Hello, im looking for a list of common issues and bad parts of this model.
i bought one and it takes a while for coming out of standby, i have to turn the gain knob all the way up and some minor humming is audible
from what i can find on the web there are only repair services that charge 200+ bucks for probably just replacing caps.
does anyone know of common parts that go bad or were of poor quality?
replacing all caps is #1 on my list.
i wonder how they manage to make it safe to use, the internal parts are not even galvanically isolated from the mains.
apparently it has a isolation transformer. ive seen some pics of them without. must be eu model or something.
i bought one and it takes a while for coming out of standby, i have to turn the gain knob all the way up and some minor humming is audible
from what i can find on the web there are only repair services that charge 200+ bucks for probably just replacing caps.
does anyone know of common parts that go bad or were of poor quality?
replacing all caps is #1 on my list.
apparently it has a isolation transformer. ive seen some pics of them without. must be eu model or something.
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Old post, but this may help others.
Capacitor C18 (100uF) on the amplifier board handles the standby timeout. Common failure. There is a simple mod to force the sub to always be awake.
All the 13V power supply caps heat up and go bad, can cause hum, and can cause greater cascade damage. These include C15, 16, 17, 7, 45, 46, 37, 38, 39, and 40 on the amplifier board. On the pre-amp board the 13V supply uses C31, 32, 41, and 42.
Be very careful desoldering the old caps. It’s too easy to lift traces and make a painful mess of the PCB.
Capacitor C18 (100uF) on the amplifier board handles the standby timeout. Common failure. There is a simple mod to force the sub to always be awake.
All the 13V power supply caps heat up and go bad, can cause hum, and can cause greater cascade damage. These include C15, 16, 17, 7, 45, 46, 37, 38, 39, and 40 on the amplifier board. On the pre-amp board the 13V supply uses C31, 32, 41, and 42.
Be very careful desoldering the old caps. It’s too easy to lift traces and make a painful mess of the PCB.
my few cents after repairing a mk2, mk4 and 2 xteq's since my last post.
sunfire used JunFu and other crap brand caps in their true lineup and samson and crapxon in their xteq's.
most of them failed by now. doing a full recap with good brand 105°C ones fixes 99% of the issues
glue them down using electronics rated silicone, dont use bathroom silicone.. i had a few now where people used this stuff, its eating away the traces below.
when the passive driver rattles, check if the wooden plate came lose. use epoxy to glue it back on.
if the woofer rattles (early ones of mk2, not the newer HiVi ones) check the spider, its glue sometimes breaks near the cone, use epoxy.
Hum can come from other stuff, the true subs didnt have balanced inputs yet, you can hook up the negative high level input to your amps negative terminal (dont do this if you got a class-d amp, their negative is usually not ground!).
later xteq models have balanced, but miss the high level inputs.
if you look for a driver replacement, look for a HiVi SP10, its the exact woofer they used in mk4 and up. (just different terminals)
if you cant find it, get a dayton UM10-22, its T/S parameters are very close to the original chassis, you just gotta wire up both coils in series to get to 4ohms.
Those sub chassis are very sensitive.. a thin cast aluminium basket that holds a huge magnet on its back, unsupported.. it snaps right off when you drop it.
its a good idea to somehow support it in case it ever gets a hit. on the EU version with the transformer inside, just add self adhesive rubber feet so when you screw the woofer back in, it presses against them.
sunfire used JunFu and other crap brand caps in their true lineup and samson and crapxon in their xteq's.
most of them failed by now. doing a full recap with good brand 105°C ones fixes 99% of the issues
glue them down using electronics rated silicone, dont use bathroom silicone.. i had a few now where people used this stuff, its eating away the traces below.
when the passive driver rattles, check if the wooden plate came lose. use epoxy to glue it back on.
if the woofer rattles (early ones of mk2, not the newer HiVi ones) check the spider, its glue sometimes breaks near the cone, use epoxy.
Hum can come from other stuff, the true subs didnt have balanced inputs yet, you can hook up the negative high level input to your amps negative terminal (dont do this if you got a class-d amp, their negative is usually not ground!).
later xteq models have balanced, but miss the high level inputs.
if you look for a driver replacement, look for a HiVi SP10, its the exact woofer they used in mk4 and up. (just different terminals)
if you cant find it, get a dayton UM10-22, its T/S parameters are very close to the original chassis, you just gotta wire up both coils in series to get to 4ohms.
Those sub chassis are very sensitive.. a thin cast aluminium basket that holds a huge magnet on its back, unsupported.. it snaps right off when you drop it.
its a good idea to somehow support it in case it ever gets a hit. on the EU version with the transformer inside, just add self adhesive rubber feet so when you screw the woofer back in, it presses against them.