OK. I am about 95% done with this project http://www.generalguitargadgets.com/index.php?option=content&task=view&id=203&Itemid=228 and I have a couple questions.
1. over which pins of the ISD chip does the disc cap get soldered?
2. What is the value of this disc cap?
3. Where do the 2 footswitches "record/play and on/off" connect to the board?
4. Where does the record safe toggle connect to the board?
5. What kind of LED does the layout call for. I see 3 connections. Is this a multicolored LED?
I know these are a lot of questions. This is my first time doing a project with a layout like this. Pot logs being numbered and so on. I tried answering these questions by looking at the schematic but since it deals with several ICs and I am not as familiar with the symbols I am having a bit of trouble. Thanks a lot guys.
Karl
It appears I was a bit hast about question 1 and 2. The link I provided gave the cap value and the pin numbers. So please disregard question 1 and 2. Sorry guys.
Karl
Hi...
I used little 0.1" pin header connectors for the off-board connections.
#3: On the connector outline labelled 'Switch', O, C and R refer to 'On', 'Common', and 'Record' respectively. 'On' goes to the node connected to pin 23 of the ISD1000. 'Record' goes to the node connected to pins 4, 9, 10, 27 of the ISD1000. 'Common' goes to 0v.
#4: You'll notice on the schematic that the Play/Record and Safe/Record switches are in series. Both of these switches have to be closed (connecting pins 4, 9, 10, 27 to 0v) for the chip to record. If either switch is open, it won't record. The Safe/Record switch is optional.
#5: On the connector outline labelled 'LED', R, C and O refer to 'Record', 'Common' and 'On'. R goes to the anode of the Record LED, O goes to the On LED anode, and C goes to both cathodes, as per the schematic. You could also use a bi-colored LED with a common cathode, But I would use a separate red LED for Record, and a green LED for On.
I didn't label things as clearly as I should have, so if you have more questions, feel free to ask! :)
Here are some notes as to how it operates:
Here's how it works. With both switches (thus LEDs) off, close the Record/Play switch, which turns on the Record (red) LED, and *arms* it to record the sample. (The Record/Safe switch is just a safeguard to not arm the chip to record a sample, to prevent accidental erasure of the current sample.) Note that it's not actually recording yet. Open the Enable switch, and you're recording *now*, and the 'On' (green) LED comes on. When done recording the sample (less than 20 seconds), Close the Enable switch to stop recording. Disarm recording by opening the Record/Play switch, and the red LED goes off. Now open the Enable switch (which turns on the green LED), and it will continue to play the sample until you close the enable switch again, or unplug it. Note that it still keeps the sample in memory even if the circuit is unplugged.
Dean. Thanks so much. It is crystal clear now. Thanks for a great explanation.
Hi,
I finished to build the mobius trip with a ISD 1020AP from smallbear but It doesn't work. I have the
I have some questions:
- I Don't understand the connections of The Switch Record /play. On the schematic , "C" goes to Pin 1 of 4001, IC 2 whereas ont the PCB, "C" goes to ground, I have the feeling that "C" and "R" are inversed.
- Is the Switch Record Play is a ON/OFF/ON switch?
- On the PCB pin 1,2,3,5,6,26 of the ISD are not connect to 0V,
I have the feeling that there are some mistakes...
thanks if you can help me
this is a good thread, bookmarking...
Mathflan:
Quote- On the PCB pin 1,2,3,5,6,26 of the ISD are not connect to 0V,
I have the feeling that there are some mistakes...
WTF?? Crap, you're right! :shock: Mine works, and uses the same board layout. I'll add the jumper tonight on my board, just to confirm it doesn't cause any problems.
Quote- Is the Switch Record Play is a ON/OFF/ON switch?
Nope, On/On.
Quote- I Don't understand the connections of The Switch Record /play. On the schematic , "C" goes to Pin 1 of 4001, IC 2 whereas ont the PCB, "C" goes to ground, I have the feeling that "C" and "R" are inversed.
No, C and R (and O) are right on the PCB. They stand for Record, On and Common - as in the common connection that goes to one side of each of the switches. There is no O, C, R designations on the schematic, and I drew it in a way to make it clear what was happening when it was being switched. I could have just as easily used SPST switches, but it wouldn't have been as clear.
Does that help? :)
Ok thanks
So Everything is ok, all works.
I'll try to add a compander to clean the noise of the ISD ans A FX sen and return
Bye
I just took a look at the PCB and see the pins that are not connected to ground. What is the best way to connect them to ground, jumper pins 6-12/13?
Ok, I just added a jumper from pins 5&6 to 12&13, and tested it with both the ISD1000AP and the ISD1020AP. Although it seems to work the same with or without the jumper, I STRONGLY recommend adding it, since it's never a good idea to leave inputs like this floating.
Dean,
I should still have a 0.1 disc cap between pins 12&13 and pin 28 right? Mines not working either but I am still going through the debugging stage and it's almost certainly a goof on my part. All the Leds light as they should in record and play position and the dry signal level pot works when the effect is engaged but its not recording. When I switch from record to play it makes slight sound like its ramping up for about a second and then silent. I will try these jumpers and see if I have some luck.
QuoteI should still have a 0.1 disc cap between pins 12&13 and pin 28 right?
Yes.
QuoteAll the Leds light as they should in record and play position and the dry signal level pot works when the effect is engaged but its not recording.
- Make sure that the REC and PLAY pots are wired correctly and are turned up.
- Try swapping the opamps. If the dry signal stops, you found the problem.
- Check solder connections and component values around U3 (the dual opamp closest to the ISD1000).
How crucial is it for the pin 12/13 to 28 capacitor to be ceramic disc?
this is just a bypass cap so you can use film or ceramic. But, ceramics are better suited here b/c this is a digital circuit (they're also low in inductance and work well for screening RF). That's not to say that all disc caps are good. If you're planning on stocking up on some ceramics for bypassing, get the axial variety that look like little beads.
HI,
I'am wondering Why the mobius trip looper and dirtysam use the Speaker's ouput, We cannot use the ANALOG OUT??
I
Quote from: mathflanI'am wondering Why the mobius trip looper and dirtysam use the Speaker's ouput, We cannot use the ANALOG OUT??I
Read the all knowning datasheet. ;)
Andrew
sorry I'am not very good in english and I didn't see anything which talk about that.
Just an other thing, I know that I post stupid questions :oops: .
Is that possible witch ISD chips to reverse the playback, that's would be cool!
No, unfortunately the ISD chip will not play backwards. In fact I don't know of any analog ic based delay that plays backward. I have seen plenty digital units that do but not analog.
Hey guys are there any analog delays that play backward or is this just not possible with analog ic based delay?
Quote from: mathflansorry I'am not very good in english and I didn't see anything which talk about that.
Well either reading the pin description or looking at the block diagram will tell you that the "analog out" pin is only the output of the internal preamp section
before the digital recording section.
QuoteIs that possible witch ISD chips to reverse the playback, that's would be cool!
Nope. Everything is controlled but internal clock and processor which there is no access to. Remember that these ICs are basically ment to replace answering machines, tape recorders, and pre-recorded audio to be called up on demand. They are NOT delays.
Andrew
Hi
I try to build this one with an ISD2560P, but the pin configuration is not the same! It have 9 adress buffers! So here is my question:
Do I have to connect A9 and A8 instead of A6 and A7, and connect all other AB to the ground? Or just ignore pins A9 and A8?
I'm a bit lost in this!
Thanks
WAAAHHH.. I *still* trying to debug my dirtysam looper. Seeing all this success here makes me pound my head into the desk. :cry:
I want this pedal way too much to toss it onto the scrap pile.
Oh well. Just venting.
I have not heard of too many success with any the loopers at this point. I'm not knocking the designers but I think there are issues with the designs from what I've seen that are causing people trouble. I think when I get some free time from my current project I might get back to this. I haven't played with it for awhile anyways.
Andrew
QuoteI have not heard of too many success with any the loopers at this point. I'm not knocking the designers but I think there are issues with the designs from what I've seen that are causing people trouble
i dont know why people are having so many problems :? , i built the mobius trip looper in one night, and it works perfectly. the bypass is a little strange, and i sacrificed true-bypass so i could have a one stomp record and a one stomp play(like Z's lofi loop junky), but that was it. the DirtySam looks a little more daunting though.
Quote from: idiot savanti dont know why people are having so many problems :? , i built the mobius trip looper in one night, and it works perfectly. the bypass is a little strange, and i sacrificed true-bypass so i could have a one stomp record and a one stomp play(like Z's lofi loop junky), but that was it. the DirtySam looks a little more daunting though.
I don't know either. I haven't built any of them so I can't give any soild explanations but I get the occasional email about loopers. My design is fairly standard with some extra options. About the only thing I was going to do differently audio was the interface on the output of the recording IC.
Andrew
I don't know either :? it's a pretty straight forward build, and it does work, when built according to my design. You may have noticed that I don't get involved in 'will it work with a ...' or 'what do I have to change if I want to use a ...' conversations. Not wanting to sound snotty, but I don't have enough time in the day to work on *my own* projects, let alone re-design my designs using different parts than my original design. I'll gladly support my circuits as best I can (time and knowledge permitting) :) If anyone wants to try any of my designs and substitute anything from a different voice chip to a head of lettuce, go for it! :wink: Will it work? Dunno, try it and see.
There was one notable exception. Steve Daniels and JD Sleep (both of whom I admire) asked me if I could simply pop in a different chip in my board and try it. Especially since this was another potential source for these chips, which would allow more people to make the device, I said 'hell Ya!' Plus, Steve let me keep the sample he sent me. 8)
BTW, thanks for the build report Idiot (Mr. Savant?? :wink: ) Anyone else build it?
QuoteBTW, thanks for the build report Idiot (Mr. Savant?? ) Anyone else build it?
no, no, no, thank YOU for designing it, the switching is a little tricky, but nothing too bad, heres a pic alongside the uglyface and ROG grace.
i'm going to add an input buffer, since it's not true-bypass, but its a small price to pay for less stomping each time i use it. :P
(http://i4.photobucket.com/albums/y130/idiot5avant/051005.jpg)
Savant, is that a Hammond BB? I've been debating what to put it in. Did you have any extra room in that enclosure, whatever it might be?
yeah theres plenty of room in a 'bb' for it, i didn't use a dc jack, so theres even a 9v in there, i was surprised how compact it really is, you *could* squeeze it into a 'b' if you notched out the corners and just used a dc-jack w/ no battery, im just not that ambitious though, as you can see i dont even paint any of my boxes. :lol:
i'll put up a gut shot later on if you want.
Quote from: Dean HazelwanterI don't get involved in 'will it work with a ...' or 'what do I have to change if I want to use a ...' conversations. Not wanting to sound snotty, but I don't have enough time in the day to work on *my own* projects, let alone re-design my designs using different parts than my original design. I'll gladly support my circuits as best I can (time and knowledge permitting) :) If anyone wants to try any of my designs and substitute anything from a different voice chip to a head of lettuce, go for it! :wink: Will it work? Dunno, try it and see.
I found some interresting documents for my conversion, so forget the question! This unit seems very great, thanks for this design!
I'd like to see that. I'm thinking about starting this project. If I could find a suitable chip here in gloomy old england I think I'd give it a shot. Savant how did you change the design to suit your switching needs? I'd be interested to know.
As Idiot mentioned, the pcb is designed to fit in a 'b', by notching out the 4 corners as per the layout. Cramming all the switches, pots and jacks into a 'b' - that's a bit more challenging! :wink:
I finished to mount it, and it works, but there's a problem: in play mode, there's a clock noise! can you tell me where it can come from?
thanks
http://www.elixant.com/~stompbox/smfforum/index.php?topic=40696.0 (http://www.elixant.com/~stompbox/smfforum/index.php?topic=40696.0)
Hope no one minds me resurrecting this thread with some new questions:
From the description at GGG:
Quote
- I mounted the disc cap across the looper chip power supply pins directly to the back of the PCB. One end of a 0.1uF cap goes to pin 12&13, the other end goes to pin 28.
Is this one capacitor between a) pin 12&13 and b) pin 28, or is it two capacitors, one between 12 and 28 and the other between 13 and 16? The schematic at http://www.generalguitargadgets.com/pdf/ggg_mobius_trip_digital.pdf seems to suggest the latter, but I'd like to have it confirmed.
Quote
- For the 5 volt voltage regulator, you can use either the 7805 (TO-220 case) or the 78L05 (TO-92 case). The PCB is laid out with the 7805 outline, with the front (the side with the writing) pointing to the right of the PCB. If the 78L05 is used, face the front of it (the side with the writing) to the left of the PCB.
What is left and what is right? Looking at the layout (http://www.generalguitargadgets.com/pdf/ggg_mobius_trip_pcb_lo.pdf) it seems "up" or "down" would be a better description. I'm using the 78L05, and I guess the side with the writing should face up, is this correct?
Hi,
QuoteIs this one capacitor between a) pin 12&13 and b) pin 28, or is it two capacitors, one between 12 and 28 and the other between 13 and 16? The schematic at http://www.generalguitargadgets.com/pdf/ggg_mobius_trip_digital.pdf seems to suggest the latter, but I'd like to have it confirmed.
- One capacitor only. One end goes to the common connection at pins 12 and 13. The other end of the same cap goes to pin 28. The other cap (between pins 13 and 16) appears (on that drawing) under the bottom-left corner of the looper chip.
QuoteWhat is left and what is right? Looking at the layout (http://www.generalguitargadgets.com/pdf/ggg_mobius_trip_pcb_lo.pdf) it seems "up" or "down" would be a better description.
- The description was correct for the original layouts. JD thoughtfully 'packaged' the layouts to make them easier for people to download. Turn the board so that the part numbers for the ISD1000A and 4001 are oriented correctly, and the description will be correct.
QuoteI'm using the 78L05, and I guess the side with the writing should face up, is this correct?
- Yes.
Hope that helps!
Thanks Dean, that is indeed helpful. A few more questions: Do I need the 0.1" center connectors, or can I just solder wire directly to the board? In the case of the latter, what do I do when I have only 2 wires to connect? (The "C" pad for the LEDs, for instance, or the center pad for IN, OUT and 9V)? Do I have to solder a bridge between the center pad and one of the others? If I want to use the 0.1" center connectors, where can I get them?
Are there any pics of a completed Mobius looper build somewhere on this forum or elsewhere?
Quote
- All of the off-board wiring is laid out to use 3 pin 0.1" center connecters that I've been using for a while. One connector for the 2 switches, one for the 2 LEDs, one for each of the 3 pots, one for each of input and output jacks, and one for 9v DC.
QuoteDo I need the 0.1" center connectors, or can I just solder wire directly to the board?
- You can just solder wires to the board. If nothing is connected to the pad in question, you don't need to use a wire as the pad isn't connected.
QuoteThe "C" pad for the LEDs, for instance
- This pad is connected, so you'd need a wire.
QuoteIf I want to use the 0.1" center connectors, where can I get them?
- In Canada, they're available from a distributor called Mode. The part # for their 3 pin header (the part that sits on the board) is 37-6203-0.
QuoteAre there any pics of a completed Mobius looper build somewhere on this forum or elsewhere
I have one that's not boxed up. If I get a chance in the next couple of days, I'll take a couple of pictures of it.
I have to admit it, I'm stuck in this build. Pictures would help, and actually I seem to need a wiring diagram as well.
Hope someone can help. :-\
built mine years ago, still works fine. I'm not sure if I have any gut pics though.
the build is pretty straight forward with the exception of the 100n cap and the jumper. the bypass is where it gets funny, here's a really REALLY old pic I made to detail the bypass switching I used:
(http://i4.photobucket.com/albums/y130/idiot5avant/schematics/looper-bypass.jpg?t=1256711620)
Hi,
Sorry for the delay, October was hell-month at work. :icon_redface:
http://i179.photobucket.com/albums/w290/extester01/Img006.jpg (http://i179.photobucket.com/albums/w290/extester01/Img006.jpg)
http://i179.photobucket.com/albums/w290/extester01/Img007.jpg (http://i179.photobucket.com/albums/w290/extester01/Img007.jpg)
http://i179.photobucket.com/albums/w290/extester01/Img008.jpg (http://i179.photobucket.com/albums/w290/extester01/Img008.jpg)
http://i179.photobucket.com/albums/w290/extester01/Img009.jpg (http://i179.photobucket.com/albums/w290/extester01/Img009.jpg)
http://i179.photobucket.com/albums/w290/extester01/Img010.jpg (http://i179.photobucket.com/albums/w290/extester01/Img010.jpg)
http://i179.photobucket.com/albums/w290/extester01/Img011.jpg (http://i179.photobucket.com/albums/w290/extester01/Img011.jpg)
Here are some pictures of the board. Hope that helps! :)
hi i have started this project and have all the parts and pcb , my problem is the offboard wiring, im not sure were to go at this point , is the layout posted above verefied and confirmed ? and the wiring for the connectors , does someone have a layout that i can use ?
please help out this rookie!!! i have the need to finish this great project already ...
thank you ..
p.s has there been any updates on mods , or fixes for this projects if so could anyone point me to the right directions
thanks agian...
hey there,
i'm in the process of building one of these as well... and i think a lot of the confusion lies in the translation between the build instructions on GGG and the addition of footswitches.... i found as i was building mine that if i plugged the wires from the IN and OUT on the board directly to the in and out jacks for the pedal, that it worked fine using the on/on switches to control it..... when i wanted to add the footswitches, i had to reroute the IN and OUT wires to go through the switches first, then to the jacks..... make sense?
when it does get working (it will, just don't give up) it really is one of the top three coolest builds i've ever done and a blast to mess around with
Thanks DEAN!!
If at some point i have time (and learn how to draw with my computer) i will do a wiring diagram for the whole kit.... TBD.....
QuoteThanks DEAN!!
No, thank you! Since so many people seem to have had problems with this project, I was tempted to ask JD to remove it from GGG. I guess if someone is finding it useful, I'll leave it up.
thank you Dean and Stanimal !! you think a wiring drawing woul help a bunch .. in the mean time you think that i can try using the wiring layout above to get it going ..
thanks for the replys..
hi everyone .. Has anybody build the möbius trip looper recently that can provide some more pics , layout and pointers !!!
sorry delaystomper, i've been slammed at work and haven't had my weekends free to get down to business of mapping this thing out.... hopefully this weekend i will have time......
Hello everyone !!! I just finished building the möbius trip looper
I had all the build parts i put them togeather but wired the off board in my breadboard according to idiot savant's
Footswitch layout , and it worked !! Its kind off noisy and gainy im not sure if its my breadboard or that how Is ment to sound. Maybe one of you guys who has build it can tell me I would like to know .
Also it's not true bypass like mentioned but once it's running and you start playing
You forget about the none true vs true bypass .. !!! It's a great project , thank you Dean , idiot savant and stanimal !!(//)
sure i will post some pics as soon as i get off my iphone ,, lot of wire though i hope they are helpful
i thought it would be a hard project to do but i guess it wasnt .
except the 3 eletrolytic caps, the remaining caps is all polyester?