Chris,
This is the way I'll assy the amp.
http://www.grotel.nl/photo/wiring scheme class d stereo3.jpg
This is the way I'll assy the amp.
http://www.grotel.nl/photo/wiring scheme class d stereo3.jpg
Regarding the bass frequency there's any consensus over the most suitable IC buffer, 5532, AD8620, OPA627, OPA2134 anything else?
Just finished the amp. for the biggest part and here is the picture of it.
Still have to make a pcb for the protection circuit psu. It is done now by a wirewrap holding the small transf.
Grounding is done like the diagram posted before.
Measuring wise the crosstalk figure now is even lower than the 1 transf. amp. design. Very hard to see anything(20khz) on the scope, it is in the noise somewhere. It is over -120Db anyway.
First impression by comparing(through an A/B switch) the sound to my 1 transf. 2 psu design shows no difference. But this has to be investigated more.
This unit has a total of 4 windings feeding 4 bridge rect.(MBR20100 16x). Used the original Hypex input cables.
Now the fun of testing it😀
An externally hosted image should be here but it was not working when we last tested it.
Still have to make a pcb for the protection circuit psu. It is done now by a wirewrap holding the small transf.
Grounding is done like the diagram posted before.
Measuring wise the crosstalk figure now is even lower than the 1 transf. amp. design. Very hard to see anything(20khz) on the scope, it is in the noise somewhere. It is over -120Db anyway.
First impression by comparing(through an A/B switch) the sound to my 1 transf. 2 psu design shows no difference. But this has to be investigated more.
This unit has a total of 4 windings feeding 4 bridge rect.(MBR20100 16x). Used the original Hypex input cables.
Now the fun of testing it😀
Bgt,
Stupid question perhaps... but wondering why you went for RCA inputs instead of XLR which are "recommended" on hypex wiring pdf?
Secondly, wondering if those heatsinks for the UCD amps are sufficiant?
regards and thanks for sharing the picture....
ssmith
Stupid question perhaps... but wondering why you went for RCA inputs instead of XLR which are "recommended" on hypex wiring pdf?
Secondly, wondering if those heatsinks for the UCD amps are sufficiant?
regards and thanks for sharing the picture....
ssmith
Nice 🙂
But...I can't help to ask...wouldn't it be better to organize the amp in the opposite way, c'est á dire, the TXs in front, then PS caps and then UCD modules next to the back plate, to make short signal and speaker wires?
Regards
M
But...I can't help to ask...wouldn't it be better to organize the amp in the opposite way, c'est á dire, the TXs in front, then PS caps and then UCD modules next to the back plate, to make short signal and speaker wires?
Regards
M
maxlorenz said:Nice 🙂
But...I can't help to ask...wouldn't it be better to organize the amp in the opposite way, c'est á dire, the TXs in front, then PS caps and then UCD modules next to the back plate, to make short signal and speaker wires?
Regards
M
Cooling/airflow for the amps. Thats the only reason. This way it stays very cool even after having it at high volume on a hot day for many hours.
ssmith said:
I use asymmetrical inputs so whats the use of XLR's?
RCA is more common so easier to use.
Chassis question?
Bert,
I guess the vented panels couldn't be reversed to put the amps near the rear panel but what about the front and rear panels, could they be swapped? I too would like to see all that wiring shortened up.
Roger
Bert,
I guess the vented panels couldn't be reversed to put the amps near the rear panel but what about the front and rear panels, could they be swapped? I too would like to see all that wiring shortened up.
Roger
Re: Chassis question?
Roger, there are folded edges on the top and bottom plate so swapping them would make the housing look terrible.
And it surely made no audible difference the way the cabling is now. Tried this last year already when I first started with the UCD's.
sx881663 said:
Roger, there are folded edges on the top and bottom plate so swapping them would make the housing look terrible.
And it surely made no audible difference the way the cabling is now. Tried this last year already when I first started with the UCD's.
Re: Re: Chassis question?
Hi Bert,
I can only echo the others concerns about your layout. I do not believe crosstalk is your only concern. Power supply harmonics WILL not might couple into your wiring with this layout.
The effects of this are unpredictable but are certainly not desirable..
All I can say is that IMO you are not maximising the potential of your amplifier this way and in fact nowhere near it.
A suggestion re the case- why not drill some holes for ventilation?
The way it is the case is determining your layout for the worse.
Regards,
Rob.
Bgt said:
Hi Bert,
I can only echo the others concerns about your layout. I do not believe crosstalk is your only concern. Power supply harmonics WILL not might couple into your wiring with this layout.
The effects of this are unpredictable but are certainly not desirable..
All I can say is that IMO you are not maximising the potential of your amplifier this way and in fact nowhere near it.
A suggestion re the case- why not drill some holes for ventilation?
The way it is the case is determining your layout for the worse.
Regards,
Rob.
i'm using the same chassis as BGT and i've done it like in the pic attached.
The panels can be reversed. In fact, i'm not sure what the "right" way is.. The top and bottom panels have small folded edges at one side. The rear of the top panel rests on the backpanel of the case so i guessed the folded edges were there to provide some rigidity at the front. If you put some weight on the non-folded edge is bends easily. With the edges, it doesn't.
And, contrary to what bgt says, it doesn't look terrible, or at least, that's what I think.
And yes, i too still have to wire in the second softstarter and clean up some wires. I thought i'd work on the psu first but ... well, as of yet I haven;t 🙄
I was planning on making a nice little pcb for it and integrate a small psu for the opamps on it.
The panels can be reversed. In fact, i'm not sure what the "right" way is.. The top and bottom panels have small folded edges at one side. The rear of the top panel rests on the backpanel of the case so i guessed the folded edges were there to provide some rigidity at the front. If you put some weight on the non-folded edge is bends easily. With the edges, it doesn't.
And, contrary to what bgt says, it doesn't look terrible, or at least, that's what I think.
And yes, i too still have to wire in the second softstarter and clean up some wires. I thought i'd work on the psu first but ... well, as of yet I haven;t 🙄
I was planning on making a nice little pcb for it and integrate a small psu for the opamps on it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Good. It was easier than I thought. 😉
To go on with unsolicited advices...
Dear Matjans, you are one step appart from true monoblocks 🙂
Have you measured your output inductor's Tº?
I believe they will run cooler with vertical orientation of UCD's PCB, to benefit from convective air flow.
Oops! maybe i shouldn't have said that 😀
Best regards.
M.
PS: I wish my own amps look half as neat as yours!
maxlorenz,
they get pretty hot -as in impossible to touch for more than a few seconds- but the current "psu-board" sticks out a little underneath the ucd modules (not really visible in the pictures). When (and if?) I go about making a new PSU I'll try to mount them vertically.
Sander Sassen from hardwareanalysis.com is currently building a new ucd400 amp & supply, of which he thinks very highly. I'm waiting for him to unveil his approach to the psu. Maybe we can persuade him to publish the details of his work over here too.
There's lots to learn on psu design for me...
they get pretty hot -as in impossible to touch for more than a few seconds- but the current "psu-board" sticks out a little underneath the ucd modules (not really visible in the pictures). When (and if?) I go about making a new PSU I'll try to mount them vertically.
Sander Sassen from hardwareanalysis.com is currently building a new ucd400 amp & supply, of which he thinks very highly. I'm waiting for him to unveil his approach to the psu. Maybe we can persuade him to publish the details of his work over here too.
There's lots to learn on psu design for me...
Matjans,
where did you find the integrated power inlet+fuse holder+switch and what was the name/manufacturer/reference? It is very neat.
I am about to start building two enclosures each with 3 trannies, one UcD400 and two UcD180 like the ones Mac had built.
Guy
where did you find the integrated power inlet+fuse holder+switch and what was the name/manufacturer/reference? It is very neat.
I am about to start building two enclosures each with 3 trannies, one UcD400 and two UcD180 like the ones Mac had built.
Guy
I have found a similar Power Entry Module at Mouser, with in addition the parallel/series 110v/220v selection 592-PS0SXDBX0 (Corcom PS0SXDBX0). Thanks for showing your beautiful implementation. 🙂
I wonder what power caps you are using (just saw on your web they are BHC sitfoils)? I will be using Solen 6.2uf polyproplene bypass caps on my Cerafine PS caps. I guess BHC T-networks 4-poles would sound perfect without bypass but they are expensive.
Guy
I wonder what power caps you are using (just saw on your web they are BHC sitfoils)? I will be using Solen 6.2uf polyproplene bypass caps on my Cerafine PS caps. I guess BHC T-networks 4-poles would sound perfect without bypass but they are expensive.
Guy
Redoing the internal setup so the amps will be at the rear end of the housing. Matjans opened my eyes on how the housing should be used. How smart 
can a person be(I mean me)? Show a pic. later on
can a person be(I mean me)? Show a pic. later onBgt said:Redoing the internal setup so the amps will be at the rear end of the housing. Matjans opened my eyes on how the housing should be used. How smart
While you're at it, how are the amps wired? I know you went with an extra transformer ETC... alot more money, but the added complication must still be addressed accordingly, both physically in the layout as you see, and right down to internal grounding structure. For instance are you still using ground lift resistors on your shields? The goal is to DC couple and eliminate any type of ground lift or even too big a loop that will allow voltage to appear across the common reference point of the channels.
These amps are capable of extreme holography, I've achieved it a few times with just a single supply, center tap configuration and plain caps ... if you consider cerafines plain caps.
The answer is always in the grounding.
BTW, you're one step away from true monoblock construction... the point of which would be the extra physical distance between all components of each channel. This should stress layout as a concern.... but while you're at it, how would you ground them if you in fact had two cases? Would it change how they've been grounded at all?
The UCD's are almost creepy in that they're they can be wired many number of ways, and not have any hum or heterodyning, but whether or not they sound flat and lifeless or holographic and musical is all in the grounding.
I'd have concentrated on getting it right with a single transformer before adding another and complicating it further, but you'll know when you've gotten it right, without question, your jaw will drop.
classd4sure,
what grounding scheme would you use when (like me) using a dual mono setup in one case?
/matt (back to salvaging my "data" partition 🙁 )
ps: bert, sorry voor het extra werk 😉
what grounding scheme would you use when (like me) using a dual mono setup in one case?
/matt (back to salvaging my "data" partition 🙁 )
ps: bert, sorry voor het extra werk 😉
Classd4sure,
I grounded it like you told me. I've the drawing some posts earlier.
It is like the way Hypex recommends it to do. No groundlift resistors. Grounded at the rca's input. Don't use XLR's because it is assymetric.
It'll be a true dual monoblock design. Only the protection is common.
Matjans, the extra effort you've put me to is just nice. This way I can have a true design like nearly having 2 monoblocks.
Still greatfull you've showed me the pic. of your amp.
I grounded it like you told me. I've the drawing some posts earlier.
It is like the way Hypex recommends it to do. No groundlift resistors. Grounded at the rca's input. Don't use XLR's because it is assymetric.
It'll be a true dual monoblock design. Only the protection is common.
Matjans, the extra effort you've put me to is just nice. This way I can have a true design like nearly having 2 monoblocks.
Still greatfull you've showed me the pic. of your amp.
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