New! WNA MKll Head-amp kit.

[FritzS]

The kit arrived today - my first photos
http://www.stockhammer.at/hifi/wna.php

I had a little problem - I can't get 100 nF polypropylene caps with RM 10 mm (RM = "Raster Mass"/"Raster measure"/"LEAD SPACING 10 MM") all distributors in Austria have only 5 mm RM (from WIMA, EVOX RIFA) - from others countries dispatch expensively for only 10 caps

I have only WIMA MKS 4 0,1 uF / 250 V with RM 10mm.
Gives there any measurably or audibly difference between Metallized Polyester (PET) Capacitors and Polypropylene film (such as WIMA MKP 10) as you use?

In the last moment I found this from Distrelec - PHE 450

#821525 PHE 450 100 nF 250 VDC

http://www.wima.com/navig/pr.htm
http://www.wima.com/mks4.htm
http://www.wima.com/mkp10.htm
http://www.evoxrifa.com/cap_catalog/pulsecap/phe426.pdf
http://www.evoxrifa.com/cap_catalog/pulsecap/phe450.pdf

What think you about compensation caps instead of the 330 kOHM as Jan Meier use them in
http://www.meier-audio.homepage.t-on...eadamp1mk2.gif
10 pF (first LM6171) and 47 pF (second LM6171)

 

[PinkFloyd]

Quote:

Originally Posted by FritzS The kit arrived today - my first photos http://www.stockhammer.at/hifi/wna.php

Nice one Fritz! looking good! that'll keep you busy soldering for a while

Quote:

Originally Posted by FritzS I had a little problem - I can't get 100 nF polypropylene caps with RM 10 mm (RM = "Raster Mass"/"Raster measure"/"LEAD SPACING 10 MM") all distributors in Austria have only 5 mm RM (from WIMA, EVOX RIFA) - from others countries dispatch expensively for only 10 caps I have only WIMA MKS 4 0,1 uF / 250 V with RM 10mm. Gives there any measurably or audibly difference between Metallized Polyester (PET) Capacitors and Polypropylene film (such as WIMA MKP 10) as you use?

I used all metallized polyester in one of my WNA amps and they sounded fine I honestly couldn't detect an audible difference between them and the polypropylenes. You can get the 100nF ones at rswww.com part number 414-7614 (18 pence each) or you can also get the same caps from White Noise.


Have fun!

 

[FritzS]

Quote:

Originally Posted by PinkFloyd I used all metallized polyester in one of my WNA amps and they sounded fine I honestly couldn't detect an audible difference between them and the polypropylenes. You can get the 100nF ones at rswww.com part number 414-7614 (18 pence each) or you can also get the same caps from White Noise. Have fun!

In the last moment I found some from Distrelec Austria http://www.distrelec.com/
#821525 PHE 450 100 nF 250 VDC

Before heating my soldering iron I wait for the Nichicon's and Black Gate's from Percyaudio

 

[PinkFloyd]

Quote:

Originally Posted by FritzS In the last moment I found some from Distrelec Austria http://www.distrelec.com/ #821525 PHE 450 100 nF 250 VDC

Ah, yes, they'll do the job nicely Fritz. So I take it you didn't buy the "full" kit from WNA? what did you get from them just the PCB?

Mike.

 

[FritzS]

Quote:

Originally Posted by PinkFloyd Ah, yes, they'll do the job nicely Fritz. So I take it you didn't buy the "full" kit from WNA? what did you get from them just the PCB? Mike.

I ordered not a full WNA kit - without case, cap's and ALPS pot.

 

[PinkFloyd]

Quote:

Originally Posted by FritzS I ordered not a full WNA kit - without case, cap's and ALPS pot.

Cool. Did you manage to source the current regulating diodes ok?

Mike.

 

[FritzS]

Quote:

Originally Posted by PinkFloyd Cool. Did you manage to source the current regulating diodes ok? Mike.

As you mean that? David has marked the current regulating diodes and I have anothers from a wholesale importer as free samples.

 

[PinkFloyd]

Quote:

Originally Posted by FritzS As you mean that? David has marked the current regulating diodes and I have anothers from a wholesale importer as free samples.

Cool. They are really the only parts which may be tricky to find, the rest of the parts are pretty much available off the shelf. So......... when are you going to start putting her together Fritz?

Mike.

 

[FritzS]

Quote:

Originally Posted by PinkFloyd Cool. They are really the only parts which may be tricky to find, the rest of the parts are pretty much available off the shelf. So......... when are you going to start putting her together Fritz? Mike.

I will make some fotos and publish it.

OffTopic - your homepage are informative - I will buy the Roger Waters "In The Flesh" CD

 

[PinkFloyd]

Quote:

Originally Posted by FritzS I will make some fotos and publish it.

That would be great Fritz.

Quote:

Originally Posted by FritzS OffTopic - your homepage are informative - I will buy the Roger Waters "In The Flesh" CD

It's not a bad CD if you like Roger. I went to see him live in Manchester and, wow, what a great show!! another album you may like is Roger Waters "amused to death" not a bad recording and some good sound effects etc.

Mike.

 

[FritzS]

Quote:

Originally Posted by FritzS I will make some fotos and publish it.

some questions

is this the right headphone jack for PCB

in which nut shold the PCB bee - the first or the secound? Or in other word the distance between PCB and case - at the PCB side the distance between connector +V 0V -V (rail splitter) is very small

inculded cables - I miss more lengh of the silver plated ptfe "green cable" - wherever should I connect the case with the ground of the amp?

 

[PinkFloyd]

Quote:

Originally Posted by FritzS some questions is this the right headphone jack for PCB

Yes and no. You have to snip the legs as shown to get it to fit on the board. I don't understand why David supplies this head socket with the PCB that has provision for a board mounted head socket...... unfortunately, this one is supplied and needs snipped so it can fit:

Quote:

Originally Posted by FritzS in which nut shold the PCB bee - the first or the secound? Or in other word the distance between PCB and case - at the PCB side the distance between connector +V 0V -V (rail splitter) is very small

Second or third slot. You can even hold the pcb in position with the volume control and headsocket nuts... there is no weight to the board so it's adequate to support it by the volco and headsocket.


Quote:

Originally Posted by FritzS inculded cables - I miss more lengh of the silver plated ptfe "green cable" - wherever should I connect the case with the ground of the amp?

Run a piece of wire from anywhere on the 0V track (ground) to the chassis. you can attach it to the chassis with a nut and bolt.

 

[FritzS]

Quote:

Originally Posted by PinkFloyd Yes and no. You have to snip the legs as shown to get it to fit on the board. I don't understand why David supplies this head socket with the PCB that has provision for a board mounted head socket......

I favor your suggestion - David tells to the same question:
The headphone jack is correct but its a bit of a story. Schurter do a pcb mounting version of the jack socket that I use but it's of lower quality than the solder tag version. So you cut the solder tags off flush with the body of the socket, then solder silver plated wires to the stubs of the solder tags, and fit these into the pcb - its all explained in the manual.

Quote:

Originally Posted by PinkFloyd Second or third slot. You can even hold the pcb in position with the volume control and headsocket nuts... there is no weight to the board so it's adequate to support it by the volco and headsocket.

I have some other ideas - that I have a case without holes, I can modify the
position of the board.

Quote:

Originally Posted by PinkFloyd Run a piece of wire from anywhere on the 0V track (ground) to the chassis. you can attach it to the chassis with a nut and bolt.

I will connect the 0V track (ground) to the chassis with a resistor, like 10 ... 100 Ohm and the case of the ALPS pot too.

The Nichicon's and BlackGate's and some Holco resistors arrived

http://www.stockhammer.at/hifi/wna.php

The both input caps (4,7uF) I will replace with a 1 kOHM Holco resistor (possibly with a Murata Ferrite bead in serial). I will start with no 330 k so I can change easy between LM6171 and AD843.

On output I will use the BlackGates in series with a 15 OHM Holco (for short circuit protection) but without Zobel at start.

In future I will use second input jacks, one direct, one with the 4,7 uF caps.

On the power input jack I will use a reverse 3 A diode in parallel - and a 35V zener diode in parallel to C7 for protection.

One is hard to get here in Austria - silver coated isolated copper wire in less assemblage - import is expensive, so I pay'd 27 USD for shipping AND 21 EUR for customs duty and tax too - and this for 57 USD value of the product.

"Prosit Neujahr!"

 

[PinkFloyd]

Quote:

Originally Posted by FritzS The headphone jack is correct but its a bit of a story. Schurter do a pcb mounting version of the jack socket that I use but it's of lower quality than the solder tag version. So you cut the solder tags off flush with the body of the socket, then solder silver plated wires to the stubs of the solder tags, and fit these into the pcb - its all explained in the manual.

It's easier to snip the tags as shown in the picture. This ensures a "perfect" fit with the head socket being flush with the PCB and saves farting about soldering six silver wires into position, hell what's the point of making provision for a potentiometer and head socket on the board and then supplying a head socket that doesn't fit.... sure you can solder wires onto the tags or cut the tags down but I'd prefer a head socket that was a perfect flush fit on the PCB... either that or make the darned holes on the PCB large enough to accommodate the gold plated head socket...... sorry but little things like this really annoy me, the whole idea of making provision for board mounted components is that the component will fit straight onto the board without having to customise it to fit. Rant over.

 

[PinkFloyd]

Looking good Fritz!