AMB Laboratories DIY Audio

[thomaspf]

My first post here so go easy.

I have a question on how to mount the 4 DN2535 onto the heatsink. Do I have to isolate the thermal pad against the heat sink with an isolation mounting kit?

Cheers

Thomas

[amb]

Those devices have individual heatsinks and they "float", so a thermal pad and/or mounting kit is optional. You can mount the devices directly with a little bit of heatsink compound.

[thomaspf]

Just to be sure on the meaning of the word float.

If I solder the heatsinks to the PCB they are connected but electrically float? I tried to figure out whether the heatsink holes on the PCB are connected to anyhting and they do not appear to but I want to be sure.

Another way to float them is to turn the heatsink by 90 degrees and only solder in the DN2535?

Thanks

Thomas

[amb]

Just to be sure on the meaning of the word float.

"Float" simply means that board holes for the heatsinks are not electrically connected to anything.

Another way to float them is to turn the heatsink by 90 degrees and only solder in the DN2535?

Not sure what you mean by that.

[nattonrice]

He means turn the pins of the sink towards the sky.

The board is not tight at all.
But if you're still worried about difficulties with changing out damaged devices at a later date just use socket cap screws so you can use an allen key.

I think the peace of mind knowing the sinks are secured outwieghts the cons.

[thomaspf]

I just send the drawings for the 4U dissipante case to Hifi 2000

https://skydrive.live.com/redir.aspx?cid=9798175bc4b358d7&page=play&resid=9798175BC4B358D7!1075

Cheers

Thomas

[thomaspf]

I am planing to diverge from the reference build and so in addition to the two σ22 supplies for each channel I am awaiting the delivery of two 800W switched power supplies. Supposedly these switchers have very low emissions which I will have to verify.

SMPS800R.jpg

I also uploaded some progress pictures of the populated boards under the link in the previous post.

Cheers

Thomas

[thomaspf]

Here is hte rear panel

case icon.jpg

I am waiting for the SMPS modules and toroids to finalize the internal layout before I can start working on cutting the threads into the heat sinks.

Cheers

Thomas

[amb]

Hmm, digital inputs. Are you going to put a DAC in there? How would you control the volume? Only in software?

[thomaspf]

MCU via an I2C link to the DAC. Controlled via a remote control.

My previous project was similar except for a less sophisticated power amplifier and only a single USB input. Planned DAC is a Buffalo II with an IVY-III

https://skydrive.live.com/redir.aspx?cid=9798175bc4b358d7&page=play&resid=9798175BC4B358D7!1057&authkey=6PbuCUBo!s8%24

Sounds like you are surprised by the approach? What would you suggest?

I build 2 similar DACs with digitally controlled analog resistor networks and it is not so clear to me that the digital volume control in Sabre ESS9018 gives much to those.

Cheers

Thomas