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My Audio Project - Headphone Amp WNA MKII
Mein Audio Projekt - Kopfhörer Verstärker WNA MK II  
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WNA MKII Headphone Amp
White Noise (WNA) will be closing its doors to business effective from 30th April 2006!
Some links are dead!

View topic - White Noise Closing Down
More about WNA MK II please see here:
New - old flaggshiff WNA MKII
New! WNA MKll Head-amp kit. - Page 1
New! WNA MKll Head-amp kit. - Page 51
Some links are dead!
WNA MKll Head-amp kit. - Page 76 - Head-Fi Covering Headphones, Earphones and Portable Audio
WNA MKll Head-amp kit. - Head-Fi Covering Headphones, Earphones and Portable Audio
WNA MKlll announced! - Head-Fi Covering Headphones, Earphones and Portable Audio
Rock Grotto Forum - I miss the WNA discussions! Suggestion .....
rock grotto - WNA MKlll minor glitches....
Rock Grotto
White Noise Audio
Rock Grotto - Forum
View Circle - White Noise Audio Forum
 My Current WNA MKII
WNA MKII - schema without any modifications:
WNA MKII headphone amp schema without any modifications

This parts I use:
C5, C6 Nichicon FG 100 uF, 25V
C11, C12 Nichicon KZ 220 uF, 25V
C7 Nichicon KZ 220 uF, 50V
C4 BlackGate NX 1000 uF 25V
C2, C3, C8, C9, C10 Evox Rifa PHE 450 0,1 uF / 250V (follower of PHE 428)
R11 (instead of lamp) 15 OHM Holco H2
instead of C1 - 1,02 kOHM Holco H4
IC1, IC2 AD797 (now) - in railsplitter LM6171
R4 = J2  Murata Ferrite bead
R1, R2, R3, R5, R6, R12, R13, R14 are Welwyn RC55Y 0.25W 0.1%
R7, R8, R9, R10 are Truohm 0.25W 0.1%
R12, R13, R14 are 0.6W 1% metal film
I1 3.5mA constant current diodes
(CRD CurrentSource  Semitec)
I2, I3, I4 5.6mA constant current diodes (CRD CurrentSource  Semitec)
Potentiometer ALPS
blue velvet 2x50 kOHM log. stereo

Currently there is no ZOBEL network, no additional 330 kOHM feedback.

Additional modification:

Bypass the Evox Rifa PHE 450 100nF (C2, C3) with WIMA FKP2 10nF/63V
and the Nichicon FG 100uF (C5, C6) with Evox Rifa PFR 220pF

This caps are mouted on rear side:

WNA MKII Railsplitter

WNA MKII Railsplitter

(1) David use a thin twisted 3 pol. wire for power connect between rail splitter and each amp - I use the twisted (red/black) wire for +V -V and the green wire for ground (on bottom side of PCB) - and use the twisted (red/black) wire for output (P2 to Jack) on forefront of PCB.

My WNA works now - the first burn in test with my Senn HD 600 headphones - "WOW" its much more better than the headphone output of my Philips CD 650 or of the Yamaha CR 2040 receiver - both are "old HiFi classics". A complete test of hearing follows - with Eva Cassidy "Live At Blues Alley" and some other music all my hairs stand up, I have never heared this so before  

(2) Modification:  Bypass the Evox Rifa PHE 450 100nF with WIMA FKP2 10nF/63V and the Nichicon FG 100uF with Evox Rifa PFR 220pF
My experience with some other OPA's   .....  from
New! WNA MKll Head-amp kit. - Page 51
New! WNA MKll Head-amp kit. - Page 76 - Head-Fi Covering Headphones, Earphones and Portable Audio
(3) Next step 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, ....
(4) Next step 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
(5) Next step 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?
(6) We had ignored Linear Technology http://www.linear.com/

Next step 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 don't 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
Rock Grotto Forum - AD847 vs AD843 in WNA MKII
But - please give the LT1056/LT1022 a chance - free samples for LT1056/LT1022 are open (2 pcs) - last both days I had some sessions ....
The LT1056 sounds warm and cold, sharp and soft, analytic and natural - so as the sound-engineer has done his work :P
Roger Waters, Amused To Death
Deeeep natural bass
Pink Floyd, Final Cut
Good micro dynamics, very subtle in background (slapping shoes, playing children, ..)
Pete Townshend "Face the face" (in german we said "fetzt so richtig") deep bass "grummel :(" and brutal drums ???
Sinéad O'Connor "GOSPEL OAK" had rare heard this so natural and realistic :( :P
I think this are twice effects -
one the LT1056
second - my K701 nearly burned in :( :( :( :(

The K701 is one of the best headphones I ever heared!
(7) Yesterday I got samples of LT1022
My first (subjective) look and feel - the LT1056 sounds better - but I will give the LT1022 a chance to burn in :P
maybe, yesterday I had a bad day to hear?! ???
additional listenings ....

sometimes a very little bit muted
leadsinger a bit more in background, quieter - but background sound a bit louder clear sound

emotionally I missing something but I cannot say what

LT1056 sometimes tiny strained in treble at sizzle cymbal, LT1022 does not.

This statements are subjektiv and emotional ......

I rate LT1056 emotionall prior to LT1022, but very close ;D

I found in my treasure chest some ....
OPA 655 http://focus.ti.com/docs/prod/folders/print/opa655.html
HIGH INPUT IMPEDANCE: 1012(ohm) || 1.0pf
ULTRA-LOW dG/dP: 0.006%/0.009°
FAST SETTLING: 17ns (0.01%)

have anyone experince about this?

and some too
AD825 (SOIC)
and ... whats about this?
(8) Thanks - now the OPA602AP is inside ;D
My first short impression without burn in or longer warming up and only one CD "PF FinalCut" ...... nearly perfect - detailled, good micro dynamic .... more later .....
After some sessions I can say (for me) the OPA602AP is one of the distinguished OPA's for the WNA MKII.
Very balanced, detailed music :(

Better than LT1056 LT1022 AD847 AD843 LM6171 LME49710?
I cant say this with guarantee :D but the OPA602AP is a new star ;D

Open to test - but what is your experience about this?
AD8065, OPA604, AD845, OPA627, AD825, AD8610, AD9631
Yesterday evening I heared Roger Waters "Amused to Death" - this was a extraordinary epiphany ;D :D
I think its near "the end of the flagpole" with my components - another OPA have a rough ride to overcome the OPA602AP in WNA MKII ???

To make a great shift in sound I must change others, ... the CD/SACD player, the headphones, .......
(9) Now I use two TLE2071 inside my WNA MK II - but no elementary difference between OPA602 and TLE2071. I think they come from the same TI (BB) familie.

Compare to the Graham Slee "green Solo" the WNA sound a little bit sharpen - PF Final Cut track 1 - rattle the coins.

The "green Solo" rattle the coins more actualise :P

Excalibur low-noise high-speed TLE207x

BB/TI OPA1632 an interesting Audio OP AMP
(10) Before I put my WNA MKII into my depot, I changed the OPA's
before AD847, then OPA134 and now OPA627 ..... and wow it tops my "green" Solo with OPA LME49720HA instead of the AD823.
With OPA627 and Denon AH-D7000 or AKG Q701 the violins shines

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 BlackGates NX 1000 uF 25V are re-burned in now (the sigle caps in signal path) 
(11) Now I test AD797 opamps (biased into class-A as all others in this place). They are different to OPA627 and offers a bit more fine details and less sharpness with AKG K812 Pro (in some music tracks hearable).
I had thought about oscillation before without compensation of AD797. But it works well without additional caps. AD797 have a bit of a diva.
(12) Two Supreme Sound Opamp V5 I used too
Supreme Sound Opamp V5 (Supreme Sound Audio)
Supreme Sound Opamp V (Burson Audio)
More about coming soon! Is now in the house!
    Supreme Sound Opamp V5
Now my WNA MKII works with Two Supreme Sound Opamp V5 S
First pictures and informations from
To WNA MKII schema
The following modifications I discuss in some DYI forums ...... as seen on   Walt Jung's Website
WTnT_Op_Amp_Audio_2 - Realizing High Performance: Buffers (Part II)
WTnT_Op_Amp_Audio_1     WTnT_Op_Amp_Audio_3      WTnT_Op_Amp_Audio_4

Suggested modification hints looks like WNA MKIII

Replace the two diodes with transistors - MPSA42 / MPSA92
connect the collectors with a pice of wire to +V or to -V (as shown in picture)
both resistors in path must be equal - 120 Ohm (Welwyn RC55C 0,25W 0,5%)
both current sources must be equal - 3.5 mA
ZOBEL network - 10 Ohm in series with a 100 nF cap (WIMA MKS4 0,1 uF 250VDC / Welwyn MFR4 0,25W 1%)
a 15 Ohm resisitor in series to the headphone
local and over all feedback resistors as described in some threads
solder a 3 A reverse diode parallel to the PSU input posts und the PCB - to protect the amp from erroneous reverse polarity
solder a Panasonic FC 2200uF 50V cap parallel to the PSU input jack

If I have this done I will publish some photos here.

Farnell InOne - weltweit führender Distributor von elektronischen, elektrischen und Instandhaltungsprodukten (MRO).

Farnell InOne, distributors of electronic, electrical and industrial component products. Online ordering and 24 hour delivery as standard.

Suggested modification schema looks like WNA MKIII:
WNA MKII headphone amp, sugested modifications
WNA MKIII - schema without any modifications:
WNA MKIII headphone amp schema without any modifications
Pictures - please klick on pictures to enlarge

First building -  please klick on pictures to enlarge


WNA MKII Headphone Amp Parts  -  please klick on pictures to enlarge

Parts from
RS Components
Parts from
RS Components

blue potentiometer, EVOX RIFA PFR5 caps, WIMA MKS4 caps, Murata Ferrite bead, Case Hammond 1455N1602, (more
interesting parts...  Welwyn RC55Y resistors)
Parts from RS Components

  Parts from
White Noise Audio

EVOX RIFA PHE 450 caps - (more
interesting parts.... Welwyn resistors, Rubycon electrolyte caps. etc.)
Parts from Distrelec / Schuricht

Black Gate NX, Nichicon KZ electrolyte caps
, Nichicon FG electrolyte caps, Holco H2/H4 resistors
Parts from
Michael Percy Audio [Ordering Information]

parts conneXion - The authority on hi-fi DIY parts and components

Headphone Amp with OP - my conception with BUF 637T or LM6181 and good OP's
NS - LM6171, LM6172, LM6181
BB / TI - OPA655P, OPA134, OPA2132, OPA2227, OPA2228, OPA627, OPA637, OPA2134, OPA227, OPA228, OPA604, OPA2604, BUF634P, BUF634T, DRV134
AD - AD711, AD811, AD797, AD9631, AD9632, AD812, AD823, AD8610, AD797, AD843, AD847, AD8065
PMI - OP279, OP113, SSM2135
ON Semiconductor -  SE5532, SA5534 / SE5534
Maxim - MAX410, MAX412, MAX427, MAX437
Look like's as in BUF634_Schemas
Or as Per-Anders Sjstrm's - QRV-04 the high performance smd headphone amplifier

Viewcom - Holco resistors    Viewcom Electronics - Main

In Forums - about WNA

   New - old flaggshiff WNA MKII
   New! WNA MKll Head-amp kit. - Page 1
  New! WNA MKll Head-amp kit. - Page 51
Some links are dead!

Head-Fi (Headphone Hi-Fi and Portable Audio) - New! WNA MKll Head-amp kit.
Head-Fi (Headphone Hi-Fi and Portable Audio) - New! WNA MKll Head-amp kit.
New WNA MKlll announced! - Head-Fi (Headphone Hi-Fi and Portable Audio)
rock grotto - WNA MKll is here!!
rock grotto - New WNA MKlll announced!!      rock grotto - WNA Headphone Amp  rock grotto - WNA MKlll minor glitches....
View Circle - White Noise Audio

My current WNA MK II Headphone Amp project
DIY Cables
My current CD 650 tuning project
DIY Tips
Graham Slee "green Solo" Headphone Amp
Graham Slee "Green" ERA GOLD REFLEX  Phono Preamp
Tuning Revox Turntable B790
My preferred Music
Audio Projects - Main
Black Gate as a super-E-Caps capacitor

Jelmax H.P. BlacK Gate - The champion of the circuit cleaning; Black Gate as a super-E-Caps capacitor

More about Jelmax H.P. and Black Gate!

Jelmax Co.,Ltd closed its doors in August 2007, Black Gate production has stopped in 2006

Black Gate capacitor (wikipedia)

Step 4 - the final circuit

It was surprising that all the problems worried about at item (3) were resolved by replacing all the capacitors with the super-E-Caps.
An amplifier made by Ippinkan, in which all the capacitors are replaced by the Black Gates, is connected to the output side.

BGN 16V 33μ2
Non-polarized Black Gate
BGN 50V10μ2
Non-polarized Black Gate
Transcendence electron transfar

     In the super-E-Caps, the lead wire is connected as follows

What is the "Super-E-Caps"?
A pair of nonpolarized Black Gate electrolytic capacitors are particularly connected in parallel or in series so that each one of the capacitors cancels the internal magnetic flux generated by the other, thereby completely eliminating internal resonance and decreasing total impedance to absolute zero as the frequency increase.

An ultimate DC current power source revolution by the ultra electrolytic capacitor Black Gate  - 無題ドキュメント

Source (C) - Jelmax H.P. TOP page

Farbcode für Widerstände 4 - Berechnung Farbcode Widerstand Widerstandstabelle Farb Code Ringe - sengpielaudio
Farbcode für Widerstände 12 - Rechner - Widerstand mit 6 Ringen Ringe Widerstandsbestimmung Farb Farbringe- sengpielaudio

Widerstand-Farbcode-Konverter für 5 Ringe und Diagramm | DigiKey Electronics

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Last modified: 30. January 2019 20:30:42.

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