[sdiy] Taking orders for Tau Phaser / Flanger Boards *now*

[JH.]

Hi,
I will be out of town on a business trip till the end of the week, and I 
thought I should post this now, and see what comes back when I return. :)


I'm offering PCB boards for the 20-pole Phaser (redesigned Tau Pipe) for 
27.00 Euro + shipping. (I'll charge actual shipping costs, no overhead.) If 
there are any Taxes / Customs to pay in your country, you have to handle and 
pay this, too.




Several people have shown interest in these boards, via mail and in 
different forums.




Regardless whether you have already sent such a mail of interest or not: If 
you are definitely willing to buy one (or more) boards, please send me an 
email in the following form:




-------------------------------------------------------------------------------------------------------------------------




send to:

jhaible at debitel.net




Subject line of Email:

Tau PCB order 1 piece (or Tau PCB order 2 pieces, etc.)




Text field of Email:




Mr. / Mrs.

Your Name

Your full international Postal Adress,

including Zip code, Country, etc.




(I will copy and paste this for your shipment adress)




paypal mail adress: (your paypal account email)

or other method of payment. Cash in Letter, or Überweisung (Germany only)




I'm ordering N (insert number) of boards for the 20-Pole Phaser for EUR 
27.00 each, plus shipping.

--------------------------------------------------------------------------------------------------------------------------------








Some remarks about this project:




(1) Time and methods of payment




I don't take advance payments. I'll only ask you to pay anything when I have 
your boards ready to ship.

Paypal is my preferred method for international payment. If you don't have a 
paypal account yet, you have a few weeks to set one up and transfer some 
money from your bank account to the paypal account.

Bank transfer (Überweisung) is an option for German buyers only.

If you, for some reason, don't want to pay with paypal, you can send me cash 
in a letter, at your own risk. Please tell me, if you want to do this, in 
your order email.










(2) Total costs of the project




Many who showed interest in this have asked about the price of the PCB and a 
bill of materials, to calculate what the whole project will cost.




Well, you know the price for the PCB now. I have not made a bill of 
materials yet (not even a complete schamatics drawing). This will all come 
as I find the time to do it. (It'lI be several weeks between the order and 
the delivery of PCBs, no need to hurry.) I have published a PDF of the 
component overlay of the board here:

http://www.jhaible.heim.at/tau/jh_tau_component_overlay_with_comments.pdf

You should be able to roughly calculate the expenses for components from 
this.

(Maybe someone is faster than me in making a bill of materials from this; it 
is encouraged to publish this and share it with others then!)




Costs for front panel components will highly depend on the quality you 
choose, and on the extras you're going to implement.

Absolute minimum requirements: 4 potentiometers, 3 audio jacks (I made the 
demos with this.)

Optional: Input and Output level potentiometers, switches for different 
modes and bypass, jacks for CV inputs and outputs.

Don't forget the costs for a front panel and enclosure, and a wall wart or 
other power supply!




(3) Project documentation




I have set up a web page for this:

http://www.jhaible.heim.at/tau/jh_tau.html

This contains all the relevant stuff, and will be updated with all major 
news.

Ongoing discussion will be on the electro-music forum:

http://electro-music.com/forum/topic-18396.html







(4) Components




Resistors:

1% or 2% metall film resistors are cheap nowadays. Don't bother to use 
anything else.

Capacitors:

For the ladder, you need 40 equal valued capacitors.

I recommend 15nF 5% Wima MKS-2 types. (5mm spacing)

7.5mm spacing Siemens MKT caps will also work.

ARP specifies capacitor tolerances of 20% for the (similar) Quadra Phaser, 
so it shouldn't bee too critical. I recommend using 5% caps, though.

Other capacitor values, see component overlay.

Bypass capacitors: You can solder SMD parts (0805) beneath each opamp; 100nF 
recommended. If you don't like SMD parts, I'm sure you can use tiny ceramic 
caps with shortened leads here, too.

Opamps: Except for one low noise OPA2134, you can use cheap TL072s.

Transistor arrays:

I recommend using 11 CA3046 ICs (10 for the ladder, 1 for the 1/x 
converter.) (tested by me)

Alternatively, you can use 1 CA3086 or CA3086 for the 1/x converter, plus 20 
LM394 for improoved SNR and precision. (also tested by me.)

Or you can use 11 CA3086s (not tested by me, but spec'ed in the similar ARP 
Quadra Phaser)

Or you can use 20 SSM2210 or 20 MAT-02 instead of the 20 LM394 (not tested 
by me), plus one CA3086 or CA3046.

Tempco resistor see below.







(5) Temperature compensation




I have used a 560 Ohm tempco resistor for my own prototype, because I had a 
few in the drawer.

You can use other values (like the ever favorite, 1kOhm). In that case, you'll 
need to also change the value of one other resistor and one trimpot. I'll 
give you assistance on this.

The effect will also work without any tempco resistor at all. In that case, 
just solder in an ordinary 560 Ohm resistor. The V/Oct tracking will 
slightly change with temperature, but hey, it's a phaser / filter / 
resonator, not a VCO after all!




(6) Power Supply




The board needs a 18V AC / ca. 5 Watt (either single secondary transformer, 
or 2 * 18V dual secondary transformer). 15V AC may be enough in most cases, 
too, but you have less margin against mains voltage drops.




I highly recommend using a completely insulated Wall Wart if you're not 
trained and experienced to work with mains voltage. That's the good thing 
about this project: just connect a Wall Wart and you have a complete, stand 
alone module.




Otherwise, if you want to build your own power supply, you must know how to 
use mains transformers, where to put fuses etc., know about safety issues - 
it's completely on your own risk. Mains voltages can be lethal!




Alternatively, the effect can be powered with stabilized +/-15V DC dual 
power supply. Then you can electrically integrate the effect into various 
modular sythesizer systems (like MOTM or others.) For this, some components 
on the board must be omitted, and wire bridges soldered in instead. I'll 
give detailed instructions for this option later.







(7) Component value printing on the PCB.




I have decided to print the actual component values onto the board instead 
of reference designators. So you *won't* have to read "R25", look up the 
value (like, 620 Ohm) in some table, then look again where to put it into 
the pcb. Instead, you have "620" directly printed on the board - what you 
see is what you solder in. That's the way I love to work. :)

Of course this is a quite daring approach for me to do this, because if I 
had to change a component value, I couln't just update a _list_. I've been 
lucky, though, and everything works as intended with the values printed on 
the board. :) But of course I expect some modifications / improovements to 
come in the future, either from myself or from the diy community.







(8) Handling of the whole project




This is my first time offering PCBs for others to build projects that I have 
designed or (in that case) redesigned. I'm not doing this professionally; as 
you all know I love to build synthesizers and effects in my spare time for 
fun, and this is (hopefully) an extension of this activity. I hope it will 
be as much fun for everybody who participates as it is for me.

Please do _not_ expect to get a foolproof construction manual (like the MOTM 
kits, for instance). You *can* expect to get the same kind of PCB as from 
which I have sucessfully built my own prototype, so with the right skill and 
with working components you can build your own effect device sucessfully as 
well. Other than that, I don't offer any guarantees, warranty, whatever. I'm 
offering this as a private person, and I will not take any PCBs back, repair 
them, or similar. (I expect lively discussion in the relevant forums and 
mailing lists, however; so relatively unexperienced builders will probably 
be able to manage that project as well.) Whether I will make similar 
projects available in the future will highly depend on how smooth this one 
will work - it's an experiment.



JH.