Ok!I think is stuff good end right
More importantly tell us how you are enjoying your amp.
I always love to hear a good story
i am doing this. already done.
before tweaks my dc out 0-10mV
after this tweaks dc out 70-80mV
why? is that normal?
btw the sounding indeed much more better after this tweaks, for me.
You have to wait a few minutes before measuring the output voltage and you have to do with the load connected.
Have you done it?
when in balanced mode, dc out is 0-25mV
when in single ended mode (-in shorted with gnd), dc out is increased to 80mV
and it is peak at 300mV.
i am using Solen MKP 220uF/400v for the C2 bypass, is that the problem?
effect on the speakers : (with RCA connectors) there come some hiss and hum.
but no problem with the XLR mode.
when in single ended mode (-in shorted with gnd), dc out is increased to 80mV
and it is peak at 300mV.
i am using Solen MKP 220uF/400v for the C2 bypass, is that the problem?
effect on the speakers : (with RCA connectors) there come some hiss and hum.
but no problem with the XLR mode.
cap can't induce offset , excpt in case of broken (leaking ) one , which certainly isn't a case
few pics and some explanation will tell what's the reason for hiss and hum , when using unbalanced
few pics and some explanation will tell what's the reason for hiss and hum , when using unbalanced
there is hum and hiss when setting like this: (dc out 80-300mV)
but will be silent with this setting: (dc out 0-25mV)
An externally hosted image should be here but it was not working when we last tested it.
but will be silent with this setting: (dc out 0-25mV)
An externally hosted image should be here but it was not working when we last tested it.
Last edited:
1. setting DC offset and bias - all inputs grounded , amp hot , lid on (take it off just for quick re-set)
2. first pic is correct for unbalanced input
3.second pic is example of nada,zilch,hogwash ; neg leg input is floating , and you're not having full gain ; it is not balanced config
so - for proper operation - either connect it as per pic 1 , for unbalanced (RCA ) input , or bring proper balanced signal (as XLR wiring - remember that ? )
give us more pictures , so we can comment your grounding scheme and find culprit why you are having hiss & hum
2. first pic is correct for unbalanced input
3.second pic is example of nada,zilch,hogwash ; neg leg input is floating , and you're not having full gain ; it is not balanced config
so - for proper operation - either connect it as per pic 1 , for unbalanced (RCA ) input , or bring proper balanced signal (as XLR wiring - remember that ? )
give us more pictures , so we can comment your grounding scheme and find culprit why you are having hiss & hum
yes Zen Mod, i know how to wire XRL or RCA'
the pic above only to shown the changes dc output voltage with -IN shorted and unshorted.
this is basically i do with the amp:
the pic above only to shown the changes dc output voltage with -IN shorted and unshorted.
this is basically i do with the amp:
An externally hosted image should be here but it was not working when we last tested it.
you must ground both inputs (+ and - ) when setting offset
have you any pic of your PSU pcb layout ?
I mean , traces - that will help to see is there any room for improvement
have you any pic of your PSU pcb layout ?
I mean , traces - that will help to see is there any room for improvement
okay i see both + and - are grounded.
this is my PSU wiring:
bleeder R and bypass Caps i mean:
according to mr pass files,
there are no setting for this amp.
so, which component should be setting?
this is my PSU wiring:
An externally hosted image should be here but it was not working when we last tested it.
bleeder R and bypass Caps i mean:
An externally hosted image should be here but it was not working when we last tested it.
according to mr pass files,
there are no setting for this amp.
so, which component should be setting?
i am using un matched IRFP244.
so voltage across each 0.47ohm are:
Right Ch: Left Ch:
R34 = 397mV 434mV
R35 = 517mV 486mV
R36 = 434mV 412mV
R37 = 508mV 496mV
R38 = 481mV 414mV
R39 = 363mV 438mV
original pass file, it should be 250mV across that resistors.
i am using this schematic:
so voltage across each 0.47ohm are:
Right Ch: Left Ch:
R34 = 397mV 434mV
R35 = 517mV 486mV
R36 = 434mV 412mV
R37 = 508mV 496mV
R38 = 481mV 414mV
R39 = 363mV 438mV
original pass file, it should be 250mV across that resistors.
i am using this schematic:
pcb seems adequate
so - for that pcb,best takeout point for gnd routing to output pcbs is point where you connected two wires from bridges , establishing gnd .
regarding Iq - do you hear benefit of increasing it , ref. original ?
so - for that pcb,best takeout point for gnd routing to output pcbs is point where you connected two wires from bridges , establishing gnd .
regarding Iq - do you hear benefit of increasing it , ref. original ?
Last edited:
this is my first time to build aleph30 amp.
so i dont know what is the difference.
i am planning to re-wiring my PSU like this one:
what do you think? will this solved the hum and hiss problems?
thanks.
so i dont know what is the difference.
i am planning to re-wiring my PSU like this one:
An externally hosted image should be here but it was not working when we last tested it.
what do you think? will this solved the hum and hiss problems?
thanks.
- Status
- Not open for further replies.