Sontec: hardware bypass, balanced THAT I/O, MS, power supply - at one PCB!

[Igor]

Soooo...cool. I did 5 MS'ed Sontecs at this moment. Everybody are happy, even me with how it sounds!
Got a lot of mails about how to make it stepped. Wait for DC Uni-Q, you will be more than surprised.
http://www.groupdiy.com/index.php?topic=47454.40

I like the cleanliness of this thread - if no questions, everything is straightforward.

 

[druu]

Igor you have email. I'm interested in a pcb and bought stereo sontec boards earlier this year.

Btw youre PM inbox is full.

 

[Igor]

Answered.

 

[druu]

Does anyone know of a relay from Farnell that will work with this? BOM says >500 OHM but I can't seem to find any suitable?

 

[druu]

Anyone?

 

[zayance]

I guess these will fit, don't have the board or the BOM.
Check pins configuration and part dimension to be sure, but Igor and others mostly use these types of DPDT Relays.

http://fr.farnell.com/te-connectivity-axicom/v23105-a5303-a201/relais-ci-12vdc/dp/1174984?Ntt=V23105A5303A201


T.


PS: Whole bunch of others that might fit

http://fr.farnell.com/jsp/search/browse.jsp?N=203396+210192169+210199667+210167039&Ns=P_PRICE_FARNELL_FR%7C0&locale=fr_FR&appliedparametrics=true&getResults=true&suppressRedirect=true&isRedirect=&originalQueryURL=/jsp/search/browse.jsp%3FN%3D203396%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Dfr_FR%26divisionLocale%3Dfr_FR%26catalogId%3D%26skipManufacturer%3Dfalse%26skipParametricAttributeId%3D%26prevNValues%3D203396

 

[druu]

Thanks zayance! I'll have a look through those links

 

[Igor]

Photos of working units and sonic impressions?

 

[druu]

Still a little while off, trying to find 2k6 and 3k57 resistors is proving difficult. :S

 

[Harpo]

Still a little while off, trying to find 2k6 and 3k57 resistors is proving difficult. :S

Resistors come with +/-% tolerances to their stated value, but a series and/or parallel config might be easier to source.
For 2k6 maybe put a 7k5 in parallel with a 3k9 (1/(1/2600+1/7500)=2566R=1.3% low) or maybe put a 1k8 in series with a 820R (1800+820=2620R=0.77% high).
For 3k57 maybe put a 7k5 in parallel with a 6k8 (1/(1/7500+1/6800)=3566R=0.1% low).

 

[druu]

Thanks Harpo! I may take that route but in no rush just yet so i'll see if I can actually find drop ins first.

Just putting finishing touches to a 3U panel design that a friend has made for me in Autocad for my switched Sontec, similar to the ones going around. If anyone wants the layout let me know and I'll put it up for download (2000 .DWG format) for FREE.

 

[druu]

BTW, newby question but are 0.5W OK to use instead? So much easier to source.

These are the closest I can buy locally:
http://www.altronics.com.au/index.asp?area=item&id=R7568 - 2k7?
http://www.altronics.com.au/index.asp?area=item&id=R7571 - 3k6?

Is a 1/2W ok for the 2M resistor?

 

[Harpo]

BTW, newby question but are 0.5W OK to use instead? So much easier to source.

These are the closest I can buy locally:
http://www.altronics.com.au/index.asp?area=item&id=R7568 - 2k7?
http://www.altronics.com.au/index.asp?area=item&id=R7571 - 3k6?

Is a 1/2W ok for the 2M resistor?

Just looking up the schematic, 2k6 and 3k57 are the voltage setting resistors in the psu.
3k6 will be fine with Iset 200R, giving 1.25V(1+3600/200)=23.75V.
2k7 will be a little high with Iset 200R, giving 1.25V(1+2700/200)=18.25V, being a little too close to the edge of the max.supply rating of some chips.
Better use a series string of resistors that add up to less than 2k68. YMMV

Your DOA will not put out more than its supply voltage, so the 2M will need a min.rating of 24V^2/2,000,000R=0.000288W. Your 0.5W rating is ample.

 

[druu]

Well I've pretty much got this front panel design finished. I'll be getting it laser engraved this week so will post pics of the results, hopefully turn out well

Here.

 

[daspalme]

Hey everyone!

I'm kinda new on this project and in this forum actually, too, so tell me to shut up if I ask things that you have already talked about several times! :-X 

I was wondering what exact model of switches protools used in his (awesome! ) sontec? Yesterday I was told alphastat.de would offer nice pots for diy-purposes, but I couldn't find any stepped switches, yet... I'd love to build this thing with those switches too but elmas are just too expensive for now.

Great project by the way, thanks Igor!

Börje

 

[druu]

http://www.ebay.com.au/itm/251121469361 for FREQ/GAIN

http://www.ebay.com.au/itm/250949846200 for Q

 

[Ben F]

I found some 23 step for freq/gain that look the same and would save modifications from 24 step? they have 2 pole and 4 pole options:
http://www.ebay.com.au/itm/320953851027?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

Also, would these work for the EQ gain? It's pre-made 50K linear 23 step:
http://www.ebay.com.au/itm/300573253532?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Druu, would be keen to ask about the front panel will PM you.

 

[druu]

Due to popular demand..

The laser place stuffed my panel up - the circle you see at the bottom wasn't supposed to be etched

DWG (AutoCAD 2000) and Vectorised PDF available at below link. Not sure how long I can host it there so maybe if somebody wants to grab them and host them. I will leave the files there indefinitely.

http://www.amnet.net.au/~amunday/sontec/

Cheers and enjoy.

 

[daspalme]

Thanks druu! Holger just told me about ultratone switches, which look pretty similiar to yours. I will keep them in mind! 8)

Börje

 

[Igor]

Looks awesome. But why don't you make your stepped units horizontally separated (mean, one channel under another)?
This way you can: avoid cutting the pcb; place one pcb right under another; shorten the wires to front panel; simplify the life etc.
Everything should fit in 3RU.

I liked the idea with Uraltone switches and smd 1206 resistors. If use metal films, Vishay etc, should be good.
Looks like very easy to solder compared to axial 1/4W - time going to trimming and cutting should be taken into acct.
Uraltone switches aren't so bad, after all)))