To clear a few things up,
The DIYinHK board came with 150uf caps for both noise reduction caps, they should really have a value ratio of 1:10 and shouldnt be that high, a trace got damaged when replacing these caps and one NR cap wasnt actually connected, this is what was causing the distortion of passive IV seen in post 179.
It was the other, undamaged channel being measured in post 180 when it gave that low distortion.
after fixing the trace both channels now look like that.
Also The DIYinHK board has spares pads for each pin, but it turns out for spare pads at the MSB trim pins arent connected to anything. Still, noise is probably too high in the ADC to trim it anyway.
The DIYinHK board came with 150uf caps for both noise reduction caps, they should really have a value ratio of 1:10 and shouldnt be that high, a trace got damaged when replacing these caps and one NR cap wasnt actually connected, this is what was causing the distortion of passive IV seen in post 179.
It was the other, undamaged channel being measured in post 180 when it gave that low distortion.
after fixing the trace both channels now look like that.
Also The DIYinHK board has spares pads for each pin, but it turns out for spare pads at the MSB trim pins arent connected to anything. Still, noise is probably too high in the ADC to trim it anyway.
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you trimmed diyinhk board and not mine? 😀 diyinhk capacitors are not in 1:10 ratio and they have to be, another thing is that there is an active filter after the I/V output, it is dual opamp of which 1/2 is working as an active filter, it significantly affects the sound (for the worse), I do not recommend that filter
Just put pcb to print.. [emoji846][emoji846] few days to get them...
Need to buy the AD1862 chips..
Anyone as some in europe?
Any reliable seller?
Need to buy the AD1862 chips..
Anyone as some in europe?
Any reliable seller?
Pistollero, did you print the board in Europe ? If yes may you please send me the link & price ?
Thanks... ah Asia is always a little bit long... I'm still waiting the AD1862 I ordered from the Middle Empire !
Last time I checked JLC are offering some different DHL service from covid, took only 7 days to delivery and only a bit more expensive than china post.
And there is no import charges according to the description.
Its true, 100 euro order arrived a few weeks ago with no custom fee.
Dont know how or why but no complaints.
And there is no import charges according to the description.
Its true, 100 euro order arrived a few weeks ago with no custom fee.
Dont know how or why but no complaints.
almost impossible in the EU (only if you buy a broken CD-player and pulled them out)
china source is fine or Rochester (pricey 🙄) because they are obsolete for a long time, I recommend China because of the low price - AD1862N from china is genuine without a doubt, old stock or something
I recommend to stock a few AD1862 at home 😀
Hi,
Which opamp could be a good substitute of OPA627P? It's a bit expensive....
There is an opamp that could fit in this design with good hifi result on around 10$/unit?
thanks
Which opamp could be a good substitute of OPA627P? It's a bit expensive....
There is an opamp that could fit in this design with good hifi result on around 10$/unit?
thanks
go with LM6171 or ADA4898-1 (needy an adapter)
be sure you get them from a trusted source, not china 😀 for opamps it is different story 🙂
be sure you get them from a trusted source, not china 😀 for opamps it is different story 🙂
By increasing IV resistor to 5k now there is something usable 🙂 and with plenty of headroom to increase gain further, ADC noise is still dominating.
Hi, I’m a beginner so it’s quite difficult follow this thread ... could you explain a little bit these results? Are the equivalent of the SINAD test on Audiosciencereview?
So this board has more or less 108db sinad and a 0,3%THD (it’s quite high, it isn’t?)?
You have to test audio with ears not scopes. You ear music with your ears, you do not measure music.
Trust your ears.
Your ears must be tool to judge.
I think people can't trace the distortion below 1% with ears ... the speakers have a fairly high distortion (5% and more?), another distortion takes place in the ear ... so additional 0.00xxx or how deep are people looking is not beneficial ...
the biggest change in sound will be brought by a change in the topology with which the IMD changes, which no one measures anymore 😀
IMD is 100x more critical than a simple THD, difficult to measure, this is why different topologies of amplifiers with the same THD and noise sounds differently .... IMD is also formed in the components themselves (for example, a type of dialectic in capacitors)
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