PCB offer: Thomas Henry's 555-VCO

logicgate · Joined: Mar 02, 2013 Posts: 11 Location: brazil

Hello guys!

Can I get away by using 1,87K 3500ppm tempcos for this project???

Cheers!

Gaetano_AU · Joined: Oct 08, 2011 Posts: 64 Location: Australia

Boards Arrived Matthias, nicely packed, thanks Smile

fonik · Posted: Tue Mar 05, 2013 2:14 pm Post subject:

fonik · Posted: Tue Mar 05, 2013 2:18 pm Post subject: payment details

i sent out PMs/emails to all who ordered PCBs/panels. please check you PM's, i am missing the response of quite a few people.

LektroiD · Posted: Wed Mar 06, 2013 5:53 am Post subject:

I'm assuming the farnell pots I linked won't fit this project?

Any other sources (that are not wildly expensive)?

fonik · Posted: Wed Mar 06, 2013 2:11 pm Post subject:

fonik · Posted: Wed Mar 13, 2013 2:42 am Post subject: Re: payment details

AlasdairMoons · Joined: Dec 03, 2011 Posts: 105 Location: East-Belgium

sorry Mathias, my 4 boards arrived, all is fine
.....
......
btw. do I really have to use tempco's??

fonik · Posted: Thu Mar 14, 2013 12:54 am Post subject:

the tempco's are to reduce drift due to temperature changes. this gets more important the longer the takes are you recording, and if you are interested in more precise tuning between the tracks.

diablojoy · Posted: Fri Mar 15, 2013 12:24 am Post subject:

boards received in OZ all good
thanks again Matthias.

jp1971 · Joined: Mar 07, 2013 Posts: 1 Location: Brooklyn, NY

Sorry for coming to this thread late. Are there any PCBs left? If so, I would like to order:

1x circuit PCB
1x eurorack PCB
1x front panel

Thanks,
jp1971

fonik · Posted: Thu Mar 21, 2013 8:11 am Post subject:

there are quite a few open orders, and i actually wanted to keep a few spares just in case something gets lost in the mail. but i will put you on the waiting list.

doobedy · Joined: Jan 12, 2009 Posts: 19 Location: Los Angeles

Man I just noticed the prototype had an LFO switch and LED. I wish those had made it to the panel as well.

Is that just a switch changing capacitor values? How is the LED done? Not that I see room on the panels to fit anything on there. I was thinking of a wave folder to go between my two VCOS, maybe I could add an LED and LFO switch to that as a custom panel.

Did TH specifically ask you not expand his circuit in any way?

modulardoom · Joined: Mar 13, 2013 Posts: 5 Location: portugal

if it would be still possible i would like to order
1 circuit pcb
1 eurorack pcb
1 front panel

Constantin · Joined: Aug 08, 2011 Posts: 2 Location: Berlin

If there are still some pcbs available, I would be in for
4 circuit PCB

thanks
Constantin

fonik · Posted: Thu May 30, 2013 10:44 pm Post subject:

interest in more of the PCBs/front panels?

i will gather/gain interest until 21 JUN 2013 and re-order what is needed...

for the front panels i would need to order at least 30pcs, though. the price for a single front panel would be 10.-EUR/13.-USD now.

jackdamery · Joined: Apr 26, 2010 Posts: 75 Location: UK

3 main boarde PCBs please and 4 euro pcbs

Boerge · Joined: Sep 02, 2009 Posts: 80 Location: Germany

I would take 1 main PCB too.

regards

Boerge

TheAncientOne · Joined: Dec 26, 2006 Posts: 144 Location: United Kingdom

TheAncientOne · Joined: Dec 26, 2006 Posts: 144 Location: United Kingdom

Oh, and I forgot: Another two are alive! A smooth build, once I found the errata notes. I used 100K trimmers for sine round, and got an easy +/-5V

One though for Fonik - could you think of leaving a larger footprint area, with perhaps multiple pinouts, (as the late Jurgen Haible did on his PCBs), for the timing caps. I have a lot of High quality 2n2 polystyrenes, (and yes - I will give batches of then out for postage), but I couldn't get them to fit. I just squeezed some 2n2 polypropylenes I had in stock into place, and I will try the COG's in future, but I think a little more flexibility in the capacitor area would be a good idea. There was plenty of PCB real-estate left. The capacitor footprint Jurgen used is no way unique or copyright, so there would be no problem in just 'lifting' it. I'm sure the man would be smiling down his approval if you did, anyway.

A minor point really. My thanks again to Thomas Henry and Fonik for a really nice VCO with a massive range., and a very easy build.

Note for other builders on transistor matching: I tested 2n3906's from a bag of 100 bought from 'Rapid' I was able to get 4 with gains identical out of 20 or so tested, and the maximum gain variation I read was +/- 10 on a nominal 230 median value. I think just using two from the same manufacturer and date code would be fine.

TH555VCO_test.jpg

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First test on 555 VCO

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jackdamery · Joined: Apr 26, 2010 Posts: 75 Location: UK

TheProf, I see you're in the UK too. Where did you get your 2k 3500ppm tempcos?

Skrog Productions · Posted: Fri May 31, 2013 1:24 pm Post subject:

Hi Matthias.

2nd order interest, could i please order.

4 - Main pcb.

Thanks.

Dave

TheAncientOne · Joined: Dec 26, 2006 Posts: 144 Location: United Kingdom

I got one batch from 'Magic Smoke Eectronics' and the others from Farnell, but it seems they only have the 2K ones in SMT, now. I future I will be using the SMT ones because it's easier to get a closer bond the to the transistor package. The could even be mounted inside an IC socket to get a close contact with a socketed dual pair, and to avoid the effects of drafts.

JasonMichener · Joined: Jun 02, 2013 Posts: 1 Location: Seattle

I would like:
2 x circuit
2 x euro
2 x panels

Thanks!