tag:blogger.com,1999:blog-6847048658257278783.post1909982085139510166..comments2024-03-29T01:36:12.851+00:00Comments on Guitar FX Layouts: McGillwell FET BoosterIvIarkhttp://www.blogger.com/profile/08416945174853142251noreply@blogger.comBlogger11125tag:blogger.com,1999:blog-6847048658257278783.post-78263705056505047172014-09-30T01:03:11.070+01:002014-09-30T01:03:11.070+01:00That is weird, I though I replied to this but I do...That is weird, I though I replied to this but I don't see it. My brain mixed up "supply" (as in 9v) with "source" (as in DSG). That's how we learn.motterpaulhttps://www.blogger.com/profile/15536330842070250774noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-28477219974984467632014-09-26T07:08:00.419+01:002014-09-26T07:08:00.419+01:00there is only 1 resistor going to the drain, the 4...there is only 1 resistor going to the drain, the 47k from +9v (supply) not grounddexxyyhttps://www.blogger.com/profile/15083992477248920480noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-23574485078147736692014-09-25T23:58:37.839+01:002014-09-25T23:58:37.839+01:00sorry - wanted to edit
to +M... above you say to s...sorry - wanted to edit<br />to +M... above you say to swap out the 47 from supply to drain with a 100k trim. Can you be more specific on which of the three 47k resistors that is (there isn't one going from supply to drain). I assume it drain to gnd? what +v do I want?motterpaulhttps://www.blogger.com/profile/15536330842070250774noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-52338291560145566102014-09-25T23:53:52.581+01:002014-09-25T23:53:52.581+01:00This comment has been removed by the author.motterpaulhttps://www.blogger.com/profile/15536330842070250774noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-35386227039205301392014-08-13T00:22:18.800+01:002014-08-13T00:22:18.800+01:00a cheaper bloviator, maybe ?a cheaper bloviator, maybe ?Anonymoushttps://www.blogger.com/profile/07132428110212372006noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-82323341138511186842014-08-08T17:59:19.311+01:002014-08-08T17:59:19.311+01:00Thanks - wish I had known that trick. I might try ...Thanks - wish I had known that trick. I might try it again, but I did tear it down already. Biasing fets is still new territory to me.motterpaulhttps://www.blogger.com/profile/15536330842070250774noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-81602238725542027952014-08-08T07:33:33.480+01:002014-08-08T07:33:33.480+01:00If you still have it on your breadboard, you could...If you still have it on your breadboard, you could try to swap that 47k from supply to drain with a 100k trimmer and see if you can bias the J201 correctly. Your low output symptoms may simply be caused by misbiased J201.<br />+mmirosolhttps://www.blogger.com/profile/02400327798106357876noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-11000445614120559842014-08-07T23:24:53.147+01:002014-08-07T23:24:53.147+01:00I built this on my breadboard today with a J201 - ...I built this on my breadboard today with a J201 - works as advertised but not much boost there with my circuit. The "sound control does "boost" at the far excursions either direction, with a noticeable loss of volume in the middle. There is gain, but pretty gritty and not much sustain. of course, with the BF245B it could be completely different. motterpaulhttps://www.blogger.com/profile/15536330842070250774noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-79213846485516772922014-08-06T01:28:00.106+01:002014-08-06T01:28:00.106+01:00I see - cool, I will have to try this out. I love ...I see - cool, I will have to try this out. I love the Brian May boost - very similar but no 'sound" control there.motterpaulhttps://www.blogger.com/profile/15536330842070250774noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-40193761983371574892014-08-05T18:34:20.499+01:002014-08-05T18:34:20.499+01:00No. It's the "Sound" control. Boosti...No. It's the "Sound" control. Boosting bassier to CCW, near unity at center and boosting trebly at CW. Or so i've heard.<br />+mmirosolhttps://www.blogger.com/profile/02400327798106357876noreply@blogger.comtag:blogger.com,1999:blog-6847048658257278783.post-85940074858670202092014-08-05T18:31:58.280+01:002014-08-05T18:31:58.280+01:00Sound 1, 2 and 3 - is this a tone control? Sound 1, 2 and 3 - is this a tone control? motterpaulhttps://www.blogger.com/profile/15536330842070250774noreply@blogger.com