FEMTOVERB /Wavefrontsemi/ PCB layout

[DaveTV]

Hi, Mark. Yes, the mix pot is used to combine the flanger/chorus effect with the dry signal. When the mix pot is turned all the way up, you hear only the flange/chorus/reverb signal from the Wavefront chip. The dry signal splits off into two paths after the first opamp. One path sends the signal through the Wavefront chips while the other path sends the dry signal directly to the mix pot.

[Mark Hammer]

Gah!! Still haven't reduced the ambiguity.

When the mix pot is set fully wet in the flanger and chorus modes, is this a) ONLY wet signal or is it b) max intensity flanging consisting of wet+dry in 50/50 proportions?

[DaveTV]

I know what you're asking, Mark. When the mix pot is set fully wet, the flanger and chorus modes are 100%. To my understanding (which I admit is fairly limited), the circuit treats all of the effects coming from the Wavefront chips the same (reverb, flanger, chorus, delay, etc). The Wavefront chips simply take the dry guitar signal, process it, and then they output what is the effect's 100% wet signal (regardless of whether the effect is reverb or flanger or chorus).

This 100% wet signal is then simply blended together with the 100% dry signal at the mix pot. Theoretically, the mix is 50/50 when the mix pot is at its midpoint, and to my ears (with a 1k pot), this seems to be the case for all the effects (although some of the effects may "stand out" more at the 50/50 point). And yes, when the mix pot is at its min and max points, you get 100% dry signal on one end and 100% wet at the other.

This blend pot seemed a little simplistic to me for a "sophisticated" digital circuit, but it's how it's done in the original schematic I took this from (and probably in the Picorverb). I had thought to try blending the signals using an opamp mixer, but I recall Peter had said this might not work well since it wouldn't allow for a 100% dry/100% wet mix (and some of the effects sound best when mixed in more than 50/50).

[Mark Hammer]

Just stumbled onto this: http://www.analog-monster.de/SingleChipReverb.jpg

Unfortunately there is no accompanying commentary, but the poster's webpage is here: http://www.analog-monster.de/schematics_en.html

From the looks of it, and the number of LEDs, I'm guessing the single momentary switch cycles the chip through the 16 programs.

[MetalGuy]

Interesting, but too many additional parts. I'd skip the LEDs and use a PIC.

[puretube]

FYI:
On monday, Wavefront Semiconductor has announced the EOL for the 1101 & 1201 for early next year...

Last Order: before December 1st, 2008.

[marmora]

So I was in the process of building another pedal and I was waiting for the paint to dry.  I figured, since I have the jacks and power supply all out and ready to go, I should hook up the Femto-Verb and see what it sounds like.  I populated the board a while back and have been waiting to hear it since.
Soldering the SMD components was pretty easy.  I had to make sure I took my time and stayed patient.   I decided to solder the passive components around the ICs in first because I felt like the less heat I had around them, the better.  Next, I took a tiny dab of glue and glued the ICs to the board.  I waited for the glue to dry and then lightly coated the legs of the ICs where they met the solder traces with paste flux.  I use the Xytronics soldering station that others here have recommended, along with 63/37 solder that has also been suggested here.  I got both from Circuit Specialists.  Setting the iron to a temperature that wouldn't scare me for use on an IC was important too.  I don't remember what it was now, but if you have an adjustable iron you start to get a feel for what works for different situations. I can honestly say that once I started soldering it was as easy as soldering anything else.  It was pretty fun too!  I used a magnifying glass to make sure there were no solder bridges. 
I jumpered the volume control and the mix pot so that the signal was entirely wet.  I wanted to hear the effect full on.  I used a Honeywell/Clarostat 510E1A48F416PB rotary encoder from AA Electric in Wisconsin.
A few things before I get to the sound.  I noticed the layout doesn't have a place for D2 or the 100uf cap.  A little searching earlier in this thread has led me to find that MetalGuy intentionally omitted them since he usually wires them directly to the power supply jack.  I have omitted them for the time being.  I did notice that the 5 volt regulator gets a little hot.  I realized I wasn't grounding it.  I added a jumper from the pad just below the 1uf cap and 100n cap that connects to the middle pin of the regulator.  I measured my power supply at about 9.2 which is what my Power-All always gives off.  On the other side of the regulator I got 5.02.  Even after grounding it, it still gets warm.
Scrolling through the settings with the encoder, I noticed, as others have, that they aren't going in order.  Right now that's not so important, but when it comes time to label an enclosure with the settings I'd like to know which one is which!  It would be more crucial for the more subtle changes in Reverb and not for the obvious settings like Flange or Rotary Speaker.
I'm enjoying all of the sounds.  The main downside is you can't control the settings - other than volume and mix of course.  You can, as others have mentioned, do much worse.  It is a nice and fairly compact layout.  The Flange is pretty standard, not too deep or fast.  The Rotary Speaker is a fun setting.  One of the Chorus settings is a little seasick sounding. Of course, since I currently have the mix totally wet, I'm only getting the echoes from the Delay settings and not my original notes.  The Vocal Cancel setting just gives me clean guitar without any effect.  The Reverbs are all decent at the very least.  I say decent because some settings might work better for other instruments/situations.  I read the review of the Picoverb someone linked to and it's an accurate description of the Femto as well.
Overall, this is a very fun effect.  Most people will probably want to buy a reverb, but for those that insist on making one, this is a great way to go.  Sadly, as noted in the previous post, these chips are likely hard to come by now.  When I ordered mine from Wavefront last spring they sent them out in less than a week.  For those that already have the chips or know where they can still get them, don't skip this project!
Many thanks to everyone who worked on this project.

[MetalGuy]

Scrolling through the settings with the encoder, I noticed, as others have, that they aren't going in order.

This has been discussed already. Check out the thread for the new way of wiring and effects ordfer.

[Michael Allen]

Since the AL1101 and AL1201 are just AD and DA converters, they can be replaced with other ADA chips right?

[flo]

I also have a question.
This has been mentioned before but no definate answer was given yet.
Has anybody tried these pre-installed boards?
They look good and are quite affordable.
I think they also use the Wavefront AL3201 chip used in the Femtoverb but I'm not sure. 

RA-FX1V
http://www.profusionplc.com/pro/gex/pcatdtl0?ipartno=RA-FX1V
http://www.profusionplc.com/images/data%20sheets/ra-fx1v.pdf

The RA-FX1V module is a tiny daughter card assembly that can be installed on main boards in products such as guitar amplifiers, mixers and portable pa systems.
Connection to the RA-FX1V is simple. It has two analog input pins and two analog output pins for easy stereo in and stereo out connection. Four digital input pins are used to select one of 16 DSP programs. An additional analogue input is used for an adjustable parameter input to add a variable parameter per program.

$ 34.80

RA-FX3C
http://www.profusionplc.com/pro/gex/pcatdtl0?ipartno=RA-FX3C
http://www.profusionplc.com/images/data%20sheets/ra-fx3c.pdf

The Module is a tiny daughter card assembly that can be installed on main boards in products such as guitar amplifiers and mixers.
Connection to the RA-FX3C is simple. It has two analog input pins and two analog output pins for easy stereo in and stereo out connection.
Four digital input pins are used to select one of 16 DSP programs.

$ 33.12

[MetalGuy]

Has anybody tried these pre-installed boards?

I haven't tried any of them but I tried this one /~30 Euro/:

It uses an ordinary pot to change program. There's an option for effect parameter control as well /haven't tried that one yet/.

http://www.fk-industrie.de/en/produktkatalog/BG/EM/381.html

The whole line of DSP modules:

http://www.fk-industrie.de/en/produktkatalog/BG/EM/0.html

The ACE99  features ready to install  LED or LCD display.

For full technical details check out data sheets.

Original manufacturer of ACE DSP modules:

http://www.thk-japan.com/

[Marcvv]

Hi,

It has been a while (2007) since I build this pedal.

I never was satisfied with the amount of effect that I got from the unit.

I changed the way the mixer was designed so I could get more "effect".

Nevertheless my build does not sound as deep as I would expect.

Today I compared it to the picoverb sounds and discovered that that one sounds way better then my femtoverb.

As far as I know it is based on the same chip set.

Could it be that there is something in the design that is not giving me the full effect.

I have checked, rechecked,checked, rechecked my build. Reflowed the solder. Components are as indicated (unless they are not good).

If I read the remarks of other build I think there are more with the same problem.

Any ideas?

Best, Marc

[MetalGuy]

I never was satisfied with the amount of effect that I got from the unit.

I'm using the board I posted earlier and with the stock 1k mix pot it goves me way more effect that I need so it's a matter of taste as well.
To me all effects are deep and juicy enough but on the same Mix setting they are not equally deep so you'll need to adjust the Mix for each effect.

Sometimes you check and recheck for a problem 10 times and you can't find out what it is but on the 11-th time you get lucky

[cloudscapes]

geh, those wavefrontsemo dacs/adcs arent very easy to find anymore

[Marcvv]

I never was satisfied with the amount of effect that I got from the unit.

I'm using the board I posted earlier and with the stock 1k mix pot it goves me way more effect that I need so it's a matter of taste as well.
To me all effects are deep and juicy enough but on the same Mix setting they are not equally deep so you'll need to adjust the Mix for each effect.

Sometimes you check and recheck for a problem 10 times and you can't find out what it is but on the 11-th time you get lucky

I guess I am up for the 12th time.



I have signal. I have effect. It is just to shallow and certainly if you compare it to the picoverb.........

Edit: I changed the mix back to 1k and dropped the mix setup construction I had before.
Works Ok still would like more effect depth.

Would it be possible to have the signal going in the AL1101 louder??

I alreday soldered a 10K across the 10k going from opamp 1 to opamp to. That changed it a bit. What would be the best way to do this?


Thanks, Marc

[Marcvv]

Bump??

[MetalGuy]

Would it be possible to have the signal going in the AL1101 louder??

I alreday soldered a 10K across the 10k going from opamp 1 to opamp to. That changed it a bit. What would be the best way to do this?

This is the easiest way to do it. Other thing you can do is to recheck everythnig again.

[Marcvv]

This is the easiest way to do it. Other thing you can do is to recheck everythnig again.

Well this was intersting.
I had checked my built several times, reflowed the connections and checked components.

Nevertheless: challenged by Metalguys remark to check again I reflowed my built again.
Now the sound is much deeper! Including the extra 10k that I had already installed I now have a better sound.

It still is puzzeling me what has happened, but that probably stays a mistery.

Thanks Metalguy for the extra encouragement.

Marc

[MetalGuy]

Thanks Metalguy for the extra encouragement.

I'm glad it worked for you.
I was speaking from experience. Sometimes you check 10 times and everything
seems to be OK. Then you decide to check one more time and you find the problem.
Sometimes you may need another 10 times...

[Marcvv]

Thanks Metalguy for the extra encouragement.

I'm glad it worked for you.
I was speaking from experience. Sometimes you check 10 times and everything
seems to be OK. Then you decide to check one more time and you find the problem.
Sometimes you may need another 10 times...

Or even then you need someone to put you back at work again..

Thanks