Showing 1 of 210 conversations about:
CEE_TEE
3406
Sep 15, 2018
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Greetings everyone, We have some excellent news! Based on community interest and feedback, we’re extending this drop by another 2 weeks. But not to worry, this will not extend the shipping date. We’re still aiming to deliver these products to you well on time. We’ve also been listening closely to the discussions and we’ve identified an opportunity to make improvements to the I/O ports. Several members expressed desire in having additional options for digital input, namely optical input (TOSLINK). The Grace Design team has found a way to revise the PCB design to accomodate a single 3.5mm port that can handle both optical input and S/PDIF coaxial input using a 3.5mm-to-coaxial adapter. This is great because it won’t increase the manufacturing lead time nor will it affect the shipping date. FROM: COAX SPDIF only
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TO: 3.5mm combo jack- Optical SPDIF or Coax SPDIF (with an adapter)
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3.5mm to RCA adapter:
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Thanks again for joining the Massdrop x Grace Design Standard DAC Balanced drop. If you have any questions, please feel free to reach out to us. Thank You, The Massdrop Team
Sep 15, 2018
AndyMok
34
Sep 15, 2018
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Sounds great! But is there any performance implications on that?
Thx :)
Sep 15, 2018
CEE_TEE
3406
Sep 15, 2018
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Yes! You can use the SDAC-B by connecting to more sources. Some people have sources with optical out like an Apple TV or a CD player. Some people prefer a fiber optic cable because it is immune to radio frequency interference (sends signals by laser light). Others prefer coaxial cable with an RCA connector. Now you can use either.
In order to be able to fit it all in that small back panel, we needed to find a less than typical jack. Looks like a standard 3.5mm headphone jack but will take a 3.5mm Toslink optical connector or an RCA to 3.5mm TRS connector. We'll need to include an adapter for the RCA to 3.5mm so it is easier, since that isn't usually something that you will have lying around.
Sep 15, 2018
iamjamestl
65
Sep 15, 2018
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I love this change. It will allow me to eliminate the optical-to-coax spdif adapter in my setup.
Sep 15, 2018
pospos
70
Sep 15, 2018
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That feels a bit strange, but I guess that is what you get when you try to please everyone and fit everything in a tiny case...
Regarding the 3.5/coax adapter, why TRS when coaxial is single-ended? Why not use a mono jack like this one: https://webobjects2.cdw.com/is/image/CDW/1212661 I think you should include one with a flexible wire to avoid stressing the 3.5mm socket when pluging rigid spdif cables in. Something like this, maybe a bit shorter: https://www.wantitall.co.za/electronics/3-5mm-rca-video-cable-gold-plated-3-5mm-mono-mini-male-to-single-rca-female-sinloon-video-cable-for-__b072pcgrkc
Sep 15, 2018
pospos
70
Sep 15, 2018
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Oh, and I love the use of torx screws in the drawing, looks much better than the phillips ones in the original photos :D
Sep 15, 2018
Z0d1Ac
199
Sep 15, 2018
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I have a computer connected to some powered speakers using a standard optical cable like this one https://www.monoprice.com/product?c_id=102&cp_id=10229&cs_id=1022904&p_id=2764&seq=1&format=2
So lets make this clear. You have a spdif out and a unbalanced 3.5mm out right? Is the adapter for the spdif or the 3.5m out and does it go to a standard optical? I ask because connecting the dac to my power speakers using optical would be nice.
Sep 15, 2018
high1
207
Sep 16, 2018
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This is what I wanted!!!!
Sep 16, 2018
high1
207
Sep 16, 2018
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As you can see, Toslink mini just fits 3.5mm size
So, inside end of Spdif jack(3.5mm) has optical something that receives optical signal and the side of Spdif(3.5 mm) receives the Coaxial(electric) signal!
It's different with 3.5 mm Unbalanced Output at all!!! Only similar looking!
Sep 16, 2018
Michael_Grace
393
Grace Design
Sep 17, 2018
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Hi ZOd1Ac, The SDAC-B has TOSLINK (optical) and SPDIF (coaxial) inputs, not outputs. The adapter is to allow connections from an RCA phono type SPDIF cable to the 3.5mm SPDIF input jack. Connection to your powered speakers would be made via the analog unbalanced or balanced connections. Cheers, Michael
Sep 17, 2018
Leoi
22
Sep 24, 2018
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Hello CEE_TEE. Thanks for the update.
Is the 3.5mm jack for use with a MINI-TOSLINK cable like the one in the following link? That is a fully optical path, isn't it?
https://www.amazon.com/AmazonBasics-Toslink-Mini-Digital-feet/dp/B07DTKWLDS
Thanks
Sep 24, 2018
rdodev
611
Sep 26, 2018
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Hey Michael,
First, thanks a bunch for all the super detailed answers and descriptions of this DAC thus far.
Second, other than space constraints, any reason why not to have 2 RCAs for unbalanced out instead of 3.5mm port?
Third, hoping you folks either with Massdrop on your own can make an external-powered version sometime soon.
Sep 26, 2018
high1
207
Sep 26, 2018
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Yes! same as I posted ~
Sep 26, 2018
Michael_Grace
393
Grace Design
Sep 26, 2018
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Hi rdodev, The dicision to use a 3.5mm jack for the unbalanced line outputs was driven by space restraints. As for external power, the SDAC alanced is easily powered by any 5V power supply with a USB jack on it. Michael
Sep 26, 2018
Michael_Grace
393
Grace Design
Sep 26, 2018
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Yes! Fully optical using a fibre like in your link. Or electrical using tip-sleeve contacts and a coaxial 75 Ohm cable.
Sep 26, 2018
high1
207
Sep 26, 2018
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Any suggestions of low noise 5v usb power source?(adapter)
Sep 26, 2018
rdodev
611
Sep 26, 2018
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But then that would not allow use of the USB port, which would defeat the purpose -- at least for me. Curious what's the operating amperage of this SDAC ?
Sep 26, 2018
Leoi
22
Sep 26, 2018
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Thanks for the explanation Michael. Are there any disadvantages in using a single 3.5 jack instead of 2 RCA's? I'm seriously considering joining the drop.
Sep 26, 2018
Michael_Grace
393
Grace Design
Sep 26, 2018
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Yes, our T900 http://www.gracedesign.com/merch/accessories.htm This is the power adapter we specified for the m9xx/m900. We tested many power supplies and this is the best we found.
Sep 26, 2018
Michael_Grace
393
Grace Design
Sep 26, 2018
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If you are using the USB port then your unit is powered. Am I missing a use case here?
Sep 26, 2018
Michael_Grace
393
Grace Design
Sep 26, 2018
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Electrically there are no disadvantages that I am aware of. Mechanically the 3.5mm jack can be more susceptible to breakage if the cable gets yanked... Some 3.5mm to rca cables may have more crosstalk than rca to rca cables. Personally, I don't feel crosstalk is a problem once it is better than 60dB or so. Micahel
Sep 26, 2018
high1
207
Sep 26, 2018
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Can you provide T900 as option for this drop?
It would be great!!
Sep 26, 2018
rdodev
611
Sep 26, 2018
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Likely it's undue paranoia, but delivering power and fast streams of data in the same cable, although perfectly within USB A/B spec, always gives me pause. If this was USB 3 rev C I'd be more at ease due to its new power delivery subsystem. It isn't as much as technical requirement as it's personal preference/paranoia :)
Sep 26, 2018
AndyMok
34
Sep 27, 2018
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Actually a Y-split will do, one for data and one for power. Pretty common on mini-type I think, not aware of any available in type B to A though.
Sep 27, 2018
db42
66
Jan 14, 2019
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Just curious since I can't find it in the specs. What is the max sample rate over optical? Is it 24/192 like the coax connection or is it limited to 24/96? Thanks.
Jan 14, 2019
AlexVallejo
84
Mar 27, 2019
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Optical will max out at 96kHz.
Mar 27, 2019
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