Unbalanced Input
Last question.
I won't use balanced input. I use only unbalanced input. I read a Nelson Pass post
http://www.diyaudio.com/forums/pass-labs/4586-p1-bosoz.html
when he says to put between unused input (minus - ?) and his ground a 221 ohm resistor.
I understood this solution using the same board of post n.18 (nelson original board). It is correct? See red circles.
Last question.
I won't use balanced input. I use only unbalanced input. I read a Nelson Pass post
http://www.diyaudio.com/forums/pass-labs/4586-p1-bosoz.html
when he says to put between unused input (minus - ?) and his ground a 221 ohm resistor.
I understood this solution using the same board of post n.18 (nelson original board). It is correct? See red circles.
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BoSoZ gerber file
Could you kindly suggest me a site or a place where there is gerber file por that pcb?
Thanks
Could you kindly suggest me a site or a place where there is gerber file por that pcb?
Thanks
I believe you can find someone to make them from pdf
I'm not aware of Gerbers publicly published
I'm not aware of Gerbers publicly published
Power transformer
Hallo, I have ordered all the parts on Digikey and now I'am choosing the power transformer. I use only one power transformer. Do you think that 100 VA 2x60V is enough? May I choose a more powerful transformer? Thank you!!!
Hallo, I have ordered all the parts on Digikey and now I'am choosing the power transformer. I use only one power transformer. Do you think that 100 VA 2x60V is enough? May I choose a more powerful transformer? Thank you!!!
Thanks Zen Mod!In effect Nelson Pass says to use two transformers 30 w each so 100 VA is more than necessary. Reading some discussion I read that 100 VA (for both channel) is minimum (???) and some people use 160 VA or more...So I asked you!!! Now I will order 100 VA transformer (for both channel)!
Nelson simply used what he had on shelve or could buy easiest ....... no need for two xformers
50VA is more than enough for stereo BOSOZ , 100VA is even better
of course , you can use even 1KVA ........ be sure to put it in other room
50VA is more than enough for stereo BOSOZ , 100VA is even better
of course , you can use even 1KVA ........ be sure to put it in other room
...minimum power may be 20VA for stereo...10w consumption for each channell Nelson Pass says! Someone used 350VA...big is better!!!! But the result is the same that small one...
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minimum power is one thing ....... and power consumption of circuit completely other
PSU power capacity must be greater at least by factor 2 , to avoid excessive ripple and thermal issues
Let me understand...In BOSOZ article Pass says "
At 60 volt regulated rails, each channel draws 80 mA of bias current (40
mA passing through each MOSFET in the gain circuit). This is about 10
watts per channel. You can power two channels off this supply, or you
can choose to give each channel its own power supply. The current
drawn by the gain stages is roughly proportional to the supply voltages,
so that the circuit draws about half the current with 30 volt rails."
It seems that 30 VA is enough for stereo😕...or do I not understand something?
thank you😉
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it is best if you stay with nominal ratings and not go oversize as you run the risk of ending up with a higher voltage due to lack of load on the transformer. I have gone oversized in my AlephP preamps and I had to use power resistors to throw away some Vs as the capacitor ratings were exceeded. 2x60Vac Plitron had 11% regulation and I had overlooked that. Not to mention the size of the Xformer getting in the way of a neat package in a small housing.
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it's simple
use either 50VA or 100VA
no need for too much thinking , all is already said in few last posts
use either 50VA or 100VA
no need for too much thinking , all is already said in few last posts
Unbalanced source to balanced preamp input
After I have finished my Aleph 30, I'm buying all the parts to build this preamp.
I must buy potentiometer and connector.
I ask you if it is possible do this.
I would use a balanced potentiometer (Alps quad pot 10 k logaritmic). I have a unbalanced source (pioneer network player N50).
May I use a BOSOZ with balanced input and connect it to unbalanced source using a unbalanced to balanced signal cable? Rca to rource and XLR to preamp?
After I have finished my Aleph 30, I'm buying all the parts to build this preamp.
I must buy potentiometer and connector.
I ask you if it is possible do this.
I would use a balanced potentiometer (Alps quad pot 10 k logaritmic). I have a unbalanced source (pioneer network player N50).
May I use a BOSOZ with balanced input and connect it to unbalanced source using a unbalanced to balanced signal cable? Rca to rource and XLR to preamp?
yes , you can
when connecting unbalanced source , connect gnd to gnd , hot to positive input of preamp , negative input of preamp connect to gnd
when connecting unbalanced source , connect gnd to gnd , hot to positive input of preamp , negative input of preamp connect to gnd
Ok, perfect, thank you! So I do a simple layout using only balanced connector with balanced potentiometer and using unbalanced to balanced cable (simply to do or to buy) to connect unbalanced source
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