Shady Lane

Posted by Audionorth (A) on January 19, 2011 at 22:45:49

I've had the post included below deleted by Brian Smith, Moderator of the Audio Note kits site (not AN UK) on the AA forum. Brian emailed me and I quote:

"Hi Mike- Here is your post -It's a good one with lots of good infor but I deleted it because of the Andy Grove bridge comment - that's all - if you want to re edit it and re post that is fine
Thanks
Brian"

he then added after I reposted the unedited version " . . .Its an unfair comment." He didn't say not factual but "unfair" . . .is the moderators perception of a factual statement grounds for deleting a post?

I was responding to another member's post which is included below in quotes. I've had a consistently bad experience with Brian as a customer but continued to deal with him as he is THE dealer for North America. I negotiated so I paid in full only after all my components arrived . . . I wouldn't deal with him again any other way . . .

So we AN kit fans have learned to put up with his abysmal customer service, lack of follow through, unanswered e-mails, unanswered phone calls, kits with missing parts, and the list goes on . . . But unilateral censorship of posts with impunity. . .really? Is this allowed or okay with the AA community or overall site moderators?

Here is the unedited "controversial" post in its entirety:


Posted by Audionorth

RE: Various questions - mono block kit & L3 pre kits
------------------------------
Hi Vincin,

Since nobody else has responded I thought I would throw out a few ideas to
get the ball rolling . . .

"1) L3 - decoupling choke/cap for 1st 5687 stage: some differences in the forum regarding the need of this in the DAC and L3. What is the consensus now? Does the AN factory unit power supply have this? Brian didnt send me the choke/cap, I have nothing to try..."

I experimented a bit with this having both choke/cap and no choke cap. I ended up after various listening tests, caps, and capacitance combinations preferring 4 x 22uf Black Gate VK caps per channel in parallel (what was available) for a total of 88uf per channel (I use 2 chokes, one for each channel). I preferred this to not having the combo from a sonics perspective but as you already know there are contrary opinions about this.

. . another listen and see what you think. . . technically it may not make sense but I went with my ears and limbic system on this one . . .


"2) power supply caps - what do you guys use these days in the mono, pre and DAC? If I can only use electrolytics, is the Jensen or Mundorf lytics better, or just dont bother (I have the JJ caps supplied)."

I tried lower value -- 100uf Mundorf Tube Caps in the PS when I first built my DAC which I liked the top end but found the bottom end significantly lacking . . . higher values may be interesting (others can comment on this). . .

I didn't experiment a lot but Tubeheadz promoted the TS-ED 450v Panasonics which are high quality, affordable, come in many sizes, and IMO sound pretty good for an electrolytic cap in the C3, C5, C6 and C7 positions. Again, up for debate but I have good results using C5 68uf, C3, C6 and C7 somewhere between 150 and 180uf 450v (excluding C5 these are all higher values than the original circuit. . .(I tried various values and landed on these for my system/preferences). This in combination with the AN coppers in C1 and C8 and using a Bendix 5852 rectifier, and either a Mullard or Telefunken ECL82. I used BGs on C9, C2 & C4

I prefer the 7119s to the 5687s and also like the 7044s but again system synergy is key . . .

"3) 300b filament caps, is there a 100uf cap at the end? mine only have two 4700uf caps."

IMO: the 100uf cap was omitted because the PCB had an error when made and doesn't allow for it. (However, the stock PCB can be tweaked and the cap used if you desire.) I had some PCBs made that allowed for the 100uf cap and greater ease of use of individual diodes instead of a bridge including different heatsinking. I don't think the heatsinking is
better just different but the connection of the PCB to the amp chassis is
more robust.

I used BGs in the filament supplies. . . why, because I'm building Audio Note amps going for Audio Note "sonics". . . ;-)

"4)6sh7 filament, I saw a post in the SET forum showing DC filament for the 6sh7 stage. Maybe I can do this to solve the remaining hum? What do you guys have?"

I used the same PCB BG cap arrangement with slightly different resistor values to get the 6.3v instead of the 5v, and same LT1085 Adj regulator for the 6SH7GT supply.

My L3 and DAC are sorted and sound great. I'm having trouble with my 300Bs which I may post about later to access any experience out there that may be useful. . .

"5) I also saw a post somewhere here regarding changing the zener diode in the M2 power supply with the OB2 tube (as used in the factory unit)? I saw a schematic posted by "Exorcist". Has anyone tried, does it work?"

This is out of my league but I believe there are some people out there working on this one. . .maybe they would like to chime in . . .

"6) any other tweaks and upgrade experience you can share?"

I added like many, the C-core opt txs to all my projects: DAC, L3 and 300Bs. Different diodes, a separate PS transformer for the DAC digital board, Silver XLR input transformer for the DAC, PLL mod to the digital board, AD744 Op amps, AD1865N-K, BGs in the digital power supply, BGs in the digital board, custom attenuator using Takman(REX)Carbon resistors for the L3, BG's and AN resistors for the line board, and of course some nice soft annealed silver wire in many places.

. . and the custom face plates because I'm not a big fan of the black and gold but that's clearly a subjective personal thing . . .;-)

I don't know if there is anything useful for you in this post until you try and compare but this will hopefully pull out some opinions of others, at least those who disagree . . .

And for anybody who believes every aspect of these kit amps were precisely designed, modeled and tuned by Audio Note UK or Andy Grove and therefore shouldn't be modified. . .can I interest you in a bridge . . .no not a rectifier . . .;-)

Good luck and report back on your experimenting . . .

M-

Edits: 01/19/11