Here's a PCB trace for a MXR Distortion+ that I traced from my fried 1980 pedal, as viewed from the component side. I want to get this etched for myself so I can replace the damaged one to repair it. I'm still working on smoothing out the curved traces but I tried to get it as close a possible. If anyone wants it to repair theirs (or to make a clone) I will post a link to a better PDF 300dpi version later. Mine is the first pre-LED block logo model but this base PCB trace pattern is the same for the script logo model too.
(http://home.comcast.net/~snmavronis/1980_mxr_distortion-plus_pcb.jpg)
Since I'm replacing the PCB with a non-original PCB and components anyway, do you think it wouldn't hurt to add a LED and DC Jack?
Here's what my broken MXR Distortion+ looks like now:
(http://home.comcast.net/~snmavronis/brokenmxrdist+.jpg)(http://home.comcast.net/~snmavronis/mxr1980distortion_damage.jpg)
Of course not. A DC jack isn't hard to hook up with the switching to dis-engage the battery, and if you convert to true-bypass and use a 3PDT you can have the LED virtually separate from the rest of the circuit.
Yeah, I guess the vintage-ness of it no longer matters (since it's fried) if I drill holes into the MXR box to mod it. I know how to do that by repeating what I did with my other clone build.
Steve... a little off topic however, quite convenient.
Do you notice the difference between your Dist+ enclosure and other Hamond/NSC-type enclosures? The weight and size proportions? I posted another thread wondering where these can be purchased which you posted in.
Did they use a sturdier metal? Different spec of Aluminum perhaps?
Quote from: Govmnt_Lacky on February 19, 2011, 03:52:07 PM
Do you notice the difference between your Dist+ enclosure and other Hamond/NSC-type enclosures? The weight and size proportions? I posted another thread wondering where these can be purchased which you posted in. Did they use a sturdier metal? Different spec of Aluminum perhaps?
Hi, no problem. I was in the same boat before I build my first clone. I was looking for a Bud or MXR box in the same proportions and shape. I settled on the Hammond 1590B. It's the same size in all LxWxH dimensions except the MXR style box has very rounded top edges and the Hammond's are sharper. It seems to me built pretty solid die-cast aluminum. I'm not sure how the weight compares. Here's a PDF datasheet with dimensioned drawings. You can rotate the 3D model too and see the shape from any angle: http://www.hammondmfg.com/pdf/1590B.pdf
I think the next closest box would be the Taiwanese B-size enclosures. I've never seen one in person to tell you if the measurements are exactly the same or not. I'd need to see a datasheet with drawings and what the cross-section looks like. I can't tell if the MXR Distortion+ box is aluminum or steel.
For my repair, optionally I 'could' make a smaller sized PCB, but I'd like to maintain a vintage replica PCB look. If I mod my broken MXR Distortion+ and add a LED and a 3PDT footswitch I need to check measurements carefully to see if a 9V battery would still fit inside. Did you know not all batteries are the same size?
(http://www.medicbatteries.com/images/BatteryComparison.jpg)
The early MXR pedals were BUD boxes, and I believe they are still making them. I think no one ever talks about them because they are a little more expensive.
Al
Check this out. My fried Dist+ PCB board dimension is 2.2" wide by 2.62" high, so in GIMP I scaled it to 660x786 (300dpi resolution) and perspective corrected to fit that. I used a 1/10" (30 pixels) grid pattern to visually guide me as I drew a layout using ExpressPCB. This is the first time I overlayed it on top of the PCB photograph so I'm pleased with the result. Now I see where to do a little bit of fine tuning! I want to try and make an exact as possible PCB replica copy to refurbish my broken pedal with.
(http://home.comcast.net/~snmavronis/snmavronis_dist_trace_overlay.jpg)
Steve,
Remaining as "authentic" as possible... Did the original Dist+ board have the wire markings, to show where they go, like you show in your layout? (i.e. D(3), O(3), etc.)
Quote from: Govmnt_Lacky on February 20, 2011, 02:13:42 PM
Did the original Dist+ board have the wire markings, to show where they go, like you show in your layout? (i.e. D(3), O(3), etc.)
No it didn't. I just have them on there temporarily to remember what goes where with the wiring. I should remove them before I make the final etch pattern. I should of had those pad ls in yellow like the part shapes and values instead of in green for the bottom trace layer.
Well, here's probably the final layout with component placement guide and PDF of just the board trace pattern at 300dpi to share with you. You can print it with Adobe Acrobat making sure any page scaling is set to none from the print dialog screen. Remember I print to transparency sheets and the pattern is a mirrored image on purpose because I flip over the sheet's printed side to make direct contact with te PCB material for UV exposure with no shadowing through the transparency plastic.
Not sure if I'll change the PCB text font in GIMP since I'm not trying to pawn off a counterfeit. I'm just making a replacement PCB to replace the original damaged fried one in my 1980 MXR Distortion+ so I'm thinking for this repair just to restore it to an original working state. I"ll probably won't have an IC socket either because I don't think there will be room to fit the lid on if I do. If I want to mod one I'll just make a custom DIY clone later on with my own PCB layout.
http://home.comcast.net/~snmavronis/distortion_plus_trace.pdf
(http://home.comcast.net/~snmavronis/distortion_plus_layout.jpg)
Let me know if you have any questions. I'll update in the coming weeks with photos of the repaired unit.
I was just updating my page (http://sites.google.com/site/snmavronis/neoclassic/mods-and-repairs) to chronicle my mods and repairs about fixing my Distortion+. I printed out the MXR Distortion+ PCB layout transparency tonight and gave it to my dad to etch a replica replacement board for me this week.
I was reading this Pedal Arena version change page (http://www.pedalarea.com/mxr_distortion.htm) and see the only differences between the original 'script' model, 'block logo' model, and first LED version was the op amp changing from a LM741CN to a UA741CP and the SPDT footswitch was changed to a DPDT for the LED and added DC jack.
Should I restore my block logo model to original condition or update it to a LED/DC jack model using a LM741CN as a 'best of' hybrid mod of the first 3 models?
Quote from: zombiwoof on February 19, 2011, 07:01:38 PM
The early MXR pedals were BUD boxes, and I believe they are still making them. I think no one ever talks about them because they are a little more expensive.
Al
Actually, I've seen Bud boxes consistently $2 - 4 USD cheaper depending on where you get them.
I think Hammond has a wider-known reputation, so they get all the attention.
With so many others making even cheaper boxes (New Sensor, 4Site) Bud just kind of disappears into the static.
Quote from: edvard on February 22, 2011, 10:06:26 PM
Quote from: zombiwoof on February 19, 2011, 07:01:38 PM
The early MXR pedals were BUD boxes, and I believe they are still making them. I think no one ever talks about them because they are a little more expensive.
Al
Actually, I've seen Bud boxes consistently $2 - 4 USD cheaper depending on where you get them.
I think Hammond has a wider-known reputation, so they get all the attention.
With so many others making even cheaper boxes (New Sensor, 4Site) Bud just kind of disappears into the static.
I just know that the Dist+ Bud box that I re-used is DEFINITELY heavier in weight BY FAR, than any of the Hammond, NSC, 4Site, etc. boxes that I have used recently.
Yep, I was just showing my dad who stopped over last night how the MXR box is heavier than the Hammond 1590B.
Here's a draft re-working of my take on a MXR Distortion+ schematic. Besides the familiar 'standard' distortion circuit inside the dashed box representing the PCB, my focus is on describing the offboard wiring as routed inside my broken MXR pedal. Is this too much info? I like the idea of looking at a thorough schematic diagram so you could wire up a pedal without seeing the real thing. I made a correction reflecting that the distortion pot's lug 1 is unused and connects internally to its own lug 2 to a ground wire.
(http://home.comcast.net/~snmavronis/mxr_distortion_plus_wiring_schematic.jpg)
Here's the PCB etched and tinned made from my ExpressPCB layout which is a 1:1 copy of the MXR Distortion+ circuit board. I still have to clean up the board edges.Tonight or tomorrow I go over my father's to use his drill press to get the holes done. Then hopefully I can use this to replace the old fried one so I can refurbish and repair my broken pedal. I can't wait to hear how it sounds! I'll post a picture this weekend of my fixed pedal if I'm sucessful.
(http://home.comcast.net/~snmavronis/mxr_distortion_plus_pcb_etch.jpg)
Quote from: Steve Mavronis on February 19, 2011, 03:23:05 PM
Here's a PCB trace for a MXR Distortion+ that I traced from my fried 1980 pedal, as viewed from the component side.
(http://home.comcast.net/~snmavronis/1980_mxr_distortion-plus_pcb.jpg)
Since I'm replacing the PCB with a non-original PCB and components anyway, do you think it wouldn't hurt to add a LED and DC Jack?
Here's what my broken MXR Distortion+ looks like now:
(http://home.comcast.net/~snmavronis/brokenmxrdist+.jpg)(http://home.comcast.net/~snmavronis/mxr1980distortion_damage.jpg)
I hope you fixed the + battery wire :D Probably what fried it in the first place. ;)
Quote from: Tony Forestiere on February 25, 2011, 07:35:05 PM
I hope you fixed the + battery wire :D Probably what fried it in the first place. ;)
Yep it probably shorted out and blew the board. The red AND black battery leads were splice twisted with no insulation! I have a whole new battery snap with wires to replace it. I might replace all the original wire because the 22 gauge I use looks thicker. Trying to decide if I should contact solder the 5 wires attached to the PCB like in the original or drill holes? But I'd like to preserve the original look as much as possible.
Hey I have a question about those 5 wire pads at the top of the board. When I first made the replacement board layout I had the normal wire holes there. I forgot the real MXR board doesn't have the wire strands going through the board to the other side. I've since corrected the PCB layout I made in PDF format not to have holes there. On my board replacement, you won't see the hole spot since the wire and solder will cover it over. What is the best method to 'contact' solder wires directly to the pads? Should I just drill them through and solder the wires normally? Thanks.
I'm not sure whether it was answered -- yes, you can fit a blue 3PDT into an MXR box without any problems. I was looking at my '78-ish D+ vs. a 1590B and a taiwan B box. The extra 1/16" depth is all in the bottom lid, oddly enough. Years ago, I added a DC jack and LED at the top of the box. Today, I would try to move the LED down below the knobs and see if the DC jack could fit next to the 3PDT...that seems more standard.
I'm just restoring this one to original condition to refurbish it. With the new PCB replica I made, trying to use close to what was in this 1980 unit. The op amp IC is a '80 Texas Instruments UA741CP with Malaysia stamped on top. In my stock of parts I do have is a Texas Instruments UA741CP with M701 (not sure if that's a date code) and Malaysia underneath so at least that is close. I have two small 1uF tantalum caps except they're yellow instead of blue. For the four ceramic caps I may try to re-use the originals since they don't appear to be damaged. I have two 1N270 germanium diodes that look identical to the originals.
After I get this together (hopefully today) and hear how it sounds, not sure if I should go beyond repair and mod the pedal to feature a red LED and DC jack. Maybe I'll keep 1980 spec integrity in this unit and if I want those added features, a complete separate clone pedal could be possible as a better option.
I soldered parts onto my replica PCB. It was a pain but I de-soldered the four ceramic caps and put them on the new PCB. The pain part was one of them flipped out of my hand and it took me an hour crawling around on the floor until I found it! Anyway, the replacement PCB is ready to be attached after I clean the solder flux off the other side:
(http://home.comcast.net/~snmavronis/mxr_distortion_plus_replica_pcb.jpg)
P.S. I made a spare PCB just in case I blow this one up!
Well that's it for this thread I suppose. The verdict is in - It works!!!
\m/
New DIY replacement board and refurbishment successful. Long live MXR Distortion+ :icon_biggrin:
Steve
wow!
*Very* neat re-build.
I think looking into photo-etch / ExpressPCB layouts is the way forwards.
Makes my hand-drawn PCBs look a little 'organic'... :icon_redface:
Congrats on getting this little beast working again.
Quote from: newfish on March 01, 2011, 11:01:19 AM
wow! *Very* neat re-build. I think looking into photo-etch / ExpressPCB layouts is the way forwards. Makes my hand-drawn PCBs look a little 'organic'... :icon_redface: Congrats on getting this little beast working again.
Thanks for the compliment! I should have posted a completed gut shot too. That one was before the final 5 wires were soldered to the new PCB.
Any way that works for you is good; hand wired, vero, perfboard, etched PCB, etc. Back in the day when I was a kid before computers, my dad used to make printed circuit boards using clear plastic sheets and manually laying strips of thin black tape with tweezers to make complicated and sometimes double layer layouts by hand. It was kind of cool in a way. It would be very tedious, but I'd like to try it the old school way like he did in the 70's.
Nice neat PCB there Steve.
Yeah back in my day at college we use to use clear acetate sheet and sheets of pads, lines, corners and Ic's you just rub them on the acetate. They were called letraset.
Hi Steve!
Etched your layout, and worked like a charm...
In fact, worked too well as it was easy to put pieces in place and box it and nothing to debug! :icon_mrgreen:
This is brilliant thanks! now I have an almost replica in my pedalboard :D
quick snap:
(http://i1217.photobucket.com/albums/dd394/jplebre/photo2-1.jpg)
Thanks! Nice job on your PCB etch. It's a 1:1 replica so MXR already did the debugging for us. ;)
I'm happy making a replacement PCB for myself allowed me to restore my 1980 Distortion+ bringing it back to life from the dead!
Just wanted to thank Steve and post an update. I got a hold of a vintage Script Logo MXR Distortion Plus enclosure in need of a little love. The paint is in excellent condition but the pedal was missing the bottom plate, Volume Pot and the entire circuit. Steve was kind enough to send me a replica circuit that he had etched for his project and I used it to re-build my pedal. Here are the finished shots... Works great.
(http://img403.imageshack.us/img403/2799/photo1lxh.jpg)
Shot at 2012-04-18
(http://img813.imageshack.us/img813/9120/photo3vjf.jpg)
Shot at 2012-04-18
(http://img13.imageshack.us/img13/8702/photo4pj.jpg)
Shot at 2012-04-18
Glad you brought back to life your pedal and my board! Beautiful job.
I love reading the classics, like this thread. Does anyone involved still have the images? Thanks CfI
If you have a vintage pedal with everything in tact but the PCB has lost traces or IC pads I suggest you try to keep it stock. People want to pay big money for, let's say, a script Dist+. If you purchase some self-adhesive copper grounding tape and cut it with fly tying or cuticle scissors, you can replace the missing trace invisibly. For the IC pads, cut a pad shaped piece out of the tape, stick it in the right place and use a small awl to create the hole. Place the IC in and solder. Put a little vinegar on the new solder to add an oxidized patina and you have a perfectly preserved pedal. Try to find the closest foam to wrap the board in as the original foam. It almost always disintegrates.
Quote from: Fuzz-O-Rama on October 09, 2017, 05:22:15 PM
If you have a vintage pedal with everything in tact but the PCB has lost traces or IC pads I suggest you try to keep it stock. People want to pay big money for, let's say, a script Dist+. If you purchase some self-adhesive copper grounding tape and cut it with fly tying or cuticle scissors, you can replace the missing trace invisibly. For the IC pads, cut a pad shaped piece out of the tape, stick it in the right place and use a small awl to create the hole. Place the IC in and solder. Put a little vinegar on the new solder to add an oxidized patina and you have a perfectly preserved pedal. Try to find the closest foam to wrap the board in as the original foam. It almost always disintegrates.
Weird side note: I have two pre-LED block logo MXR pedals (Dist+ and a dynacomp). The foam totally disintegrated. I also have a LED block logo MXR Dist+ pedal, and the foam is strangely intact. They must have switched foam sometime around then.
I have a couple of old MXR pedals with disintegrated foam. When Dunlop started making the CS reissues with the foam in them, I emailed them to see if I cold buy a couple of foam pads from them for those pedals. They ended up sending me six foam pads for free!. I can't say that they would do that for everyone, but I may have been the only one to ask about that at the time.
Al
zombiwoof,
Your comment about dealing with Dunlop was heart warming. It is a lesson that a considerate person should never hesitate to "ask". So to express my gratitude to Dunlop, I would like to say that in my opinion, the Dist+ is the best overdrive ever made when used at a very low distortion setting. Don't take my word when it is easy enough to try. Full disclosure; I spent a great deal of time searching for the magical version of the 4558. That is what I love about pedals. So many pleasant discoveries. I just wish they didn't take a lifetime. So, when I have the time, and it is appropriate, I will post these things. As to the analog chip suffixes, they can denote plastic or ceramic, mil spec, temperature rating, etc.. Newer ones also specify Pb free. I hope I haven't bored people too much!