FX Audio 6j1 tube preamp - a $31 wonder

The stock volume pot on the 6n3 is it's weak point. The FX's pot is far better and I counted 40 steps on it. They're small clicks but they're there.

The volume pot for me is good since I replaced - so it's a conundrum. Upgrade to a nicer new tube pre like the XiangSheng (awesome looking component but not a lot written about it and more expensive of course). I'm not sure I'd hear much difference with 6J1 vs 6N3. They seem very similar.

Or for a little more than the 6J1 - I could roll some GE 5670 5 star tubes into my 6N3, kind of leaning that direction after reading about them.
 
I've rolled lots of replacements for the 6n3 but none that beats the WE 396A/2c51. I have them in my Sainsmart but they are expensive. A single at Tubestore goes for $80. A few years ago I bought a Dared MP-2a3 amp and was ready to send it back because the sound sucked. The seller told me to replace it's 4 Chinese 6n3's with WE 396A's and when I did it totally transformed the Dared into a great sounding amp.

Better tubes can make a huge improvement but it's not always night and day like an upgraded power supply. With a better psu I think the FX is the better preamp.
 
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Should have my power supply this weekend. Went with this one https://www.amazon.com/gp/product/B07GWCB534/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1
Didn't want to go with a big Astron and the Pyramid's are kinda ugly. Hey looks matter. ;)

Out of interest,is there a benefit of using that type of power unit over a wall wort type such as this?
https://docs-emea.rs-online.com/webdocs/0531/0900766b8053153c.pdf
I take on board the flexibility of the Nobsound unit but once the output voltage is set at 12VDC that should be it.
From a price point,the 3 pin is £15 or cheaper and the Nobsound is £80.
Also is there a maximum and minimum load current to supply the FX?
Im asking this as I don't want to buy cheap,but then have to buy twice.
 
Out of interest,is there a benefit of using that type of power unit over a wall wort type such as this?
https://docs-emea.rs-online.com/webdocs/0531/0900766b8053153c.pdf
I take on board the flexibility of the Nobsound unit but once the output voltage is set at 12VDC that should be it.
From a price point,the 3 pin is £15 or cheaper and the Nobsound is £80.
Also is there a maximum and minimum load current to supply the FX?
Im asking this as I don't want to buy cheap,but then have to buy twice.

The one you linked to is an unregulated supply. They typically have a lot of ripple and other noise on the DC power. Fine for charging batteries not so fine for audio circuits.
 
Thanks. I can not solder, so that's out of the equation.

Now I am thinking of putting a passive preamp volume control nob between the Dilvpoetry and Emotiva SA-250 main amp (with 23.5k Ohm input impedance). I am thinking of basically cranking up the volume on Dilvpoetry tube preamp to eg. 12PM and then use the passive pre for actual volume control.

I'm looking at some reasonably priced FV3 units on the bay. I am confused about the impedance though, should I get 10k or 50k version? And should I go with ALPS RK27 or RK168 potentiometer?

ALPS specs:
https://www.alps.com/prod/info/E/HT...otentiometers/RotaryPotentiometers_list1.html

Answering my own question, I think I am gonna go with a 10k Ohm pot. Good calculator here:
http://dact.com/html/ac_calculator.html
 
Thanks. I can not solder, so that's out of the equation.

Now I am thinking of putting a passive preamp volume control nob between the Dilvpoetry and Emotiva SA-250 main amp (with 23.5k Ohm input impedance). I am thinking of basically cranking up the volume on Dilvpoetry tube preamp to eg. 12PM and then use the passive pre for actual volume control.

I'm looking at some reasonably priced FV3 units on the bay. I am confused about the impedance though, should I get 10k or 50k version? And should I go with ALPS RK27 or RK168 potentiometer?

ALPS specs:
https://www.alps.com/prod/info/E/HT...otentiometers/RotaryPotentiometers_list1.html
Would not recommend this as being an unfavorable loading for the little pre.
 
What do you guys think about the video I posted page 42 ?

To me the preamp ad a little something in the tightness of bass frequencies. It's still very subtle.
The only bad thing to me is the hum I can percieve when there is no music (what would cause that ?)
 
What do you guys think about the video I posted page 42 ?

To me the preamp ad a little something in the tightness of bass frequencies. It's still very subtle.
The only bad thing to me is the hum I can percieve when there is no music (what would cause that ?)
Forgetting the words and riffing.
Seriously, the hum could have a number of factors, added gain of the signal chain amongst them.
 
To me it sounds like a transformer hum.
No hum when I remove the preamp from the chain.
Could be a ground loop, or just the added gain with the pre in the chain. I'm a minimalist as far as the signal chain goes, the least to get the best result and no more.
 
Would not recommend this as being an unfavorable loading for the little pre.

What would be my best option? Should I just go w/ Harrison attenuators? And should I put them on the input or output side of the tube preamp?

Or can I put the passive preamp volume knob on the input side of the tube preamp?
 
The addition of the power supply has definitely been a worthwhile addition. Bass has been tightened up and better defined. And there has been increase of detail across spectrum. Very happy with the purchase.
 
What do you guys think about the video I posted page 42 ?

To me the preamp ad a little something in the tightness of bass frequencies. It's still very subtle.
The only bad thing to me is the hum I can percieve when there is no music (what would cause that ?)

I have experienced this using a switching power supply,I have another two switching power supplies that don't give out hum though without music playing at a 12 o'clock at the volume setting there is noise.
As other posters have pointed out to me the power supply needs to be uprated to a linear.
 
I'm not completely sure about the output configuration of your preamp, but the loading of your power amp may be all it should have to drive. Adding a 10k passive between will make it 3-4X the load of the power amp alone. The amp also needs a pre for full output.
 
I've rolled lots of replacements for the 6n3 but none that beats the WE 396A/2c51. I have them in my Sainsmart but they are expensive. A single at Tubestore goes for $80. A few years ago I bought a Dared MP-2a3 amp and was ready to send it back because the sound sucked. The seller told me to replace it's 4 Chinese 6n3's with WE 396A's and when I did it totally transformed the Dared into a great sounding amp.

Better tubes can make a huge improvement but it's not always night and day like an upgraded power supply. With a better psu I think the FX is the better preamp.

Picked one up and am burning it in. So far seems more "bassy" than the 6N3-EV, which in all honesty was subtle in what it added compared to direct.

The 6J1 is nice little unit, too bad it doesn't have input selector and I am glad my SMSL DAC has some gain control for low level listening. If I use it, will need to add another small "box" to my mini component system, DACT passive pre perhaps?
 
While I'm crazy about the the FX preamp and the DACT passive preamp I would only use them in separate systems. They both control the volume but in different ways. A simple switch box provides multiple sources for the single input FX and it does not degrade the signal. The DACT passive preamp OTOH comes with 4 source inputs. The FX with it's extra gain is ideal paired with the Miniwatt while the DACT passive sounds best with the single ended EL84.
 
While I'm crazy about the the FX preamp and the DACT passive preamp I would only use them in separate systems. They both control the volume but in different ways. A simple switch box provides multiple sources for the single input FX and it does not degrade the signal. The DACT passive preamp OTOH comes with 4 source inputs. The FX with it's extra gain is ideal paired with the Miniwatt while the DACT passive sounds best with the single ended EL84.

Good to know, the DACT has me thinking for other setups too. For now will experiment a bit using different amps with the little 6J1.
 
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