DIY Analog-to-Digital Converter project.Audio measurements tool

[Frex]

You wrote the answer.

Frex

[luvdunhill]

Would it be possible to get a bit more info on a few parts (perhaps part numbers which I can cross-reference datasheets with to make sure the parts are equivalent?):

S5
S4,S6
U17
RR1
L1-L6

Also, a few parts I'm having trouble finding substitutes, are these the only parts that will work in these cases?:

TR1
TR2
U13

Also, 10M .1% resistors with the specs listed seem hard to find as well.

Thanks!

[Valeriano]

Originally Posted by luvdunhill

Would it be possible to get a bit more info on a few parts (perhaps part numbers which I can cross-reference datasheets with to make sure the parts are equivalent?):

S5
S4,S6
U17
RR1
L1-L6

Also, a few parts I'm having trouble finding substitutes, are these the only parts that will work in these cases?:

TR1
TR2
U13

Also, 10M .1% resistors with the specs listed seem hard to find as well.

Thanks!

Hello Luvdunhill,

I completed mine a couple of days ago.. I sourced everything from mouser and farnell except APEM miniature switches which are available only at RS.

here we go:

RR1 mouser ref. 858-BCN164A473J7
U17 mouser ref. 549-C3391-24.576
L1-L6 mouser ref. 70-ILHB1812ER601V
TR1-TR2 mouser ref. 771-BSS123-T/R
U13 farnell ref. 1225776 (newark in US)

S5 RS ref. 664-294
S4,S6 RS ref. 132-3067

please note: R49 and R50 values are swapped, those resistors are used for setting lt1763 output which should be 5V (see schematic and datasheet)

pay attention to lower mounted leds, terminals may touch BNC metal shells on the other side of the pcb.. It took me headaches to discover this problem on mine..

happy building..
regards
Vale

[Frex]

Hello luvdunhill and thank to Vale for his answer.
I complete below with mine.

S4,S5,S6 are APEM toggle switches.
S5 is a 3 stable positions inverter right angle PCB mount, APEM
ref:TL39WW050(Radiospares 664-294)
S4 and S6 are a 2 positions astable right angle PCB mount, APEM
ref:TL32WW050(Radiospares 132-3067)


About the oscillator U17, it have a dual PCB pattern to allow use of standard IQXO70(SMD) or DIP8( through hole) oscillators.
You can use any 24.576MHz oscillator using one of these pattern (working
with 3.3V supply).

RR1 is a standard quad resistors array in 1206 package.
Any value between 10k to 100k is ok.

L1..L6 are chock inductors. These parts are used to attenuate high frequency noise.
If you don't find the exact reference in the BOM, you can use others type.
It is not very critical.
(Note that if you omit all and replace them by short circuits, the ADC will
work too...)


TR1 or TR2 are a SPDIF transformers.
The SC947-02(TR1) is high performance version but it is hard to find and
expensive.
You can use a DA101MC(TR2), it's a Murata low cost transformer that you can
easily find to your reseller.
Both work perfectly.(Farnell 132-2401 // Mouser 580-DA101C).
(If you are not able to get any of these, you build yourself the transformer
with small ferrite toroid and
some turns of copper wire.)

For the 10M resistor,the precision in the BOM is a mistake.
You can use 1% or 5% value without any problem.
Just use metal film type, no carbon(high noise).



Note too that a DIYers has inform me of an error:

The resistor R49 and R50 are inverted.
For proper work you should use;
R49=750 Ohms (but no 249)
R50=249 Ohms (but no 750)

Regards.


Frex

[Valeriano]

Originally Posted by Valeriano

TR1-TR2 mouser ref. 771-BSS123-T/R

sorry. this part no. is for T1 and T2 on BOM. my mistake.

as correctly stated by Frex, TR1 and TR2 are spdif transformers.

I used murata da101c which is through hole part.. simply bend the terminals to adapt it for smt mounting. da101mc which is the smd part is not available at mouser.

regards
Valeriano

[luvdunhill]

Thanks!

The only remaining question is the 10M .1% resistor. I cannot find anything in this tolerance, is this important?

[noSmoking]

It's a 10 meg at 1% I don't think they make .1% ,,,,correct me if I'm wrong!

[noSmoking]

BTW has your board arrived yet?
Mine has not.....

[jackinnj]

Originally Posted by noSmoking

It's a 10 meg at 1% I don't think they make .1% ,,,,correct me if I'm wrong!

Caddock make 10M in 0.01% and 0.02% but they are around $20 each.

[AR2]

I am happy to report that, today, my board showed up im my mail box! Frex has sent this board on Dec.15th, by the date on custom's label. Stamp shows 2011, but exact day I cannot read. So the package left France most likely some 21 days after it was sent. Now that I am remembering, the same thing happened to me with parcel from France a few years back. I do not mind as long as if arrives. This one came in a very good shape and it looks good.

Thank you Frex!

Like I mentioned before, now in my collection from you, I am missing DAC