My own FV-1 PCB, work so far

[Ice-9]

I have followed the thread from Octfrank about his FV-1 reverb module. While i wait for the availability of Franks module I decided to have a go at my own as i have managed to get hold of an FV-1 chip, I've started to make my own PCB which i will be putting all the input/output buffers and controls on as well. Up to now i have drawn up a PCB that has all the main circuit plus the 3 FV-1 control pots taken directly from the datasheets and i have quite a different idea on the external program eeprom which i will be posting about as soon as i manage to get a pattern for the components in my pcb program.

Here is a pic of the PCB and component overlay upto now and the next draft i hope to add all the buffers and mix circuit in the unused pcb space. The plan for these at the moment is a single input driving the left and right inputs of the FV-1. The outputs from the FV-1 then going each to an opamp buffer that has a dual gang mix control which in turn feeds two opamps to the stereo outs.


temp ground plane.


basic pcb

[octfrank]

Looking good to me!

[Ice-9]

I thought i would do a little update to this thread as i have now just about finished the schematic and have a prototype pcb etched. I hope to populate the board over the weekend, here are a couple of pictures of the schematics and the etched pcb.




The mix pot is missing from the schematic as is the 3.3v reg, both are included on the pcb.

[solderman]

Looks really good all tough I can't really understand the in/out buffer part and follow the signal path but that surly is going to be clearer soon I hope. 

[Ice-9]

Looks really good all tough I can't really understand the in/out buffer part and follow the signal path but that surly is going to be clearer soon I hope.  

Sorry that's part down to the way my program draws out the schematic and i have become lazy not drawing on the input output terminals. I have updated the audio path to show the connections.


The "to module" connection goes directly to both the left and right inputs at C1 and C2 giving a mono input.
The  left and right outputs from the module are taken from the junctions of R5 /C7 for left and  R6/C6 for right and are connected to the "from module" left and right respectively (through the dual gang pot)

[octfrank]

Schematic looks good to me, but then again I may be just a "little" biased as it uses an FV-1 and is very similar to the example schematic for our module. Will you hand solder the surface mount parts or use solder paste and a toaster oven?

[rustypinto]

Yea, looks good.

I have a layout and a few FV-1's calling my name. One day i'll get around to them.

If you ever get into your own DSP programs, i recommend adding a footprint for an external EEPROM (and a switch of course to tell the FV-1 to look for the EEPROM), along with a header to do in-circuit programming. These are tremendously useful!

[Ice-9]

Schematic looks good to me, but then again I may be just a "little" biased as it uses an FV-1 and is very similar to the example schematic for our module. Will you hand solder the surface mount parts or use solder paste and a toaster oven?

I have for this prototype circuit, based it on the schematics in your datasheets Frank, i have started to solder up the components and intend to build all the preamp/buffer section first just to make sure it works before mounting the FV-1 chip . I have no problems soldering by hand as i have experience soldering 48 and 56 pin TSOP chips which are much smaller pin spacings. This project has really got me interested again and all my other projects have been put to one side again. The key to good hand soldering of SMD is a flux pen.

Yea, looks good.

I have a layout and a few FV-1's calling my name. One day I'll get around to them.

If you ever get into your own DSP programs, i recommend adding a footprint for an external EEPROM (and a switch of course to tell the FV-1 to look for the EEPROM), along with a header to do in-circuit programming. These are tremendously useful!

I haven't put a footprint in for the external eeprom but there are connections for someting else in its place. I will take a picture of what i intend to use and post it, all will be clear and this is the bit that is really exciting me about this chip.
Off to take the pics now.

[Ice-9]

This following info is what has excited me about the FV-1 and the ability to use external programs on an EEprom chip. The first time i saw the fv-1 about 1 1/2 years ago  i noticed that the external eeprom was selected by a SPST switch.
So on to the idea , when a smart card is inserted into it reader socket it make a switch contact and in this case enabling the external eeprom (on the card) so my idea is to build a pedal that can be totally changed to any effect  by the insertion of a smart card which is easily programable on the computer. I think the picture will give the idea.
any feedback on this idea is appreciated.

[octfrank]

We've thought about doing a cartridge based pedal but haven't had the time to work on it. I know of another that is doing a cartridge based item but its not a pedal and not using smart cards. Look forward to seeing your pedal running!

[solderman]

That's the most exiting idée since the invention of the wheel.   It would be really cool to have a set of stomp boxes in your wallet. I also find myself attracted to the idée of building with SMD as I've sort of find more challenge in shrink things in to a 1590a enclosure than just build another "easy to fit in b MXR style box". So I just love this idée. Is it possible to use a mobile phone SIM card. In that case you can have your sound in your mobile.

[Ice-9]

So I just love this idée. Is it possible to use a mobile phone SIM card. In that case you can have your sound in your mobile.

If that was possible it would open up the posibility of adding bluetooth to the effect and sending patches to the pedal/effect via phone direct using  bluetooth, ah i think iv'e went a step to far , lol.

I am going to try and populate the pcb tonight with the components i have already, so i will try and get a picture up when done.

[Ice-9]

I've managed to solder in all the components i had at hand, i was missing a few capacitors and the watch xtal so will have to order them.
I had to buy some new photoresist copper board and the brand i normally get was out of stock. After etching a PCB I don't usually clean off the photoresist (it leaves a coating on the copper that protects the copper from corroding) but when it comes to soldering the component, the heat from the iron melts it off at the solder point, very like creating a solder mask. This brand of copper board didn't quite work out like that so i should have cleaned the coating off with acetone, it would have made for a cleaner looking soldered board.

Plenty of scope to miniaturise the PCB more and get the card reader mounted directly on the PCB (next prototype)

[rustypinto]

Just FYI, make sure that resist isn't conductive. It could make for a lot of shorts around the circuit.

Looks real good though!

[solderman]

I've managed to solder in all the components i had at hand, i was missing a few capacitors and the watch xtal so will have to order them.
I had to buy some new photoresist copper board and the brand i normally get was out of stock. After etching a PCB I don't usually clean off the photoresist (it leaves a coating on the copper that protects the copper from corroding) but when it comes to soldering the component, the heat from the iron melts it off at the solder point, very like creating a solder mask. This brand of copper board didn't quite work out like that so i should have cleaned the coating off with acetone, it would have made for a cleaner looking soldered board.

Plenty of scope to miniaturise the PCB more and get the card reader mounted directly on the PCB (next prototype)

Nice work well done!
-   What CAD program did you use to make the PCB, Eagel? DIY layout creator is not sufficient for SMD boards.
-   Did you use a normal soldering iron with tip or a hot air iron to solder with?

[Ice-9]

Just FYI, make sure that resist isn't conductive. It could make for a lot of shorts around the circuit.

Looks real good though!

thanks for the tip there rustypinto I have just checked that now, and all seems OK as I can't find any shorts with he multimeter

-   What CAD program did you use to make the PCB, Eagel? DIY layout creator is not sufficient for SMD boards.
-   Did you use a normal soldering iron with tip or a hot air iron to solder with?

.
Thanks for the kind words, It's a little messy around the 8pin 3.3v reg as I soldered it in place the wrong way round, -TWICE-
I have used Diptrace free ver2 to make the PCB, I find it a very easy program to use and quick to learn.
yeah i just used an antex iron with a 1mm point tip.

Therest of the parts have been ordered now from Rapidonline so i hope to get this finished and some sound clips by the weekend.

[octfrank]

Looking real good so far!

It's a little messy around the 8pin 3.3v reg as I soldered it in place the wrong way round, -TWICE-

LOL! I did the same thing to the first module PCB with the EEPROM! Caught it before I applied power.

[Ice-9]

I haven't go much futher yet ! I have got all components soldered up , I just have to get jack sockets and psu conected  before i can test it but i ran out of time tonight, I hope testing works first time.

[Ice-9]

I got back to this today after a few problems with the 3.3v and ground being shorted. It looked like one of the pot connections was causing the problem, anyway i have sorted that out and was hoping there was no damage to the FV-1 chip.
So new battery in hand and i plugged it all in and to my amazement i had a working reverb. The onbaord sounds are really nice , the flanger can be made to get that Van Halen sound easily , chorus is nice and crisp is perfect for the "nothing else matters" intro.  Pitch shifting is truly weird, (+/- 4 semitones) .

with the addition of the external eeprom i think this chip has huge possibilities and my next step is to get the smartcard bit assembled for this.

I don't have a recording set up at the moment but i will set something up to get some sound clips as this report is pointless with no sounds to check out.
I can see this prototype going into a little practice amp i have planned.

Thanks go to Frank for all the info and help !!

[Skruffyhound]

Well done, I'm watching this thread with great interest, good luck with the next stage.