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Uncle Krunkus
Moderator
Joined: Jul 11, 2005 Posts: 4761 Location: Sydney, Australia
Audio files: 52
G2 patch files: 1
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Posted: Sat Feb 28, 2009 8:27 am Post subject:
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Hey Lofi,
You should really be using Germanium diodes, they'll make it sound heaps better. I'd match all 4 if you can. _________________ What makes a space ours, is what we put there, and what we do there. |
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Lofi Ninja
Joined: Oct 25, 2008 Posts: 143 Location: Jupiter
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Posted: Sat Feb 28, 2009 9:52 am Post subject:
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Ok uncle krunkus, I'll see if I can find some.. But which diodes are the pairs ? because I'm thinking adding rotary switches to different diode pairs.. Oh, the video is up.. CRAZY NOISE ! http://www.youtube.com/watch?v=8qOC4x3mtIA Btw. If you haven't checked my channel on utube you should! _________________ www.youtube.com/user/lofininja |
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Lofi Ninja
Joined: Oct 25, 2008 Posts: 143 Location: Jupiter
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otherunicorn
Joined: May 11, 2008 Posts: 136 Location: Australia
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Posted: Fri Mar 06, 2009 6:32 pm Post subject:
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I have tried schottky, germanium and silicon.
germanium. Between 2.6V and 3.6 V drop depending on the diode. Obviously they need matching.
schottky. Approx 2.5 V drop. Sounds less harsh than germanium.
silicon (1N4148). Quite harsh, and with a higher output volume than germanium, possibly to do with germanium zenering at around 9V, or to do with the extra harmonics.
The brand or type number of the germanium is largely irrelevant.
The old computer I pulled the initial diodes from was built in 1969. It was all discrete transistor/diode/resistor, with a tiny core memory (256 bit). ROMs were 6" x 5" x 10" plug in modules connected by a pin matrix (200 odd pins?) and were full of diodes and in one case even relays. It had been upgraded in 1971 to include a 1k x 8 core memory. _________________ http://www.cgs.synth.net/ |
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Sebo
Joined: Apr 27, 2007 Posts: 564 Location: Argentina
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Posted: Sun Mar 08, 2009 1:14 pm Post subject:
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Thanks otherunicorn for the info! _________________ Sebo
---------------------------------------
My Music:
https://www.facebook.com/cosaquitos/ |
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Fenris
Joined: Jul 30, 2008 Posts: 145 Location: Horbury. UK
Audio files: 1
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Posted: Thu May 07, 2009 4:23 pm Post subject:
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I made one today with 4 germanium diodes. I didn't match them though. So one piece of veroboard later I was set. I have tested it with an MP3 Player, my WSG and my LM386 amp and it works I am well pleased and will be trying all sorts with it.
Regards
Fenris |
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certain2
Joined: Nov 21, 2008 Posts: 5 Location: yorkshire
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Fenris
Joined: Jul 30, 2008 Posts: 145 Location: Horbury. UK
Audio files: 1
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Posted: Wed Jun 10, 2009 5:02 am Post subject:
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Nice one . They are pricey though aren't they. But well worth it for the simplicity of integrating it into a system. I would be interested in any comments of the benefits of matching your diodes. Does it really make a difference and how much?
regards
Fenris |
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crochambeau
Joined: May 18, 2008 Posts: 31 Location: earth.
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Posted: Wed Jun 24, 2009 10:02 pm Post subject:
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Fenris wrote: | I would be interested in any comments of the benefits of matching your diodes. Does it really make a difference and how much?
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I've found the tighter the diodes are matched the more carrier (either source, really) suppression occurs.
When the effect is engaged and modulating signal I can't discern a difference (though I've yet to record balanced vs. unbalanced for A/B); it's when one input is silent that the matching really makes a difference. |
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emdot_ambient
Joined: Nov 22, 2009 Posts: 667 Location: Frederick, MD
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Posted: Tue Mar 30, 2010 8:10 am Post subject:
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Reviving the thread...anyone have sound examples of various diode configurations? Mouser's 1N34A are like 5.55 times more expensive than their Schottky BAT48 signal diodes. I'm not sure which will sound better for my style of music (think 40s Klaus Schulze or Tangerine Dream...spacy with sound FX but more melodic in nature)...or if it would make a lot of difference.
Wonder how many I'd need to buy in order to find 4 closely matched diodes? |
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emdot_ambient
Joined: Nov 22, 2009 Posts: 667 Location: Frederick, MD
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Pantheon
Joined: Feb 17, 2011 Posts: 36 Location: Edinburgh
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Posted: Fri Feb 18, 2011 8:23 pm Post subject:
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looking at the mouser reference you posted, it seems like they will work just fine.
You should be able to place them in anyway around, because the impedance is the same on both sides. For the side that only uses two pins, just leave the central pin from the transformer unattached. _________________ the8bitpimp.wordpress.com |
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emdot_ambient
Joined: Nov 22, 2009 Posts: 667 Location: Frederick, MD
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sneakthief
Joined: Jul 24, 2006 Posts: 569 Location: Berlin
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emdot_ambient
Joined: Nov 22, 2009 Posts: 667 Location: Frederick, MD
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Posted: Sat Feb 19, 2011 11:36 am Post subject:
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Interesting. Thanks for that. Those won't fit the CGS PCB, but I'm sure one could make them work (screwed on the PCB mounting bracket and just wired)...would be really interesting to hear the difference.
It would be great to hear a lot of different transformer/diode combinations with the same input signals. I'm sure the results would change quite a bit and it would be nice to be able to design them to your taste without going through the whole exercise yourself...Lazy? Moi? _________________ Looking for a certain ratio since 1978 |
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sneakthief
Joined: Jul 24, 2006 Posts: 569 Location: Berlin
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Posted: Sat Feb 19, 2011 11:44 am Post subject:
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This is the problem with those little 600:600 transformers:
In other words, you lose a lot low frequencies.
Compare this to the Edcor:
(audio interface: Roland M-16DX) _________________ Sneak-Thief - raw electrofunk |
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JoeMorris
Joined: Apr 26, 2009 Posts: 161 Location: Brighton
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Posted: Wed Apr 27, 2011 3:44 am Post subject:
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I have one of these cool little boards, what would happen if I literally use as is with the ins and outs as a passive unit? would it just be a matter of makeup gain on the outputs, or is there a more complex solution needed? |
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andrewF
Joined: Dec 29, 2006 Posts: 1176 Location: australia
Audio files: 4
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Posted: Wed Apr 27, 2011 8:04 am Post subject:
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do you mean the passive version:
?
yes it works as is, no need for a power supply. Must be the simplest module ever, but it sounds great. there is slight signal loss so turn it up further down the patch |
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JoeMorris
Joined: Apr 26, 2009 Posts: 161 Location: Brighton
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Posted: Wed Apr 27, 2011 9:21 am Post subject:
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thanks, thats great. will wire up asap. no sine oscillators at the mo though! maybe I need to build a waveshaper pronto. |
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CZ Rider
Joined: Dec 14, 2006 Posts: 17 Location: Southeastern,PA
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Posted: Fri Feb 08, 2013 4:37 pm Post subject:
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Old thread, but wanted to say thanks for the tip on the Edcor transformers.
Thanks sneakthief!
Picked up a set and clipped together the circuit after matching the Ge diodes.
Wanted this for my old Moog, and wanted to stay with discrete circuits. Was not sure how this would sound as those old Moogs are temperamental to outside devices. The Moog 901 oscillators are only about 1.2V P-P.
Anyhow, this circuit sounds sweet with the Moog 901's. A small MP3 sample of one 901 ring modulating the other. Usually these sound great with a slight rolling detune. But that ring circuit sounds really different, almost like PWM or something. On the scope the waveforms are dancing. It's alive!
Moog 901's ring modulated MP3 3MEG download
And yeah, those 901's stay in tune over 5 octaves, even beating against each other! |
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