Test the rectified voltage of your PSU. If it is below 63V then you are ok to use it with your UCD400 (It should be fine though, probably more like 58V)
The Predator PSU can go quite a bit higher, up to the rating on the caps. You can ask LCAudio to put in 80V caps if you need them (or buy your own)
The Predator PSU can go quite a bit higher, up to the rating on the caps. You can ask LCAudio to put in 80V caps if you need them (or buy your own)
My UCD400 setup
Hello folks,
While I'm waiting for my UCD400s with OPamp 6820
upgrade, I want to share my setup ideas with you
so others may benefit when building an UCD400 amp!
I plan to build either a monoblock (two enclosures)
or a double mono configuration (single enclosure).
My drawing contains details and the part list.
Hope you like it!
Michael
P.S.: In case of monoblocks in two enclosures, I will
get the Galaxy alu cases from audiokit.it. Slim look- love it!
Hello folks,
While I'm waiting for my UCD400s with OPamp 6820
upgrade, I want to share my setup ideas with you
so others may benefit when building an UCD400 amp!
I plan to build either a monoblock (two enclosures)
or a double mono configuration (single enclosure).
My drawing contains details and the part list.
Hope you like it!
Michael
P.S.: In case of monoblocks in two enclosures, I will
get the Galaxy alu cases from audiokit.it. Slim look- love it!
Attachments
I've now got my two UCD400 modules. I've got an offcut of some 50mm by 10mm aluminium bar which I'll be using to fix the modules to the heat sink to adapt the modules to replace the original PCBs in a Quad-405 power amp.
I'm still using the original Quad 405 power transformer. I'll let people know how it sounds when I get everyting finished.
I'm still using the original Quad 405 power transformer. I'll let people know how it sounds when I get everyting finished.
5 channel amp
Hi,
Well, the enclosure arrived last weekend and it is big enough. There are 4 rails in it which keep it all together, but they can be made a lot shorter and still keep the enclosure together. The UcD400's can be put at the sides vertically, so there are no more problems with that.
The soft start module has arrived also from LCAudio and I have solderred it together.
I only have to get screws for the UcD's and the neutrik XLR posts and I have to wait for the Loudpeaker connectors.
I saw on the Hypex-site that they sell 50cm shielded twisted pair cables with the right connector (for the UcD's) on it, so I have to get them too.
What should I use for the power supply cables and the cables for the loudpeaker connectors?
Frans
Hi,
Well, the enclosure arrived last weekend and it is big enough. There are 4 rails in it which keep it all together, but they can be made a lot shorter and still keep the enclosure together. The UcD400's can be put at the sides vertically, so there are no more problems with that.
The soft start module has arrived also from LCAudio and I have solderred it together.
I only have to get screws for the UcD's and the neutrik XLR posts and I have to wait for the Loudpeaker connectors.
I saw on the Hypex-site that they sell 50cm shielded twisted pair cables with the right connector (for the UcD's) on it, so I have to get them too.
What should I use for the power supply cables and the cables for the loudpeaker connectors?
Frans
How does the sound change with the supply voltage ? I only need about 50 w for a midbass horn so a lower voltage could be used. Any advantages ?
It was covered a little on the UCD180 thread. Basically, the opinion was that this module plays best with a decent powersupply. Lowering the supply voltage, only has a minor decrease in the idle consumption, and the amp is 95% efficient when running.
So basically, put in a reasonable size powersupply even if you won't need a lot of watts
(By the way, this is all heresay: I have no experience to back this up!)
So basically, put in a reasonable size powersupply even if you won't need a lot of watts
(By the way, this is all heresay: I have no experience to back this up!)
Maybe I was not clear, I will use a big size supply but with a lower Voltage. Some amplifiers like the Gainclone change the sound with the voltage and maybe the UCD also will get another sound ?
According to Bruno, the UCD400 is quite insensitive to
a different voltage so long you drive them close to the
recommended specs (25V of course wouldn't make much sense)
I will try this myself when my UCDs arrive.
Regards,
Michael
a different voltage so long you drive them close to the
recommended specs (25V of course wouldn't make much sense)
I will try this myself when my UCDs arrive.
Regards,
Michael
Hi
Just hooked up two UcD 400 modules to a 1KVA trafo intended to sreve as powersupply for 8 UcD 180 modules. It delivers 50.6 V DC from two 33.000uF (will be 16 X 10.000 in the final design and will have an overvoltage reg.)
WOW These are good. They are so good that I need a lot longer time to reveal defficiencies if any is present. The only thing so far is I triggered the current protection a couple of times, but I have low efficency loudspeakers with a nasty imepance dip in the bass and I was palying loud in a 60 sgmeter room.
From what I hear now, we are talking genuin High-End !!!
A question to Bruno:
Would it be possible, if one only wants to drive the modules ( the 180 in the 8ch amp) from a unbalanced source , to ground the - input of the UcD driver (thru 1.8 K?) and connect the + to the source, thereby bypass both the op-amp and the two 22uF ?
Another thing: IMHO it would be very wrong not to use Soft Recovery Diodes as rectifiers..! You can use decpoupling caps on these as well if you like , but I for one feel it is unnessesary then. Normal (slow or fast) rectifiers makes a lot of noise, it is better to avoid the noise rather than reducing with caps..
see post 77 here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=8683&perpage=10&pagenumber=8
Koldby
Just hooked up two UcD 400 modules to a 1KVA trafo intended to sreve as powersupply for 8 UcD 180 modules. It delivers 50.6 V DC from two 33.000uF (will be 16 X 10.000 in the final design and will have an overvoltage reg.)
WOW These are good. They are so good that I need a lot longer time to reveal defficiencies if any is present. The only thing so far is I triggered the current protection a couple of times, but I have low efficency loudspeakers with a nasty imepance dip in the bass and I was palying loud in a 60 sgmeter room.
From what I hear now, we are talking genuin High-End !!!
A question to Bruno:
Would it be possible, if one only wants to drive the modules ( the 180 in the 8ch amp) from a unbalanced source , to ground the - input of the UcD driver (thru 1.8 K?) and connect the + to the source, thereby bypass both the op-amp and the two 22uF ?
Another thing: IMHO it would be very wrong not to use Soft Recovery Diodes as rectifiers..! You can use decpoupling caps on these as well if you like , but I for one feel it is unnessesary then. Normal (slow or fast) rectifiers makes a lot of noise, it is better to avoid the noise rather than reducing with caps..
see post 77 here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=8683&perpage=10&pagenumber=8
Koldby
For Jan-Peter
Can you upload here the analog input schematic of the UcD400 as you have done for the UcD180?
Thanks in advance.
Can you upload here the analog input schematic of the UcD400 as you have done for the UcD180?
Thanks in advance.
Jan-Peter,
Have you done any bench test in regard to performance against temperature. Mattjk has mentioned his Zap's seem to perform better when they ran hot.
Have you done any bench test in regard to performance against temperature. Mattjk has mentioned his Zap's seem to perform better when they ran hot.
Chris,
We have done a temperature test, till 115oC (temperature of heatsink), everything was ok 😀
The UcD400 performs very well on the AP and has no problems with performace and temperature. Don't forget the UcD are having feeback after the outputchoke whereby the most other Class-D amps has feedback before the outputchoke......
So, no problem with probably more distortion by heating up of the outputchoke.
Regards,
Jan-Peter
We have done a temperature test, till 115oC (temperature of heatsink), everything was ok 😀
The UcD400 performs very well on the AP and has no problems with performace and temperature. Don't forget the UcD are having feeback after the outputchoke whereby the most other Class-D amps has feedback before the outputchoke......
So, no problem with probably more distortion by heating up of the outputchoke.
Regards,
Jan-Peter
With a perfect +-60 VDC source it should get you 225W in 8 Ohm (right?), but with the safety margins we need to have on an unregulated powersupply so that it doesn't exceed 60 VDC we'll probably end up closer to 50 VDC and only a little more than 150 W in 8 Ohm.
Jan-Peter: How's it coming with the cap replacement and change to over-voltage protection such that we can safely use transformers with 2x40 VAC secondaries?
Right now I'm trying to decide if the UcD400 is enough or if I can wait for the UcD700 (900?) 🙂
Jan-Peter: How's it coming with the cap replacement and change to over-voltage protection such that we can safely use transformers with 2x40 VAC secondaries?
Right now I'm trying to decide if the UcD400 is enough or if I can wait for the UcD700 (900?) 🙂
Hansen,
All caps on the UcD are rated for 100V. When you know your mainsvoltage you can probably go safe to 2x60VDC as an unloaded voltage. In my private home the mains is quit stable and goes from 225V to 235V. Our 500VA transformer gives you 56VDC by 230V mains.
2 times 40VAC must be safe.
You can remove two protectiondiodes, so you don't have the overvoltage protection. But you must definatly add a capacitor to avoid DC coupling.
We don't recommend this, so this idees are on your own risk.
Regards,
Jan-Peter
All caps on the UcD are rated for 100V. When you know your mainsvoltage you can probably go safe to 2x60VDC as an unloaded voltage. In my private home the mains is quit stable and goes from 225V to 235V. Our 500VA transformer gives you 56VDC by 230V mains.
2 times 40VAC must be safe.
You can remove two protectiondiodes, so you don't have the overvoltage protection. But you must definatly add a capacitor to avoid DC coupling.
We don't recommend this, so this idees are on your own risk.
Regards,
Jan-Peter