Clangora with LM13700/LM13600... also Tunable Noise Gen.

[thefunk]

I noticed that the Bass++ is basically a UD1 with the 566 oscillator replaced with an LM13700 oscillator. So, I was wondering if anyone has replaced the 566s in the Clangora with lm13700s? All three 566s are outputting just outputting a triangle wave which seems like a simple job for 1/2 a 13700. Also, the 566s are over $10 each now on ebay!

thanks.

[Uncle Krunkus]

"I noticed that the Bass++ is basically a UD1 with the 566 oscillator replaced with an LM13700 oscillator"

I just checked the schem, and it's not quite that simple. In the Bass++ the LM13700 is setup to act like an AM VCO (I think?)

BTW Not trying to be a killjoy, just trying to understand the schem a bit better, as I've got a board for the Bass+ and I'm keen to get it happening.

[thefunk]

Ah. I should have led with the internet caveat... IMHO
The first half of the lm13700 in the Bass++ looks to me like it was taken, almost exactly, from the lm13700 datasheet as the 'Single Amplifier VCO' which seems to match with the 566 oscillator in the UD1. Maybe the magic is in the second half of the 'shell' circuits? In any case, it looks like the 2 circuit parts are almost interchangeable with adjustments for frequency etc. If I I was more knowledgeable, I'd have a go at switching out the oscillators in the Clangora. Maybe, someone has already done this?

[AnalogCustom]

NE566 Clangora frecuency times (fixed controls):

Figure 3:
IC7: 100Hz to 5.8KHz (R69)

Figure 4:
IC8: 640Hz to 6.4KHz (R23)
IC9: 50Hz to 2.6Khz (R65)

Triangle output level= 2.8Vpp

schematic with LM13600 soon...

Marco.

[thefunk]

Wonderful! I await with great anticipation. And, thanks for the frequencies. I calculated the IC8 frequencies, from the formula, to pretty close to your numbers, but struggled on the other two.

[AnalogCustom]

Here the circuit:




Circuit in PDF:
https://sites.google.com/site/cardenassynthruments/config/pagetemplates/archivos-sintetizadores/clangora%20566%20to%2013600.pdf


I do not recommend BASS++ circuit (1/2 LM13600) for this project. This design produces a small distortion of the triangular wave a bit difficult to filter. The best option is to use a full-LM13600 for the oscillator core. For my taste the best sound is that similar to the sine wave.

I have not built the Clangora. I have only been tested with Ic's mentioned.
I had saved a LM566 for 10 years...

(Sorry for my English )

Cordiales saludos!!!

Marco Antonio

[thefunk]

Awesome! I'll be etching a couple of Clangora boards in the not to distant future. I'll be sure to make one with your conversions to compare the two.

A couple of questions...
1. Is there a reason to specifically use the TL062? Or, would a TL072 etc. or any standard op amp work?
2. On the oscillator core, you have the square wave output after the first stage and the triangle wave output after the second stage. On the datasheet, the outputs are reversed. Which is correct?

And, Thanks Again!

Martin.

[AnalogCustom]

[thefunk]

just checking

[AnalogCustom]

other...

Tunable Noise Generator (by Thomas Henry):
http://www.nutsvolts.com/media-files/11/November%201999%20Thomas%20Henry%20-%20Build%20a%20Tunable%20Noise%20Generator.pdf
NE566 frecuency range (fixed control): 100Hz to 12KHz.
Output Triangle WF (without noise fm modulation): 12Vpp aprox.

----------------------------------------------------------------------------------

Tunable Noise NE566 to LM13600 conversion schematic:



in PDF:
https://sites.google.com/site/cardenassynthruments/config/pagetemplates/archivos-sintetizadores/tunable%20noise%20566%20to%2013600.pdf

Marco.