LO Posted May 10, 2004 Report Share Posted May 10, 2004 HiHoping someone might be able to help meI have attempted to design a .brd file for the preamp schematic donated by synapsys in the direct injection thread (a couple of topics below)http://synapsysllc.com/guitarpreamp.htmI have a couple of main questions they are pretty basic so dont be too mean....1. Does the IC pinout shown apply to all 4 IC's?2. The upsidedown triangle symbol's are earth's right???3. Is anyone prepared to check my design? If so let me know in this thread and i'll email you the brd file (no webspace!).Any help appreciatedcheersLO Quote Link to comment Share on other sites More sharing options...
moebius Posted May 10, 2004 Report Share Posted May 10, 2004 Hi,I'll try to answer:1. Yes, but there are only 2 IC's. Both of those are Dual OPAMPs, check markings inside opamp symbols and you'll see.2. In THIS case, yes. (In some schematics it refers to negative power supply.. What, Standards, eh?! (But usually it's marked somewhere))3. I wouldn't trust myself on this :D (and I'm also a bit "Eagle restricted")I hope this helped, Moebius Quote Link to comment Share on other sites More sharing options...
LO Posted May 12, 2004 Author Report Share Posted May 12, 2004 Thanks Moebiusthats a big help, there are 4 IC's total but yes only 2 different types :)If no-one is keen to check it I guess i will just have to try it!If it works??? and anyone wants the .brd file just let me know and I can send it to you...pEaCe.. Quote Link to comment Share on other sites More sharing options...
stryd_one Posted May 12, 2004 Report Share Posted May 12, 2004 no webspace? What about the portal? I'm not sure if the portal is designed for these things though...anyone know? Quote Link to comment Share on other sites More sharing options...
LO Posted May 12, 2004 Author Report Share Posted May 12, 2004 mmmm try this http://avishowtech.com/midibox//home/avishowt/www/midibox/photos/preamp_v2.brdum no that didnt work? Quote Link to comment Share on other sites More sharing options...
pilo Posted May 12, 2004 Report Share Posted May 12, 2004 mail the file to smash ;)By the way there are 2 op amp in a NE5532 package ;) Quote Link to comment Share on other sites More sharing options...
smashtv Posted May 12, 2004 Report Share Posted May 12, 2004 Try:http://avishowtech.com/midibox/photos/preamp_v2.brdThat one works ;)hopefully one of these days I can build a better upload script, that does not give the wrong URL to the uploader! BestSmashTV Quote Link to comment Share on other sites More sharing options...
LO Posted May 13, 2004 Author Report Share Posted May 13, 2004 cool Thanks! ;DI have a feeling that I may have the IC's "flipped"?But I guess I could always mirror the board....Thanks[tt]LO[/tt] Quote Link to comment Share on other sites More sharing options...
moebius Posted May 13, 2004 Report Share Posted May 13, 2004 Ok, let's see..Yeah, IC's are flipped.. anyway: DO IT AGAIN!!Ever wondered, WHY you have 2 same type of opamps, but signals are wired to differend pins (besides of power)?! :o OPA2604 and NE5532 are DUAL OPAMPs, so there are 2 separate OPAMP circuits inside. Those OPAMP symbols marked U1 are build around one IC and same goes to U2.You better believe me  ::) and do the next version with only 2 IC's, ok ;)(Yeah, sorry.. It's good to exercise some schematic reading.. sometimes it get's really cryptic, when some logic chip is marked somewhere in the schematic, but its gate symbols are spread around)Also, I'd like to add that in my board creation process, I usually break circuit in smaller subsets in my mind, then place IC's first, and then rest of the components.And when routing, power goes first, and then "troublesome" signals (long traces/ with crossings).Bye, Moebius(<opinion> p.s. Autorouters just give you a looong coffee break, before you can start working</opinion> Quote Link to comment Share on other sites More sharing options...
LO Posted May 13, 2004 Author Report Share Posted May 13, 2004 oh shite I understand........ I really do have to do it again; dont I! there is only one 5532 & one 2604....der.....mmmmmm this is fun??? 8)Thanks :D i'll post again soon as I get some time to redesign the circuit Quote Link to comment Share on other sites More sharing options...
LO Posted May 14, 2004 Author Report Share Posted May 14, 2004 OK OK, would be real nice if someone could cast there eye over this........http://avishowtech.com/midibox/photos/preamp_v3.brd I think I have got it this time???My main concern is I have got pin 5 of the IC's to earth but in the schematic http://synapsysllc.com/guitarpreamp.htm it has a "+" next to pin 5 although they run to earth...harder than it looks this circuit design. Quote Link to comment Share on other sites More sharing options...
moebius Posted May 14, 2004 Report Share Posted May 14, 2004 Ok, back to OPAMP basics:OPAMPs have 2 inputs: inverting and non-inverting.Those OPAMP stages, with signal connected to minus (input) and plus (input) grounded are configured as inverting amplifiers. So, there's nothing to worry about. If you want to dig deeper in theory check:http://www.williamson-labs.com/480_opam.htmBy, Moebius Quote Link to comment Share on other sites More sharing options...
moebius Posted May 14, 2004 Report Share Posted May 14, 2004 Ok,I had a quick peek at your V3 design, and didn't see any errors. I think that you could get rid off jumper wires altogether, with some modifications. Like rotating cap C2 90 degrees, and running trace (C-D) under it and manipulating orientation of battery connections.;) Moebius Quote Link to comment Share on other sites More sharing options...
LO Posted May 16, 2004 Author Report Share Posted May 16, 2004 hey thanks very much!!!!!thanks to all who helped me ;D ;DI'll try and make it now :o Quote Link to comment Share on other sites More sharing options...
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