Good News / Bad News: Final update on the Linestage and 6DJ8 articles

Standing on the Shoulders of Giants


by Steve Graham


Since the last update I’ve been corresponding with Hari S. (I hope I’ve spelled his name correctly now), the buyer of the first N-F-P.  Hari had questions about improvements to the N-F-P.  Before returning the tubes used in the 6DJ8 shootout to, I decided to have one last listen to the Genalexes in the prototype N-F-P.  After that I connected the ARC Ref 3 back into my system.

The tube set in the prototype is the same as the one Hari bought, NOS Tesla input tubes and new production JJ in the output positions.  The tracks used for comparison were: Digging in the Dirt from Peter Gabriel’s Secret World Live, Golden Heart from Mark Knopfler’s album Golden Heart and The Mystic’s Dream from Loreena McKennitt’s album The Mask and Mirror.

The following comments I sent to Hari:

The Tesla/JJ combo: Not the ultimate in resolution but pleasing sound.  The bass, depending on personal tastes and the system they’re used in could be called a little over-ripe or if it matches your tastes you might call it “organic” as I do.  The midrange and treble are pleasant, again not the ultimate but they play together well and don’t seem like separate entities the way they do with some tubes.

The Genalex reissues: The bass is tighter than the Tesla/JJ set but slightly less deep.  It is more articulate and better defined than the Tesla/JJ though.  Both male and female vocals are clearer and more detailed than the Tesla/JJ combination but not over-prominent.  The treble is detailed but not “etched” or fatiguing.  The soundscape is also more spacious compared to the Tesla/JJ set.

The REF3: The NFP with the Genalexes has gotten closer to the REF3 than I thought possible.  The two line stages sound quite similar!  The REF3 doesn’t have the congestion in high level passages that is sometimes a bit apparent in the NFP with the Genalexes.  This might be related to the fact that the REF3 is a noticeably more dynamic over all.  The REF3 is more articulate across the spectrum but not by a whole lot.  The imaging is better layered with the REF3 if I listen for it specifically.  I don’t “listen” for imaging when I listen for pleasure but I notice it when it is poor and the music seems two dimensional.

The N-F-P continues to surprise and delight.  That this little 3½ by 7 inch (9 by 18 cm) circuit board together with a 25 dollar transformer, a volume pot, a couple of switches, some cheap jacks, a few pieces of wire and a handful of other inexpensive parts can sound as good as it does never ceases to amaze.  That’s the good news.

The bad news:  

As always it costs more to get more.  A set of 4 Genalexes will set you back almost $300 CDN, taxes and shipping in.  Two JJs and two Teslas, $150 CDN.  Regardless of the tubes chosen, the N-F-P treats them gently.  Assuming two hours’ use a day, every day, a set of tubes should last 3 or 4 years minimum.

Three hundred dollars may sound a bit steep for 4 tubes, but here’s my plan: If you frequent our nation’s favourite coffee emporium, Canadians will know what I’m referring to, once a day on your way to work you’ll spend $300 minimum in about 30 weeks.  If you make coffee at home before you leave, the 15 cents it will cost you will about balance out the gas you’ll save not waiting in the drive-thru line. So essentially, coffee will pay for your tubes.

The other thing I’ve discovered while playing and prodding the N-F-P prototype is the Aikido circuit works best when the input tubes, V1 and V2, have well-matched sections.  What I mean is both triodes in any particular tube should test within 4% of each other or better.  Pay a little extra, maybe $5 a tube, to have the tube vendor of your choice select two tubes out of their stock where each tube has sections with nearly identical measurements.  Section matching, as far as I have been able to determine, isn’t quite so critical for V3 and V4.


The N-F-P prototype has gone to a new home as well.  Jan W. of Saanich, B.C. couldn’t resist the temptation of tubes, though he did comment that he might be testing the tolerance of his lovely, beautiful and (up to this point) understanding girlfriend.  As with the first N-F-P, Jan’s purchase price will go to the Georgian Bay General Hospital in Midland Ontario for the capital equipment renewal program too.

Thanks again to Midland Tool & Machine, LaserMark Engraving and for their support on these projects.

The box of tubes used in the 6DJ8 shootout has gone back to Thetubestore, but it was four tubes lighter.  I purchased two Teslas and two Genalexes for my “inventory”.

This is the last you’ll hear from me on the N-F-P line stage and 6DJ8 tubes for a while, I promise.


As always please feel free if to leave a question or comment.  We love hearing from you if it’s positive and even if it’s criticism of the “constructive” sort.



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3 Comments on Good News / Bad News: Final update on the Linestage and 6DJ8 articles

  1. Hi everyone…this is Jan W. and I just want to say that I LOVE my new NFP and (other than more music) it truly is the best $450 that has been spent on my system. And it is really cool that the money goes to charity so thanks to all who donated their time and efforts to make the NFP come into being…. Jan (a happy man)

  2. Steve Graham // 2017/02/15 at 2:31 pm // Reply

    Thanks for leaving a comment Jan, I’m pleased you like the NFP. I’m actually rather surprised both of the NFP’s sold. I had interest from as far away a Hong Kong but Hari for the first NFP and Jan for the prototype were the first ones to send money so thank you both.

    If I can quote myself briefly from the end part 4 of the NFP series “…..if you have an old un-loved component that could supply a ‘donor’ chassis and maybe even the input selector switch, jacks and a volume control, the cost of making this line stage can probably be driven down to around the $500 mark. In fact my audio pal Dougie, who took the N-F-P out for a spin and commented on the performance back in Part 1, has a ghastly, non-functioning, opamp chip-sporting Quad preamp that could be the perfect ‘donor’ chassis. Hmmm.”
    Well, Dougie presented me with the old Quad and said in effect, “have at it”.
    It guess it serves me right for taking on the smartest kid in the class. Dougie had a doctorate degree in laser physics, what was I thinking trying to match wits with him.
    But the old Quad has a decent case and an Alps Black Beauty volume control, a good place to start from. Looks like the time and budget for next winter’s project has already been spoken for.

    All the best, Steve Graham

  3. It has been more than 4 months since I receive Steve’s NFP (Aikido 12V) and live by it. Evaluate it; so I know a bit by now. It is a truly wonderful unit in my opinion for price performance ratio. The fact that it uses 6922s are nothing but good in this case. Tried many 12AU7, 12AX7 and 6SN7s before. It has been a journey; of course it is circuit dependent. Also, worth to mention that Steve and others do toward Midland Hospital are very special. Kudos and thanks.


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