*** The DIY Audio Thread ***

[Kanifee]

I was thinking along the lines of the input/output shorted with ground or some sort of interference from ground

 

[ChrissyT88]

Just a quick question...

I got my dantimax kit the other day - its all assembled, and to me the soldering looks good. But the wretched thing doesnt work... Essentially, its a relay based 64 step attenuator, currently set up as a 50k attenuator. There is one part of the assembly i am not sure about - i need to load the attentautor with an extra pair of resistors to match the input of the poweramp (the amp6 basic). In order to work out the value i need, i need to know the input impedance of the amp6. Im not 100% sure what this is - is it the value of the input resitors (ie 22k), or is it something completely different...?

 

[p4radox]

Any chance of a circuit diagram?

You might be able to measure it simply by using a multimeter on the input with the amp powered on.

 

[ChrissyT88]

I'll upload some images tomorrow, along with some of the details from the manual. My lack of knowledge is crippling me on this one. I should have done it in the original post but I didn't think... Tbh I'd had enough of it for today. Won't have much time in the next few days, so maybe a day or two off may help!

 

[waso_dude]

I want to do something like this.

What do people think is the best kit to start with?

Soldering ect isn't a problem for me i have a Btec in electrionics

Just want something that i can use from the optical on my p5k or from my X-Fi, what ever will give the best output.

Cheers

 

[gurusan]

If you want to build your own DAC the Alien DAC is pretty good http://www.myexposition.com/diy/usbdac/overview.html

but not only is the SMD soldering a bit tricky but it's also for portability and is outperformed by the assembled china kit we've all been working with.

and for a headphone amp most people start with the cmoy because it's cheap, simple, and just basically a good starting point. After that I hear people recommending the SOHA.....I went for the Millet Starving Student because I managed to get a kit with everything I need...and it's supposed to sound decent with HD580/HD600s too.

 

[ChrissyT88]

Ah.. nothing like a bit of sleep and clear head to make you realise what an idiot you have been! I read through the assembly instructions again this morning and looked at the schematic (its awful... it really is....) and realised i had put two jumpers in where they were not needed, creating a nice short to ground on the output of the attenuator. Still, nothing a few snips with wire cutters couldnt fix. I now havw to move on to the (possibly much harder to solve) problem of the LCD display not working. Anyone have any experience with either DEM16216 or DEM16217 displays...?

 

[MikeHunt79]

I want to do something like this.

What do people think is the best kit to start with?

Soldering ect isn't a problem for me i have a Btec in electrionics

Just want something that i can use from the optical on my p5k or from my X-Fi, what ever will give the best output.

Cheers

The chinese DAC would be fine... It does need modding to reach 96k, so you'll be able to to do a little soldering at least.

 

[gurusan]

Finally completely done with the CMOY....just had a few little upgrades to do just changed my rail splitter to a lm741 buffered little power thingy Also changed out the input caps to 3.3uF for a 4.8Hz -3db point and bass is punchier and more defined. listening to Dire Straits FLAC rips and it sounds amazing.

On my next build I'm going to attempt to organize my wiring a little better lol

 

[waso_dude]

The chinese DAC would be fine... It does need modding to reach 96k, so you'll be able to to do a little soldering at least.

Anyone feeling free to link me up what i neeeed

I'm a proper noob at all this audio stuffff

 

[gurusan]

just search for "DAC kit" on a certain auction site

 

[waso_dude]

anything else i need to go with this?

This will give me a optical/USB input to a co-axal?

 

[MikeHunt79]

anything else i need to go with this?

This will give me a optical/USB input to a co-axal?

Get the one with the transformer, and they'll send you everything you need to get it up and running.

It has optical and co-ax inputs, but no USB.

 

[gurusan]

you will also need a 50k pot and a headphone jack if you want to use the onboard output stage to drive your headphones (not tried this so don't know how good it is), along with the appropriate coupling caps ...or you can build a separate amp and bypass the DAC output stage.

 

[p4radox]

you will also need a 50k pot and a headphone jack if you want to use the onboard output stage to drive your headphones (not tried this so don't know how good it is), along with the appropriate coupling caps ...or you can build a separate amp and bypass the DAC output stage.

A 50k pot will need to be quad gang to use between the DAC and the output stage, and a dual gang one after the output stage won't work very well. Coupling caps aren't really needed in either case.

 

[gurusan]

well without the coupling caps I get 2.5V dc going through the outputs...

 

[adamau5]

chaps -

the onboard output stage is not designed to drive low impedances.

 

[p4radox]

well without the coupling caps I get 2.5V dc going through the outputs...

Ah, sorry. I was forgetting that I'd repopulated the output stage.

 

[gurusan]

chaps -

the onboard output stage is not designed to drive low impedances.

ok then. ignore what i said before lol

Its just that in the instructions it says something about a 50k pot?

 

[adamau5]

yes, it can drive a large impedance (easier - doesnt need to pass as much current).

good old ohms law.

In the same vein, the cmoy isnt designed to drive high impedances e.g. 50k inputs.