Does it already have two pins connected on each side?
Damn, I had notes here on the A-20's but can't find them, if all else fails Bill Fuss will be able to help on those.
I seem to remember some member posted that the A-20's sounded the best to him when he took out all the resistors, i.e bare A-20 between the dac output and the RCA's.
I think Bill recommended resistors in line with each of the primary legs of between 250ohms and 1k.
I found this by Bill, but I don't know if it is referring to the A-20's
Originally Posted by Bill Fuss View Post
I started with 270s on the primaries then tried 500 and 1k, I liked 500 the best, with a 500pf cap across the primaries. Secondaries straight to the output with a 1Kohm/.001uf RC filter across the jacks. Works for me, YMMV
I found this by Bill, but I don't know if it is referring to the A-20's
Originally Posted by Bill Fuss View Post
I started with 270s on the primaries then tried 500 and 1k, I liked 500 the best, with a 500pf cap across the primaries. Secondaries straight to the output with a 1Kohm/.001uf RC filter across the jacks. Works for me, YMMV
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Also found this
"First off, on the a20s do you have 3 connected to 4, and 9 connected to 10. You won't get anything if you don't.
Is your chassis properly grounded.
Whats the switch for, and are you sure it is wired correctly.
The RCAs should be isolated from everything but the a20s and not wired together, possible ground loop. "
I wish we had that guide up already 😉
Try reading the thread from this point.
http://www.diyaudio.com/forums/digital-line-level/137976-experience-diy-dac-131.html
"First off, on the a20s do you have 3 connected to 4, and 9 connected to 10. You won't get anything if you don't.
Is your chassis properly grounded.
Whats the switch for, and are you sure it is wired correctly.
The RCAs should be isolated from everything but the a20s and not wired together, possible ground loop. "
I wish we had that guide up already 😉
Try reading the thread from this point.
http://www.diyaudio.com/forums/digital-line-level/137976-experience-diy-dac-131.html
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Ive measured my dac too, but im using the monacor ltr-110, not the opamps:
Bild: 3t26n.jpg - abload.de
it doesnt look as linear as my m-audio but i think its not possible to hear the non-linear frequency response
Bild: 3t26n.jpg - abload.de
it doesnt look as linear as my m-audio but i think its not possible to hear the non-linear frequency response
Thanks for the plot.
The values below 40Hz seems to be due to the lower frequency limit of this tranny.
And upwards 10kHz: it is the perfect curve for my 54 years old ears, it does compensate my ears roll off...
This must be some ringing. Did you check a 1kHz square wave?
Franz
The values below 40Hz seems to be due to the lower frequency limit of this tranny.
And upwards 10kHz: it is the perfect curve for my 54 years old ears, it does compensate my ears roll off...
This must be some ringing. Did you check a 1kHz square wave?
Franz
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whats that and how to check that?
and btw: the curve is only +1 db, i think u cant even hear that curve
Hi,
I've a little experience with these things 😀. I've put together a basic structure based on your note, here;
DIY DAC - Your phrase here..
Hope this makes a good start!
Cheers
Chas
RichLund - thanks.
brianco - me too when it comes to web apps!
I have created an account, it does look a tad daunting. I will investigate this weekend. No promises!
Wow, my Jensens arrived!!! 🙂
After 5 weeks, from California to Holland....
Hope it will sound so good to compensate for the waiting.
And still had to pay 32 euro to the mailman 🙁
Will report soon...
After 5 weeks, from California to Holland....
Hope it will sound so good to compensate for the waiting.
And still had to pay 32 euro to the mailman 🙁
Will report soon...
The step up transformers have around 50k at the output: what do you suggest for matching? Or is there something I missed?
Wiki
Oops - sorry, I missed Chas' post. Big Boss Man was hovering at the time, I had snuck in to post a quickie.
THANK YOU Chas, that saves a whole lotta learning curve. Having that set up and being able to have a play makes it much easier to get to grips with.
Think I'll make a start on Computer Source this weekend.
Cheers
Oli
Oops - sorry, I missed Chas' post. Big Boss Man was hovering at the time, I had snuck in to post a quickie.
THANK YOU Chas, that saves a whole lotta learning curve. Having that set up and being able to have a play makes it much easier to get to grips with.
Think I'll make a start on Computer Source this weekend.
Cheers
Oli
It's the JT-11P-1.
Jensen shows a lot of specs on their webpage and they look like the best.
Maybe other trafo's are better but nobody shows all the specs so how do we find out????
Not connected yet, first the children needed their attention.🙄
Gigaworks DAC
Hi Guys,
Anyone please help me figure out a circuit to select inputs instead, of using those jumpers. A selector switch ? I have a LM DAC3 type.🙂
Hi Guys,
Anyone please help me figure out a circuit to select inputs instead, of using those jumpers. A selector switch ? I have a LM DAC3 type.🙂
Actually, it's more confusing than just looking at the trafo impedance rating. The resistor used as a load for the I/V conversion will determine the output impedance, and to make it more confusing, you can load either primary or secondary with appropriately sized resistors and get different sonic results. The load determines the actual output impedance. The load should be chosen by what the dac chip wants to see, and that will be reflected through the trafo at whatever ratio the trafo has.
You can just use a standard two pole four position rotary switch. You can even wire up an extra input to the unused input on the CS8416. Look at the data sheet for the info.
Just connected the Jensen and had a listen.
Although my ears are suffering from an small infection(?) its easy to hear the difference with the monacors.
The mids/highs sound less bright/hard and give more 'microdetails'. The bass sounds more integrated with the rest of the music and the acoustics/space are more clear with stability and depth.
Now back to listening and enjoying!
(No resistors and caps yet)
Although my ears are suffering from an small infection(?) its easy to hear the difference with the monacors.
The mids/highs sound less bright/hard and give more 'microdetails'. The bass sounds more integrated with the rest of the music and the acoustics/space are more clear with stability and depth.
Now back to listening and enjoying!
(No resistors and caps yet)