Sunday, May 31, 2009

My Love - Westlife



Peace In Our Lifetime.


Nature ~ Humanity ~ Environment
UNITING ALL CAUSES, ALL PEOPLE, ALL CULTURES, NATIONS, ALL BELIEFS & NON~BELIEFS

Go to: "Peace In Our Lifetime"

PLANTING SEEDS

a SEED is:







a BEGINNING
of a new possibility

a START
of something new

a STARTING POINT
to make it real and let it grow

to SOW we:















PLANT SEEDS
of possibility, that

SPREAD
everywhere and

PROPOGATE
in it's own unique way, and naturally

DISSEMINATE
to wherever it leads us - we

INTRODUCE
new paradigms and ideas and

IMPLANT


FREEDOM in everything we do

Analog VU meter kit (ver.2) From JM7RTI Institute


Ever wanted to add a nice analog VU meter to you headphone amplifier project or your amplifier projects. Well you need the analog VU meters and in addition a VU meter driver amp board. It's a bit of a hassle, but I found a nice kit for the driver amplifier board for analog VU meters from JM7RTI Institute shipped to me for US$20.00. You just need to add your own VU meters, or you can also order seperately a set from them.

"JM7RTI Blog & Information page"

If you are interested, drop JM7RTI, Kimura Hideki san an email to order: jm7rti@gmail.com He will accept PayPal payments.


Valve Substitution Table.

Table for valves substitution


12AX7

:

12AX7WA, 12AD7, 5751, 6057, 6681, 7025, ECC83, ECC803...

12AU7

:

12AU7WA, 5814, 6067, 6189, 6680, 7318, 7730, ECC82, ECC802, ECC186...

6DJ8

:

6922, E80CC, E88CC...

12AT7

:

12AT7WA, 6060, 6201, 6679, 7316, 7728, 7730, ECC81, ECC801, ECC85, 6AQ8...

6CA7

:

6L6GC, 5881, 7581, EL34, KT66...

6BQ5

:

EL84, 7189...

6550

:

KT88, 7027...

6SL7

:

5691, 5755, 6188, ECC35...

6SN7

:

6BL7, 6BX7, 5692, 6180...

6CA4

:

6V4, EZ81, EZ80...

5U4

:

5AS4, 5AU4, 5R4WGB, 5931...

5AR4

:

5AW4, 5AQ4, GZ34...

Saturday, May 30, 2009

Audio Space Acoustic Laboratory AS-2.8i Tube Intergrated Headphone Amplifier (4 x 6V6, 2 x 12AU7, 1 x12AX7)

Teaser Pics Now, Details Later


Vacuum Tube Integrated Headphone Amplifier
Model No. : AS-2.8i
(275 x 266 x 160) mm Weight: N.W. 7.8kg/ch / G.W. 8.9kg/ch
Input Impedance:
Output Impedance: 4-16 Ohm
Output Power: 10W x 2 Class AB1 P-P(Ultralinear), 15W x 2 Max.
Power Consumption:
Damping Factor: > 3
Frequency Response: 20Hz - 30KHz / -1dB
T.H.D.: <1% 20Hz - 20kHz(Ref. Output)>
Total Gain: 30dB
Input Sensitivity: 300mV - 600mV
S/N Ratio: 89dB

Channel Balance: /- <
1dB 20Hz - 20KHz (Max. Volume)>
Channel Separation: > 60 dB (1KHz - 3.3KHz)
Tubes: 6V6 x 4, 12AX7 x 1, 12AU7 x 2
Hum Noise:
less then 3mV

Present tube Rolling:

I have left the present stock Sino black glass 6V6 tubes in place since I have not decided on tube rolling types. However have rolled the following:

12AX7 changed to Telefunken Smooth Plate 12AX7 (ECC83) -


2 x 12AU7 changed to NOS Matched Pair Tungsram 12AU7 (ECC82)-



Saturday, May 23, 2009

The Homebrew 6DJ8 Single Tube Headphone Project.

New beginnings, I am embarking on the construction of a 6DJ8 Single tube headphone amplifier and will during the course of construction add photos and description on the work and components. This is a tube hybrid amplifier. The first set of photos are of the cabinet and the pcb board being measured and prepared for mounting to the cabinet. the cabinet is lovely DIY cabinet called "Oceania" which is designed for headphone amplifier projects. The power for the pcb is 24V DC (low voltage) and on board regulation is accomplished by the LM317 (in my case I have upgraded to Linear Technology LT-1085). The volume use in this instance is a Blue Alps 2 x 100K A pot.


The power supply used will be a 24 V switching power supply and will be outboard and not housed in the same cabinet.

Stage 1 ( Cabinet & Hardware):


Above: The PCB for the amp layed in the bottom cabinet being measured for placement.


Above: The 6DJ8 Headphone Amp. front panel facia.



Above: The top half of the slide on cabinet.



Above: The hardware, knobs, feet and on/off button.


Stage 2 (PCB population):

Stage 2 is the population of components on the PCB, the following photos show the speed of which the components have already become populated.

Sorry for the quality of some of the photos, the digital camera will need to be replaced at some stage!

Above: The front panel beginning to take shape, the phone socket fitted, the Alps volume pot fitted and a nice custom made Goncalo Alves Wooden 1/4 gloss finish knob fitted.

Components:

Tube Socket: Gold Plated / Ceramic Tube Socket for 6DJ8

Tube: NIB NOS Tungsram 6DJ8


Regulators: LM-317 - Replaced with Linear Technology LT-1085

Semicon.: K117 x 2, K310 x 2


2SK117 x 2 :
Field Effect Transistor Silicon N Channel Junction Type Low Noise Audio Amplifier Applications.

Toshiba 2SK117 Data Sheet PDF.

3SK310 x 2 : 2SK310 Silicon N-Channel MOS FET (High Speed Power Switching) - Hitachi Semiconductor.

Hitachi 2SK310 Data Sheet.


Resistors: Dale Vishay & Tokyo Ko-on


10 ohms x 2
13 ohms x 2

15 ohms x 2
35 ohms x 2
100 ohms x 2
220 ohms x 2
2K ohm x 1

2.2K ohms x 2
1M Ohms x 2 (1watt)

VR - Blue Alps 2 x 100K A

On board VR: 2 x 1K ohms Bourns

Fuse (pcb mount): Silver plated contacts

Capacitors:

Musicap "Hoviland" 0.1uF PP x 2

220uF x 2 Black Gate 16V
1000uF Elna "For Audio" 50V
1000uF Nichicon 35V


Misc:

1 x Headphone Chassis

1 x gold plated panel mount headphone socket
2 x gold plated panel mount RCA sockets

1 x 24 DC panel mount DC connector
1 x LED

1 x push button on/off for panel mount
4 x isolation feet
1 x 24 DC switching power supply housed seperately
4 x heatsinks for semicons

The Finished Project:


I finally finished the project on 26th June, 2009 and here are the photos of the completed single tube 6DJ8 headphone amplifier which is up and running and using a NOS Tungsram tube:


The heatsinks were replaced on the FET's and regulators with larger ones, the amp does not run too warm and is quite cool. One drawback is the LED configuration (refer to the circuit diagram), this is a bad design to be taking voltage for the LED from this location as it does cause oscillation when powering up the amplifier and you "Must" not plug in the headphones as you will hear a high pitched whinning sound. Only when the LED is fully lit and the circuit becomes stabilized should you plug in the headphones. The designer should rethink about the LED issue! I am using an off the shelf 24V DC (2amp) switching mode power supply which is available everywhere (ebay) and it is very quiet, the supply is not housed in the same cabinet and is external to the unit to minimize on any further noise. Of course you may choose to use a linear supply if you wish.

Dynamics and transients are extremely good, bass impact is extremely good and mids-highs are well balance with high resolution. The NIB NOS 6DJ8 from Tungsram is an extremely high resolve tube and well suited to the amplifier. The sound stage is extremely deep and location of musical instruments is very precise. I expect things to further improve as the Hoviland "Musicaps" begin to burn in, since I have currently about 50 hours of time on the amp. One can hear the changes each time, the bass appears to be becoming tighter and better controlled.

The
Linear Technology LT-1085 regulators will be a night and day difference over the original LM-317 regulators and my advice is not to skimp on these regulators and change them to the Linear Technology regulators! You will have a much faster amp and the difference is stunning to say the least.

I have used
Musicap "Hoviland" 0.1uF PP x 2 caps. as I have found that these give the warm SQ that I want from this tube. Other caps used ar Black Gates and Nichicon, you must experiment with caps as these will alter the SQ signature of the sound. Overall, it is a very quiet amp and audio qulaity is very good once completely warmed up. The circuit board can be found on ebay and sells for about US$8.00.

I have received enquires about the cabinet and volume knob, the cabinet is off the shelf made for headphone amplifiers and can be found on ebay, whilst the
Goncalo Alves Wooden 1/4 gloss finish knob is a custom turned knob and is a once off item.

Friday, May 15, 2009

Sheryl Crow.


I Dont Wanna Know - Sheryl Crow





Artist: Sheryl Crow
Song: Wildflower

Wildflower - Sheryl Crow

Capo – 3th Fret

Intro
E|---1-----1----5----5----5----5----5----5----|
B|---3-----3----6----6----6----6----6----6----|
G|---2-----2----5—---5----4----4----3----3----|
D|---0--0----0----0----0-----0---0-----0---0--|
A|--------------------------------------------|
E|--------------------------------------------|

E|---1-----2----5----5----5----5----5----5----|
B|---3-----3----6----6----6----6----6----6----|
G|---2-----2----5—---5----4----4----3----3----|
D|---0--0----0----0----0-----0---0-----0---0--|
A|--------------------------------------------|
E|--------------------------------------------|


(First Verse)

Quiet eyes You have always been my
E|---1-----1----5----5----5----5----5----5----|
B|---3-----3----6----6----6----6----6----6----|
G|---2-----2----5—---5----4----4----3----3----|
D|---0--0----0----0----0-----0---0-----0---0--|
A|--------------------------------------------|
E|--------------------------------------------|

Wildflower Showing up wherever
E|---1-----2----5----5----5----5----5----5----|
B|---3-----3----6----6----6----6----6----6----|
G|---2-----2----5—---5----4----4----3----3----|
D|---0--0----0----0----0-----0---0-----0---0--|
A|--------------------------------------------|
E|--------------------------------------------|

Beauty's lost its way Your heart must break
E|---------------------------------------------------|
B|--1----1-----3------3----3-----3-------------------|
G|--2----2-----3------3----4-----4------5--4---------|
D|-----3---3---3---3----3--5---5---5----3-----7—5----|
A|--3----------1-----------5------------5------------|
E|--1----------------------3-------------------------|

E|---2-----2----5----5----5----5----5----5----|
B|---3-----3----6----6----6----6----6----6----|
G|---2-----2----5—---5----4----4----3----3----|
D|---0--0----0----0----0-----0---0-----0---0--|
A|--------------------------------------------|
E|--------------------------------------------|


I was free Until I heard the song
E|---1-----1----5----5----5----5----5----5----|
B|---3-----3----6----6----6----6----6----6----|
G|---2-----2----5—---5----4----4----3----3----|
D|---0--0----0----0----0-----0---0-----0---0--|
A|--------------------------------------------|
E|--------------------------------------------|

you sang me to me Pulling me away from
E|---1-----2----5----5----5----5----5----5----|
B|---3-----3----6----6----6----6----6----6----|
G|---2-----2----5—---5----4----4----3----3----|
D|---0--0----0----0----0-----0---0-----0---0--|
A|--------------------------------------------|
E|--------------------------------------------|

Every thing I knew To be with
E|---------------------------------------------------|
B|--1----1-----3------3----3-----3-------------------|
G|--2----2-----3------3----4-----4------5--4---------|
D|-----3---3---3---3----3--5---5---5----3-----7—5----|
A|--3----------1-----------5------------5------------|
E|--1----------------------3-------------------------|

you
E|---2----2---5---5---2------|
B|---3----3---6---6---3------|
G|---2----2---5---4---2------|
D|---0--0---0---0---0-0------|
A|---------------------------|
E|---------------------------|

And everything I know just fades away
E|---------------------------------------2-----2-----|
B|----1---1--1--1--3----3----31—---3-----3-----3-----|
G|----0---0--------2----2----2-----2-----2-----2-----|
D|----3---2--0-----3--3---3--3--3----3---0--0-----0--|
A|--------------3--2---------1-----------------------|
E|---------------------------------------------------|


And every time you go it hurts me
E|---------------------------------------|
B|----1---1--1--1--3----3----31—---3-----|
G|----0---0--------2----2----2-----2-----|
D|----3---2--0-----3--3---3--3--3----3---|
A|--------------3--2---------1-----------|
E|---------------------------------------|

so I don't know why but I know we're
E|--------------------------------------------------------------|
B|--1----1---8-----8-----3-----3----------------------3---------|
G|--2----2---8-----8-----3-----3----3h5p3p0-----------3---------|
D|--3--2---2-8---8---8---5--5----5------------------3--3--------|
A|--3--------6-----------5--------------------0--1---------1--0-|
E|--1--------------------3------------------4-------------------|

free Free to
E|---------------------------------0---|
B|--3-----3---------------3----2—3-----|
G|--3-----3---------------3----3-------|
D|--5--5----5----------3----3--2-------|
A|--5-------------0--1---------1-------|
E|--3----------4-----------------------|

fly
E|---2-----2----5----5----5----5----5----5----|
B|---3-----3----6----6----6----6----6----6----|
G|---2-----2----5—---5----4----4----3----3----|
D|---0--0----0----0----0-----0---0-----0---0--|
A|--------------------------------------------|
E|--------------------------------------------|


(Second Verse)

Here we are
Burning faster than the cursed star
Falling back down to the Earth
I love you so it sometimes hurts

Closer still
You will find me standing on the hill
Waiting for you with my arms stretched open wide
Now, come inside

And everything I know just fades away
And every time you go it hurts me so
I don't know why but I know we're free
Free to fly

And everything I know just fades away
And where the wildflower grows it picks its space
And that's the way it is when nature plays its lovely hand
We'll understand everything

E|---2-----2----5----5----5----5----5----5----3|
B|---3-----3----6----6----6----6----6----6----2|
G|---2-----2----5—---5----4----4----3----3----3|
D|---0--0----0----0----0-----0---0-----0---0--0|
A|---------------------------------------------|
E|---------------------------------------------|


Everything, everything
(Resolves on F major)

Thursday, May 14, 2009

Portable Cans: (Japanese) Excel Sound EH-98 Dynamic Portable Headphones.


A friend was recently traveling through Tokyo taking the opportunity of the cheap air fares currently available. It was nice of him to think of me when he was in Akihabara, he stopped into one of the hi fi shops and picked up a pair of portable headphones and brought them back as a gift for me. What is unusual is that he choose to pick up a pair of headphones by a Japanese company called "Excel Sound" which is basically not known at all outside the Japanese domestic market. The cans indeed do not look like anything special, a very rudimentary pair of plastic portable cans, but only available for sale on the Japanese market. So they are indeed rare to be found outside of Japan.

The cans are the portable / fold able "Excel Sound EH-98" dynamic cans and from what I can understand of the Japanese, they have 40mm drivers and have OFC headphone cable.

On first listening to them I was taken back by the fact that they did not sound at all bad, quite neutral, in fact they were pretty good. I am burning them in over the next few days and will give you more details on these rather rare cans. Of course some more photos will be taken. The pair I have is the EH-98bk (bk = black), if fact the plastic is more like charcoal grey. The inset photo is what I could find on the Japanese site on the EH-98.

Comfort wise, they are very comfortable, lightweight with no clamping of the head and ears.

Tuesday, May 12, 2009

Oumeidanji KT-88 Valve Amplifier.

The Oumeidanji KT-88 Valve Amplifier is a unique amplifier since it is capable of using the KT-88, 6550 or the EL-34 tubes in the same amplifier. The amplifier was designed as a small integrated for driving a pair of speakers and it does support a headphone amplifier out with an impedance of between 300 - 600 ohms. I would not recommend to drive headphones of lower impedance since it would become a burden on the amplifier. The amplifier runs in Class A and once warmed up it does run hot, so strongly ventilated areas are recommended. Since the amplifier will drive 300-600 ohm cans, these are well suited to the likes of by Darth Beyers or other Beyer Dynamic headphones.

Driving the pair of KT-88 are a pair of Chinese 6J8P tubes, and I did not bother with these. The western equivalents are the 6SJ7 or the premium 5693 metal cans. From the photos below you can see that I rolled the amplifier at first with a pair of RCA NIB NOS 6SJ7 matched pairs and then a pair of General Electric 5693 matched pair "Red Tubes". A note about the "Red Tubes", regardless of what brand you find imprinted on them, all "Red Tubes" are manufactured by RCA.

Whist the Black Metal RCA 6SJ7 Tubes were good, they were sonically no match for the superior "Red Tubes" and this accounts for the vast difference in price between the two in the market place.

The supplied pair of KT-88 tubes are from "Shuguang" of China, but I am very likely to change these to a pair of "Gold Lions" in the near future.

RCA 5693 "Special Red" Tubes

Replaces 6J8P, 6SJ7, and 6SJ7GT tube types. The RCA "Red" tubes (5690, 5691, 5692, 5693) were designed for 10,000 hours of use. RCA claimed the 5693 tube could withstand shocks of 100 G's for extended periods of time! These are the best upgrade tubes for this amp.







Photos below show the amplifier rolled with the General Electric 5693 "Red Tubes" which are NOS matched pairs.


In fact regardless of what brand is printed on these red metal cans, all the "Red Tubes" were manufactured by RCA.


The "5693 Red Tubes" are sonically superior to the 6SJ7 Black Metal Tubes and of course far superior to the stock 6J8P which I did not even bother with.




The Specs:

  • Shuguang KT88 X 2 , 6J8P X 2
  • Output Impedance : 8 ohm
  • Output Power :2 x 10 W (Class A)
  • Earphone Output Impedance 300-600 ohm
  • Frequency Response:5HZ-200KHZ
  • T.H.D. <>
  • Length 160mmx Height 170mmx Depth 320mm
  • Weight: 9kg
  • Color :Black
  • Power: Switchable 110V - 240V (50Hz -60Hz)
Review CD's:

1. Audiophile "Timeless Best Collection" 24 bit / 96khz DSP Mastering URCD;
2. Wild Blue "Jeanne Newhall";
3. We Miss You, Leslie "Chris Babida";
4. Dark Side of the Moon "Pink Floyd";
5. Tubular Bells "Mike Oldfield";
6. Variations "Andrew Lloyd Webber";
7. Hotel California "Eagles" - Japanese CD pressing;
8. 2AM "Danny Summer" XRCD;
9. Natural Elements "Acoustic Alchemy";
10.Breakdown "Paulinho Da Costa";
11.Gold Lion KT88 Vacuum Tube Audiophile Recordings "HECM - Musical Fedelity Recording";
12.Eternity "Angella Christie";
13.Hi-End Audiophile Test Demo "HD Mastering - ABC Recordings";
14.The Tube Hi-Fi Saxaphone " High Resolution Tube Recording - ABC Recordings";
15.Headphone Test Disc "ABC Recordings";
16.Memorial Version 30 years - Tubes "ABC Recordings";
17.Luxman 2009 Demonstration Disc " DSD recording";
18.Blue Skies "Stan Getz";
19.vol.SOUND "S.E.N.S."


Update 1: 30th May, 2009

Burn in is approaching close to 90 plus hours and the amplifier appears to be beginning to open up, the red tubes make a substantial difference to the overall timbre and sonic performance of the amplifier. I have still yet to decide on rolling of the KT-88 tubes and will leave them for now. I can hear the bag end (bass) tightening up and becoming better controlled. Once I near the 150 hour burn in mark I will report again. One thing, this is an amp for 300-600 ohm phones and it does not like the low impedance types - you will hear some hum with the low impedance phones. Phones in the right category work great with it!