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DAC Kit - what else do I need?

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you could always take the spdif output of the mux - that'd probably be a bit easier. The cs8416 on the dac board is only accepting spdif input anyway I think.
 
I should point out that if you do not want USB or up-sampling then this one is avaliable:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=140391444680

There is no transformer with this version, so get this instead. R26-34 is the one:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=290411037999&rvr_id=&mfe=sidebar

I2S has been done by people on Diyaudio so is possible. Don't forget DIR9001 module is avaliable which may be better. I plan to get one of these and a PCM1794 DAC module which has a higher output apparently.
 
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Sam - with regard to your question on switchable Coax inputs, this is the answer I recieved on Diyaudio:

"You can convert all 4 inputs to coax if that's what you are after. The 4 inputs on the 8416 are identical, and you can use the jumper matrix for switching with a 2 pole 4 pos rotary switch. "

Hope this helps

Rich
 
Hi Colin.

Good to see another fan of this DAC. Not bad is it? Did you try any of the op-amp or transformer mods with it?

I have to be honest I haven't heard that many DAC's in my time and would love to hear a really high end machine. But compared to the Beresford, Cambridge and a M Audio DAC, this one is better in my opinion. Especially with UTC A-20 transformers. Lovely sound. When I listen to it I wonder how good do you need to get?
 
OK, DAC & OPA627 OpAmp mod. ordered and dispatched from the seller.

Wading through some of the other threads relating to this DAC it does seem as though going the transformer route will be the next logical step should I decide to upgrade in future. I don't yet understand how or why this works but no doubt I'll learn in the process.

I currently use a Lavry DA10 & it'll be interesting to compare the two. Assuming I manage to put the thing together...
 
Hi Tony,

I threw this kit together as my first diy project a few months ago. If you can solder it's really straight forward. The 627s are a great choice as the stock op amps are somewhat lacking in my opinion. I put Tamura GA80080 output transformers on mine which improved the DAC in terms of clarity and space but made the presentation a little restrained. Lots more tinkering to be done!

Good luck with the assembly.

Andy
 
Hi LoBo

Good to see another fan of this DAC. Not bad is it? Did you try any of the op-amp or transformer mods with it?

I have to be honest I haven't heard that many DAC's in my time and would love to hear a really high end machine. But compared to the Beresford, Cambridge and a M Audio DAC, this one is better in my opinion. Especially with UTC A-20 transformers. Lovely sound. When I listen to it I wonder how good do you need to get?

I used the standard toroidal transformer from snow48, i was tempted to improve the power supply but i may go for the Twisted pair Buffalo after i have finished bi amping my copy atc scm50 speakers with another avondale amp.
 
I'm expecting to receive my kit sometime this week & I'd like to get on and put it together, but I'm not sure what size of enclosure I'll need.

Would it be better to go for a "Full-size", i.e. approx. 43 cm wide/ 7 - 8 cm high, or a shoe-box (half-width) size, bearing in mind I want to fiddle around & upgrade it?

Also, is it best to get a metal or a plastic one?
 
Wow, that looks just the ticket! I shall order that very one, and many thanks for all the help you're giving me LoBo.

I assume the two big grey things are transformers? I believe that might be my next upgrade once I've made the DAC work.
 
The kit arrived this morning with the Op-amp upgrade in the package. Very fast service, everything packed well. Here's a photo of the bits laid out :-

DAC-1st.jpg


Everything's there except the case and the power lead, no need to solder anything. Even the two wires from the transformer which need to go into the same screw terminal are soldered together!

I elected not to go for the upsampling but I've marked where the module plugs in :-

DAC2-up-sampling-board.jpg


I haven't got the case yet so I've mounted the kit onto a bit of spare pine flooring with screws & spacers to hold it away. Plugged in and, by george, it works!:D

dac3-on-board.jpg


As I'm using the optical input from my iMac I had to change the jumper (marked) but other than that the other switches etc. were set correctly for non-upsampling operation.

Soundwise, it's early days but I'm seriously impressed. I currently use a Lavry DA10 & coming straight from that to the Gigaworks reveals no nasties, and a very strong bass performance.

I intend to run this in over a few days before swapping over the op-amps. It'll be interesting to make the comparison.

Thanks for all the help folks!:)
 
Excellent Tony. It seem you have a sexy blue version! They have been red and black previously. I like the blue...

The OPA627's are very good indeed you should notice the difference. Dont forget that LM4562 and LME49720NA are also very good and might give a presentation you enjoy more. Lots of tweaking to be done on this DAC. Do take time to read the other forum threads on improvements and let us know how you find it.

Rich
 
I decided to swap the op amps to the OPA627s yesterday & the DAC's been playing ever since. It's starting to really open out now, excellent bass definition & extension, clear, perhaps slightly strident top end, but overall very impressive!

Some more questions for you LoBo if you don't mind (well, you said I could ask ;)) I'm intrigued as to why you've presumably bypassed the op amps in your DAC & are using the transformers instead. The latter appear to be a very old design but presumably they give a better result? I found these on the internet yesterday -

http://www.audioupgrades.co.uk/burson.shtml

I know it's difficult to compare, but this appears to be a viable route to go down also (if the advertising is to be believed!) & looks more straightforward to implement to my uneducated eye.

Also, is it necessary to have those bright red LEDs illuminating the board? Do they serve any function, and would it be possible to snip them off, perhaps replacing just one with a green LED on long wires so I can lead it to a hole in the casing to show if the DAC's on or off?

Finally, at the moment to change inputs you have to move the jumper to the relevant position. Is it possible to solder a selector switch of some sort directly to those pins so you can just turn it to select different inputs?

I have been wading through the thread on DIY Audio but I confess to getting a bit lost as it wanders off in all directions, much of which I can't understand yet!

Thanks for your help in anticipation.
 
Hi Tony, no problem ask away...

To be honest when I first bought this DAC I didn't know about the output transformer upgrade. When I discovered the Diyaudio thread, I took heed and made the decision to try transformers to see what all the fuss was about. If I didn't like them, I could always sell them on. Well, I'm so glad I did because they sound brilliant.

Essentially the main purpose of an interstage audio transformer is to isolate the DC and couple the signal, with minimal loss. Valve amps and top flight mixing desks (primarily what the UTC A-20's were designed for) use this principle.

Here is an excerpt from the web explaining 1:1 output transformers:

"A unity transformer allows an audio signal to pass unmodified from the primary to the secondary while blocking DC voltage and radio frequency interference (RFI). Also, since the primary and secondary are insulated from each other, a unity transformer will electrically isolate different pieces of equipment. This can solve hum problems by isolating ("lifting") the grounds of different devices"

I guess it is a cleaner, simpler circuit than the dual op-amp circuit on the DAC. Although the DAC is well designed, some feel that op-amps are a compromise, considering production costs etc.

The Burson op-amps you linked to are supposed to be very, very good. However, as Martin Clark pointed out in a thread recently, there is no reason why a properly implemented IC op-amp should be any worse. It is a case of finding the right one for the circuit and ensuring the circuit is optimised for the op-amp. (For the same money you could get a nice pair of quality output transformers)

If you are really keen to try a discreete op-amp then these are loads cheaper and seem highly recommended. The 'Sun' dual model especially:

http://www.audiocominternational.co...ucts_id=134&osCsid=03sqdp5v1c4b1r8n8nh157tq31.

The LED's are part of the regulator circuit. So best to leave them in. I have removed one and have replaced it with a blue LED attached to flying leads to allow it to be inserted in the front panel as an 'On' indicator. The rest won't be seen if in a case.

As for the selector switch, you only have to move one jumper so a single pole switch will work. Hook the pole to the center pin and the switch positions to the outer pins. You could also use a SPDT toggle switch.

Hope this helps. I am no expert but have recieved loads of help so am glad to pass on the info.

Rich
 
Many thanks again for your invaluable assistance LoBo. I'll just let this settle down a bit & then perhaps go for the transformer. Fun, isn't it?
 
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