there any downside to this?
I was in contact with Toroidy and they can make these, also cheaper than two trafos.

 

[stuartmp]

What do you all think about one 1200 VA

I prefer two 500 or 600VA transformers stacked as you'll use up the vertical space in a 5U chassis and develop more space between the transformer and the pcb.

 

[fireanimal]

I dont see why not, but it might not be much more for a 1500VA 😀

 

[NSP]

Yeah it will probably have a very large diameter. Need to check with them. Should I go for a 1500VA? 😀 How about the sagging with 50 volt ac?

 

[fireanimal]

I think the 1500VA and 1200VA should be the same diameter, but check and see. What outputs are you using and chassis size?

 

[NSP]

I'm going to use either MJL3281/MJL1302 or MJL4281/MJL4302. Not sure yet, any thoughts? I have them both on hand. The chassis the big 5U.

 

[fireanimal]

I'd run the 4281/4302. You should be good with 1500VA then.

 

[MilkyChance]

I would choose DIYA PSU boards but I’ve also used this one twice, one for Class A amp at +\-24V and a Class AB (like Wolverine) at +\-75Vdc and both work well no issues for more than 2 years. Buy blank boards and buy quality parts, can be used in multiple amp builds. https://www.ebay.com/itm/1652244994...P4bno5HRiy&var=&widget_ver=artemis&media=COPY

What caps did you use for 75v? I can't find any high uf for that form factor

 

[fireanimal]

https://www.mouser.ca/c/passive-com...rating dc=80 VDC&instock=y&sort=capacitance|1

This may help

 

[fireanimal]

I use this board If you want to try the LT4320 active rectifier. I have extra of these PCB's

https://www.mouser.ca/c/passive-com...rating dc=80 VDC&instock=y&sort=capacitance|1

 

[MilkyChance]

Thats all 80v caps though, not 100v. I dont want any problems with unregulated voltage. Maybe i'll just look for a separate rectifier and cap boards or something that works with screw-on caps. Does anyone have any suggestions for those?

 

[fireanimal]

If your rails get close to 80V DC then you will have more to worry about then just the caps.

 

[MilkyChance]

ok, thank you. I will go with the 80v then.

 

[69383]

If its fits in the cabinet including some shiel

Thats all 80v caps though, not 100v. I dont want any problems with unregulated voltage. Maybe i'll just look for a separate rectifier and cap boards or something that works with screw-on caps. Does anyone have any suggestions for those?

I use these with screw terminals from KEMET 36,000 uF 100V
https://mou.sr/3KeRgE1
Life expectancy is way better then from through hole electrolytic capacitor.

 

[hcpower]

The ALS70 and 80-series from KEMET are good capacitors.
I have used the 36.000uf/100v in many applications due to "good value for money", and they perform well! Long lifespan

 

[MilkyChance]

What power supply do you use with the KEMET?

 

[69383]

1 kVA 2x45V, 4 bridges and 16 C, for 2 channels hard wired.

 

[deerhunt]

4 bridges

Why 4? You mean diode bridges?

 

[Mainframe]

I'm wondering how I can put this 1200VA that came in a busted audiolab 8000x7 to use, maybe it could do a 50V wolverine using one secondary?... hmm

Looks like the 38V used to run 3 channels and the 39.5V ran 4 channels.

 

[wcwc]

Could do a dual mono approach with a regulator for each voltage pair.