B1 Rev. 2

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#22
Some other bits to help out...
 

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#23
I have a few test pcbs and jfets incoming so I will be able to comment in a couple of weeks.

About the output resistor, I remember experimenting with 50R on my DCB1 with very nice results. My cables are really low capacitance though, and I remember Salas telling me to test for oscillations anyway.
 
#24
I have a question.
In this power supply example, is 0V ground left floating, connected directly to chassis earth, or connected to chassis earth via thermistor to chassis earth?
Also remembering the bigger picture of multiple interconnected pieces of equipment.
 
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#31
diyRookie said:
Yeah Marc - probably the last place on earth you can still find them - at a huge cost for guys like us outside of the first world. Pity there are no alternatives for the SJ74's. Maybe Juma can come up with a plan?
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Papa and the guys here at diyaudio are very nice about sharing. It's very much appreciated by those without secret stashes of unobtanium components. [emoji106][emoji5]


Sent from my iPhone using Tapatalk
 
#34
Zen Mod said:
Picodumb you are the true, one and only, undisputed, even dumber than myself, King of Dumb :worship:
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Now that you have finally conceded defeat here. :rofl:
Thank you. Don't worry I'll remain humble in victory.
I have a question.

Have you tested anything crazy like:
1) Switchmode supply ---> CCS ---> Shunt regulator. Or
2) Switchmode supply ---> RC ---> CCS ---> Shunt regulator
 
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#35
according to your signature , if you have decent shunt reg ( by definition CCS cell followed by shunt cell) , then it's pretty irrelevant which sort of dreky source you have in front

however , I prefer one less prone to whinging and malfunction

and - do not underestimate importance of unnecessary overkill to quality of good sleep
 
#36
Zen Mod said:
1) if you have decent shunt reg ( by definition CCS cell followed by shunt cell) , then it's pretty irrelevant which sort of dreky source you have in front

2)however , I prefer one less prone to whinging and malfunction

3)and - do not underestimate importance of unnecessary overkill to quality of good sleep
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1) Yeah the thought just occurred to me, that if the Switch Mode supply sees the CCS as the load, we can then do all crazy shunt stuff afterwards without sending the switch mode supply into a crazy fit.

2) Me too, but I have 2 x 30V switchers laying around and this might be fun to experiment with.

3)I agree, I don't have time to thoroughly test and compare every bloody idea, to see where the point of diminishing returns are for audio quality, best to go over kill and remove all doubt, and sleep better at night.
 
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#37
ya know - for testing purposes - everything is good (even using xmass tree lights as load :rofl: ) , but when really finishing some gadget , I have experience that cutting angles is big no-no .

so , I'm usually erring in other direction

edit- I know that , by 1) , you made a typo ; CCS is working as shock absorber , not as load
 
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#38
Zen Mod said:
edit- I know that , by 1) , you made a typo ; CCS is working as shock absorber , not as load
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I sought of meant both. I like the term shock absorber, that's a good description.

If the CCS of the shunt regulator is say 100mA, then the load on the switchmode supply is a constant 100mA, regardless of what is happening downstream at the shunt when music is playing, as the CCS is usually set significantly higher (I usually go for 3 times higher) than the preamp circuit will ever draw.
 
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