On Apr 11, 2018, at 10:48 PM, john slee indigoid@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:
Hi,You could feasibly have a different max resistance across the CdS cell in your DIY vactrol**, vs. the max resistance across the cells in the VTL vactrols?You'll need to do some measuring
** I assume by "plain 3mm LEDs" you actually meant "CdS cell + 3mm LED inside a bit of black heatshrink tube", no?JohnOn 12 April 2018 at 11:39, andrew buscher hansbuscher@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:Thanks for the replies guys.The vactrols are Excelitas Tech. I'm using plain 3mm LEDs to avoid blowing the VTLs till I figure this one out. Maybe hot is just how it's supposed to be. :)Thank You-Hans Buscher310-776-0143 text
On Apr 11, 2018, at 5:39 PM, JAMIE logan jammie.emma@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:
if your using xvive vactrols your need 2 trimmers to get them to act right and its better to use 2 singles than the dual types.
as the variation is so large.
first trimmer is for current limiting the xvive use brighter leds so on the 208 redesign we did we added current limit trimmer so you can taylor the current so it performs the same.
if you need a matched pair you need a jig one trimmer for current limiting and 2 trimmers after the resistor ldr so you can trim so that the voltage out is the same.
xvive are not drop in replacements and the c4 are more like the original c3 types.
On 12 April 2018 at 01:20 "Ken Stone otherunicorn@... [cgs_synth]" <cgs_synth@yahoogroups.com> wrote:
I wonder if the voltage drop of whatever you are using as Vactrols is different to genuine vactrols. Are you using genuine or the recent "clones"?On Thu, Apr 12, 2018 at 10:15 AM, andrew buscher hansbuscher@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:
Hello again.I checked the board, resistance values and it follows the schematic. I went ahead and breadboarded the same circuit and get the same result. The 3 240R resistors and the paired transistors get hot. Circuit still draws 33ma. Head Scratcher...
Thank You-Hans Buscher310-776-0143 text
On Apr 10, 2018, at 6:09 PM, Ken Stone otherunicorn@... [cgs_synth] < cgs_synth@yahoogroups.com> wrote:
Check the values of the other resistors, and look for shorts etc. Something is turning on the transistors way harder than they should be.On Wed, Apr 11, 2018 at 5:29 AM, andrew buscher hansbuscher@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:Hello. Recently built this phaser. It works but the 3046 and 220Rs get quite hot. I swapped the 3046 with BC550s in 4 positions and the 123 transistor is boiling.
When manipulating the Phase control I get a +2.2v to +4v swing at pin 8. With only the 3046 and vtl5c3/2s in, the circuit draws 33ma on the +15vdc side. I'd like to know more about this part of the Phaser. I looked around for other "vactrol driver" schemes and found nothing that looks like this one. Very interesting.
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Thanks Ken!
-Hans Buscher
310-776-0143 text
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