LO Posted April 2, 2004 Report Share Posted April 2, 2004 HiShould be easy to answer this one? Is it OK if I plug a guitar straight in to the line-in on the PC sound card? Will it do any damage?I understand that ideally you should have a DI box but I cant afford to shell out for one at the moment (or perhaps some DIY plans anyone?)pEaCe Quote Link to comment Share on other sites More sharing options...
Rowan Posted April 2, 2004 Report Share Posted April 2, 2004 Hi LOI could get you one at wholesale price, which will probably cost you less than building one. Let me you if you like me to look into it for you. (I'm in central auckland)Rowan Quote Link to comment Share on other sites More sharing options...
Rowan Posted April 2, 2004 Report Share Posted April 2, 2004 HiPrices start at $65, not as cheap as I thought.laterRowan Quote Link to comment Share on other sites More sharing options...
LO Posted April 2, 2004 Author Report Share Posted April 2, 2004 HiThanks for the offer!!well even at $65 that sounds better than a kit from JayCar ($75)Do I really need one? or is it OK to plug in to the line in?Im just off Symonds st so ur nice and handy!Cheers Quote Link to comment Share on other sites More sharing options...
Rowan Posted April 2, 2004 Report Share Posted April 2, 2004 HiI'm in Parnell. small world. As far as I know you won't damage anything by connecting a GTR directly into the line in on your card. There will be two problems that come to mind.1/ Your soundcard's line ins won't have enough gain.2/ The output impeadance of the pick-ups will be MUCH higher that the input of your soundcard's line ins. Because of this most of the power will be developed in the pick-ups themselevs, not the inputs of your soundcard. This will cause a very weak signal "seen" by you card.Good thing about a DI is that it will balance the signal and isolate the earth of the GTR which should reduce noiseRowan Quote Link to comment Share on other sites More sharing options...
uclaros Posted April 3, 2004 Report Share Posted April 3, 2004 Hi,you will surely do no harm to the sound card but only to your ears.Clean sounds may not sound very bad, but when it comes sto distortion....I think 65$ is worth spending if you plan on recording on the PC. Quote Link to comment Share on other sites More sharing options...
LO Posted April 4, 2004 Author Report Share Posted April 4, 2004 Thanks for the help guysI'll have a go at connecting it directly in the next week or so May come back to you on your offer Rowan! Quote Link to comment Share on other sites More sharing options...
Guest psytron Posted April 4, 2004 Report Share Posted April 4, 2004 you will need a preamp(diy ok). i am sure you could try out a few home made preamps for $65.perhaps there are samples of these floating about.other method plug guitar into amp then amp into comp.hopefully your amp has a lineout if not you sould try the fx send line. just dont use the ext spkr plug. you might make smoke hehe Quote Link to comment Share on other sites More sharing options...
Synapsys Posted April 4, 2004 Report Share Posted April 4, 2004 Hi LO,Here is a schematic for a preamp that works well with a guitar. It can be built for far less than $65 (under $15 USD for parts). I used this circuit as the front end of a guitar effects processor I built several years ago. The circuit requires both positive and negative supply voltages. I built a power supply for the processor but I do not recommend that due to the danger of working with mains. For a DI box I believe two 9-volt batteries as showm on the schematic would work okay. Or you could use two 9-15vdc wall warts if batteries wear out too fast. Hope this is useful... :)http://synapsysllc.com/guitarpreamp.htm Quote Link to comment Share on other sites More sharing options...
LO Posted April 5, 2004 Author Report Share Posted April 5, 2004 thanks for the schematic!ill check out the availability of the parts over hereThanks Quote Link to comment Share on other sites More sharing options...
LO Posted April 16, 2004 Author Report Share Posted April 16, 2004 Hey psytronthe op amp TL062 doesnt seem to be available anymore however I have found a TL072https://www.onsemi.com/pub/Collateral/TL071C-D.PDFCan you or anyone else tell me if this is a suitable replacement?After the instrument input and before the ground plane there appears to be a pot (or is that a diode?) but no value what did you use here? Also what is the IC (U2) labeled 5532 I cant find anything on that!Thanks alot Quote Link to comment Share on other sites More sharing options...
Steven_C Posted April 17, 2004 Report Share Posted April 17, 2004 5532 - that would be NE5532N, I guess. I think even Jaycar have them. Quote Link to comment Share on other sites More sharing options...
pilo Posted April 17, 2004 Report Share Posted April 17, 2004 hey Synapsys can you tell us mre about your fx processor project? I'm working on a linux embedded fx processor too...does this schematic works great for guitar? thanks! Quote Link to comment Share on other sites More sharing options...
uclaros Posted April 18, 2004 Report Share Posted April 18, 2004 U can find both OPA2604 mentioned on the schematicand  RC4580 (a replacement for ne5532) as free samples at www.ti.com !question: what type are the caps labeled 22BP?? Quote Link to comment Share on other sites More sharing options...
Synapsys Posted April 18, 2004 Report Share Posted April 18, 2004 The 22BP caps are bi-polar electrolytics (DigiKey # P1177-ND made by Panasonic) Quote Link to comment Share on other sites More sharing options...
Synapsys Posted April 18, 2004 Report Share Posted April 18, 2004 Hi pilo,Yes the circuit in the schematic works very well for guitar. I use it for electric as well as acoustic with bridge based pickups. The OPA2604 is the key to this circuits success. It is very low noise and has very high input impedance (necessary particularly for acoustic pickups).My fx processor project I mentioned is completely analog. It contains a tube preamp (can be switched in/out of signal path), some filters for cabinet emulation, a four band EQ and a compressor/limiter. I used the (relatively) low voltage tube circuit that can be found at www.PAIA.com. It works pretty good but I think if I were to build another I would want to drive the tube with a higher plate supply voltage (not recommended for most hobbyists since the higher voltage is dangerous … even deadly :o).The RC4580 is a good replacement for the NE5532 but watch the supply voltage. The RC4580 is max'd at +-15 volts whereas the NE5532 is max'd at +-22 volts.The TL072 chip is good for line level signals. I used the TL074 for the EQ circuit. It is also good for peak detectors but I would avoid using this chip as the output driver. My experience is that it does not perform well driving long cables.Psytron,There is no component at the point you indicated. The input jack is a shorting type (thus the up arrow). The ground plane indicates that the signal path to the capacitor on the PCB is surrounded by the ground plane to reduce noise. I use PCB mount jacks to reduce cabling that certainly all MidiBox fans know is a real pain. :'( Quote Link to comment Share on other sites More sharing options...
Guest psytron Posted April 19, 2004 Report Share Posted April 19, 2004 synapsys i think you mean "lo" not me its a marvelous place www.ti.com thank you ;D Quote Link to comment Share on other sites More sharing options...
LO Posted April 19, 2004 Author Report Share Posted April 19, 2004 Thanks for all the advice! :) ;) Quote Link to comment Share on other sites More sharing options...
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