New! WNA MKll Head-amp kit. - Page 51

I preferred both the ad847 and the ad8065 to the ad843 - though all were better than the lm6171 - in the head amp at least. I only have the WNA headamp left now.

Look this new project on:

http://www.audiodesignguide.com/DAC_final/DacFinal.html

see end of web page

Now I found the LME49710 (single version from LM4562)

http://www.national.com/pf/LM/LME49710.html
http://cache.national.com/ds/LM/LME49710.pdf

and ordered some LME49710 to test them in WNA MKII

It's a exciting game LME49710 and LM4562 vs. AD843, OP275, AD823, ect

LME49710 in WNA MKII

Hi,
now I use three LME49710 in WNA MKII in my modified WNA MKII, instead of AD843 (amp) / LM6171 (railsplitter).
First I cannot hear any difference between. First I heared with senn HD 600.

I think for exact compare I must use two WNA's so I can change very quick between to hear very small differences

Some of CD/SACD's I used:
KODO (Japan SONY), Concord Jazz SACD sampler, PF Final Cut, ....

LME49710 vs AD843 in WNA MKII

Hi,
now I am going back to AD843 (amp) / LM6171 (railsplitter)

It's imagination from me or not - with LME49710 and K 701 I feel the trap is littleness sharper .........
music SACD Ray Brown - Summer Wind - Live At The Loa

I test the AD843 in railsplitter - it oscillates

AD847 vs AD843 in WNA MKII

Hi,,
now I run two AD847 in my modified WNA MKII (with AKG K701 and Marantz SA 7001 KI)

My first experience:
More punch
More "metal" than "soft" in "brass"
Music come to the fore
Not for quiet sound level - here is the AD843 "king"

My opinion - this statements are subjektiv - objective are only ABX tests with two similar amps but different OPA's and a ABX switcher.
But this statement is be true for the most of the DIY test's ..... or?

Has anyone test the AD847 (singel) or AD827 (dual) too?

We ignore Linear Technology Linear Technology - Linear Home Page

Now I use two LT1056 in place of the both AD847
There are very little differences ....

First test - from the first tick I hear - I am snoopy why after a burning in time
Treble (cymbals) are a little bit softer, silkier, darker, more natural
Micro Dynamics - more than AD847 - more in background too.

2nd & 3rd test - as far as I can see the LT1056 is a "big player" like AD843 too

Natural, detailled sound with good micro dynamics, open wide and deep stage.

I think one must be changed: The WNA design use a ferrite bead between the output of the OPA and the powerstage. This is not calculated for other OPA's. The datasheet suggestions of LT1056 use a little cap 10 ... 33 pF in NFB:

"When the feedback around the op amp is resistive (RF), a
pole will be created with RF, the source resistance and
capacitance (RS, CS), and the amplifier input capacitance
(CIN ≈ 4pF). In low closed-loop gain configurations and
with RS and RF in the kilohm range, this pole can create
excess phase shift and even oscillation. A small capacitor
(CF) in parallel with RF eliminates this problem. With RS
(CS + CIN) = RFCF, the effect of the feedback pole is
completely removed."

But I dont hear oscillation in audible range or distortion. Only very good sound

And all this with an "old design" 5.5 MHz, 14V/us OP - silmilar to the OPA602

Next I will test LT1022 if I get some samples

Speed are not essential
Gain Bandwidth / Slew Rate
LT1056 5.5MHz 14V/us
LT1022 8.5MHz 23V/us
OPA602 6.5MHz 35V/us
AD847 50 MHz 300V/us
AD845 16 MHz 100V/us
AD843 34 MHz 250V/us
LM6171 100MHz 3600V/us
AD817AN 50 MHz 350V/us

I want to use my WNA MKII on a second place in my house - with the old Philips CD650 too.
Headphone is the 25 Ohm impedance Denon AH D7000

Last testing OPA was the LME49710NA - it plays very good - but I am not totally happy with it.

So I searched further, after the LME49710NA I put in ...

OPA134 similar, but a bit more musically than the LME49710NA
OPA604 similar to the OPA134, but a bit more muted
LM6171 that's is - very detailed, more punch, the D7000 likes the LM6171 in the WNA MKII

My special mods in the WNA you found here
blue-danube DIY audio - WNA MKII Modifications

I hear music if I write this text - the longer, the better the music are played, the WNA and CD640 burning in - they had a longer time out before

Music:
Audio - Digital Masters I / Sara K. + some Chesky & Telarc (Classic) samplers
Audio, das Magazin für Hifi, High End, Surround und Musik - AUDIO 01/10

The Klezmatics - Live in Berlin
The Klezmatics - Grammy Award Winning Music

Neil Diamond - Jonathan Livingston Seagull
Paul Simon - Graceland

PS: My opinion - this statements are subjektiv - objective are only ABX tests with two similar amps but different OPA's and a ABX switcher.
But this statement is be true for the most of the DIY test's ..... or?

Hi,
before I put my WNA MKII into my depot, I changed the OPA's
before AD847, and now OPA134 ..... and wow it tops my "green" Solo with OPA LME49720HA instead of the AD823.

It's only an imagination?

The WNA MKII sounds a bit more naturally, warmer
Solo inclines sometimes to a little bit sharp tails ...

The WNA MKII source impedance: 15 OHM (series resistor in the output)
Solo use 33 OHM

Tested with my AKG Q701 (I know some prefer 120 OHM as source impedance with this headphone)

 

The next step are

now with OPA627 .. and the violins shines ....

and my Denon AH D 7000 like it too

Max Bruch, Violinkonzerte Nr. 1 & 2, Salavatore Accardo, Gewandhausorchster Leipzig, Kurt Masur, CD
Max Bruch, Violinkonzerte Nr. 1 & 3, Tortsen Janicke, Gürzenich Orchester, Markus Stenz, SACD

and the both BlackGates NX 1000 uF 25V are re-burned in now (the sigle caps in signal path)

 

more about

http://rockgrotto.proboards.com/index.cgi?board=m&action=display&thread=8052

PS: For two month I had an AKG K1000 as guest - now I must then give back - the K1000 is an very gread headphone!