I'm finally getting around to building up a pair of UCD700 mono amps. I have all the parts and now I'm working on the case design. After looking at the UCD700s, I have a few questions.
1. What is the best orientation for the amplifier module? I'll be mounting it to the back of the aluminum case. My guess is to mount it sideways with the small PCB towards the bottom and the output inductor above. I think this should provide the best flow of cooling air past the module.
2. How should the 4 power supply wires and the 2 speaker wires that go to the faston connectors in the center of the module be routed? Just run them all together out the side of the module above the output inductor? Or route the power supply wires separate from the speaker wires? If so, where?
3. Would it be worthwhile to flip the power supply fastons on to the back side of the board? It would make the wiring much simpler and neater and I have plenty of room to do this, but I'm a little leary of damaging the PCB or unsoldering a couple of surface mount parts in the process. Any negatives otherwise to this idea?
4. The case will be roughly a 9" (225mm) cube. Is 1/8" thick aluminum adequate from a heatsink standpoint, or should I go to 1/4" material for the back plate?
Here's a picture to help in visualising what I'm talking about.
1. What is the best orientation for the amplifier module? I'll be mounting it to the back of the aluminum case. My guess is to mount it sideways with the small PCB towards the bottom and the output inductor above. I think this should provide the best flow of cooling air past the module.
2. How should the 4 power supply wires and the 2 speaker wires that go to the faston connectors in the center of the module be routed? Just run them all together out the side of the module above the output inductor? Or route the power supply wires separate from the speaker wires? If so, where?
3. Would it be worthwhile to flip the power supply fastons on to the back side of the board? It would make the wiring much simpler and neater and I have plenty of room to do this, but I'm a little leary of damaging the PCB or unsoldering a couple of surface mount parts in the process. Any negatives otherwise to this idea?
4. The case will be roughly a 9" (225mm) cube. Is 1/8" thick aluminum adequate from a heatsink standpoint, or should I go to 1/4" material for the back plate?
Here's a picture to help in visualising what I'm talking about.
Attachments
Hi GregD,
I'm at the same point you are in building two UCD700 based monoblocks. I've also gone through the same thought processes regarding the mounting. I had to smile when I read your idea about moving the Fastons to the back of the module. I had the same idea but decided it was too much of a mod to do at the outset.
I am using a 17"x10"x 4" Hammond aluminum chassis as a case. I am lining the bottom with a .125" aluminum plate for added stiffness and more thermal mass. The toroid main transformer mounts at one end of the case and the connectors come out the other end. There is a 1" aluminum angle mounted across the chassis next to the power transformer for more stiffening. The module will mount near the I/O connectors with the component side up using a 2"x2" aluminum angle thats cut to 1"x2" The 1" side mounts to the bottom of the case and the 2" side mounts to the ends of the T section on the module. I haven't decided on how long these angle sections should be. The aluminum angle was bought at the local Ace hardware store and cut with a table saw.
IMO the best way to mount the module from a thermal point of view is with the top of the T section mounted against a serious heat sink. I really don't like the thermal design of the UCD700. It is a step backwards from the UCD400. I figure they must have originally tried to build a bigger UCD400 style unit but for some unavoidable layout problems they had to flip the heatsink around. It certainly didn't make my day when they did that.
It's good to see someone alse actually building an amp with the UCD700. There have been surprisingly few projects or posts regarding this module considering all the anticipation of it's release a year ago, and considering as well the claimed improvements in sound over the UCD400. I guess the expense and added complication have put a lot of people off. Perhaps the UCD400 has enough power for most people.
Good luck with your project. I look forward to hearing about how your it turns out.
Cheers,
Graeme
I'm at the same point you are in building two UCD700 based monoblocks. I've also gone through the same thought processes regarding the mounting. I had to smile when I read your idea about moving the Fastons to the back of the module. I had the same idea but decided it was too much of a mod to do at the outset.
I am using a 17"x10"x 4" Hammond aluminum chassis as a case. I am lining the bottom with a .125" aluminum plate for added stiffness and more thermal mass. The toroid main transformer mounts at one end of the case and the connectors come out the other end. There is a 1" aluminum angle mounted across the chassis next to the power transformer for more stiffening. The module will mount near the I/O connectors with the component side up using a 2"x2" aluminum angle thats cut to 1"x2" The 1" side mounts to the bottom of the case and the 2" side mounts to the ends of the T section on the module. I haven't decided on how long these angle sections should be. The aluminum angle was bought at the local Ace hardware store and cut with a table saw.
IMO the best way to mount the module from a thermal point of view is with the top of the T section mounted against a serious heat sink. I really don't like the thermal design of the UCD700. It is a step backwards from the UCD400. I figure they must have originally tried to build a bigger UCD400 style unit but for some unavoidable layout problems they had to flip the heatsink around. It certainly didn't make my day when they did that.
It's good to see someone alse actually building an amp with the UCD700. There have been surprisingly few projects or posts regarding this module considering all the anticipation of it's release a year ago, and considering as well the claimed improvements in sound over the UCD400. I guess the expense and added complication have put a lot of people off. Perhaps the UCD400 has enough power for most people.
Good luck with your project. I look forward to hearing about how your it turns out.
Cheers,
Graeme
Hi Brian,
You are absolutely right. Very few speakers need more power than the UCD400 offers and multiple amps with line level crossovers are the way to go.
However, I have Magnepan MG3.6's and they really do need as much power as you can afford. These UCD700 mono's will be the bass amps in a bi-amp set-up I am building. I don't think it's overkill.
Cheers,
Graeme
You are absolutely right. Very few speakers need more power than the UCD400 offers and multiple amps with line level crossovers are the way to go.
However, I have Magnepan MG3.6's and they really do need as much power as you can afford. These UCD700 mono's will be the bass amps in a bi-amp set-up I am building. I don't think it's overkill.
Cheers,
Graeme
gl said:
In that case you may just be be better off with the 700s
Those speakers have quite the reputation... What kind of transformer and caps are you using to supply the modules?Greg - if you have to flip the fast on terminal to get a better layout then why not? It's very simple and shouldn't effect performance at all, provided you solder the terminal back on nicely.
Hi Brian,
I am using a 1000VA Hammond p/n 182R60 from Mouser for each amp. There is also a small 30V-0-30V toroid for the other supply voltages.
The filters are 10,000uf/100V Panasonic TS types - four for each rail. The diodes are IXYS soft recovery types that I've used before and like. I don't remember the part number offhand. I intend to experiment with a CLC supply arrangement as well to see if that makes an improvement.
Cheers,
Graeme
I am using a 1000VA Hammond p/n 182R60 from Mouser for each amp. There is also a small 30V-0-30V toroid for the other supply voltages.
The filters are 10,000uf/100V Panasonic TS types - four for each rail. The diodes are IXYS soft recovery types that I've used before and like. I don't remember the part number offhand. I intend to experiment with a CLC supply arrangement as well to see if that makes an improvement.
Cheers,
Graeme
GregD said:
Hi,
The only way of mounting the UcD700 is to put them down on an heatsink, whereby the solder side becomes visible. Or sideways with the small Modulator PCB on bottom and the output inductor above.
You can run the cables just between the heatsink/mounting plate and the component side. Is no problem at all to have all wires very closes with each other, of course you could replace the fastons to the other side, but be careful with the small SMD!
1/8” thick aluminium will be fine.
gl said:
It’s indeed less easier mounting as the UcD400….but we have done this to make the EMI as low a possible.
For the most people the UcD400 is sufficient, but for lower impedance loudspeakers or at higher volumes the UcD700AD is the way to go!
We have some PA customers who use 4 of the UcD700 in a two-two bridge configuration for a 2500W subwoofer…
Regards,
Jan-Peter
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