FX Audio 6j1 tube preamp - a $31 wonder

Those aren't 6AK5, they are small signal twin triodes.
I do not not know when hobbyists adopted either.
Certainly not dump fodder now, my 6AK5s (lost in storage and probably trashed) were acquired in the 1950s as hand-me-down milsurp, and afaik were mainly used in radar IF strips.

If you refer back to your post ( # 271 ) you're dissing the 6n3 by saying they are an odd ball line stage, with no market and no demand for them. Nothing could be further from the truth.
 
If you refer back to your post ( # 271 ) you're dissing the 6n3 by saying they are an odd ball line stage, with no market and no demand for them. Nothing could be further from the truth.
It was true when tubes were the dominant technology, these tubes had to my knowledge no consumer applications. That was what I was referring to.
Hobbyists have explored audio apps for common inexpensive military/industrial types as well as TV tubes since then, lotsa fun on the cheap for diy types. That complete user friendly componentry is on offer using them is a boon for non-diy enthusiasts, this is a relatively recent phenomenon.
 
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It's pretty obvious that you don't care for the 6j1/6ak5 tubes that come in the FX.

My question is why are you even interested in the the FX and this thread?
I never said that, I find it interesting as an application for a surplus tube without audio bona fides.
The usual suspects for this app are the families of linear dual triodes, single linear triodes, and the occasional 6AU6 or EF86 pentode when higher stage gain is desired. Small low power RF pentodes like 6AK5 for audio do not show up in the tube bibles like Langford Smith's Radiotron Designer's Handbook. That's what makes the application an "oddball".
 
Do you put this unit right after the source or after the pre/phono and before power amp? Just got one had to try it out
 
The FX has one pair of inputs and one pair of outputs. A single source ( CDP, DAC etc ) connects to the inputs with RCA cables. The FX's pair of outputs connect to the amp's input via RCA cables. If you want to use several sources with the FX you'll need a switch box.
 
Yes, it takes a line level source from a phono preamp or other signal source and feeds it to a power amp with a bit of boost.
It doesn't have a really high level output capability, but should be sufficient for most basic setups.
 
How about a SINGLE 10 amp 13.8 Volt DC Pyramid Bench Power Supply to power BOTH the FX and +D ?

I dont see why not
 
Bought a pair of Elac B6.2 that were on sale before Christmas. Swapped out my Caintuck Betsy's for the Elac's this weekend to see how they would do with a Tripath chip amp and the FX Tube01.

The Elac's sound very good. Compared to the Caintuck's, some detail is lost, the crossover smears, and the bass is flabbier, but they are still eminently listenable.
 
Just out of interest, does anyone know how much electricity these bulbs consume in standby? I'm used to leaving my amp turned on 24/7, but that's probably not so smart with this tube buffer?! I'm not a rich man :))
 
according to my kill a watt 4w just plugged not playing, so it uses the same power as a night light ... an insignificant amount

i don't know how long the stock tubes will last, but one of the recommended tubes are the military jan 5654w should last thousands of hours or more in standby and the tubes are inexpensive so i keep mine on 24/7
 
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