Jovi Bon Kenobi
Well-known member
I bit the bullet and picked one of those up recently. No regrets!
The Mesmerizer ( weird pedal )
- Thread starter griff10672
- Start date
griff10672
Active member
seems like almost a necessary piece of gear the more I think about it
geekmacdaddy
Well-known member
Had one for a LOT of years. even resoldered one of the leads. Couldn't live without it.
griff10672
Active member
OK .... the pressure from my peers is to much .... ordering one now ....... lol
griff10672
Active member
Interesting info I found on the XR2206 chip from someone else that had problems .... funny ... the five chips I bought all have the F0919 # on them .... which this guy states his issues with ( that seem to make sense involving my pedal not functioning properly )
so I found a place here in the states that carries the F0918 branded ones for 8.00 a piece ... expensive I know .... but if they work it will be worth it to me anyway ... I included the info I found below ... just in case someone else might be thinking about building one .
" Recently smoked this chip in an analog/Digital Trainer and ordered some replacements on line, none of them worked in the existing circuit. I downloaded the data sheet for the chip and breadboarded the sample circuits and tried the chips in them, with little or no success. Eventually I found by adjusting the supply voltage, and the values of the external resistors and caps I could get them to a least partially function. I noticed that the original chip had a batch number of F0918 and the ones I received had a batch number of F0919 and were from china. I had a second Function Generator that used the same chip, so I pulled it and tried it in the unit I smoked the chip in and it works just fine. I than tried it in the test circuits from the data sheet and it also worked fine in them. I found a source for the chips stateside, called and customer service checked stock and confirmed their stock had batch number F0918. Ordered and received them they work just fine.
Bottom line here is my experience with the china version of XR2206 is the external components must be custom selected for the particular chip and will not work as a suitable substitute for XR2206cp F0918. Also, I was never able to get the FSK circuit on the china version to work no matter what I did.
I know the previous posts regarding this chip are old but since china started making this chip maybe this will save some people some time and aggravation. "
so I found a place here in the states that carries the F0918 branded ones for 8.00 a piece ... expensive I know .... but if they work it will be worth it to me anyway ... I included the info I found below ... just in case someone else might be thinking about building one .
" Recently smoked this chip in an analog/Digital Trainer and ordered some replacements on line, none of them worked in the existing circuit. I downloaded the data sheet for the chip and breadboarded the sample circuits and tried the chips in them, with little or no success. Eventually I found by adjusting the supply voltage, and the values of the external resistors and caps I could get them to a least partially function. I noticed that the original chip had a batch number of F0918 and the ones I received had a batch number of F0919 and were from china. I had a second Function Generator that used the same chip, so I pulled it and tried it in the unit I smoked the chip in and it works just fine. I than tried it in the test circuits from the data sheet and it also worked fine in them. I found a source for the chips stateside, called and customer service checked stock and confirmed their stock had batch number F0918. Ordered and received them they work just fine.
Bottom line here is my experience with the china version of XR2206 is the external components must be custom selected for the particular chip and will not work as a suitable substitute for XR2206cp F0918. Also, I was never able to get the FSK circuit on the china version to work no matter what I did.
I know the previous posts regarding this chip are old but since china started making this chip maybe this will save some people some time and aggravation. "
Very interesting post. I build a simple signal generator with this chip several years ago. I ordered a couple of the chips from Amazon and will see if they work if I swap them into the signal generator. Based on the info above I won't be surprised if they are not working substitutes for the older chip.
Robert
Reverse Engineer
Coincidentally I just had a friend email me last night with troubles on a Mesmerizer build. I suspect the XR2206 is the issue with his as well.
He has reordered another IC from Jameco, they're a bit more expensive but most likely legit parts.
I'll follow up when I hear back.
He has reordered another IC from Jameco, they're a bit more expensive but most likely legit parts.
I'll follow up when I hear back.
griff10672
Active member
I ordered a few from Jameco myself the other day .... won't be in till Tuesday though ..
Robert
Reverse Engineer
XR2206 from Jameco (with batch number F0918) cleared up the problem, hopefully that'll take care of yours too.
griff10672
Active member
perfect !!! Thanks ...
griff10672
Active member
All set !!! circuit worked as soon as I popped the new chip in ....
This is the first time I've got burned buying chips ....
Beware of XR2206 marked with batch # F0919 they are bogus ... I purchased them from Amazon
Jameco here in the states has legit ones .... marked F0198
Chuck D. Bones
Circuit Wizard
Love the name & the graphics!
Maybe the LFO is running too fast? Verify C12 is 4.7uF and the RATE pot is not shorted. Or maybe the DEPTH pot is shorted? Been a very long time since I used XR2206. If memory serves, C12 should not be a polarized cap. According to the data book, the voltage on the timing cap swings both directions.
Maybe the LFO is running too fast? Verify C12 is 4.7uF and the RATE pot is not shorted. Or maybe the DEPTH pot is shorted? Been a very long time since I used XR2206. If memory serves, C12 should not be a polarized cap. According to the data book, the voltage on the timing cap swings both directions.
Chuck D. Bones
Circuit Wizard
I've seen it done both ways; with polarized electrolytics capacitors and with back-to-back electrolytics. The EXAR Function Generator Databook is silent on the use of polarized capacitors. It does contain this simplified schematic of the oscillator which shows the capacitor waveform swinging positive and negative, but it's only 2 Vbe peak-to-peak. Usually takes more than that to make polarized capacitors leak current.
Hmm, is this batch number definitely bad? I got a chip from EBay marked F0919 and my build is a great boost pedal but does not put out any tremolo. I'm unsure whether it is a problem with the chip or with the JFETs (I used one SMD and the others were through hole). If it's certain that batch number is bad or fake, then it should be straightforward to deal with the vendor on Ebay.
griff10672
Active member
yeah man ......... your having the exact same problem I had ............ F0919 are crap-ola
Chuck D. Bones
Circuit Wizard
Maybe the real solution is to design in an oscillator built with parts we can buy today. With a quad opamp, some diodes and a handful of Rs & Cs, we can have sine, triangle and squarewave.
Another alternative would be to write FV-1 code that emulates the Mesmerizer.
Another alternative would be to write FV-1 code that emulates the Mesmerizer.
Robert
Reverse Engineer
The Harmonic Tremolo FV-1 patch is fairly close.
I've been meaning to yank out that XR2206 for a while... I started monkeying around with a version that uses an ATTINY for the LFO but it has fallen through the cracks for now.
