Idiot Question No. (1)

[Wiu]

So I've been ordering parts for my Phonic Taxidermist.  The electrolytic capacitors were delivered today and the 1uF and 10uF ones are freaking tiny.  I guess I lucked out on the 100uF and 470uF ones.  In true village idiot fashion, I kind of thought they were all standard sizes and the sizes increased the larger the uF amount.  So anyway, I was wondering if using small sized capacitors was okay?  They do fit the board and are rated correctly.

Thanks for any help,

Ian

I had a quick look around the forum, but couldn't find any threads on the Phonic Taxidermist yet, so posted it here as it's a component related question.

[Circuitbenders]

Most 10uF caps are probably around 5mm in diameter, as are 1uF 50v ones, but you can get smaller ones that might be pennies more expensive for when space is at a premium.

The physical size doesn't really matter as long as the voltage is equal to or above the voltage stated in the guide, and they'll actually fit in the space.

[Wiu]

Thank you for the reply 

[Wiu]

Finally getting around to putting together 2 of these beasties.  I have a few more dim questions though...

Firstly, I just need to order the switches but having trouble figuring out which ones I need.  For the Mic/Line selector the build instructions say to use an SPDT which I'm assuming is an On-On?  Would the Freq Band Switches be the same or SPST's like these?

http://www.ebay.co.uk/itm/5-x-On-Off-Mini-Miniature-Toggle-Switch-Car-Dash-Dashboard-SPST/262013055814?hash=item3d0131f346:g:GVMAAOSwa-dWnq4~

I'm guessing the Delay Return will be the same switch as the Freq Band switches, but I'm really not sure.  Also, the switches seem to show power resistances etc.  Are these suitable or is there anything to be aware of when getting the switches?

Secondly, I plan to house both in a 1 or 2U rack.  Is it possible to power both from the same power supply or would this require quite a major mod (or major for a moron like me at least)?

Will be great to get these built so I can have a crack at a Harmonic Engine!

Sorry again for the idiotic questions and thanks for any help. 

Ian

[Circuitbenders]

The mic/line selector switch needs to be SPDT as it need to swap between two different inputs i.e. the middle pin is connected to either one or the other of the other pins depending on the switch position.
The frequency band switches can be either SPST, or SPDT being used as an SPST i.e. only using two of the pins of the SPDT so it just works as an on and off switch..
Just buy SPDT switches and you can use them for everything. Theres not much point to SPST ones here.

There ratings on the switches aren't really relevant here. They are maximum tolerance ratings and unless something is VERY wrong you won't be approaching anywhere near those values.

You can easily power two of these boards from one power supply input on a rack.

[Wiu]

Thank you very much for the reply.  That's a great help

[Wiu]

Sorry, it's me again 

So I have a few more questions:

(1) I've put a 78L09 in REG1 and am going to use a 12V supply.  Am I correct in assuming it uses a center pin negative supply?  And what rating mA would be best?

(2) I'm going to use a female power supply jack socket connector.  From that, can I just simply solder a small amount of wire off it, then split off to each board separately?  Or would it be better to run to one board first and then the other from there?  Or is there something a lot more involved required to power both boards at once?  And am I correct in thinking I can just solder the wire to the PCB as all the pictures of other peoples builds seem to have some sort of 10 pin spiked thingy fitted?  If I do need a spikey thingy, what are they called as despite searching, I've been unable to find anything like it.

(3) How difficult would it be to add a power switch?  Is it as simple as adding a suitable switch to either the positive or negative wire?

Again, my apologies for the less than primary school level of knowledge on my part, but sadly I'm a moron.  But a moron that is slowly learning, so thank you for any help!  I hope this is the last time I have to bother you

[Circuitbenders]

1 - If you wire the negative pin to the centre terminal of the power socket then it'll use a centre pin negative supply. wire it the other way around and it'll use a centre positive supply. It doesn't really matter which way round you wire the DC socket as long as the power is the right polarity at the board.

2 - Is there such a thing as a male DC power supply socket?
You can wire power directly to the board. You only need a set of pin headers if you're using a modular synth power connector.
You can either wire the power to one board and then the next in series, or just take two lots of wire from the power socket in parellel. I'd probably advise doing in in series as the +12v input terminal has two holes connected together, as does the ground, so you can take 12v into one hole and then out of the other into the next board. The same for the ground.

3 - Just wire a switch across the +ve connection between the socket and the first board. This is another advantage of wiring the power in series.

[Wiu]

Thank you very much for taking the time to answer my questions again.  Much appreciated 

[Wiu]

Hello,

So I finally got both boards built.  Both power up fine and the distortion section seems to work fine - the original faulty HT8955A I bought from you doesn't actually seem that bad either.  Anyway, I'm getting nothing apart from really high pitched noise from the delay part from both boards.  Just wondering if you have any idea what would be causing this or could it be a combination of many things?  I'm assuming it's either an incorrect or faulty component as the exact same thing is happening on both boards?  I was really careful ordering and soldering in parts, but it's more than likely I've messed up somewhere.

Worse case scenario, the high pitched noise is completely removed with the delay switch off, so I guess I've got a distortion unit for my efforts!

Thanks again for any advice you can offer.

Ian