FX Audio 6j1 tube preamp - a $31 wonder

Just hooked mine up about 10 minutes ago. Looks ridiculous sitting next to my McCormack DNA amp...TIIIIINNNYYY little preamp sitting next to a rather large amp. Sounds good though. I'd like to disable the red LED's, I might do that but it's very low on my overall priority list LOL.
 
Very nice. And ‘piano keyboard’ is one of your inputs? Sounds like fun.

Yep :) Simple Yamaha keyboard that the kids like to play and practice on. My wife asked if it was possible to hook up the keyboard to the main system, and I of course obliged, improving the overall WAF :)
 
One question for the circuit knowledgeable folks on this forum. This preamp seems to have quite a bit of gain compared to my Mapletree 2ASE (6SN7 point to point wired preamp)which has 10 db gain, The FX Audio seems to have maybe twice as much gain? Is this gain from the tubes or is there an OP amp hiding in there somewhere? I looked at the picture of the bare preamp but it's all Chinese to me :)
 
use chrome to translate automatically. but the text doesnt matter much, I posted mostly for the pictures and the graphs.
overall, it didnt measure stellar but the guys measurement equipment is very iffy.
 
One question for the circuit knowledgeable folks on this forum. This preamp seems to have quite a bit of gain compared to my Mapletree 2ASE (6SN7 point to point wired preamp)which has 10 db gain, The FX Audio seems to have maybe twice as much gain? Is this gain from the tubes or is there an OP amp hiding in there somewhere? I looked at the picture of the bare preamp but it's all Chinese to me :)
Model without tone controls is all one single triode wired small-signal pentode per channel, with a dash of cathode degeneration.
The model with tone controls has ICs handling the tone chores with the little triode wired pentodes doing the rest. As usual, the one minus the tone controls is the simpler "cleaner" path.
 
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Measurement-wise, it isn't lab standard gear, nor was it meant to be. It's a fun little budget tube preamp stage without pretentions. There are equally bugetary preamp stages using ICs that measure much better.
 
I have the gold pinned Ericsson 5591's and love them. RCA makes a 6AK5 with the identical construction, except for the gold pins, which do not make an audible difference IMO.
I also ordered the Japanese version because it has a separate switch, which controls the gain without effecting the volume.
The FX Audio "toys" are getting pricey, I paid $68 for the FX Audio 01J and saw two sellers offering the same unit at $169!
 
I haven't had much chance for critical listening, but since putting the FX in the chain with the Voskhods I think the bass may be sounding a fair bit quieter/rolled off, while the mids and highs are sounding forward, clear and lush. Anyone else finding this at all?!
I'm using the Voskhods an
I haven't had much chance for critical listening, but since putting the FX in the chain with the Voskhods I think the bass may be sounding a fair bit quieter/rolled off, while the mids and highs are sounding forward, clear and lush. Anyone else finding this at all?!

I´m already using the Voskhod 6J1P-EV (the ones with rocket logo, OTK and Rhombus)
The fact is I noticed the bass quieter / rolled off with the chinese tubes.
By the time I connected the Voskhod the bass became much more present, to the point that I had to lower the volume of the subwoofer. Yesterday, listening to "Red Hot Chili Peppers - Under the Bridge", Flea's bass sounded spectacularly.
 
I'm using the Voskhods and ...Flea's bass sounded spectacularly.

Thanks for your experience. I don't have a sub, and only bookshelf speakers so the bass is never going to blow me away. But with the FX 01 out again briefly yesterday the bass did seem more present again. It's not so much the amount as the definition. I think that in my system the buffer adds some tube sweetness (especially highs which are less harsh) at the expense of some mids detail and lower frequency tightness, for want of better terms to describe it! Still on the fence whether to keep it.
 
Is anyone running the Tube-6J1 pre-amp with a turntable? Going from the turntable to the 6j1 and then into a receivers Phono input? I”m not sure if I can do that. Since the phono board in the reciever may not be compatable with the output from the 6j1 tube buffer. I have gone from my phono pre amp to the 6j1 and then into dynaco st-70, that works great. But I'm not sure of going into a receivers Phono input.
 
Is anyone running the Tube-6J1 pre-amp with a turntable? Going from the turntable to the 6j1 and then into a receivers Phono input? I”m not sure if I can do that. Since the phono board in the reciever may not be compatable with the output from the 6j1 tube buffer. I have gone from my phono pre amp to the 6j1 and then into dynaco st-70, that works great. But I'm not sure of going into a receivers Phono input.
Yep,Audionote TT1 into Project phono,FX and Allo.Sounds detailed,warm and sweetly conducts itself.:)
 
I also ordered the Japanese version because it has a separate switch, which controls the gain without effecting the volume.
The FX Audio "toys" are getting pricey, I paid $68 for the FX Audio 01J and saw two sellers offering the same unit at $169!

Looking forward to your comments on the version with separate gain switches.
 
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My Dilvpoetry TUBE-6J1 has the tone controls, and quite a bit of gain. The manual claims 'Preamp gain 5 times'

Dilvpoetry_Tube_6J1_2019_02_15 8_21 AM Office Lens.jpg
 
Is anyone running the Tube-6J1 pre-amp with a turntable? Going from the turntable to the 6j1 and then into a receivers Phono input? I”m not sure if I can do that. Since the phono board in the reciever may not be compatable with the output from the 6j1 tube buffer. I have gone from my phono pre amp to the 6j1 and then into dynaco st-70, that works great. But I'm not sure of going into a receivers Phono input.

You want to go from the TT to the FX pre-amp and then into the phono stage on your receiver?

Don't do it.
Your phono stage isn't going to like that input level at all.

More than that, unless your receiver allows you to run it as a power amp, you don't want to be plugging the FX into any of the other non-phono connections either.
Receivers/integrated amps already have a built-in line stage.
Essentially, you'd be running one pre-amp directly into another.
 
To run a tube stage into a preamp line input as a "tube sound" filter would best require a unity gain cathode follower stage, to avoid the additional gain problems and polarity inversion factor. Too bad FX doesn't offer this to folks that just want a touch of tubeage.
 
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