Jambo DAC - DIY USB/Optical/Coaxial DAC kit now available!

Jambo · 4th July 2008, 10:30 AM

Hi everyone,

I've mentioned this a few times on here and those that are members of head-fi will already be aware of it... But my DAC kit is now available.

The block diagram is shown below:

An externally hosted image should be here but it no longer works. Please upload images instead of linking to them to prevent this.

It has 4 inputs (USB, Coax and Optical x2). These are selected by a microcontroller talking to a WM8805 which converts SPDIF to I2S. The DACs are two WM8740s in dual mono configuration. The board also supports the WM8741 if you can get hold of some.

Output filters are built around AD797, but the opamps are socketed so you can play around with whatever single opamps you fancy.

Here's a pic of a completed board:

An externally hosted image should be here but it no longer works. Please upload images instead of linking to them to prevent this.

Note that the main supply caps are taller than what comes with the kit.

The price for the kit is £85, with shipping at £4 UK, £7 Europe, £10 ROW.

Note that a power supply is required, as are switches and LEDs to change source and indicate the currently selected source. The HID switches on the PCM2706 are currently not working but I think that is a software issue.

Let me know if you have any questions.

Cheers

Jamie

TriLithium · 4th July 2008, 07:24 PM

This is a very interesting kit indeed. What are the physical measurements of the board if I may ask (incl. height).

Jambo · 5th July 2008, 01:16 AM

Of course... The PCB is 5.5 x 4 inches approximately and the tallest component in the kit version is the dual RCA socket which is (according to the datasheet) 26.5mm tall - meaning the complete assembly will be no more than 30mm tall.

I hope this answers your questions.

tinears02 · 5th July 2008, 02:59 AM

Can it read from a thumb drive or does the
Jambo dac operate in slave mode only with
usb input?
I ask because I saw the ucontroller thought
perhaps the dac can now be used as
master and an external usb device as a
slave.
I'd like to play wav files in the usb drive thru
the dac.

tinears

Jambo · 5th July 2008, 11:28 AM

tinears02 - I'm afraid that the USB functionality is slave only - it connects only to a PC. I did actually think about doing what you suggest using devices from FTDI but I didn't need the functionality myself and wasn't sure how popular it would be.

I also meant to mention in my first post that the kit will come with the microprocessor soldered and programmed as I can appreciate that this is a hassle for many people.

Jambo · 1st August 2008, 06:16 PM

Hope nobody minds too much if I bump this - hoping to sell all of the kits before I move to Baku in September where I won't be able to offer as much support...

zigzagflux · 1st August 2008, 07:12 PM

Could you possibly provide a schematic, generic or specific, of the output stage? Would be interested in exploring direct-to-tube from WM8740 outputs.

Jambo · 2nd August 2008, 04:46 PM

Hello zigzagflux, full schematics can be downloaded from the first post in the build thread which is located here: http://www.head-fi.org/forums/f6/jam...thread-344585/

It would be easy to extract the outputs directly from the DACs (prior to opamp filters) as they are all available on vias which are 0.7mm holes which can easily accept a wire. It may not look as neat as you would like, but it would work.

Any further questions let me know.

Jambo · 20th August 2008, 09:41 AM

Just to let anyone who's thinking about it know that I will only be able to supply these for one more week, then I'm moving abroad.

4th July 2008, 10:30 AM	#1
Jambo diyAudio Member Join Date: Jan 2008	Jambo DAC - DIY USB/Optical/Coaxial DAC kit now available! Hi everyone, I've mentioned this a few times on here and those that are members of head-fi will already be aware of it... But my DAC kit is now available. The block diagram is shown below: An externally hosted image should be here but it no longer works. Please upload images instead of linking to them to prevent this. It has 4 inputs (USB, Coax and Optical x2). These are selected by a microcontroller talking to a WM8805 which converts SPDIF to I2S. The DACs are two WM8740s in dual mono configuration. The board also supports the WM8741 if you can get hold of some. Output filters are built around AD797, but the opamps are socketed so you can play around with whatever single opamps you fancy. Here's a pic of a completed board: An externally hosted image should be here but it no longer works. Please upload images instead of linking to them to prevent this. Note that the main supply caps are taller than what comes with the kit. The price for the kit is £85, with shipping at £4 UK, £7 Europe, £10 ROW. Note that a power supply is required, as are switches and LEDs to change source and indicate the currently selected source. The HID switches on the PCM2706 are currently not working but I think that is a software issue. Let me know if you have any questions. Cheers Jamie

5th July 2008, 02:59 AM	#4
tinears02 diyAudio Member Join Date: Sep 2003 Location: earth	regarding the usb input Can it read from a thumb drive or does the Jambo dac operate in slave mode only with usb input? I ask because I saw the ucontroller thought perhaps the dac can now be used as master and an external usb device as a slave. I'd like to play wav files in the usb drive thru the dac. tinears

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4th July 2008, 07:24 PM	#2
TriLithium diyAudio Member Join Date: Oct 2004	This is a very interesting kit indeed. What are the physical measurements of the board if I may ask (incl. height).

5th July 2008, 01:16 AM	#3
Jambo diyAudio Member Join Date: Jan 2008	Of course... The PCB is 5.5 x 4 inches approximately and the tallest component in the kit version is the dual RCA socket which is (according to the datasheet) 26.5mm tall - meaning the complete assembly will be no more than 30mm tall. I hope this answers your questions.

5th July 2008, 11:28 AM	#5
Jambo diyAudio Member Join Date: Jan 2008	tinears02 - I'm afraid that the USB functionality is slave only - it connects only to a PC. I did actually think about doing what you suggest using devices from FTDI but I didn't need the functionality myself and wasn't sure how popular it would be. I also meant to mention in my first post that the kit will come with the microprocessor soldered and programmed as I can appreciate that this is a hassle for many people.

1st August 2008, 06:16 PM	#6
Jambo diyAudio Member Join Date: Jan 2008	Hope nobody minds too much if I bump this - hoping to sell all of the kits before I move to Baku in September where I won't be able to offer as much support...

1st August 2008, 07:12 PM	#7
zigzagflux diyAudio Member Join Date: Oct 2006 Location: Charlotte, NC	Could you possibly provide a schematic, generic or specific, of the output stage? Would be interested in exploring direct-to-tube from WM8740 outputs.

2nd August 2008, 04:46 PM	#8
Jambo diyAudio Member Join Date: Jan 2008	Hello zigzagflux, full schematics can be downloaded from the first post in the build thread which is located here: http://www.head-fi.org/forums/f6/jam...thread-344585/ It would be easy to extract the outputs directly from the DACs (prior to opamp filters) as they are all available on vias which are 0.7mm holes which can easily accept a wire. It may not look as neat as you would like, but it would work. Any further questions let me know.

20th August 2008, 09:41 AM	#9
Jambo diyAudio Member Join Date: Jan 2008	Just to let anyone who's thinking about it know that I will only be able to supply these for one more week, then I'm moving abroad.