| redrabbit |
Um.......I want to power this with:
+, -, ground.
http://www.lh-electric.4t.com/bin/8038gen.gif
But I'm not sure where Ground (0v) goes.....???
....also, can you tell me if I should add a buffer (after the transistor....... or instead of the transistor?), to make (and hear) the signal at line-level.
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| redrabbit |
confused........??? the link isn't allowed here? or.... it won't connect/work ??
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| richie00boy |
T1 is already a buffer so there is little point adding another.
The chip is designed for single-ended applications, you can check the datasheet to be sure. You need to capacitor couple the output then the output lead is taken from the 0V rail and the cap. |
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| AndrewT |
Hi,
I used (still use) one of these.
It drives 600r, just.
It really needs a better buffer on all the outputs.
It has severe problems. poor distortion performance. poor voltage stability as frequency is swept. poor waveform purity (spike on the sinewave peaks and gets worse at upper frequencies). Triangular is very rounded, square is even worse.
becomes sawtooth and asymetrical with frequency.
Very wide frequency range (1Hz through a speaker cone looks weird-watching the surround flex and change shape is very instructive).
I used lissajous firgures from an accurate 1001Hz source (test disc in a CD player) to calibrate the variable resistor. I was surprised how accurately I could set up a 5:8 ratio for instance and eventually I found almost thousands of these obscure ratios.
I added a -20db cut on the output, absolutely invaluable.
I also made up a switched 600r attenuator. Steps from 0db to -60db in 0.05db increments. A few accurate resistors and 2pole switches, very cheap and again superbly flexible when testing amps etc. |
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| redrabbit |
Thanks for all the replies. :worship:
The datasheet, and the "application guide" suggest some different (better) buffer topologies than this schemo...I'll try.
I have had this 1/2 built for a year, and set it aside. Now I am building a ring-modulator (using a CA3019 diode array). I thought I'd finish this oscillator, and use it for the carrier signal. If I get the two working together :c_flag:, it will be the most advanced project so far, for me, in that I'm not following a "tested" set of plans :bfold: . I am swimming on my own a bit (slightly upstream). :magnet: :crackup:
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