[tacitapproval]

OPA2365 seems to be backordered for the next month or so at the usual sources. How much of a trade-off is it to use AD8656 as a line-level source?

 

[amb]

Quote:

Originally Posted by CodeToad /img/forum/go_quote.gif Would it be possible to run both an M3 and a Gamma2 from one S11?

Aside from the voltage difference that Linuxworks mentioned, there is also the issue of real ground vs. virtual ground. When you connect a σ11 to a M³, the TLE2426 on the M³ splits it into a dual-rail supply and creates a virtual ground. When you connect the same σ11 to the γ1/γ2, the "ground" is actually M³'s negative rail. When you then connect the two together, you've created a short circuit and the result would be instant TLE2426-death.

Keep the DAC and the amp separate, running on separate supplies, and it will save you from all these hassles.

 

[amb]

Quote:

Originally Posted by tacitapproval /img/forum/go_quote.gif OPA2365 seems to be backordered for the next month or so at the usual sources. How much of a trade-off is it to use AD8656 as a line-level source?

IMHO not much tradeoff, both are excellent, with the slight nod going toward the OPA2365.

At any rate, Allied seems to have OPA2365 in stock, but you have to buy in multiples of 5:
Texas Instruments - OPA2365AIDG4 - Allied Electronics

 

[R4ABigman]

Quote:

Originally Posted by amb /img/forum/go_quote.gif Aside from the voltage difference that Linuxworks mentioned, there is also the issue of real ground vs. virtual ground. When you connect a σ11 to a M³, the TLE2426 on the M³ splits it into a dual-rail supply and creates a virtual ground. When you connect the same σ11 to the γ1/γ2, the "ground" is actually M³'s negative rail. When you then connect the two together, you've created a short circuit and the result would be instant TLE2426-death. Keep the DAC and the amp separate, running on separate supplies, and it will save you from all these hassles.

I'm glad to see the y2 out -- once I've got my y1 working then I forsee some additional components on order!

From the y1 thread (http://www.head-fi.org/forums/f6/y1-...ml#post6011452), would it not be possible to regulate the power for the y1/2 from the o11+m3 combo as such:

I know everyone says its a bit of a faff and everything should be in separate boxes etc etc, but I'm really keen to get this working in a single box.

Alternatively, I'm considering the idea of two transformers within the same box, one for the o11 and one + regulator for the y1/2. Just wondering how clean the power supply actually needs to be to get good performance (I understand there is some on-board regulation)?

 

[TzeYang]

what about 2x regulators?

drop to 12V --> 5V.

 

[Beefy]

Quote:

Originally Posted by TzeYang /img/forum/go_quote.gif what about 2x regulators? drop to 12V --> 5V.

The first regulator would still be dropping 12V at up to 0.3A, for 3.6W. Not to mention the increased current output and thus heat production from the S11 for no particularly good reason.

It would make much more sense to run a small 6-9VAC transformer and a Tread.

 

[linuxworks]

stepping back a bit; this is high end audio (pretty much). you WANT to have independant power supplies for 'important parts', so to speak. pushing the 'isolation' all the way back to the trafo level (ie, adding a separate trafo and regulator stage after that) would only help specs and improve the quality of the overall implementation.

what this world needs is an easy source of multi-winding trafos

one big trafo with all our desired secondaries would solve SO much of the world's problems.

ok, well, at least our audio power supply problems (lol).

I just can't find good selections of anything over than dual 'same' windings on secondaries. I often need a 5v winding for digital things, a 10 or 12v winding for things and maybe a dual rail 12 or 15 for analog things. can't find such toroids very easily. so I end up with multiple smaller ones, which I admit is less elegant.

 

[dumbears]

I'm interested in making one for myself, however, I've a lot of questions to bother you guys. Thanks in advance for your patience and help.

May I ask if the SQ of audio socket in gamma-1 is the same as that of the audio socket in gamma-2? The other question is whether it's possible to have one audio socket for amp and the other for headphones/earphones? If it's possible, which is which?

Moreover, if I'm to use BG NX Hi-Q 47uF/6.3V, should I add 1uF film cap parallel to it? I personally prefer Roederstein, may I use KP1830 series for both the 100pF and 220pF caps?

Thanks!

 

[Beefy]

You should price up some custom options. So long as it doesn't have a huge power rating, it might be cost effective. SumR would be a good place to start to ask for that sort of thing.

 

[Beefy]

Quote:

Originally Posted by dumbears /img/forum/go_quote.gif May I ask if the SQ of audio socket in gamma-1 is the same as that of the audio socket in gamma-2?

If they were the same, then nobody would bother building the gamma2, would they?

 

[Billyk]

I am sure the output sockets on the y2 will be superior to the one on the y1. This is an upgrade after all.
Quote:

Both RCA phono jacks and 3.5mm stereo mini jacks are provided for the analog output. You may use either depending on which cables you have, or use both simultaneously to drive two amplifiers

Powering headphones (low impedance) requires a specific op-amp, it is noted in the parts list.

 

[MisterX]

Quote:

I personally prefer Roederstein, may I use KP1830 series for both the 100pF and 220pF caps?

http://www.vishay.com/docs/26016/kp1830.pdf

The dimensions for the 100pF and 220pF caps are listed in the datasheet linked above as:
5mm pitch. 4.5mm wide. 7.2mm long. 6mm tall.

From the Gamma 2 part list page:

Quote:

C15-C18 and C21-C24 are through-hole, radial-lead metallized polypropylene or polypropylene film capacitors for the analog low-pass filter. Their lead spacing is 5mm and the footprint should be no larger than 7.5mm x 4.5mm, with a maximum height of 6mm. 5% tolerance or better is recommended for accurate filter response.

 

[linuxworks]

Quote:

Originally Posted by Beefy /img/forum/go_quote.gif If they were the same, then nobody would bother building the gamma2, would they?

the BIGGEST thing about the y2 is the ASRC chip.

that turns it into something entirely different, in terms of class.

the new wolfson chip is also more 'tweaky' in that you can play with various filter settings (via a switch). I never bother, myself; as I can't hear any major diffs between them. they seem like splitting hairs, to me; but some people really like to experiment with tweaks like this.

the asrc is the #1 reason to go with the y2, imo. its claimed to have a good effect on jitter. how can you NOT want that?

 

[Cankin]

Are there any differences (measurement or audit) between SRC4192 and AD1896?

 

[jnewman]

Quote:

Originally Posted by Cankin /img/forum/go_quote.gif Are there any differences (measurement or audit) between SRC4192 and AD1896?

A quick perusal of the relevant datasheets shows that SRC4192 has significantly lower THD+N (total harmonic distortion plus noise), but both are so low I can't see it making much a difference. Depending on input and output frequencies, SRC4192 THD+N is at -141 to -137 dB and AD1896 THD+N is at -133 to -120 dB.