[Billyk]

Quote:

Originally Posted by m1abrams /img/forum/go_quote.gif Yep I ran into the same problem and the Toslink receiver is only available at Farnell. Tip - the case and the regulator are also at Farnell, so if you add a couple other items you can meet the $20 min. order at Farnell.

I may be confused... Tried Farnell all prices were in GBP so 20.00 GPB minimum order was $32.40 USD and shipping was like $25.00. A bit more than I can spend at the moment.

 

[m1abrams]

Quote:

Originally Posted by Billyk /img/forum/go_quote.gif I may be confused... Tried Farnell all prices were in GBP so 20.00 GPB minimum order was $32.40 USD and shipping was like $25.00. A bit more than I can spend at the moment.

Sorry yeah min. is 20 GPB not dollars, however I did not get $25 shipping. My shipping ended up to be about $5, my total order cost was $37 with shipping.

 

[amb]

Interesting, m1abrams. Good info, I didn't know that one could order directly from Farnell in the US. That's a great solution for both TORX147PL and TOTX147PL.

 

[ruZZ.il]

Group buy them for shipping with boards?

I haven't seen the BoM yet, but what's the source count on it? Any possibility to drop that count via AMB shop? Would go a long way for us abroad-ers.

 

[amb]

γ2 doesn't use either of these parts, but γ1 does. The optical receiver is not used in the γ1 Lite, and the optical transmitter is only used for USB-to-S/PDIF or full++ configs. This makes it unwieldy for me to include them with boards. Also, the optical receiver shortage is only temporary -- Digikey will restock them by late September.

 

[luvdunhill]

Quote:

Originally Posted by amb /img/forum/go_quote.gif Interesting, m1abrams. Good info, I didn't know that one could order directly from Farnell in the US. That's a great solution for both TORX147PL and TOTX147PL.

Just order them through Newark and pay the Farnell drop ship fee:

TOSHIBA|TOTX147PL|TRANSMITTER, FIBRE OPTIC | Newark.com

You may have to call to add the TORX147PL, but Newark will allow it to ship from Farnell.

 

[amb]

In case it's not obvious, since γ2 takes I²S as input, it could be used standalone (without γ1) with any source that outputs I²S. Just add a 5V regulated power supply (connect to VCC at either J1 or J5), connect the I²S.lines to either J2 or J4, and then short across JP1.

This would make an excellent upgrade DAC for CD player transports that output I²S., as an example.

Just another application idea for γ2...

 

[Mr.Duck]

Quote:

Originally Posted by amb /img/forum/go_quote.gif In case it's not obvious, since γ2 takes I²S as input, it could be used standalone (without γ1) with any source that outputs I²S.

It's obvious now that you mentioned it

It's good if you've got an I2S output already. But if not, would there be any advantage in NOT pairing gamma2 with gamma1?

 

[amb]

Quote:

Originally Posted by Mr.Duck /img/forum/go_quote.gif It's good if you've got an I2S output already. But if not, would there be any advantage in NOT pairing gamma2 with gamma1?

γ2 is designed specifically to pair with γ1, electrically and mechaincally. γ1 provides the 5V power, excellent input receivers for USB, coax and optical S/PDIF, and the whole thing fits neatly into an integrated package. I don't see any reason not to use a γ1 unless you already have an I²S source and a regulated 5V PSU. Since I²S is not usually an external interface, this would be a "specialty" application such as internal to a CDP.

 

[Lifthanger]

about the output caps. Just found some mundorf MKPs but with 3-5uF only.
It seems that the highpass at the output would have a corner frequency of below 2Hz with 3.3uF.

Is this usable, or is the input impedance of the next stage important, too?

also I'm not sure wether using this caps makes sense in the first place.

 

[amb]

Quote:

Originally Posted by Lifthanger /img/forum/go_quote.gif about the output caps. Just found some mundorf MKPs but with 3-5uF only. It seems that the highpass at the output would have a corner frequency of below 2Hz with 3.3uF. Is this usable, or is the input impedance of the next stage important, too?

Yes, the input impedance of the next stage is in parallel with R9/R16 and needs to be taken into account when computing the high-pass corner frequency.

Quote:

also I'm not sure wether using this caps makes sense in the first place.

The issue is not simply capacitance. Space is tight between the boards (when you plug the γ2 into the γ1. Also, parts on the two boards must not physically hit each other. As it stands, using the default/recommended parts, the two boards fit together like a jigsaw puzzle with not much room to spare. I doubt that the Mundorf can fit in there.

If you don't like electrolytic capacitors as output caps (even though "audio grade" ones are specified), and if your next stage has high input impedance (10K ohms or more), then you could omit C20/C26 and use 3.3uF 50V Wima MKS2 caps for C19/C25. That will fit.

 

[wiatrob]

Quote:

Originally Posted by amb /img/forum/go_quote.gif This would make an excellent upgrade DAC for CD player transports that output I²S., as an example.

Or a sound card for that matter - I've just been looking at modding two cards I have on the bench for I²S output. In fact, the y2 is compact enough to fit in the computer case - tho' I'd hate to pull the 5V from the computer power supply...

But I must resist any new projects!

 

[Lifthanger]

Quote:

Originally Posted by amb /img/forum/go_quote.gif Yes, the input impedance of the next stage is in parallel with R9/R16 and needs to be taken into account when computing the high-pass corner frequency. The issue is not simply capacitance. Space is tight between the boards (when you plug the γ2 into the γ1. Also, parts on the two boards must not physically hit each other. As it stands, using the default/recommended parts, the two boards fit together like a jigsaw puzzle with not much room to spare. I doubt that the Mundorf can fit in there. If you don't like electrolytic capacitors as output caps (even though "audio grade" ones are specified), and if your next stage has high input impedance (10K ohms or more), then you could omit C20/C26 and use 3.3uF 50V Wima MKS2 caps for C19/C25. That will fit.

thanks amb, really appreciate this. the next stage will (of course

) be one of your amps with 50k impedance on the input, so it should be fine.

honestly, I haven't got a clue about which caps I like, this was rather an informal question. the standard caps arrived today with the whole gamma2 order and they'll be installed at first. but maybe later I could wire the mundorfs between the output and the rca jacks in a larger case.

 

[digger945]

Just ordered the box enclosures case from Farnell and got a little taste of what it's probably like for those who live outside the US.
Minimum order requirement, no idea what the shipping will be as it said TBA when I finally checked out. I have no idea if the stuff is located in the US or UK. At any rate I ordered an extra TOTX to have if anyone wants. I was digging around in the parts boxes and came up with one from the Gamma 1 build so I'm set to build one now.

Is there a minimum voltage rating for C20 and C26?

 

[amb]

Quote:

Originally Posted by digger945 /img/forum/go_quote.gif Is there a minimum voltage rating for C20 and C26?

Given that the circuit is powered by a 5V source (and regulated down to 4.5V or 4.75V for the analog supply), and then these caps typically "see" only half that, 6.3V or 10V voltage rating is high enough.