AudioSector-chip amp kits, dacs, chassis

[mikelm]

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How does it sound with the case on ?

You mentioned earlier that a wooden base was best.

[Peter Daniel]

Sure I prefer wood, but this one is easier to make. This is for AudioZone DACs, and it matches Amp-1 appearance. My personal unit is without any case, just resting on a piece of acrylic.

With a board in a metal case, the sound becomes a bit less open. Not a bigh difference, but still noticable.

[metalman]

Peter,

What method are you using to transfer the "DAC-1" lettering to the aluminum plate? Been trying to figure out how I'm going to get lettering on my pre-amp chassis!

Terry

[Peter Daniel]

I'm using dry transfer method and sheets with lettering can be bought at graphic supply outlets: http://www.diyaudio.com/forums/attac...amp=1032685651

[Peter Daniel]

Soon a new board will be available from AudioSector.com

It is a replacement for a previous parallel only LM4780 board. The new board allows all 3 configurations: stereo, bridged and parallel.

I'm testing it presently in a stereo version, and it sounds very good. The price of the new board will be $25, featuring as usually 2 amp channels, as well snubber option for PS. I will be also offering half of that board only (for half the price), allowing to build a stereo amp (like the one in a picture), using one LM4780 chip.

Copper spreader was used to improve heat release from a chip.

[Peter Daniel]

Here's a closer look at the complete assembly. 1000/50 caps are mounted directly to rectifiers board and that board is attached to amp's board using standoffs, forming a one piece module. 100/50 caps are mounted directly at the chip and all the connections are minimized.

[Hanzwillem]

Received the DAC kit on friday, immediately started soldering. Fairly easy job, only the SMD regulator was a bitch because I lost my tweezers. Everything checked, looked OK so plugged it in, but it remained dead silent . It appears I have a short between +UD and DGND, but I cannot trace it, everything looks ok, so probably I have a cap with a short or something...

The dales still measure 20 Ohms and the C3 is being charged 'properly' (too low voltage due to short). After two days of checking still can't find it... I hope tomorrow...

[Peter Daniel]

Check all the voltages first. You should have approx 10V between R1/R2 and R3/R4 and then check all voltages after the regulators: 5V in 3 places and 8V on a DAC chip. One of the Canadian customers already built the DAC and it worked fine. He actually had a problem with a fuse, but after replacing it, the DAC worked OK.

[Hanzwillem]

I've found the defect. UA was the proper 10V, UD=0V, at the trafo side of the dale resistors it was 11,5V. By disconnecting L3 and L4 and later the Oscon C15 I found I have a short between IN and GND of U1. I really cannot see a incorrect joint or malfunction in the PCB so my guess is that this unit is defective. I will try to locate an AN8005 at a local dealer to replace it. I hope that will solve the problem...

[BrianGT]

Originally posted by Hanzwillem
I've found the defect. UA was the proper 10V, UD=0V, at the trafo side of the dale resistors it was 11,5V. By disconnecting L3 and L4 and later the Oscon C15 I found I have a short between IN and GND of U1. I really cannot see a incorrect joint or malfunction in the PCB so my guess is that this unit is defective. I will try to locate an AN8005 at a local dealer to replace it. I hope that will solve the problem...

You might have heated up the regulator too much when soldering them to the pcb. I had a similar problem soldering small transistors to my original Mini-A layout, and eventually decided to just solder the TO-92 part on the SMD pads.

--
Brian