Come on, let ZM offer the 252 first... we don't need new ideas and he shouldn't be diverted...Planning for XA10002?
Babelfish XA252 / Babelfish XA252 SIT / Babelfish XA252 SET
- Thread starter Zen Mod
- Start date
I think I need more heatsink....
Do you happen to have hd graphs at Lq of 1A (presumably +-30vdc)? A single 600VA trafo would be sufficient for running this at 1.7A, correct? (1.7*30*2)*2 channels=204.
Two to three times the power consumption would be 400 to 600VA.
I didn't made any measurements at 1A of Iq nor I intend to do that (lazy or not wanting to promote idea?)
though, I believe my friend when he's saying that there is no difference to speak of, with his sensitive speakers
he's having exactly the same as shown here: https://www.zenmod.in.rs/sonido-15-way-speakers-by-zm-woland-edition/
amp is made to operate in bracket of 30Vdc to 35Vdc per rail
if you go for 30vdc, there is opening to use 35Vdc caps in cap bank, they will endure wiith ease short unbiased ampp condition during power up sequence, when rails are unloaded
if you go for 35Vdc, you must resort to 50Vdc caps as minimum
taking in account usual multiplication factor of 1.25 (AC to DC), applicable to heavy loaded rectification/filtering block, that calls for 24Vac secondaries in first case, or 28Vac secondaries in second case
give or take half a volt, who cares
now, targeted Iq is 1A7, but remember - due to Square Law transfer function , number isn't exactly carved in stone - it can be lowered without much penalty ( no louder KlunK!)
so, 35Vdc rails, 1A7 Iq ; that's 119VA; doable with Modu 5U/500 (Babysitter during Summer just for ease of sleep and prolonged caps life)
say that I'm Chicken, so no less than 300VA of Donut power per channel
will you go with two of that size or one double - your choice
if Cheapskates of Yore, producing Tube amps in numbers, could use common cathode resistors for both OS channels, there is no reason one can't use common PSU for both amp channels - it increases organicity of sound and it enlarges Mono Base ( coherence of Soundscape )
matter of choice, but let's make it informed (choice)
- sorta important detail - advisable to use separate secondaries/one bridge per secondary arrangement; as with majority of my little amps, also in case of Babelfish XA252 SET and Babelfish XA252 SIT - dynamic loading of rails is not uniform - result of complementary connected output devices not exactly being complementary, so having different/wakoo transfer characteristic
let's phrase it differently - whenever you have proper mosfet in one rail and SIT or Schaded mosfet in another rail, proper mosfet is having greater xconductance than it's partner
that resulting in greater dynamic loading of rail where proper mosfet is situated
so, if there is usual power xformer arrangement - center tapped secondary, entire rails loading difference will transpose to Center Tap ( used as Audio Gnd) , and xformer - happy stupid critter - is subjected to see it as nothing else as intermittent DC
We all know that xformers don't like DC and completely normal consequence is nothing else than buzz ........ and spoiling of xformer transfer characteristic
spoiling is going to result in spoiling AC coming from transformer, putting garbage back in rails, so some smearing of supposedly beautiful Soundscape ......
go figure
wouldn't be easier that I really ended as Construction Engineer, instead of messing with multilegged fuses in Papaland ?
though, I believe my friend when he's saying that there is no difference to speak of, with his sensitive speakers
he's having exactly the same as shown here: https://www.zenmod.in.rs/sonido-15-way-speakers-by-zm-woland-edition/
amp is made to operate in bracket of 30Vdc to 35Vdc per rail
if you go for 30vdc, there is opening to use 35Vdc caps in cap bank, they will endure wiith ease short unbiased ampp condition during power up sequence, when rails are unloaded
if you go for 35Vdc, you must resort to 50Vdc caps as minimum
taking in account usual multiplication factor of 1.25 (AC to DC), applicable to heavy loaded rectification/filtering block, that calls for 24Vac secondaries in first case, or 28Vac secondaries in second case
give or take half a volt, who cares
now, targeted Iq is 1A7, but remember - due to Square Law transfer function , number isn't exactly carved in stone - it can be lowered without much penalty ( no louder KlunK!)
so, 35Vdc rails, 1A7 Iq ; that's 119VA; doable with Modu 5U/500 (Babysitter during Summer just for ease of sleep and prolonged caps life)
say that I'm Chicken, so no less than 300VA of Donut power per channel
will you go with two of that size or one double - your choice
if Cheapskates of Yore, producing Tube amps in numbers, could use common cathode resistors for both OS channels, there is no reason one can't use common PSU for both amp channels - it increases organicity of sound and it enlarges Mono Base ( coherence of Soundscape )
matter of choice, but let's make it informed (choice)
- sorta important detail - advisable to use separate secondaries/one bridge per secondary arrangement; as with majority of my little amps, also in case of Babelfish XA252 SET and Babelfish XA252 SIT - dynamic loading of rails is not uniform - result of complementary connected output devices not exactly being complementary, so having different/wakoo transfer characteristic
let's phrase it differently - whenever you have proper mosfet in one rail and SIT or Schaded mosfet in another rail, proper mosfet is having greater xconductance than it's partner
that resulting in greater dynamic loading of rail where proper mosfet is situated
so, if there is usual power xformer arrangement - center tapped secondary, entire rails loading difference will transpose to Center Tap ( used as Audio Gnd) , and xformer - happy stupid critter - is subjected to see it as nothing else as intermittent DC
We all know that xformers don't like DC and completely normal consequence is nothing else than buzz ........ and spoiling of xformer transfer characteristic
spoiling is going to result in spoiling AC coming from transformer, putting garbage back in rails, so some smearing of supposedly beautiful Soundscape ......
go figure
wouldn't be easier that I really ended as Construction Engineer, instead of messing with multilegged fuses in Papaland ?
do it with Viking Axe, or just ask Peppennino to make it, with his 'Talian Viking Axe, for you
Babysitter is out of the question. Would 6U400 do it? 6U600 would for sure.I didn't made any measurements at 1A of Iq nor I intend to do that (lazy or not wanting to promote idea?)
though, I believe my friend when he's saying that there is no difference to speak of, with his sensitive speakers
he's having exactly the same as shown here: https://www.zenmod.in.rs/sonido-15-way-speakers-by-zm-woland-edition/
amp is made to operate in bracket of 30Vdc to 35Vdc per rail
if you go for 30vdc, there is opening to use 35Vdc caps in cap bank, they will endure wiith ease short unbiased ampp condition during power up sequence, when rails are unloaded
if you go for 35Vdc, you must resort to 50Vdc caps as minimum
taking in account usual multiplication factor of 1.25 (AC to DC), applicable to heavy loaded rectification/filtering block, that calls for 24Vac secondaries in first case, or 28Vac secondaries in second case
give or take half a volt, who cares
now, targeted Iq is 1A7, but remember - due to Square Law transfer function , number isn't exactly carved in stone - it can be lowered without much penalty ( no louder KlunK!)
so, 35Vdc rails, 1A7 Iq ; that's 119VA; doable with Modu 5U/500 (Babysitter during Summer just for ease of sleep and prolonged caps life)
say that I'm Chicken, so no less than 300VA of Donut power per channel
will you go with two of that size or one double - your choice
if Cheapskates of Yore, producing Tube amps in numbers, could use common cathode resistors for both OS channels, there is no reason one can't use common PSU for both amp channels - it increases organicity of sound and it enlarges Mono Base ( coherence of Soundscape )
matter of choice, but let's make it informed (choice)
- sorta important detail - advisable to use separate secondaries/one bridge per secondary arrangement; as with majority of my little amps, also in case of Babelfish XA252 SET and Babelfish XA252 SIT - dynamic loading of rails is not uniform - result of complementary connected output devices not exactly being complementary, so having different/wakoo transfer characteristic
let's phrase it differently - whenever you have proper mosfet in one rail and SIT or Schaded mosfet in another rail, proper mosfet is having greater xconductance than it's partner
that resulting in greater dynamic loading of rail where proper mosfet is situated
so, if there is usual power xformer arrangement - center tapped secondary, entire rails loading difference will transpose to Center Tap ( used as Audio Gnd) , and xformer - happy stupid critter - is subjected to see it as nothing else as intermittent DC
We all know that xformers don't like DC and completely normal consequence is nothing else than buzz ........ and spoiling of xformer transfer characteristic
spoiling is going to result in spoiling AC coming from transformer, putting garbage back in rails, so some smearing of supposedly beautiful Soundscape ......
go figure
wouldn't be easier that I really ended as Construction Engineer, instead of messing with multilegged fuses in Papaland ?
fans are for s*****s. Real men use big iron
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then do not use it
I said - when it's 30+C outdoors ( and I'm avoiding to use AC when I don't need it; using it only in Workshop to avoid sweating of forehead thus spectacles), I just have OCD about caps in amp