tag:blogger.com,1999:blog-6847048658257278783.post9181985031823978039..comments2024-03-28T18:53:30.726+00:00Comments on Guitar FX Layouts: Landgraff MO'DIvIarkhttp://www.blogger.com/profile/08416945174853142251noreply@blogger.comBlogger118125tag:blogger.com,1999:blog-6847048658257278783.post-33662036085325306492023-08-19T17:15:57.875+01:002023-08-19T17:15:57.875+01:00Thank you for this. I had built it to the layout a...Thank you for this. I had built it to the layout and felt it did not sound good: too bassey and congested. I put the clipping diodes before the Filter pot to Lug 1 and also put that 22n cap between the 1.5k and FET Gate and that helped a lot. I haven't tried the 1uf in place of the 10uf and only had 1-100KA pot which I used for the gain and that improved the range a bit.Dhttps://www.blogger.com/profile/12565916202097899589noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-70297655416056662042023-08-14T03:01:38.906+01:002023-08-14T03:01:38.906+01:00This comment has been removed by the author.Dhttps://www.blogger.com/profile/12565916202097899589noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-3791932440983113832019-07-30T10:11:55.974+01:002019-07-30T10:11:55.974+01:00I once played a friends rat (don't know which ...I once played a friends rat (don't know which version) and wasn't really impressed. Built this one and it sounds huuuuuge! No squealing, actually very quiet, and a good range of tones. Makes me want to play some stoner riffs. <br /> <br />Thanks for the layout! <br />The only thing I changed is a logarithmic pot for volume as usual. Eli_Klngsmkthttps://www.blogger.com/profile/04271664305312932268noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-23947413069954448122016-10-07T07:15:51.931+01:002016-10-07T07:15:51.931+01:00This is an issue that's quite common with a Ra...This is an issue that's quite common with a Rat and derivatives. Up the compensation cap to 100p and the issue should be gone.<br />+mmirosolhttps://www.blogger.com/profile/02400327798106357876noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-87838267717966397902016-10-05T08:50:58.938+01:002016-10-05T08:50:58.938+01:00Hi..I build this pedal and it works fine. The only...Hi..I build this pedal and it works fine. The only thing I don't understand is why it squeals if I increase the volume and the gain. <br />Anybody had/have this problem? Thanks. <br /><br />Davide ZeroDieci_Labhttps://www.blogger.com/profile/10029028378671987263noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-42617368129016786242016-09-02T06:32:53.268+01:002016-09-02T06:32:53.268+01:00If you're in the US, smallbear is a reliable s...If you're in the US, smallbear is a reliable source for legit JFETs. <br /><br />You could try using a switched jack for the input and link the input to the switched sleeve lug so that the input is grounded when no plug is inserted. If it still squeals at that point, I wouldn't be too worried about it. No point in using a pedal with no instrument plugged in anywayTravishttps://www.blogger.com/profile/00836791717229314419noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-90175327839511204222016-09-02T05:54:00.806+01:002016-09-02T05:54:00.806+01:00True. By the way has anybody found an Ebay seller ...True. By the way has anybody found an Ebay seller who still has (I assume they are not being made anymore) genuine or "in-spec" 2n5457´s?<br /><br />Here is a quote from some seller:<br /><br />"Buyers beware of far eastern fake JFET's being offered on eBay at reduced prices. The fake parts often have an abrasion on the print face (presumably due to the oringinal marking being buffed off) and often have the date/batch code number C521. This applies to both 2N5457's and J201's. Faichild parts usually have two capital letters followed by two numbers for the batch code.<br /><br />The printing is often smudged. Another indication of fake parts is the small recess on the circular part of the device having no marking. The genuine ones that we have on offer are marked with a number usually 0 to 7 or a capital letter L to Q. <br /><br />I have tested some of these cheap parts(both J201 and 2N5457) and most work as JFET's but are way out of specification and some do not work at all. I can only assume that they are remarked 2SK types<br /><br />Genuine parts should have clear legible printing, shiny appearance and a character in the recess as described above. <br /><br />Please note that the above is based our own observations from purchased samples and does not apply to all JFET's being offered on eBay. This for your guidance only."levishttps://www.blogger.com/profile/01465011254642338089noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-78560454772406541422016-09-02T05:43:53.059+01:002016-09-02T05:43:53.059+01:00Ok, thanks for the info. But the grounded input-by...Ok, thanks for the info. But the grounded input-bypass wiring does not do the trick. I´ve always used that kind of footswitch-wiring and always got the squeal with these type of pedals (RAT).levishttps://www.blogger.com/profile/01465011254642338089noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-81337471954986056932016-09-02T04:03:51.394+01:002016-09-02T04:03:51.394+01:00Just to add to what ciaran said. Out of spec doesn...Just to add to what ciaran said. Out of spec doesn't mean it's fake. If it's fake it's a part that either been a FET of a different type that's been relabeled or it's not a FET at all. So keep that in mind. Zachhttps://www.blogger.com/profile/00044917566185720896noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-24026476027427320942016-09-02T01:42:27.859+01:002016-09-02T01:42:27.859+01:00Use a switch wiring scheme that grounds the input ...Use a switch wiring scheme that grounds the input when in bypass. Check out the Offboard wiring section at the top of the page.<br /><br />The FET here is just used as a buffer so any FET, in spec or not, should work fine. Ciaran Hasletthttps://www.blogger.com/profile/14841971807120256954noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-81211871939934158272016-09-01T21:20:28.345+01:002016-09-01T21:20:28.345+01:00Hi! Any suggestions to fix the squealing when no g...Hi! Any suggestions to fix the squealing when no guitar is connected to the pedal input? Also, would J201 work in place of 2N5457 in this pedal? Do you guys use the ebay fake 2n5457`s and do they work like genuine ones in applications like this for example?levishttps://www.blogger.com/profile/01465011254642338089noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-21507494060820149832016-09-01T21:15:55.333+01:002016-09-01T21:15:55.333+01:00This comment has been removed by the author.levishttps://www.blogger.com/profile/01465011254642338089noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-48246890038763461932016-07-17T01:11:20.653+01:002016-07-17T01:11:20.653+01:00Update: Double checked for bridges and put a new c...Update: Double checked for bridges and put a new chip in and all is working perfectly. Thanks for the help.Anonymoushttps://www.blogger.com/profile/03672164085922626372noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-30779925886567608132016-07-08T01:22:01.417+01:002016-07-08T01:22:01.417+01:00Thanks for the reply. I ran an audio probe over it...Thanks for the reply. I ran an audio probe over it and as you suspected, the signal entered at pin 3 but did not exit. I ordered some new 308's. Plenty of time to make sure my solder job is up to snuff. Thanks again.Anonymoushttps://www.blogger.com/profile/03672164085922626372noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-65379649428475681942016-07-07T06:15:30.237+01:002016-07-07T06:15:30.237+01:00Your voltages on the IC are way too high on all pi...Your voltages on the IC are way too high on all pins, except for the supply pin which should be around 9V. Pins 2, 3 and 6 should be way under 5V. This seems to me like a short that's burned the opamp.<br /><br />Knife the gaps, triple check all cuts / component positions and swap the chip. Also, double check your supply. If you are using a battery, then it's dead at 7,6 volts.<br />+mmirosolhttps://www.blogger.com/profile/02400327798106357876noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-67790741305028380972016-07-07T04:06:36.980+01:002016-07-07T04:06:36.980+01:001-7.17v
2-6.25v
3-5.69v
4-0/fluctuating
5-61mv/flu...1-7.17v<br />2-6.25v<br />3-5.69v<br />4-0/fluctuating<br />5-61mv/fluctuating<br />6-6.38<br />7-7.69<br />8-5.93<br /><br />D-7.69<br />S-2.31<br />G-1.5Anonymoushttps://www.blogger.com/profile/03672164085922626372noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-7298563740064167502016-07-06T17:21:51.612+01:002016-07-06T17:21:51.612+01:00I know this thread is pretty old but I'm stuck...I know this thread is pretty old but I'm stuck. I too only get a quiet "brap" sound and only on the bottom string when plucked hard. Any ideas what the issue could be?Anonymoushttps://www.blogger.com/profile/03672164085922626372noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-1444346655081153172016-07-06T17:20:27.723+01:002016-07-06T17:20:27.723+01:00This comment has been removed by the author.Anonymoushttps://www.blogger.com/profile/03672164085922626372noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-39565792519630533152015-07-17T21:29:31.946+01:002015-07-17T21:29:31.946+01:00This sounds great! Used blue LED's. Me like......This sounds great! Used blue LED's. Me like...thnx everyone...Blackwinghttps://www.blogger.com/profile/16864575046719143800noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-37019072034610379922015-05-10T18:52:48.859+01:002015-05-10T18:52:48.859+01:00Finally got this one working. Built it about a yea...Finally got this one working. Built it about a year ago and couldn't figure out what was wrong with it. Went through my few dodgy builds today to see if i had missed something. Guess what staring me straight in the face was a resistor connection in the wrong place. Makes you realise you should never throw out a build just because you can't see the problem immediately, put it to one side and go back to it later. Maybe not as long as a year though.<br />Anyway, this sounds fantastic, the clipping switch gives a level drop on both options but that's ok.Hozy31https://www.blogger.com/profile/16714771534041521767noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-69354487804944638812015-03-11T10:22:31.126+00:002015-03-11T10:22:31.126+00:00Is there a link to the schematic used for this Lay...Is there a link to the schematic used for this Layout?<br />I'm finding different schematics on the MO'D wich all seem to be more like the original RAT<br />The main differences:<br /> - 100K instead of 47K for the voltage divider (which is probably very insignificant!!!)<br /> - clipping diodes/LEDS before the filter pot instead of after the filter pot<br /> - a 22n between the 1K5 and the FET gate which is missing on this layout<br /> - a 1uF from the 4,5 volt to ground instead of a 10uF<br /> - all Logarithmic pots instead of lineair pots<br /> - a 1nF parallel to the 100uF at the 9V supply (wich also seems to be quite unnecessary)<br /><br />I'm probably gonna build both on the breadboard first but i'm just curiousSeg@fredohttps://www.blogger.com/profile/17829974182999631886noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-55228401296158537932015-03-03T12:52:34.812+00:002015-03-03T12:52:34.812+00:00Yes, but for the clipping switch it doesn't ma...Yes, but for the clipping switch it doesn't matter as long you just have one in opposite direction of the other...Seg@fredohttps://www.blogger.com/profile/17829974182999631886noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-29859787567700368432015-01-18T00:33:37.064+00:002015-01-18T00:33:37.064+00:00Hey there is the shaded side of the LED's the ...Hey there is the shaded side of the LED's the negative side? Thnx!Blackwinghttps://www.blogger.com/profile/16864575046719143800noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-45414135313687006612014-04-09T22:49:18.624+01:002014-04-09T22:49:18.624+01:00the pot was bad...swapped it and now we're goo...the pot was bad...swapped it and now we're good! Thanks!thebrettmoorehttps://www.blogger.com/profile/05904082462907835796noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-31241085269036275612014-04-09T18:14:08.643+01:002014-04-09T18:14:08.643+01:00The pot may have failed causing the issue, maybe a...The pot may have failed causing the issue, maybe an internal short between pins 2 and 3 making the pedal at its loudest all the time irrespective of the rotation. Either that or maybe an unwanted solder bridge maybe between pins 2 and 3? Whatever it is the volume pot is certainly the problem so I would be paying attention to that, and maybe swapping it if necessary.IvIarkhttps://www.blogger.com/profile/08416945174853142251noreply@blogger.com