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FX Audio TUBE-03MKII BT Tube Preamp & Headphone Amp
01 / 08
FX Audio TUBE-03MKII BT Tube Preamp & Headphone Amp
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166 requests
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232 Sold
Product Description
Between your audio player and your headphones, several pieces of equipment can improve your sound. If you’re looking for signature tube warmth, you can get them all in one device: the TUBE-03MKII from FX Audio Read More
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keyboard_arrow_downwilliam4037
1
Oct 21, 2020
I am newbie, but can this be used as both a dac and amp or is it just a preamp and I still need a dac and amp?
InvisibleInk
118
Oct 23, 2020
Let's say for the sake of example that the source of your music playback is a laptop PC. The PC has a built-in DAC that sends an analog signal output through the headphone jack. In order to use this Amp directly with the laptop, you would need a cable which has a 3.5mm connector on one end (the laptop) and two RCA (Left & Right) connecters on the other end (for Amp). Then, what is typically done is to max out the volume on the PC as a proper setting for the Amp. Then you are all set. Technically, an additional DAC purchase is not strictly necessary.
Enthusiasts generally prefer to introduce a DAC between the PC's USB output and the Amp. There are many reasons for wanting to do this, but it all boils down to whether or not the PC's own sound is good enough or not.
(Edited)
Cyberthingy
289
Oct 22, 2020
Actually that site has pictures that are both correct and incorrect. One picture shows the flawed printing and another from a different angle shows the correct labels. Odd!
carthago
9
Oct 22, 2020
CyberthingyTrue. Thanks for pointing this out. I had not noticed it. Seems the manufacturer has released images of the product in different stages of development to the retailers. What I find most concerning is that those (respected) retailers themshelves have not even checked what they publish on their websites, thus leaving room for consumers to suspect that they may be selling counterfeit products.
ReadWryt
67
Oct 21, 2020
These tubes want 120 Volts at the plate and grid. How they derive that from 12 V @ 1 A is anybody's guess. This is what they call a Starved Plate design, and it doesn't really employ the tubes as anything but a cheesy trick. Whenever you see something purporting to be a "tube preamp", look for the hefty transformer needed to make a real tube pre work, that's your first tip off. This is less preamp and more of an Audio Effects device, but at $45...if it makes your material sound better to you, what does any of that matter in the long run?
Peccavi101
23
Oct 24, 2020
Yes, thank you, and I have seen that one and others like it and the power supply is obvious on some, but what I was wondering, and excuse my ignorance, for as an audiophile (long absent from that as my hobby/work) I had not spent much time exploring tube pre-amps, but though that perhaps some smaller units might be using an outboard PS (??), PLUS, of course there's quite a price difference.
ReadWryt
67
Oct 25, 2020
This demonstrates nothing that cannot be done with a quality solid state preamp though. Again, personal sound tastes aside, the tubes here are merely a gimick. Starved plate systems really don't do what a real, fully powered tube preamp does.
SunZmSpark
4
Oct 20, 2020
MitchhThe photos are horribly edited. Is it me or do the tubes look crooked? Looks like they were added to it in Photoshop.
BlooKazoo
374
Jun 1, 2022
D21esI wonder this too, just looks like some garbage off amazon or aliexp. Can't believe drop is selling this.
Rowdy2026
803
Jun 2, 2022
BlooKazooWhat’s even more baffling is people claiming they can ‘tube roll’ with positive effects on this underpowered solid state amp…not to mention the power supply couldn’t actually keep a candle burning.
InvisibleInk
118
Oct 19, 2020
I think I want one of these. Anybody have a recommendation where I can by tubes (e.g., "6J1, 6J4, 6AK5, 6K4")?
Frogmeat
562
Oct 20, 2020
InvisibleInkEbay, tons of them on there. But try it with the tubes that come with it first, they aren't the usual crappy Chinese 6J1 model that's tossed in most times.
mattris
1272
Keyboard Club Member
Jun 3, 2022
thmsIn the description: "The onboard headphone op-amp (OPA1656IDR) can also be replaced by higher-end op-amps like the MUSE02 or AD827."
SuperFlyEDSguy
58
Jun 6, 2022
thmsGreat question!
The dual replaceable Op-Amps are used to provide additive graphic equalization for the bass and treble controls via their pots (Rf) being in their respective feedback loops. The included Op-Amps are okay, are not really used for “coloring” audio, and will likely add a maximum 14dB to 15.5dB of bass or treble. It’s actually kind of a neat way to achieve equalization! You could of course add premium Op-Amps to help “color” the audio. To me, Burson V6 Classic Discrete Op-Amps would seem the natural choice. The Burson V5 would be more of a value specific choice, but you can’t go wrong with Burson (just NOT the V5i as you won’t find the overall value with them!!!) Just check the datasheets to ensure that you won’t go over the maximum current draw!!!
Note that two Dual Op-Amps are used. Each Channel (Left & Right) will require a separate Dual Op-Amp as the Bass frequencies are needed for one and the Treble for the other. The frequencies are then recombined before going to their respective Left or Right tube. This is why Dual Op-Amps are required (or four total ‘amplification’ paths), but only one tube is needed per channel.
The tubes, I can assure you, are most definitely real, though do yourself a favor and get yourself a closely matched-pair of NOS GE 5654W from Riverstone Audio! These tubes do color the sound, but don’t add amplification as that would call for about a minimum of 10x the voltage as per the datasheet. You will still get the “coloring” regardless as even a very small current being present will offer it. I have the first revision of this device along with the Riverstone tubes followed-up with an O2 Amp, and it sounds great!
Let’s not forget that this is ideally a solid preamp as preamps are not designed to amplify other than to (1) bring voltage to line-level when necessary or to (2) “color” sound, which may require a bit of amplification as a means to an end. Otherwise, preamps by definition could be used to (3) select audio-pathways (ins/outs) for amplification at a later stage. By looking at the board, the power circuit looks decent enough, the 5-band (blue) resistors are high quality, excellent caps are used to avoid noise at the beginning and final stages. The ultimate test is how it sounds though, and with the addition of the above tubes that cost me maybe $25, it sounds pretty damn good!
Good luck and be well!
——
Edits:
1) Fixed typo.
2) Added note on Dual Op-Amps.
(Edited)
mpearce
1
Jan 7, 2021
Just received mine, no RCA cable, no Bluetooth antenna and wrong tubes, what a joke.
kkkcok
3
Jan 6, 2021
Just received today one month delayed. It came with 6K4 tubes instead of the GE5654 tubes and no RCA cable.
SuperFlyEDSguy
58
Jun 6, 2022
kkkcok6K4 tubes are basically ‘generic’ GE5654 tubes, did the description say that they’re including the OEM GE tubes? Either way, it’s the GE 5654W tubes that you really want as they’re military grade, originally designed for and used on military radar systems, and sound exponentially better!
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