Very cheap FX Audio tube-01 preamp

bryblob

Super Member
I bought this preamp/buffer a week ago, I wanted to try something that was tubed. I have had only solid state since I started this hobby maybe 15 years ago. I know this thing isn't exactly giving me the full tube experience, but for the money, pretty damn good. I swapped the tubes for some nos GE 5654w's, and it sounds really good, the stock tubes weren't doing it for me. Anyone tried one of these?
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I have pretty much the same thing with a headphone jack on the front. The GE 5654W's made a huge difference, very quiet. The chinese 6j1's were horrible. kinda cool, I use it for a headphone preamp and a preamp for testing on my bench. Takes up very little room! How does yours sound? It should be tubes in the front end and single ended SS output. I thought it sounded pretty dang good for $50 + $10 worth of tubes.20161201_113439.jpg
 
i have the same preamp but i have it set up to my turntable. The volume it is providing is very low and i cant really hear it through the headphone i have plugged in
 
i have the same preamp but i have it set up to my turntable. The volume it is providing is very low and i cant really hear it through the headphone i have plugged in
Does the turn table have a MM cartridge? Do you have a phono preamp between the turntable and headphone amp? Plugging a tt into a line level input without a phono preamp will get you only very low volume.
 
low volume: you need a preamp with 40+ db gain to amplify the signal UP. also,
it needs the RIAA phono filter curves to properly process the LP signals.

there are really cheap phono amps off ebay - about $12.
 
Yes, I have one and really like it. I have it hooked up in my main system between the pre and power amps. It sounds sweet with the GE 5654w tubes!
 
Hey guys,

Picked up one of these with the GE tubes here on AK awhile back. Maybe from one of you! Can’t remember for sure.

Anyway, I’m wondering if anyone here can answer a couple questions for me.

First, I’m seeing this referred to as a preamp and also as a buffer. It seems more often to be called a buffer.

Is this a buffer? If so, and I have a receiver I’d like to try this out with, can I just stick this between the pre/main sections of the receiver? (It has jumpers)

If so, any suggestions on where to put the FX volume control? Is there just a sweet spot where it’s neutral. No gain, no attenuation?

I realize I can experiment with that, but my wife friendly LR system is a chore to get in and out of, so a good starting point would make this simpler.

Anyway, thanks in advance to anyone who wishes to offer advice.

Regards,
John
 
Hey guys,

Picked up one of these with the GE tubes here on AK awhile back. Maybe from one of you! Can’t remember for sure.

Anyway, I’m wondering if anyone here can answer a couple questions for me.

First, I’m seeing this referred to as a preamp and also as a buffer. It seems more often to be called a buffer.

Is this a buffer? If so, and I have a receiver I’d like to try this out with, can I just stick this between the pre/main sections of the receiver? (It has jumpers)

If so, any suggestions on where to put the FX volume control? Is there just a sweet spot where it’s neutral. No gain, no attenuation?

I realize I can experiment with that, but my wife friendly LR system is a chore to get in and out of, so a good starting point would make this simpler.

Anyway, thanks in advance to anyone who wishes to offer advice.

Regards,
John

Yes, I have one and really like it. I have it hooked up in my main system between the pre and power amps. It sounds sweet with the GE 5654w tubes!

Dur, I was a little buzzy last night when I found this thread! Clearly I missed this post by Dunhill. So, any advice on where the sweet spot for the volume will be? Gonna give this a shot tonight.

Thanks!
 
I have an unwieldy system - Alternate Audio 4' planar speakers with ribbon tweeters and 6.5" cone woofer, and a Velodyne subwoofer, tri-amped with an old Electrohome SET (for the ribbons), Conn Push-Pull tube amp for the main planars, and a Nikko Alpha II dual mono SS power amp for the woofers. Preamp is from a Rotel RX-855 receiver. Source is a Thorens TD-160, with Benz-Micro Wood SL (most expensive component of this system!) to a Benz-Micro Lukaschek PP-1 MC phono stage, or a PS Audio Digital Link III DAC.

To this weird but wonderful system, I have just added the El Cheapo FX-Audio Tube-01 tube buffer/preamp (in front of the main Conn PP amp).

Holy Moly! Big improvement in matching the Conn to the planars! Before, the planars would distort with timpani and other low frequencies, when driven very loud. Now there is almost no distortion!

I imagine it has something to do with the tube buffer making the impedance matching much better. Can anyone with more technical knowledge chime in with why there would be such an improvement?

I am very happy with this $40 CAD (including 12V power supply) little gizmo. No noticeable extra noise or hiss, which I was worrying about the most. And the volume knob feels good, and the tubes glow a nice bright red.
 
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I have an unwieldy system - Alternate Audio 4' planar speakers with ribbon tweeters and 6.5" cone woofer, and a Velodyne subwoofer, tri-amped with an old Electrohome SET (for the ribbons), Conn Push-Pull tube amp for the main planars, and a Nikko Alpha II dual mono SS power amp for the woofers. Preamp is from a Rotel RX-855 receiver. Source is a Thorens TD-160, with Benz-Micro Wood SL (most expensive component of this system!) to a Benz-Micro Lukaschek PP-1 MC phono stage, or a PS Audio Digital Link III DAC.

To this weird but wonderful system, I have just added the El Cheapo FX-Audio Tube-01 tube buffer/preamp (in front of the main Conn PP amp).

Holy Moly! Big improvement in matching the Conn to the planars! Before, the planars would distort with timpani and other low frequencies, when driven very loud. Now there is almost no distortion!

I imagine it has something to do with the tube buffer making the impedance matching much better. Can anyone with more technical knowledge chime in with why there would be such an improvement?

I am very happy with this $40 CAD (including 12V power supply) little gizmo. No noticeable extra noise or hiss, which I was worrying about the most. And the volume knob feels good, and the tubes glow a nice bright red.

After spending a month with the FX, its shortcomings are now apparent.

I finally set the gain past 50%/12 o'clock, and distortion is very audible (and not the euphonious tube kind). Not much of a power supply with this thing, so I imagine that's where most is coming from.

Still, it works as a volume attenuator in my tri-amped system, to lower the volume of the solid state Nikko amp.
 
What's the output voltage on the wall wart power supply? I usually keep old laptop power supplies. They can have better filtering and more available current.
 
What's the output voltage on the wall wart power supply? I usually keep old laptop power supplies. They can have better filtering and more available current.

12VDC if I remember correctly. I remember I wanted to see if a couple of solar panels would run it in the sun!
 
Listening to the FX in my bedroom system, and it sounds really good here. Dual 1009 SK mkII, Excel ES70EX4 cartridge, NAD 3020, and Goodmans Minister speakers.
Putting the FX in the tape loop of the NAD, there is a subtle difference if I get the two volume controls so that the volume is almost identical whether the tape monitor is engaged or not.
Slightly better bass, nice midrange and highs, seems like more detail comes through.
 
I just picked up the FX-Audio Tube-01 and inserted it between a U-Turn Orbit Walnut with Pluto internal and a pair of Edifier RT1280Ts in a budget office system. At first I thought meh, didn't seem to do much except add the potential for gain, but as it warms up I may be hearing a wider soundstage. It certainly does not hurt the sound and may be adding a touch of warmth and separation. It could be in my head of course, but for $34.99 shipped, to add a little glow to the set up cannot hurt right?

I've ordered the GE replacement tubes available on amazon and will see whether they make any discernable difference.

For those using the Tube-01, where have you been happiest with the gain?
 
I just picked up the FX-Audio Tube-01 and inserted it between a U-Turn Orbit Walnut with Pluto internal and a pair of Edifier RT1280Ts in a budget office system. At first I thought meh, didn't seem to do much except add the potential for gain, but as it warms up I may be hearing a wider soundstage. It certainly does not hurt the sound and may be adding a touch of warmth and separation. It could be in my head of course, but for $34.99 shipped, to add a little glow to the set up cannot hurt right?

I've ordered the GE replacement tubes available on amazon and will see whether they make any discernable difference.

For those using the Tube-01, where have you been happiest with the gain?

Do you mean what setting? I keep the volume pot no more than at 12 o'clock, usually closer to 10:30 o'clock. I am one of those people who likes the main amp volume pot on the high side, so keeping the FX down helps here.
 
Tried to find a more powerful 12VDC power supply in my junk room, but seemed to have everything but (9-24VDC). So I just ordered a 12VDC 5A supply. Hopefully this will improve distortion when cranking the FX volume pot past 2 o'clock.
 
I have been using this little FX-audio (with OEM Chinese tubes) for a couple of hours now and I think I like it. Differences are subtle but I feel like I might hear more openness to the sound, more separation perhaps. Like I said before, it's subtle and possibly all in my head. We'll see if there is any difference made by the GE tubes once they arrive. Luckily I'm getting zero noise out of this little jobbie even with high gain. I've been playing around with gain settings between it and the Edifier 1280T volume control.

This hobby is both wonderful and cursed. Endless tinkering, thank goodness there are super cheap ways to tinker.
 
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