Dang, mess with a guy's instant gratification why don't ya.For those patiently waiting for the power supplies to become available for purchase separately, they should be available soon.
155 of them just shipped to the warehouse today! Give it 2-3 weeks for them to arrive and then be checked in.
Also, if anyone has opted to build the power supply with input choke / clc, what size of choke did you end up with?
The R8 and R9 values in general will be different. The key thing is to make the voltage drops across R6 and R7 fairly close while keeping the DC offset near zero. (100mV is about the upper acceptable limit and you shouldn't have any trouble trimming that down much lower. )
For soft pads (e.g. silpads and Keratherms) one does not use thermal paste. Paste is needed for hard pads like mica.
For soft pads (e.g. silpads and Keratherms) one does not use thermal paste. Paste is needed for hard pads like mica.
Would 0,745 and 0,730 V drop across R6 and R7 fairly close if DC offset is 2mV?
What would be more important voltage drop to be same or 0mV DC offset?
How that affects sound?
^ You've got it 'perfect'.
Additional 'tweaking' to match the bias between channels will not affect the sound even one tiny teeny little bit (IMO). The bias current will vary that much just by blowing on the boards.
2mV of DC offset is "nothing". Nicely done.
Screw down the top cover and enjoy the music.
Additional 'tweaking' to match the bias between channels will not affect the sound even one tiny teeny little bit (IMO). The bias current will vary that much just by blowing on the boards.
2mV of DC offset is "nothing". Nicely done.
Screw down the top cover and enjoy the music.
The numbers are good.
Since the bias is affected by temperature, when dialing in the bias you should keep the lid on except when you are actually adjusting the pots. Then you put the lid back on and let the amp stabilize. Repeat as needed. 🙂
Enjoy your amp.
Since the bias is affected by temperature, when dialing in the bias you should keep the lid on except when you are actually adjusting the pots. Then you put the lid back on and let the amp stabilize. Repeat as needed. 🙂
Enjoy your amp.
I think that's part of the character of this amp. It's rather charming playing old records from the 60's-70's where the vocals have some twang to them. It helps to have a bright & forward phono stage like a Pearl 3.
(PS I think that's ZM in front)
Not sure if this was posted yet but AnTek 3218 transformers are back in stock.
Of note, Antek AS-3218, AN-3218, AS-3220, AN-3220, AS-4218, AN-4218, AN-4220, AS-4220 can all be used with this project.
Yes, centre-tapped works. See the first PS schematics in this doc in the first post: https://www.diyaudio.com/community/attachments/f5m-diy-amplifier-power-supply-v1r1-pdf.1301722/
Awesome, thank you, that's the doc I remember seeing but somehow didn't have saved.
They both work, but is there any advantage to one over the other? The dual secondaries uses two bridges, but is there any advantage to using two over one or vise versa?
No real advantage one way on another in our application. Use what you have, it’s going to be great.
I suspect the transformer manufacturers like to make dual secondary transformers (instead of C.T.) as they are more flexible in use - they can be wired as center tap, as well as parallel, series, and dual output.
I suspect the transformer manufacturers like to make dual secondary transformers (instead of C.T.) as they are more flexible in use - they can be wired as center tap, as well as parallel, series, and dual output.
What would be the max bias for F5m when using 5U 500mm case? Right now I have 1.6 A. I do not have thermometer so a good advise would be great. 🙄
Another question is if is good to use some small heatsink on the top plastic side of the mosfet aswell or it does not matter?
Another question is if is good to use some small heatsink on the top plastic side of the mosfet aswell or it does not matter?
40W of heat per device is sane, 45W and 50W calls for exquisite thermal interface - Keratherm 86/82 or ceramic alumina pads+goop
heat per device is Vrail*Iq
small hsink on ceramic side will give you just funny estetic
heat per device is Vrail*Iq
small hsink on ceramic side will give you just funny estetic
Higher than recommend bias doesn’t actually do much aside making your listening room warmer.
Nope
Rectifier A positive DC side
Rectifier A negative DC side
(Edited to add - at least that's how I interpret it... and I could be wrong).
Rectifier A positive DC side
Rectifier A negative DC side
(Edited to add - at least that's how I interpret it... and I could be wrong).