Hello all, I am new here but I have a familiar tale to tell …
Owned my Rogue from new in 84 …suffered the usual failing power supplies then mothballed it for 25 years …
Recently bought a new p.s.u. …switched it on and hoped for the best which turned out to be promising…
However I have a problem with the contour generator … It is not working properly.
Get keyed and bypass but “contour” isn’t. It is as continuous as bypass. Black goo of death has been cleaned and sliders and switches have been cleaned in-situ.
I gave changed the 4007 and 4558 chips ( as well as the 3080a) but am now stumped to know where to look next . Any help would be gratefully accepted !
For what it’s worth the oscillators, noise and filter all work and are sonically still pleasing to my ear … Slight tuning issue, but liveable with for now
Do the slider pots for the Contour section (attack and decay) work as they should when measured with a ohmmeter ?
Does the flip switch actually makes contact on its pins when in the contour position (again checking with a ohmmeter) ?
More often than not, the Foam Of Death has also creeped inside and invisibly contaminated the contacts of sliders and switches.
Yes, thats the very first you should do what Alain said, take a look also at the the "Amount" slider. Then, very important, pull all pin connectors, clean their sockets carefully, take a look at their soldering points if theyre o.k, or if the entire unit is wiggling.
And finally, check the CV "OUT and “Trig” Out jacks if they`re working properly, first clean them or replace them.
Thank you both for the replies.
I will follow your advice, hopefully over the weekend.
Keyboard-in works fine from my Microbrute (scaling issue excepted until I build the correct lead). Not checked S-trig yet.
I have checked the resistance of the Attack and Decay sliders , they both seem to be ok. The filter Amount slider is functioning too. I have checked the diodes and capacitors within the envelope and auto- trigger circuits, all seem o.k. Auto- trigger will not fire the envelope in Contour mode , still the same as Bypass.
I have replaced the 4007 I.c.
I am still puzzled. If it is the switch I may be hard pressed to find a replacement ?
I have still to check the transistors Q1 and Q8 2n3904, and Q2. 2n3906. I have these as spares.
On the positive front I have tuned the oscillators across the full range. The pots responded well. It is now more tuneful than it was in 1989 !!!
I am really pleased with the warmth of the filter, as well as the screaming banshee oscillator sync.
If I can cure the attack- decay problem I will be very pleased. I have had some good fun running the Microbrute through the audio - in to generate some para phonic single finger chords already. If I hook up my Volca Keys too then I could generate some truly obese sounds !
I would like to thank Alain and Mega for their help so far . I found 2 dry joints , the power light, and more importantly the keyboard connector header. Both repaired.
Thinking a longer time not about this I forgot the main culprit that causes your Contour problem, and helped formerly several people to fix this:
Garcol:
Every key of your keybed has two small springs, One is for adjusting the pitch FIRST ! And then the second comes into action when the key is pressed down. The second is for triggering the note.
Its very likely like I suffered from on my pedal unit that youve got a steady trigger-contact with one or more of the keys. If this is the case youll have your described steady bypass of the notes. Check the contacts with a magnifire carefully. Its very likely that we´ve found the bug now…`.
Many, many thanks to you Megavoice ! I am hoping you may well be correct in your diagnosis. It will be Thursday before I can check this out. My intuition was telling me there was a stuck contact. I tried to trigger the envelope from my Soundmaster drum machine with no success …
But I was able to hear a rise and fall in the amplitude of the envelope.
We shall on Thursday !
Eureka ! I now have fully functioning Rogue. Found the culprit after staring at the schematic for a while longer … A faulty 2n3904 transistor Q8. In went the new one and voila … A fully operational contour generator after 25 years of hibernation. Many thanks to Mega and Alien for their encouragement. Let’s see how long I can make music without the need of a soldering iron !
Congrats Have fun now.
But let that iron stay hot.
I used my T2 very, very rarely up to five years ago. and despite in a sudden the output op-amp was broken…written upon “Made in Malaysia”…
Have fun now.