[leeperry]

 
Dimensions: 5.5 x 11 x 7.5 cm(fully WAF compliant).
 
After several months of use, time for a proper review

 
The good sides of the Bravo are:
-compatible w/ ADuM4160 to kill any groundloop from the computer and improve the USB signal quality being fed to the Tenor chip
-compatible w/ their linear regulated Supplier DPS w/o any soldering or DIY skills required, for a much improved SQ(thicker/more dynamic sound). The Tenor chip feeds 3.3V so everything runs off the discrete PSU, the computer USB +5V is discarded completely.
-no software drivers required, and no need to whine for hypothetical bugfixes
-all inputs are reclocked by WM8804, to output 50ps jitter coax no matter what(try it to reclock toslink to coax, and be stunned): http://hifiduino.blogspot.com/2010/02/programming-wm8804.html
-can be used as a reclocker in your current rig if you don't use a computer source, hence don't need the USB input.
 
the bad sides:
-no 88.2 or >96kHz...tbh, I only have one 88.2 DVD-A from Seal and one 192kHz DVD-A from Grover Washington Jr., so it's not much of a concern to me.
-it's not USB powered(only a drawback for ppl on a laptop).
 
Anyway, I keep upgrading my rig and this transport scales amazingly well...I've never been this close to my music

 
I honestly don't see how this transport could act as a bottleneck...it's just a high potential gateway to computer audio, and I'm saying this after 9 months of daily use and comparing it against quite a bunch of other USB audio solutions.
 
There's a web review here: http://www.digitalaudioreview.net.au/index.php/audio-reviews/digital-source-reviews/item/79-firestone-audio-bravo-24-96-digital-processor
 
Too bad he didn't use the Supplier PSU(which sounds much better than the wallwart SMPS) and he overlooked RCA/RCA male adapters..you're not FORCED to use a snake oil coax cable.

 

[leeperry]

hey, was wondering if anyone tried this? http://www.firestone-audio.eu/shop/products/allproductslisted/bravo.php
 
it seems to support 24/96 over USB w/o drivers: 
http://www.gfec.com.tw/ics.php
 
http://www.gfec.com.tw/pro_flypage.php?language_page=big5&class1_serial=141&class2_serial=169&class3_serial=&p_serial=131
 
on a Supplier DPS, it should be goooood

 
I'm not sure whether the USB ground is galvanically isolated, but there seems to be a pulse transformer on the coax output anyway: http://www.firestone-audio.eu/shop/products/allproductslisted/bravo.php

 Digital output: 1 of Coaxial jack (isolation pulse transformer output), 1 of Optical jack

 
I've found a "review" here, the guy is using it on a Spitfire DAC: http://translate.google.com/translate?hl=en&sl=ja&u=http://ranmaru719.exblog.jp/12872832/&ei=_fARTNeQO8mM4gayjeSsCA&sa=X&oi=translate&ct=result&resnum=4&ved=0CBUQ7gEwAzgK&prev=/search%3Fq%3Dfirestone%2Bbravo%26start%3D10%26hl%3Den%26safe%3Doff%26sa%3DN
 
Firestone tell me that it supports 24/96 KS/ASIO4ALL/WASAPI on W7, or you can use DS on XP(w/ all the sliders maxed out) to get bit-perfect anyway: http://www.hydrogenaudio.org/forums/index.php?showtopic=49350&view=findpost&p=522247
 
It can also be used as S/PDIF inputs to the computer apparently.
 
This guy looks happy too: http://www.stereo.net.au/forums/showthread.php/24469-Bad-transport-jitter-correction-good-transport?p=364288

 The Bravo makes a significant improvement to the sound of the Firestone DAC

 
and this Tenor TE7022L unit($350 Stello U2) measured well in that test: http://www.stereophile.com/digitalprocessors/lindemann_amp_stello_usb-spdif_converters/index4.html

 the Stello U2. The sidebands at ±229Hz are higher than with the Lindemann, which is why the Miller Analyzer measured 455ps p–p of jitter, but the noise floor is significantly cleaner than with the German data converter. Possibly—just possibly—this is why I slightly preferred the Stello in my auditioning.

I like the idea of drivers-free 24/96 and DPS

 

[leeperry]

OK, I've pulled the trigger on this thing...and if I like it I'll get a Supplier DPS for it, so expect a review soon. I'll also take this opportunity to give a shot at W7

 
What sold me is the drivers-free/low jitter 24/96 over USB, but no KS on XP apparently...so it'll be a take it or leave it kinda deal towards W7 

 
the Ploytec drivers might work on XP, time will tell whether they'll automatically switch sample rates. The Teradak ASIO drivers should work fine too(same chip/same windows ID)
 
BTW, this unit is USB1.1 so I'll prolly try that USB isolator:
http://www.circuitsathome.com/mcu/usb/usb-isolator
 

 
that guy sure seems to enjoy it: http://diyparadise.com/forum/index.php?topic=1063.msg11167

it is funny, all the sounds are there, some details too,
it just doesn't  sound so realistic without the USB-isolator. Music Dies away. Some of the magic dies out, the room perspective, depth is not so clear.. It's not coming out of the speakers properly without the isolator... Funny!

 
so the BRAVO would be isolated from the computer ground, run on a linear regulated DPS and runs a pulse transformer on its coax output....all those things run in their own discrete faraday cages too, neato

 
PS: it's good to see that both DIR9001 and WM8804 carry a 50ps jitter spec: http://www.wolfsonmicro.com/products/WM8804

 

[Pacha]

Too bad it requires DS for XP, KS support could be fine.
 
Let us know how it sounds when you receive it.

 

[leeperry]

Well, blame it on XP I guess...but the ploytec drivers might very well work wonderfully!
 
BTW, Firestone have told me that this unit is isolated from the USB ground..so that's good! I will make pictures of the inside and also test for galvanic isolation: I read some USB DAC manufacturer saying that a quick test was to check w/ a multimeter if the USB ground would make it to the analog audio ground...he said it wouldn't on their top range model.
 
Firestone told me that there's a pulse transformer on the coax output, so I could always check for isolation between the coax input ground, the case and the USB ground. They also tell me that using a Supplier PSU won't really improve the SQ, but I like the idea of having all the stuff that's in the audio path on a clean PSU...besides I got a friend who wants to ditch his, so it would be a cheap upgrade for me anyway.
 
now I need the shortest cable to make it to my Spitfire DAC, I don't really see the RCA male/male adapters working this time..I need a 10cm coax cable, and nobody seems to sell those. Luckily I got some RG59 cable here and some RealCable RCA plugs, so I'll make it myself I think. RG59 is indeed 75Ω

 
I also asked for more details about their "Fi-Reclock" technology, and more details about the 2 RMAA measurements they provide....Firestone is not very good at the audiophool bs ppl crave for so much. They make very good products to my ears but they don't play the marketing bs game, I feel them as being honest about their gear....they don't realize that most companies are just full of it, so it usually takes a lot of explanations/proofs to make ppl believe in what you say. They told me to try the reclocker and decide for myself, sounds like a plan!
 
I guess their RMAA measurements boil down to this technique: http://www.head-fi.org/forum/thread/446451/jitter-measurement#post_6027819

 

[Pacha]

As a few others I begin to think also that the USB transport market will be going towards good quality products and cheap prices.
At least I really hope so as it's a bit a new born sector which has a lot of potential for improvement.

 

[leeperry]

well, those Tenor chips sure look attractive! drivers-free up to 24/96 over USB....you get bit-perfect KS/WASAPI w/o bloated/beta drivers, the key to success!
 
They don't seem to run asynchronously, but even Centrance say that when properly implemented asynchronous doesn't have any advantage anyway(click on "design philosophy"): http://www.centrance.com/products/dacport/

  Some manufacturers may lead you to believe that Asynchronous USB transfers are superior to Adaptive USB transfers. This no more true than saying that you "must" hold the fork in your left hand. If you know what you are doing, you will feed yourself with either hand.

 
These ppl seem to licence their USB technology to many high-end DAC manufacturers, and not going asynchronous allows using "USB audio class 1.0" compliant generic drivers.
 
As I previously said, the two chips taking care of S/PDIF in the Bravo are spec'ed for 50ps jitter. My old Spitfire DAC runs a CS8416 receiver(200ps jitter from what some ppl say?) and I currently use a Dayton glass toslink cable(toslink is said to be a jitter feast), so there'll be some major headroom for any "reclocking" improvement

 

[ironmine]

Leeperry,
 
How much does your DAC cost? Aren't you going overboard with this converter?  Why do you think it will be better than Musiland?

 

[leeperry]

Well, you're only as strong as your weakest link! I love my DAC the way it is atm, I've picked my favorite opamps and favorite media players/VST plugins...now my weak link is the connection to the DAC, the 01USD is nice but I like the idea of drivers-free/low jitter operations. And I also love the sound of that Dayton glass toslink cable, but toslink is said to often be in the 800ps jitter region...so I'm eager to hear what a reclocker can do for me

 
That's my DAC: http://www.firestone-audio.eu/shop/products/allproductslisted/spitfire.php
 
and its linear regulated PSU: http://www.firestone-audio.eu/shop/products/allproductslisted/supplier220vac.php
 
This PSU sounds so good that I'm sure I'll be grabbing another(second hand from a friend) for the Bravo...and all those things run in their own faraday cages, big added value here for me as my neighbors flood me w/ wifi

 

[ironmine]

Quote:

 toslink is said to often be in the 800ps jitter region...

Why don't you use a coax digital cable then?
 
Can you not use one PSU for both Firestone devices?

 

[leeperry]

Firestone have told me that a single Supplier is not beefy enough to feed both units...they also said that the Bravo wouldn't really benefit from a clean PSU anyway.
 
Well, I really like the sound of that glass toslink cable tbh...I do need 8ft between the computer and my DAC, and toslink is immune to interferences by design: http://www.agoraquest.com/viewtopic.php?topic=27534&forum=51

 

[leeperry]

OK, got the unit in good order! I will test it and post photos in due time

 
And after months of using the Supplier PSU on the Spitfire, I'm trying the wallwart adapter for giggles...hah, let's just say I'm a PSU believer

 
BTW, that's the chip taking care of clock generation(50ps jitter): http://focus.ti.com/docs/prod/folders/print/pll1707.html

 

[leeperry]

Too bad it requires DS for XP, KS support could be fine.
 
Let us know how it sounds when you receive it.

Well, yesterday I was lazy and simply used it as a reclocker...very impressive improvement! the SS was wider/deeper and the sound far less distorted, but it was essentially about polishing a turd

 
My CMI8768 board prolly has stellar jitter(Dogbert's bit-perfect drivers can't do nothing about it), and the Dayton 8ft glass toslink cable isn't any better(toslink is often spec'ed at 800ps jitter): http://www.parts-express.com/pe/showdetl.cfm?Partnumber=180-954
 
Anyway, that Tenor chip provides native KS/WASAPI on W7...so this is fully covered. The good news is that on XP, ASIO4ALL works like a charm...the same way it does for a PCI soundcard, there's no asynchronous buffer that needs to be filled etc etc..you click, you get audio..feels like rocket science these days

 
And to answer your question, KMixer only takes care of the volume attenuation for the WAVE slider....the Windows Master volume is supposedly always hardware accelerated by design, meaning that:
-for music, I leave both Master volume/WAVE sliders at 100% and use my media player volume attenuation(done in 64bit float in uLilith and Foobar)
 
Reclock on XP does need KS, and KS is no workee on XP w/ those generic drivers...so I leave the WAVE slider at 100%, Reclock internal volume at 100% too. XP is bit-perfect w/ everything at 100%: http://www.hydrogenaudio.org/forums/index.php?showtopic=49350&view=findpost&p=522247
 
The beauty of drivers-free is that you don't depend on some random coder to find and fix bugs...it all works perfectly fine right off the bat, which also seems like rocket science these days.
 
I'm expecting my second Supplier PSU BTW, so hopefully it'll make for another drastic SQ improvement

 
EDIT: that Tenor chip is USB 2.0 low speed, so it's fully USB1 backward compatible...I'm currently using it in USB1, so I'm about to order that USB Isolator

 

[leeperry]

ok, continuing the monologue

 
so KMixer only takes care of the WAVE slider, so if we leave it at 100% on XP= bit-perfect
 
at page 71 of the USB audio specs, they give the details of the Windows Master volume attenuation: http://www.usb.org/developers/devclass_docs/audio10.pdf
 
They don't give the bit-depth accuracy(possibly hardware accelerated?), but quite frankly it sounds clearer than uLilith's(64fp) and Reclock(53fp) volume attenuation to my ears...nice to see USB can do things right from time to time

 

[SP Wild]

This looks like the product I have been waiting for - that external PSU addition makes this a serious item.  Any Idea how the jitter performance on this thing as compared to the popular Hi-Face.  Does it have BNC or AES connections?