Help - FX-AUDIO TUBE-01 Best Board Revision? Tube-01 vs Tube-03?

[veronica77]

Hey guys I posted this on another forum but wasn't getting any hits so I posted over here too:


I’m looking to get a really cheap tube buffer or preamp to add a slight bit of color. The two buffers I’ve been looking at are the FX-AUDIO Tube-01 and Tube-03 models.
However, there are 2 different board revisions of the Tube-01, and I’m not sure which is better:

Revision 1.0 (text on board). FX-AUDIO Tube-01:

https://www.audiophonics.fr/17139-large_default/fx-audio-tube-01-valve-6j1-stereo-preamplifier-black.jpg

Revision 1.2 (text on board). Dilvpoetry Tube-01. No copper wire wrap compared to the FX-AUDIO (rev 1.0) above. Not sure of other changes:

Photo #8:

https://m.ebay.com/itm/2017-Dilvpoetry-TUBE-01-6J1-preamp-valvular-tube-amplifier-audio-amplifier-/253112557863

Any idea which one of these looks to have the better board??? The FX-AUDIO rev 1.0 is more popular but maybe older?



Compared to the winner above, does anyone have any opinions or statements about the FX-AUDIO TUBE-03? This buffer is newer, and comes with tone controls (which might be good for me) but the distortion seems higher. What do you think of this buffer vs the Tube-01? Not really sure if anything jumps out any anyone regarding the board layout:

https://www.audiophonics.fr/en/ampli-casquepreampli-preamplificateur/fx-audio-tube-03-valves-6j1-stereo-preamplifier-black-p-12400.html#idTabHCOM

Thank you very much! I really don't know which to pick!!

 

[DavidTT]

Tube purists aren't fans of the tube buffers available for cheap. I own an fx-audio tube-01 and have enjoyed it. I bought it to insert between a turntable and SS amp and believe it sounds great and looks cool too. I appreciate the ability to add gain and the unit has worked flawlessly. I did change out the tubes to GEJANs for sale on Amazon.

Whether the models with tone are good I cannot offer an opinion. I wish I had the model with tone but didn't know it was available when I bought the 01.

 

[veronica77]

Oh no worries, I'm not concerned about belonging to any purist camp. I'm all about getting the best possible for the ABSOLUTE LOWEST possible cost. I barely make ends meet as it is, so super budget stuff is all I can possibly go for anyways. I'm also very good with hardware mods, SMT soldering and the like. I enjoy tweaking everything I obtain to squeeze every ounce of capability from said unit.

Likewise, I'm using SS amps on a mostly digital setup (so preamp not usually needed anyways) but wanted to simply color the sound ever so slightly.

I'm hoping someone can explain the difference in Tube-01 board revision/changes and whether one is preferable to the other.

The Tube-03 looks interesting with Tone control, but I really wasn't sure about it. I'm not sure what to look out for in good/bad board layouts, etc.

 

[doctor fuse]

Oh no worries, I'm not concerned about belonging to any purist camp. I'm all about getting the best possible for the ABSOLUTE LOWEST possible cost. I barely make ends meet as it is, so super budget stuff is all I can possibly go for anyways. I'm also very good with hardware mods, SMT soldering and the like. I enjoy tweaking everything I obtain to squeeze every ounce of capability from said unit.

Likewise, I'm using SS amps on a mostly digital setup (so preamp not usually needed anyways) but wanted to simply color the sound ever so slightly.

I'm hoping someone can explain the difference in Tube-01 board revision/changes and whether one is preferable to the other.

The Tube-03 looks interesting with Tone control, but I really wasn't sure about it. I'm not sure what to look out for in good/bad board layouts, etc.

Well, then, best value for absolute lowest price would be the Tube-01. Very nice volume knob for the price, so if you ever find yourself in need of a volume attenuator, this unit will come in handy.

The change in sound is very subtle. Not so much "euphonic" low, even order harmonic distortion, but it does add air, definition, better bass and a bit more resolution (weird!) to my NAD 3020 (in the tape loop).

 

[kmolles]

Veronica77.....if you pull the trigger and buy one, I'll send you a pair of USA made 6AK5 tubes free as an upgrade!

 

[DavidTT]

+1. I've been surprised and quite happy when I add the Tube-01 to my SS setups.

Well, then, best value for absolute lowest price would be the Tube-01. Very nice volume knob for the price, so if you ever find yourself in need of a volume attenuator, this unit will come in handy.

The change in sound is very subtle. Not so much "euphonic" low, even order harmonic distortion, but it does add air, definition, better bass and a bit more resolution (weird!) to my NAD 3020 (in the tape loop).

 

[veronica77]

Hey I just wanted to update you guys regarding my selection! I went with the Tube-01 ($28 from Fasttech with free ePacket shipping!!). The version I got was the FX-AUDIO version with PCB version 1.0. I was advised from some others to NOT buy the alternate version by Dilvpoetry.

I absolutely love it. It does exactly what I need it to do, which is tighten up the low end a bit and get rid of some of the thump (the SA-98E amp is fairly warm). Helps a lot when I'm watching TV @ night and don't have to worry about waking everyone!

Things I've noticed:

1. It DOES provide gain, so definitely more than just a simple buffer. The people complaining that it doesn't, are likely trying to use it with a turntable or other device with an insanely low signal level. I've tried 3 devices in the "input", and this little buffer provides gain for each of them (different amounts however)

2. There is literally ZERO noise even when cranked to 100% volume. Same can be said with distortion... I just can't detect any.

3. The included default tubes are terrible. I picked up a wide assortment of 6ak5(w) / 5654(w) / 403b tubes and couldn't be happier.

4. Depending on which tubes I have in, it sounds WAY different. For example, the set of "National Union 6ak5 JAN" basically remove 90% of the low end and bass altogether (not very pleasant). But the sound is so vastly different to using another tube like the Raytheon JRP (1950s yellow print). The National Union tubes are pretty awful lol. But I'm glad I bought them, because it really woke me up as to how much this cheap device can affect/color the sound.

4. So far my favourite tubes are the 'JAN CHS Sylvania 6ak5' (currently on sake @ dbtubes for $3 each). They are sparkly, with really beautiful highs and mids, with very nice bass. It can be punchy and bass heavy but only when it's actually warranted. The PERFECT tube in my opinion. My second choice would either be my '1970s GE FAA (same as JAN) 5654w' or the 'LM Ericsson 5591/403b'.


But thanks to everyone who posted their advise, I really appreciate it. I hope more people will read this thread who are considering this device. This really should be the first device someone buys if they are on the fence about trying tubes. Nothing to lose @ $30 cost! I'm brand new to tubes, so I'm learning a lot as I go.


As for mods, I'll likely just replace the caps with better ones. I'm considering buying some tube sockets so I can strap pin 2 and 7 like the Little Lot AMP users do, to provide a much greater assortment of compatible tube families. Not sure if a higher MA power supply would be an advantage at all (likely not).

Would replacing the volume knob/POT be a worthwhile mod? I'm not sure if I'm using the correct word lingo so please don't flame me! Lol.

Cheers

 

[Nixxuz]

I got the Dilvpoetry and it seems just fine to me. I replaced with GE JAN 5654 and it really brought out a clarity and sparkle compared to the awful Chinese tubes. I use it as a buffer from my tablet/DAP, and for a little additional gain.

 

[KlipschFan61]

I use one between my Rotel CD player and my GemTune GS-02 KT88 amp. Swapped out the OEM power supply for an old school transformer 12VDC 1.5A power supply and stopped an annoying squeal the provided power supply was adding to the signal path.

 

[veronica77]

Swapped out the OEM power supply for an old school transformer 12VDC 1.5A power supply and stopped an annoying squeal the provided power supply was adding to the signal path.

I'm glad you mentioned that!! In all the reviews I've seen, I've noticed that the PSU that is included can be a different model from unit to unit. This would explain why so many folks notice the amp is dead quiet, while some others experience noise from the shady PSU.

I wired up a custom SMPS to use for my main AMP PSU and it is basically noiseless now. So maybe a 12v low noise SMPS (or linear) would be a step up!

I'll likely end up doing that anyways, but would really recommend it to any folks who say they can hear noise.


Does anyone know how the volume knob/pot works on this thing? Would there be any advantage to using a higher quality part here??

 

[FONSguy]

I JUST got one (Tube -01) on Saturday and had it between my CD player and poweramp/speakers. Saturday it sounded fine but just OK. Sunday (Left it on all night, playing quiet classical music) but Sunday it has a nicer sound stage and image. It will end up between my Mac Mini and amp speakers in computer room.

 

[cuchu]

Hi everyone!
A few days ago I changed the stock tubes for a pair of Voskhod 6J1P-EV. Now the sound is awesome! With the stock tubes I barely heard the bass. Now the sound is brilliant, magic, with much more character. The bass is present all over the room. The tubes seller recommend a 100 hours burn-in, to get the tube's best performance. In my case, it sound brilliant since the very first moment, so I won't force the burn-in time.

My audio set up is:
Raspberry Pi 3 (volumio software) + IQaudio Pi dac+ + Fx Audio Tube 01 (Voskhod tubes) + Pioneer VSX 324 amp + Q Acoustics 2020i speakers + Pioneer S-21W subwoofer.

At this time I haven't changed yet the Fx Audio power supply. The fact is I don't hear any distortion or noise using the stock wall wart. In other threats here (audiokarma), folks insists on the importance on using a regulated power supply to improve the performance of the Fx Audio.
I would like to know your opinion about that.

 

[Lorenzoextre]

Hi veronica77,

I was highly interested by your post about the FX tube 01that I own since past february.
Bought at Amazon Spain, and I immediately replace the chinese tubes by various :
5654W - GE and later 6J1P-EV 6ZH1P-EV EF95 6F32 NOS TUBE VALVE RÖHRE VOSKHOD 80's.
I have followed your advice about 'JAN CHS Sylvania 6ak5' and got them from dBtubes as indicated.
Thank you very much indeed ! i just set the tubes this morning , it might be too soon to appreciate
the full benefit of those new tubes but I already noticed a difference like more natural sound.
Bass sounds deeper but firm. Many hours more playing will reveal more I believe.A real good upgrade for this fantastic little device. As an amp I have a FX502S PRO modified thank's to the people here :
https://www.diyaudio.com/forums/class-d/315681-tpa3250-listening.html I am not keen at all in DIY but just follow advices to switch from the two TPA 3250 chips to new LME49720NA and the result is outstanding
considering the price of the FX. Thank's again , have a good day and keep enjoying music !

 

[petemcfc]

Theres a lot more info to be gleaned here.A long thread though you will be well served to read all the posts.
https://audiokarma.org/forums/index.php?threads/fx-audio-6j1-tube-preamp-a-31-wonder.848535/

 

[micho]

I just hooked up my Tube-01. There is a pretty loud humming through my speakers. When there is no tubes installed, dead quite. I just did that to test for 3 seconds. I know turning on isn’t a good idea without the tubes installed.
I tried different tubes, same problem. What could be the problem?

 

[tonyg88]

I just hooked up my Tube-01. There is a pretty loud humming through my speakers. When there is no tubes installed, dead quite. I just did that to test for 3 seconds. I know turning on isn’t a good idea without the tubes installed.
I tried different tubes, same problem. What could be the problem?

R u using phone? Is it grounded

 

[micho]

Tube-01 is connected to my Marantz amplifier. My source is Logitech SB Touch streamer/DAC. My speakers are 86db, not too efficient. My cables are little messy in the back meaning touching each other but I highly doubt that’s a reason for high buzz. I understand little hiss/buzz is OK/normal but this isn’t little.

 

[micho]

Problem solved.

I would have never guessed a power adapter would cause this issue! I didn’t use the original one since I had a “better” one to use. Obviously not better. I used a different 12V and boom! No noise whatsoever.

 

[micho]

One more thing to add; some people say this amp does not have enough gain. That is not true at all. This unit has a lot of gain, actually I think more than it should.