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Firestone Audio, Fireye HD Impressions

post #1 of 29
Thread Starter 

Just ordered the new Fireye HD will post pics and first impressions as soon as it arrives

 

Cant find much of a mention apart from a short reference to a prototype

 

Anybody already have one ?

 

Anybody want one ?

post #2 of 29

I was the one who posted the very short impressions regarding the prototype. The production version sounds nice. As with all FSA products, it won't have the 'blow me away' quality; that isn't FSA's M.O. but it has a nice wide soundstage with good spacing between instruments. Bass boost function is... functional, but not really impressive, unlike the bass knob of a Triad L3, for example. Not really a fair comparison, but you get what I mean. Build quality is really, really nice. You'll be impressed.

 

I may do a shootout of it against another portable amp one of these days, but I'm undecided whether I actually want to or not (trying to balance my time commitments for now).


Edited by tomscy2000 - 9/19/12 at 1:08am
post #3 of 29
Thread Starter 

Thanks for that, it sounds like just what I was looking for.

 

I intend to pair it up with some heir audio 3ai iems in the near future so the bass boost probably wont be required.

 

I just found it odd that the Fireye HD had been on the market for over three months and until I stumbled on it in one of my favorite on line shops I had not seen it.

In contrast the Fiio E12 doesn't even have a release date and there is already a strong discussion.

 

Anyway, I just got the shipping notice so it wont be long now.

 

I don't have any other portables of this quality the best I have is the Fiio E11.

However I have a quality main system and I can test the Fireye HD's ability to run low impedance iems (Shure SE215) and full size headphones (Senn Hd650, Beyer Dt770 600Ohm and Hifiman He500)

 

As the specifications claim the ability to run headphones from 16 to 600 Ohms it should perform well

I have found often however that low gain is not really low enough and high gain is not high enough

I will find out soon enough and all will be revealed.

post #4 of 29

The Fireye HD should be quite noticeably better than the E11, IMO. I was never impressed by the E11 except for its driving power.

 

I don't know what the Fireye HD's output impedance is; I could try to found out, though.

post #5 of 29

Should be a good amp for the right phone but expect an output impedance close to (maybe higher than) the 16 ohms that they say is suitable to drive. The chip used needs about 10 ohms of short circuit protection besides not being a low output impedance device to start so low/mid impedance IEMs may not be the best coupling. Could be great on high impedance cans but they may have that conservative response spec may be due to the high output impedance combined with the min. 16 ohm recommendation. That said, they could have a pair of transistors etc. after the chip which would change everything.

 

I also didn't think the E11 special.


Edited by goodvibes - 9/19/12 at 8:46am
post #6 of 29

Yeah, I didn't realize the amp was based on the TPA6120; should be nice for big cans though. The thing easily powered an HD600 in my memory.

post #7 of 29
Thread Starter 

When I checked out the TPA6120 and it said "high current" and "dangerous" I was sold.

 

Re the IEMs I don't mind a sensitive volume pot but noise will be a problem. As you say it should work well with the full size cans so all will not be lost.

 

An article on the store sight where I ordered the Fireye stated

"The Fireye HD is the top of the line portable head amp and offers a fully discrete circuit topology....."

Clearly the presence of the TPA6120 means this is not correct however a transistor stage somewhere would explain the confusion.

This would also help to explain the large price difference between the HD and HA models.

post #8 of 29
Quote:
Originally Posted by Dogmatrix View Post

When I checked out the TPA6120 and it said "high current" and "dangerous" I was sold.

 

Re the IEMs I don't mind a sensitive volume pot but noise will be a problem. As you say it should work well with the full size cans so all will not be lost.

 

An article on the store sight where I ordered the Fireye stated

"The Fireye HD is the top of the line portable head amp and offers a fully discrete circuit topology....."

Clearly the presence of the TPA6120 means this is not correct however a transistor stage somewhere would explain the confusion.

This would also help to explain the large price difference between the HD and HA models.

 

LOL.

 

IIRC There's a decent amount of play on the pot in low gain mode for IEMs, but don't quote me on that. It's not noisy, but rather, I'm concerned about the damping factor not being high enough for IEMs.

 

The HA is an entry-level amplifier; it's not exactly terrible, but it's not really great, either. The one I heard had some issues with a muddy upper bass/lower midrange.

post #9 of 29
Thread Starter 

If the output impedance of the amp is indeed above 10 Ohms the damping factor would be a problem in theory, however I don't think balanced armature drivers are particularly reliant on electrical damping since they are so small. Looking at the Ti spec sheet for the TPA6120 the output impedance in circuit could be as high as 23 Ohms which would mean in theory it would best suit headphones around the 200 Ohm mark. There is still the possibility of a discrete output stage which would change everything.

 

I will test the amps performance with the Shure SE215 I already have in my collection as these are a worst case scenario with an impedance of only 20 Ohms and a dynamic driver.

If they have problems I may rethink the whole IEM idea and just stick with the senn 650, it may even turn out to be great with the HE500 that would be nice.

 

I notice you didn't get on too well with the 3Ai, just not your cup of tea.

post #10 of 29
Quote:
Originally Posted by Dogmatrix View Post

If the output impedance of the amp is indeed above 10 Ohms the damping factor would be a problem in theory, however I don't think balanced armature drivers are particularly reliant on electrical damping since they are so small. Looking at the Ti spec sheet for the TPA6120 the output impedance in circuit could be as high as 23 Ohms which would mean in theory it would best suit headphones around the 200 Ohm mark. There is still the possibility of a discrete output stage which would change everything.

 

I will test the amps performance with the Shure SE215 I already have in my collection as these are a worst case scenario with an impedance of only 20 Ohms and a dynamic driver.

If they have problems I may rethink the whole IEM idea and just stick with the senn 650, it may even turn out to be great with the HE500 that would be nice.

 

I notice you didn't get on too well with the 3Ai, just not your cup of tea.

 

Actually, in my experience the damping factor is quite important with BA earphones, perhaps even more than dynamic driver earphones, the reason being that certain drivers have very irregular impedance curves that can drop to as low as 3 ohms in some cases. The enclosed box shape of BA drivers creates a highly irregular magnetic field that affects driver response greatly if not driven properly. Conversely, dynamic drivers usually have fairly uniform impedance curves. Regardless, as long as what you have sounds good out of the Fireye HD, it's all gravy.

 

Yeah, the 3.Ai's not my thing, but that doesn't mean others might not like it.

post #11 of 29
Thread Starter 

I think you are probably right on the BA front but I still think Firestone may have a trick up its sleeve. Seems strange to me that they would build a portable amp with a low gain setting which is really not suitable for most portable earphones/headphones.

 

I need to stop speculating and wait for delivery day.

post #12 of 29
Quote:
Originally Posted by Dogmatrix View Post

An article on the store sight where I ordered the Fireye stated

"The Fireye HD is the top of the line portable head amp and offers a fully discrete circuit topology....."

Clearly the presence of the TPA6120 means this is not correct however a transistor stage somewhere would explain the confusion.

This would also help to explain the large price difference between the HD and HA models.

 

My best guess would be that it has a discrete gain stage and uses the TPA6120 as an effective current buffer. 

post #13 of 29
Thread Starter 

Sounds like a good guess to me, I suppose we will find out when someone pull the guts out of one. I don't have the tech knowledge to know what I was looking at.

 

The Fireye arrived a couple of hours ago, the battery was flat so it had to be charged which took around 90 minutes from completely dead.

 

Straight out of the box (after charging) I have tried a couple of tracks with the SE215 then switched to the HD650 I will post some detail and pics tomorrow.

 

Its looking good so far no sign of any distortion with the low impedance IEMs, there is channel imbalance at absolute zero on the pot but it levels out very quickly still at a very low volume level. Background is absolutely black and response seems very neutral.

 

More tomorrow.

post #14 of 29
Thread Starter 

 

 

 

 

 

Just a quick pictorial, have not had much listening time, will build some firm impressions over the weekend, all good so far.

post #15 of 29
Thread Starter 

 

 

The following contains my impressions of the Firestone Audio Fireye HD and its performance with a range of headphones.

 

Rig as pictured running apple lossless files.

 

 

Fireye HD

 

High quality is in evidence everywhere with the Fireye HD, from the slick grey finish to the feel of the controls. A highlight for me is the unmistakable click of a relay a second after the power is toggled on or off. Placement of the gain and bass boost between the volume knob and the jacks is a little awkward but not a real problem in use. 

 

 

Fireye HD  + Shure SE215

 

Bass boost not required here, gain low.

Volume sensitivity is good with around 90 degrees of usefull travel. Noise floor is absolute zero, even with the ipod paused and the volume cranked to full on high gain there is no detectable noise.

Bass is a little heavy and the treble rolls of early but that's what the 215's bring to the party.

Overall it is the best performance I have heard from the SE215.

 

 

Fireye HD + Sennheiser HD650

 

Bass boost not required again, gain high

Volume range excellent with my preferred highest level at around 50% of travel on high gain

Ease and authority come to mind with this combination, there is synergy here for sure.

Sound stage is wide open with clean air between instruments. Bass is tight and strong, mids smooth and well placed, treble crisp and clear

Overall this was my favorite combination.

 

 

Fireye HD + HiFiMan HE500

 

Bass boost, in this combo I felt the sound was very natural and true without the bass boost. With bass boost engaged the sound was clearly colored but still fun and quite addictive.

Gain high, this time my preferred maximum level was around 80% travel 

Bass is a little blurred in complex passages, mids are glorious really superb, treble is a little off like something has been lost but still passable.

Overall while the Fireye HD lacks the power and control of my balanced Violectric set up with the HiFiMan it is surprisingly competent.

 

 

Fireye HD + Beyerdynamic DT770 Premium 600 Ohm

 

For the first time I felt the bass boost was required to achieve a normal level.

Gain high, obviously approaching the limits of the Fireye HD preferred highest level was around 90% travel

Bass boost engaged the bass response is well defined and strong, mids are again enchanting with a tube like air and warmth, treble is beginning to show some ragged edges when pushed.

Overall performance here is ok but showing signs of pushing the envelope.

 

 

Verdict

 

Everything I have connected to the Fireye HD has performed true to its signature, the little amp has no obvious flaws or shortcomings.

Overall the Fireye HD is a high quality high definition unit with a strong and neutral character.

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