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Rear USB ports

Posted: Wed Sep 24, 2014 2:48 pm
by CanadianMaestro
Hi,

Just wanted to post my recent observation that a 1-TB pocket drive (G-Drive) CAN work when plugged into the bottom rear USB port of my BDP-1. Previously, I had used only two 500-GB G-drives at the rear ports, concerned that there wasn't enough power to drive a 1-TB self-powered (no AC cord) hard drive. This particular 1-TB drive CAN in fact, also work simultaneously with two thumb-drives inserted in the two front slots. Not sure what the power requirement is for this G-drive, and couldn't find any such specs on their website.

Haven't yet tried plugging in a 500-GB and a 1-TB to the two rear slots. I suspect there may be issues? Anyone try this yet?

Thanks for reading, and I'm very glad to see a separate Bryston users' forum here! Good job, Bryston!

Re: Rear USB ports

Posted: Wed Sep 24, 2014 4:45 pm
by cdinsmore
I'm not technically inclined, so take my response accordingly.....but my understanding is that as long as each USB drive requires less than 500 ma of current they should work. I'm currently using one 1-TB OWC Mercury Elite Pro Mini, which requires 300 ma and it works great in all regards. I'm expecting to be able to hook another of these up to the back when the time comes with no issues.

Re: Rear USB ports

Posted: Thu Sep 25, 2014 3:43 am
by Chris Rice
cdinsmore wrote:I'm not technically inclined, so take my response accordingly.....but my understanding is that as long as each USB drive requires less than 500 ma of current they should work. I'm currently using one 1-TB OWC Mercury Elite Pro Mini, which requires 300 ma and it works great in all regards. I'm expecting to be able to hook another of these up to the back when the time comes with no issues.


Your understanding is most certainly correct, the 500GB recommendation found in the manual is nearly four years old and even back then was a rather loose rule of thumb that was objected to by some but ignored.

Cheers,
Chris

Re: Rear USB ports

Posted: Thu Sep 25, 2014 10:44 pm
by CanadianMaestro
Hmm...just found on the back of my 1-TB G-drive the spec "900 mA", and it still works connected to the rear USB of my BDP-1. I guess that's a maximum current rating on the drive and BDP-1 can still power it?

Re: Rear USB ports

Posted: Fri Sep 26, 2014 1:30 am
by Chris Rice
It's more likey that the drive occasionally bursts to 900mA and it's either short enough not to upset the BDP-1 or it hasn't spiked that high while playing music off of it. I can assure you that BDP-1 can't sustain much more then 500mA per supply.

Cheers
Chris

Re: Rear USB ports

Posted: Fri Sep 26, 2014 10:58 am
by CanadianMaestro
Chris Rice wrote:It's more likey that the drive occasionally bursts to 900mA and it's either short enough not to upset the BDP-1 or it hasn't spiked that high while playing music off of it. I can assure you that BDP-1 can't sustain much more then 500mA per supply.

Cheers
Chris



Hi

Thanks for the tip. It's working fine, no fails. Probably not drawing more than 500mA even with the fastest music.

Question: What's your view on USB cables between the pocket drive and BDP-1? I use the short stock cable, about 30cm. I don't subscribe to buying uber-expensive USB cables like some do. For me, the critical digital circuitry are inside the components, not in the USB cable itself.

Cheers,
M

Re: Rear USB ports

Posted: Mon Sep 29, 2014 4:31 pm
by Gary Dayton
The thing about USB cables between drives and players is that the data on the drive isn't really music until it is decoded by the player. It's just files. These files are transferred in packets - chunks of data rather than a sample to sample bitstream precisely metered like a digital audio signal moves. So, based on our current body of science, there's no reason a high end (or trashy, for that matter) should influence sound quality provided that it meets the appropriate USB spec in terms of speed and structural integrity.

That being said, some people have noted sound quality variations based on the cable used. I am certainly in no position say that they are wrong. If you try these cables, please share your impressions with us!

--Gary/Bryston

Re: Rear USB ports

Posted: Tue Sep 30, 2014 10:57 am
by CanadianMaestro
Thanks for the insight, Gary. The "they're only 0's and 1's" school of thought is still very prevalent around the audio forums. I gotta say that I am in the cheap USB cable school myself. Over such a short distance (for me, <0.3m), signal transmission infidelity is unlikely to occur, imo.

I use a Furutech Formula-2 USB to connect a G-Drive 500-GB or 1-TB drive to BDP-1. I don't notice any audible change in SQ over the black stock cord provided by G-Drive. (Use the same type of drive and stock cable to back up my Apple computers at work and home). The Furutech is thick, and well-shielded from external EMI (supposedly, but have not tested this!).
http://www.adl-av.com/products/cables/usb/

I actually have the pocket G-drive resting atop my BDP-1, with no noise issues whatsoever.

Cheers,
M.

Re: Rear USB ports

Posted: Tue Sep 30, 2014 1:32 pm
by Gary Dayton
It's not so much that it's just "1s and 0s" - I have a fancy digital audio interconnect between my BDP2 and BDA2 because I think it sounds better. But the method of signal transmission between a drive and a computer is robust and designed against sensitivity towards faulty transmission, so a higher end cable there is not as likely to be a benefit.

--Gary / Bryston

Re: Rear USB ports

Posted: Tue Sep 30, 2014 2:31 pm
by CanadianMaestro
Which sounds better to you, the BNC or the AES/EBU between BDP and BDA?

I like the BNC. Didn't hear anything better with AES.

Cheers,
M.