Print Page - DOD FX90 rev H schematic?

Title: DOD FX90 rev H schematic?
Post by: lars on January 09, 2019, 05:35:47 AM

I have searched pretty much everywhere, and cannot find any of the revision schematics for the DOD FX90. After the initial version, it went through several significant revisions. The particular version I have is from 1987, revision "H". It is quite a bit different circuit-wise than the schematic everybody (and their grandma) posts as "the FX90 schematic". Mine uses an input buffer and a 1458 op amp, and has no capacitors larger than 10uf. The DC circuit is actually more like the DOD 585, with a jfet-regulated input. It also has a different circuit layout than the pervasive "1985" version. I've seen pictures of the FX90 board I have all over the place; it's very common; so the lack of a correct schematic for it is puzzling.
Does anybody happen to have any of the revision schematics for the FX90? (I'll post a pic of the one I definitely do not need)
(https://i.postimg.cc/XJ4x4CqZ/dodfx90.jpg)

Title: Re: DOD FX90 rev H schematic?
Post by: lars on January 10, 2019, 04:11:15 PM

A fellow beaner provided the correct schematic; thanks! (it was from a site that doesn't pop up on any search results for the FX90; part of the hidden, useful Internet that's buried under the Google Internet). And yes, the Rev H is very different than the heavily-regurgitated Rev A schematic.

Title: Re: DOD FX90 rev H schematic?
Post by: artstomp on January 10, 2019, 11:20:47 PM

Hi lars...i've got 2 diff vintage DOD90...one is working the other has dry signal but no delay...they have different trannys and capacitors value...i think i might need the schematic...would you mind posting it here or you can send it to my email...vidworks@yahoo.com
Thank you

Title: Re: DOD FX90 rev H schematic?
Post by: madbean on November 23, 2020, 07:23:12 PM

Does anyone still have the RevH schem? I have a revF board and I want to compare what the differences are (and also to know if I need to do a full trace on it).

Title: Re: DOD FX90 rev H schematic?
Post by: artstomp on November 24, 2020, 01:11:03 AM

Hi Brian..i still have the H schem sent by jMoreno...

Title: Re: DOD FX90 rev H schematic?
Post by: madbean on November 24, 2020, 03:29:54 AM

Quote from: artstomp on November 24, 2020, 01:11:03 AM
Hi Brian..i still have the H schem sent by jMoreno...

Thank you!

The FX90 is definitely going to be a thing in the near future here. I bought 3 of them about a decade ago. One for $27! I got all of them out today and realized I never pulled the MN3005 out of two of them. But, after I plugged them in again I realized they actually have something pretty cool going on (despite their barely working condition). So, some new analog delay is on the horizon.

Title: Re: DOD FX90 rev H schematic?
Post by: artstomp on November 24, 2020, 04:37:39 AM

Yes!!!.looking forward to madbean's fx90 release!..thnx in advance

madbeanpedals::forum

General => Open Discussion => Topic started by: lars on January 09, 2019, 05:35:47 AM