tag:blogger.com,1999:blog-5481402030233340127.post3245236741611695045..comments2024-03-28T01:15:58.057-04:00Comments on Perf and PCB Effects Layouts: MXR Script Phase 90dtgehringhttp://www.blogger.com/profile/09555201436004501222noreply@blogger.comBlogger86125tag:blogger.com,1999:blog-5481402030233340127.post-86205026912283799272023-07-26T01:35:23.992-04:002023-07-26T01:35:23.992-04:00You can series a 47k resistor on lug3 of the 200k ...You can series a 47k resistor on lug3 of the 200k trimmer.regarding on the phasing try check the bias voltage and that zener diodeJun dhttps://www.blogger.com/profile/07905810487041216546noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-35162550937353751162023-07-26T01:30:08.445-04:002023-07-26T01:30:08.445-04:00Caps in parallel not in series sir.Caps in parallel not in series sir.Jun dhttps://www.blogger.com/profile/07905810487041216546noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-6487220001425156942023-01-19T11:01:49.211-05:002023-01-19T11:01:49.211-05:00you can add 2 electrolytic cap in series
10uf + 4...you can add 2 electrolytic cap in series<br /><br />10uf + 4.7ufZaraki1337https://www.blogger.com/profile/04815656896624384794noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-72637461921720855182023-01-17T01:40:19.482-05:002023-01-17T01:40:19.482-05:00Hi...is there a sub for the 15uf besides tants? Da...Hi...is there a sub for the 15uf besides tants? Damn its pretty hard to find this kind of valuesTheUnknown311318https://www.blogger.com/profile/14975839584588984384noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-75997361193177861712022-11-10T11:16:37.258-05:002022-11-10T11:16:37.258-05:00The Phase 90 is a one-knob phaser. As such it was...The Phase 90 is a one-knob phaser. As such it was designed to provide a number of compromises. The width of the sweep was a compromise for something that worked reasonable well for fastest and slowest speeds (one usually wants a narrower sweep for faster speeds). The resonance/feedback was also a compromise setting, as was the range of where the sweep occurred.<br />So here are some options for achieving a broader range of sounds out of the basic design, and making more like what you get with a 3 or 4-knob phaser.<br />1) There is a 1M resistor coming off the trimpot, feeding the gates of all the FETs. Replace that with a 510k fixed resistor in series with a 500 pot, using as a variable resistance. This will provide variable offset to move where the phasing occurs in the spectrum, from lower and gurgly to higher and swirly.<br />2) Right beside that 1M resistor is a 3M9 resistor connecting the 15uf cap to the same "blue" trace where the 1M resistor goes. That resistor sets the amount of LFO current fed to the FETs, and is summed with what comes off the trimpot. In other words, what the FET gates see is a combination of the default bias setting from the trimmer, PLUS whatever the LFO adds on top of that. Increasing the value of the 3M9 resistance will shrink the width of the sweep, and reducing it will make the sweep wider/farther. which is ideal for very slow sweeps. I would not go much higher than 4M3 for narrow bubbly tones, and much lower than 2M7 for ultra-wide slow sweeps. Worth noting that some issues of the P90 used 3M3, which is a little better for slower sweeps but a bit too jarring for the fast bubbly stuff. Note that pushing TOO much current at the JFET gates can cause some irritating glitches at one end of the sweep. So don't use a lower resistance coming off the LFO and trimpot at the same time. It won't damage anything, but won't sound pretty.<br />Finally, note that the need for "matching" of JFETs is greatest when one aims for wider sweep. If the sweep is narrow, then the odds are good all JFETs will be similarly altered by the LFO. If the sweep is wide, then the risk increases that one or more of the JFETs will not change its drain/source resistance as you approach the peak or trough of the sweep. So if you don't know if your JFETs are reasonably matched, it may be best to avoid ultra-wide sweeps.<br />3) The first issue omits any feedback/resonance, it would seem. If you wish to add some, then you would connect a resistance between pin 6 of that last op-amp in the lower left of the drawing, to pin 2 of the *second* op-amp from the top in that column of chips to the left. In other words, it goes from the output of stage 4 to the input of stage 2. Over various issues, you will find values of 22k or 24k. You can probably go as low as 20k or even 18k, but I would caution against going any further. Increasing the resistance value will reduce the amount of feedback. So, an 18-20k fixed resistor, in series with a 20k variable resistance/pot would yield a reasonable range of resonance/feedback settings.<br />Mark Hammerhttps://www.blogger.com/profile/00503974282701369321noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-4756225913433918782022-09-10T23:33:17.707-04:002022-09-10T23:33:17.707-04:00Verified with TL061's , 3 x 2SK30A Y, 1 x 2N54...Verified with TL061's , 3 x 2SK30A Y, 1 x 2N5457. 2SA1015 .Used a 220K trimmer as tht was all I had. Nice sounding phaser,thank you!pufffinhttps://www.blogger.com/profile/00042875634673862373noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-56916553455879176962022-04-15T18:09:33.805-04:002022-04-15T18:09:33.805-04:00If you use 2n5457's, just remember that the Dr...If you use 2n5457's, just remember that the Drain/Source/Gate is set up opposite from the 2n5952's; they face the opposite direction. I pulled up schematics for the 2n5952's and had my 2n5457's facing the same way that the 5952's would face (opposite of the 2n4125 at the top), and spent hours trying to diagnose what the problem was. I fixed it, and now the pedal sounds awesome.<br /><br />Derekhttps://www.blogger.com/profile/03947322623675705748noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-31971501952345620732022-03-16T21:05:56.734-04:002022-03-16T21:05:56.734-04:00This comment has been removed by the author.CrispyFunkhttps://www.blogger.com/profile/16856275092086072789noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-49553647135410002072022-01-29T07:31:41.096-05:002022-01-29T07:31:41.096-05:00Very good. 2v of Vgs would be 2v of Vgs off? And w...Very good. 2v of Vgs would be 2v of Vgs off? And what does would be matching within 3mv or 30mV? Would be the maximum difference about each Fet? Thank You!! Roberto Gabrielhttps://www.blogger.com/profile/14336197570547458314noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-65511507018702703932021-12-06T06:30:54.592-05:002021-12-06T06:30:54.592-05:00I succeeded it worked using 2n5952 and 2n4125 ic u...I succeeded it worked using 2n5952 and 2n4125 ic ua741cp thanks again from thailandAnonymoushttps://www.blogger.com/profile/00818401956600191911noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-7992431016060286352021-09-28T18:46:05.212-04:002021-09-28T18:46:05.212-04:00I can verify this also. I did find,as mentioned ea...I can verify this also. I did find,as mentioned earlier, that speed 1 should be speed 3 in order to increase by turning clockwise. Thanks for this layout!! 125Signalhttps://www.blogger.com/profile/05782204285402823187noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-80788335946753356802021-09-17T05:38:04.679-04:002021-09-17T05:38:04.679-04:00Hi everyone can I use bf256b instead of 2n5952 and...Hi everyone can I use bf256b instead of 2n5952 and bc558b instead of 2n4125?Alireza69https://www.blogger.com/profile/15476418184756927018noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-2187473164000189672021-07-31T23:27:06.959-04:002021-07-31T23:27:06.959-04:00For trim por u can use also 220k trim
I think its ...For trim por u can use also 220k trim<br />I think its written 224<br /><br />I have made few phasers with 220ktrim<br /><br />And for pot<br />Use a B1M pot and solder 1megaohm resistor from lug 1 and 3 that sud simulate c500k pot<br />U can also just keep B1M with out resistor<br /><br />I have done both..<br /><br />I do t think 2n4125 is Jfet. U need jfet for this 2n5457 is a jfet.by googling i found 2n4125 to be pnp bjt<br />Ull need jfet for this<br />And all 4 jfet sud be matched u can finemd how to match on youtube.<br /><br /><br />Lm741 is goodZaraki1337https://www.blogger.com/profile/04815656896624384794noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-237217355594192432021-07-18T08:58:34.779-04:002021-07-18T08:58:34.779-04:00Hi.
I have problem with trimmer and potentiometer....Hi.<br />I have problem with trimmer and potentiometer. I cant find 250k trimmer and C500k pot in here. Just 200k 500k and A and B type potentiomer. I have tried A500 and B100. I also tried 200k and 500k trimmer with 220 resistor solder to leg 1 and 3 but no phasing. The pedal bypass when turn off but when on, i cant here anything. Any suggestion? Btw, im using 2n4125 and 2n5457 trnsistor and Lm741 opampNobbie88https://www.blogger.com/profile/04912383723335376320noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-26990676900698659892021-06-14T22:25:41.918-04:002021-06-14T22:25:41.918-04:00Its verified!! Mine with 2n5485 trans works fine! ...Its verified!! Mine with 2n5485 trans works fine! Tnx and more power! Regards fr Philippines. Jun.Jun dhttps://www.blogger.com/profile/07905810487041216546noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-58927488531186221422021-05-31T22:19:08.919-04:002021-05-31T22:19:08.919-04:00This comment has been removed by the author.AEhttps://www.blogger.com/profile/12719688877939488379noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-22323215091455954632021-04-09T14:11:04.550-04:002021-04-09T14:11:04.550-04:00Is there a way to add additional knos of depth or ...Is there a way to add additional knos of depth or something else?Zaraki1337https://www.blogger.com/profile/04815656896624384794noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-61192147068869901392021-04-07T20:32:05.286-04:002021-04-07T20:32:05.286-04:00VerifiedVerifiedZaraki1337https://www.blogger.com/profile/04815656896624384794noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-39032929318785675762021-04-02T00:01:51.504-04:002021-04-02T00:01:51.504-04:00Can you please make a layout with quad or dual op...Can you please make a layout with quad or dual op amp..<br />:)Zaraki1337https://www.blogger.com/profile/04815656896624384794noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-33699495766404974772021-03-29T11:50:36.611-04:002021-03-29T11:50:36.611-04:00I am intrestedI am intrestedZaraki1337https://www.blogger.com/profile/04815656896624384794noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-83042536211932290512021-01-27T07:27:33.545-05:002021-01-27T07:27:33.545-05:00Hmmm..
2N5952 change to 2SK30A..Hmmm.. <br />2N5952 change to 2SK30A..ImpostorXXXhttps://www.blogger.com/profile/09242315595152782677noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-22124646372037364432020-12-14T21:47:22.475-05:002020-12-14T21:47:22.475-05:00Do you have the original vector file for better pr...Do you have the original vector file for better print quality?diouhttps://www.blogger.com/profile/09039907774966886389noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-43602061270466172712020-03-29T04:56:24.851-04:002020-03-29T04:56:24.851-04:00is there anyone to answeris there anyone to answerdj_shen18https://www.blogger.com/profile/07055448488571145796noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-12155070137154550422020-03-29T04:55:27.256-04:002020-03-29T04:55:27.256-04:00I'm trying to build an MXR Phase 90 but using ...I'm trying to build an MXR Phase 90 but using J113 as the JFETs instead of the original 2N5952. All the J113 are matched, but the output is slightly distorted. It's not as noticeable when lightly strumming some chords, but picking strings with some amount of force will produce some ugly bass-y distortion. I've also tried different FET configurations according to these designs but none of them seemed to help. I noticed on the data sheets that the J113 I'm using has a forward gate current of 50mA while the original 2N5952 has only 10mA. Would it be worth it to get another set of JFETs more in line with the 2N5952, or does that spec not matter?dj_shen18https://www.blogger.com/profile/07055448488571145796noreply@blogger.comtag:blogger.com,1999:blog-5481402030233340127.post-2054829128411029822020-03-17T09:58:57.815-04:002020-03-17T09:58:57.815-04:00????????????????????????????dj_shen18https://www.blogger.com/profile/07055448488571145796noreply@blogger.com