[leeperry]

A friend of mine was seeking a good sounding cheap solution to computer audio...Firestone recently decided to update their 24/96 Spitfire S/PDIF DAC w/ a 16/48 USB input and a swappable opamp.
 
I've received it today, as he wants me to pick a matching opamp for him.
Unpacking:
 
Let's hope it'll sing "Jingle Bells" when you shake it

 
So we have a USB cable, a RCA cable, the wallwart, the manual, a wrench to open Pandora's box and a warranty card:

 
Gold plated USB baby

:

 
Currently feeding it w/ the Firestone Bravo via coax:

The stock opamp(used as PCM1793 LPF) is the highly praised LM4562NA:

 
The old Spitfire w/ the dragon on its front panel was also running PCM1793 and also had a swappable DIP8, but it was running the now obsolete CS8414...the new one was running DIR9001 but had a soldered LM4562MA, so no more rolling possible

 
Now the Spitfire MKII runs PCM1793, 24/96 DIR9001, 16/48 PCM2704 and the swappable DIP8 socket opamp is back w/ a vengeance...using some nice WIMA caps(to minimize oscillation I would guess). the WIMA's are famous for their "energic" sound, compared to the "laid back" signature of the Mundorf's I believe(but don't quote me on that).
 
Anyway, doing A/B comparisons against the old Spitfire is a clear knock out...everything's you've read about the CS841x/DIR9001 difference is very real. Tighter sound is the motto. 
I've already rolled the opamps of course (

), and I will compare the wallwart/Supplier PSU and the coax input against the PCM2704 USB input later on.
 
So far w/ the Supplier > Bravo+Supplier > ADuM4160 and opamps more to my taste, it sounds extremely good...I shall try a dual LT1028ACN8 module within a few days.
 
Just like all the Firestone DAC's, it's fully able to drive headphones via its RCA out...my Fostex ortho sounds really good...of course I've only tried easy to drive headphones, You can't really expect a dual opamp to drive a K701 on its own. The nice thing is that there's no volume pot, which either ruin the SQ when they're cheap or cost a lot of money to sound good. What could possibly sound better than 64bit digital volume attenuation anyway?
 
It's sold at a discount until the end of the year, and so far it's a great DAC...after going through a lot of DOA and crappy sounding ebay DAC's, finally my friend will be delighted

 
PCM1793 is known for its chirurgical and uncompriming sound, and I can only agree...the old Spitfire did good in RMAA, when using its Supplier linear regulated PSU: http://www.firestone-audio.com/rmaa/SPITFIRE.htm
 
It's easy to understand why Firestone sold so many of those Spitfire's, it's small and highly efficient...this is a great sounding solution for the members of Team "shortest signal path". The opamps are fed w/ ±12V, and it's recommended to stick to "unity gain stable" chips whenever possible.
 
More impressions later.

 

[gattari]

Pcm 1793 is not a top chip,  pcm 1794 is a clear step up.
Perhaps this dac sound very good but not for the used chip.
Ciao

 

[leeperry]

OK, doing more tests on the USB input this time:
 
I very much prefer the SQ through the ADuM4160 dongle...as usual, the sound is more natural, less edgy and much clearer, the instruments are much better separated. Galvanic Isolation does matter w/ computer audio IME(my computer PSU is not grounded and its ground is very dirty, so YMMV)...whatever from the wallwart or the Supplier PSU, it makes a drastic change to my ears.
 
The Supplier linear regulated DPS adds another layer on top, the SS is wider, the bass tighter and the sound much more "dynamic"...all those tweaks add up in the end, but I'm sure he'll be happy w/ the bare Spitfire MKII for now, and slowly upgrade to enjoy each improvement.
 
Tomorrow I will try another more advanced USB isolation dongle, time will tell.
 
PCM2704 sounds very different from DIR9001(even CS8414 does), more laid back and less audible "resolution"...DIR9001 is very very tight and as "in your face" as can get, it digs very deep.
  

Pcm 1793 is not a top chip,  pcm 1794 is a clear step up.
Perhaps this dac sound very good but not for the used chip.

 
I think we all know that the chip themselves are irrelevant outside their circuit? On paper, the Sabre's kill the competition...why bother w/ PCM1794 at all? 132dB sounds appealing, I'll give you that. It's been a long time that the DAC chips manfacturers have been playing the figures game...SNR, ASRC, oversampling, THD+N...yet, it seems that the best sounding DAC's using the Sabre's actually disable their ASRC.
 
We're talking about a $200 DAC here btw, it's not meant to compete w/ the big boys.
 
and I was mostly referring to this comparison found on diyaudio.com, made with a DAC that had exchangeable DAC-chip boards. The output stage was transformer coupled (no chips nor other active parts): 

The CS 4398 has a kind of analogue quality. It offers a more relaxed, warmer sound. It gives a large soundstage by bringing out more of the mid. The top end is softer and less extended. The bass is less defined. It is very forgiving with recordings of lesser quality and it seems well adapted to shrill sounding recordings of pop music. It seems a bit compressed and it does not excel at pin point reproduction of the room ambiance, nor does it reveal the more hidden information like breathing noises etc.  
The BB PCM 1793 is a more technical affair. On first hearing it is much more clinical with less midband warmth. However, it does give much more ambiance information, and it retains the original dynamics far better. Weak sounds like breathing is much more audible. The bass is much tighter and less compressed. The top end is more extended and less smeared. When listening to high quality acoustical recordings (classical or jazz), it is a treat, but when fed with low-fi pop music it is much less forgiving.

 

[gattari]

Lee, pardon off topic.
I have followed with interest your post about usbiso dongle in other tread, are you aware of why the hiFace does not work with these adapters?
Thanks

 

[leeperry]

It seems that their proprietary drivers refuse to work at 12Mbps, unlike the Musiland Monitor's.

 

[lavagolem]

you recommend this dac for a grado ms1 with little dot i+ amp? thanks ^^

 

[leeperry]

Well, for the $200 it currently sells for it seems rather hard to fault this unit. You can slowly upgrade its PSU and opamps...and without resorting to ugly lab PSU's at that. Many of the currently available DAC's have soldered OPA2134's and so...you can do much better than that IME. Anyway, it's a highly customizable DAC, and it sounds pretty sweet off its USB input as well.

 

[jonjonjon3]

Hi, Just picked up a Spitfire MKII myself. I'll be very interested to hear how the different opamps that you try compare to the supplied LM4562....

 

[leeperry]

I've done a bit of rolling, and you could use this page for reference purposes. You can do much better than LM4562NA IME...you could just get a dual AD797BR(same chip as AD797BRZ) module off ebay for cheap, and you'd be really stunned by the SoundStage of this chip 

 

[Dynobot]

This is great info Lee, but I would rather hear more about your Burson.
 
Did you crack it open yet and have a look inside?

 

[leeperry]

I don't mind cracking open a $200 DAC w/ a swappable DIP8 opamp, but there's nothing to roll in the Burson HA-160D....it's under warranty and there's lotsa inside shots in the 6moons review already

 

[Dynobot]

Just curious, seeing that you have been so used to tinkering with gear, do you think you will get bored with the Burson even though is sounds so good?
 
I think you really enjoy the ability to swap and change things.  You might end up buying a toy Dac just to play with.....

 

[leeperry]

I will keep my old Firestone Spitfire, I might A/B it against the built-in Burson DAC from time to time...in order to kill boredomness as you just said. I don't mind sticking to excellent sounding gear, like my pimped Fostex T50RP ortho that truly sounds astounding when fully damped and using sa5k earpads

 
I prefer to have a few great sounding components than 10 average sounding headphones and sources. Quality over quantity.

 

[SP Wild]

Quote:

OK, doing more tests on the USB input this time:
 
I very much prefer the SQ through the ADuM4160 dongle...as usual, the sound is more natural, less edgy and much clearer, the instruments are much better separated. Galvanic Isolation does matter w/ computer audio IME(my computer PSU is not grounded and its ground is very dirty, so YMMV)...whatever from the wallwart or the Supplier PSU, it makes a drastic change to my ears.
 
The Supplier linear regulated DPS adds another layer on top, the SS is wider, the bass tighter and the sound much more "dynamic"...all those tweaks add up in the end, but I'm sure he'll be happy w/ the bare Spitfire MKII for now, and slowly upgrade to enjoy each improvement.
 
Tomorrow I will try another more advanced USB isolation dongle, time will tell.
 
PCM2704 sounds very different from DIR9001(even CS8414 does), more laid back and less audible "resolution"...DIR9001 is very very tight and as "in your face" as can get, it digs very deep.
  

Pcm 1793 is not a top chip,  pcm 1794 is a clear step up.
Perhaps this dac sound very good but not for the used chip.

 
I think we all know that the chip themselves are irrelevant outside their circuit? On paper, the Sabre's kill the competition...why bother w/ PCM1794 at all? 132dB sounds appealing, I'll give you that. It's been a long time that the DAC chips manfacturers have been playing the figures game...SNR, ASRC, oversampling, THD+N...yet, it seems that the best sounding DAC's using the Sabre's actually disable their ASRC.
 
We're talking about a $200 DAC here btw, it's not meant to compete w/ the big boys.
 
and I was mostly referring to this comparison found on diyaudio.com, made with a DAC that had exchangeable DAC-chip boards. The output stage was transformer coupled (no chips nor other active parts): 

The CS 4398 has a kind of analogue quality. It offers a more relaxed, warmer sound. It gives a large soundstage by bringing out more of the mid. The top end is softer and less extended. The bass is less defined. It is very forgiving with recordings of lesser quality and it seems well adapted to shrill sounding recordings of pop music. It seems a bit compressed and it does not excel at pin point reproduction of the room ambiance, nor does it reveal the more hidden information like breathing noises etc.  
The BB PCM 1793 is a more technical affair. On first hearing it is much more clinical with less midband warmth. However, it does give much more ambiance information, and it retains the original dynamics far better. Weak sounds like breathing is much more audible. The bass is much tighter and less compressed. The top end is more extended and less smeared. When listening to high quality acoustical recordings (classical or jazz), it is a treat, but when fed with low-fi pop music it is much less forgiving.

 
Holy Crap!!! that was the exact same conclusion I made about my Bryston DAC...which uses 2 of CS4398 against the PCM1704 Reference 7....like I wrote the same thing in my shootout of these two.  I think DAC chips and opamps play a larger role in sound than even the output stages.  The CS4398 is warmer than all my DS BB chips...except the R2R PCM1704...which so far seems to combine the best of DS, NOS and R2R traits.
 

 

[jonjonjon3]

Lee, thanks for the info. I'll probably upgrade to the firestone power supply before looking at the opamps 

.