FX Audio 6j1 tube preamp - a $31 wonder

 
 
manizkrishn said:
If you are using Pyramid power supply, consider adding a 10,000uf / 16V output capacitor from Nichicon. I did this for my Musical Fidelity V90 DAC Pyramid power supply. It made huge difference for sure. The Highs and mids were smoother and bass was still tight and punchy. It was recommended by one of the amazon reviewer.
capacitor : https://www.digikey.com/product-detail/en/nichicon/UKA1C103MHD/493-4604-ND/2786979
https://i.imgur.com/ttbcMsy.jpg
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hummm... I'm not sure I understand 100%
 
newriverrat said:
I have searched/read a lot and my knowledge here is zilch, but I ain't afraid of that....Would the 6J1 work as a phono pre? I'm thinking of putting the 6J1 between the TT and the aux input on a h/k 730.
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OK, I'll flow the streaming through this and vinyl through this:


617NAF7VqZL._AC_SL1200_.jpg

71COJQDT4CL._AC_SL1200_.jpg
 
Frank Sol said:
hummm... I'm not sure I understand 100%
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Here is the original message :
Like many on Amazon I got this to replace the wall wart that came with my MF V-DAC mkII. I was a little disappointed with the sound. I have a high resolving system with Emotiva mono blocks and Paradigm S2 speakers. The addition of the PS3 to my system improved the bass extension, but I felt that the mids were muddied (vocals) and the subtile dynamics were lost. I listened with the PS3 in the loop for two days to much of my 192 and 96 24bit reference material. I decided to try to modify the power supply by adding a 10,000uf / 16V output capacitor from Nichicon. I fitted the cap right on the output terminals and did not even have to open the box. The increase in output capacitance filled in all that was missing. The bass remained very punchy/dynamic and the mids came back to life!
 
manizkrishn said:
Here is the original message :
Like many on Amazon I got this to replace the wall wart that came with my MF V-DAC mkII. I was a little disappointed with the sound. I have a high resolving system with Emotiva mono blocks and Paradigm S2 speakers. The addition of the PS3 to my system improved the bass extension, but I felt that the mids were muddied (vocals) and the subtile dynamics were lost. I listened with the PS3 in the loop for two days to much of my 192 and 96 24bit reference material. I decided to try to modify the power supply by adding a 10,000uf / 16V output capacitor from Nichicon. I fitted the cap right on the output terminals and did not even have to open the box. The increase in output capacitance filled in all that was missing. The bass remained very punchy/dynamic and the mids came back to life!
Click to expand...

You mean you soldered the capacitor to the L&R output RCA jacks? Please forgive my absolute lack of knowledge regarding anything electrical lol.
 
TheLex said:
You mean you soldered the capacitor to the L&R output RCA jacks? Please forgive my absolute lack of knowledge regarding anything electrical lol.
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yes. Solder the cap to power supply across the +/- terminals. Electrolytic caps are polar so you should not switch the positive and the negative terminals (the negative will have a black line down the side)
 
manizkrishn said:
Yes that is correct. You don't even have to solder. Sorry I didn't see the rca jacks in the comment. Here is a photo.
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While I Completely Agree with this working, the real question becomes choosing the correct cap value based on the specs of the given power supply. So I agree with 16v's for the cap voltage when using a 13.8v PSU, what really needs to be determined is the correct cap uF value for the actually DC wattage output of the given power supply unit.


Rob43
 
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Rob43 said:
While I Completely Agree with this working, the real question becomes choosing the correct cap value based on the specs of the given power supply. So I agree with 16v's for the cap voltage when using a 13.8v PSU, what really needs to be determined is the correct cap uF value for the actually DC wattage output of the given power supply unit.


Rob43
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I have no idea what is correct cap uF.. When i first used the pyramid power supply the bass was fantastic. The attack and timing was perfect. It was huge improvement from wall wart . It also made highs and mids sound bad. I just followed the amazon reviewer recommendation.It cost me $10 and It definitely helped.This is what the guy told me how the capacitor helps.

" Because it is linear does not mean it does not modulate the output voltage when it tried to regulate - in fact it does. Perhaps this is what we head as "muddy" sound. I would need to put a scope to actually confirm this. The cap on the output acts much like a large water tank and smoothes out transients. So give it a try and post your result here. Its very easy to install I just crimped the cap leads with the terminals. And yes electrolytic caps have a black stripe on the cathode (-) end."
 
manizkrishn said:
I have no idea what is correct cap uF.. When i first used the pyramid power supply the bass was fantastic. The attack and timing was perfect. It was huge improvement from wall wart . It also made highs and mids sound bad. I just followed the amazon reviewer recommendation.It cost me $10 and It definitely helped.This is what the guy told me how the capacitor helps.
Click to expand...

I'm certainly not calling you out or complaining, the info you're sharing is fine; it just needs to be taken a full step further.

I own the same 3 Amp Pyramid as you and it puts out roughly ~35 to ~41 watts. It wants/needs the correct value cap at 16 volts to operate at its full potential. So far the 10,000 uF cap looks like a guess, and I'm personally guessing that it's way to big a cap value for a ~35 watt PSU. There's a mathematical equation to determine this cap value, I just need to dig it up...


Rob43
 
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