Vintage Synth Repair

Dear Group,

has anyone of you calibrated one or more CS80s?

I'm stuck on mine at step 1 on page 11. It tells me to adjust VR7+VR8 and set CP3 to 4.3Vpp. The highest value I can reach is around 2.8Vpp.

I have found another owner who had exact the same question and the same behavior and it seems, the value in the adjustment manual seems to be wrong.

Funny thing is, the readings on all boards before adjusting show around 7.8Vpp on CP2 and just 800mVpp on CP8 (which should be 2.2Vpp according to the manual)

I have found the CS60 tuning manual which tells to set CP2 to 7.6Vpp which I can reach, but I'm not sure if it applies to the CS80 tuning.

Maybe someone can say something about it?

Michael

Since CS40, 60 and 80 all had the same voice cards, I would try the 60 setup, it was common to have errors in manuals then.  One combo manual showed the assemble of a stand with the word "fuck" pointing to a hook.  Hook, hooker, fucker, fuck.


Bottom line, if the CS60 adjustment works, and sound proper, use it.  I remember trying to do the complete setup once, and running into problems, possibly the same issue you have, but this was in the late 70!


Ps, I just found in my parts a complete and new CS-60 tap assembly(voice tabs) if anyone needs.
--------------------------------------------
On Wed, 12/23/15, yahoogroups@... [vintagesynthrepair] <vintagesynthrepair@yahoogroups.com> wrote:

 Subject: [vintagesynthrepair] CS80 adjustment procedure: VCF alignment
 To: vintagesynthrepair@yahoogroups.com
 Date: Wednesday, December 23, 2015, 2:28 AM


  









       Dear Group,
 has anyone of you calibrated one
 or more CS80s? 
 I'm stuck
 on mine at step 1 on page 11. It tells me to adjust VR7+VR8
 and set CP3 to 4.3Vpp. The highest value I can reach is
 around 2.8Vpp. 

 I have found another owner who had exact
 the same question and the same behavior and it seems, the
 value in the adjustment manual seems to be
 wrong.
 Funny thing is, the readings on
 all boards before adjusting show around 7.8Vpp on CP2 and
 just 800mVpp on CP8 (which should be 2.2Vpp according to the
 manual)
 I have found
 the CS60 tuning manual which tells to set CP2 to 7.6Vpp
 which I can reach, but I'm not sure if it applies to the
 CS80 tuning.
 Maybe someone can
 say something about it?

 Michael









 #yiv9684484276 #yiv9684484276 --

Also, back in the day I used to do mods on the CS80/60.  One mod added 6 LFOs, so that there were a total of 8 instead of the stock 2.  This was wired so each voice got separate LFOs for PW and VCO/VCF,  This makes for a fatter sound, since there is only one VCO per voice.


A mod to makes unison(all 16 voice card in unison for a big lead synth) and it also doubled (4 voices per key).


And custom re-voicing of the presets.  The stock string were the most commonly done.  I have charts for each with voltage reading going to the voicing circuits points filed away, one sheet for every artists preferences of final tweaks.
--------------------------------------------
On Wed, 12/23/15, yahoogroups@... [vintagesynthrepair] <vintagesynthrepair@yahoogroups.com> wrote:

 Subject: [vintagesynthrepair] CS80 adjustment procedure: VCF alignment
 To: vintagesynthrepair@yahoogroups.com
 Date: Wednesday, December 23, 2015, 2:28 AM


  







    

       Dear Group,
 has anyone of you calibrated one
 or more CS80s? 
 I'm stuck
 on mine at step 1 on page 11. It tells me to adjust VR7+VR8
 and set CP3 to 4.3Vpp. The highest value I can reach is
 around 2.8Vpp. 

 I have found another owner who had exact
 the same question and the same behavior and it seems, the
 value in the adjustment manual seems to be
 wrong.
 Funny thing is, the readings on
 all boards before adjusting show around 7.8Vpp on CP2 and
 just 800mVpp on CP8 (which should be 2.2Vpp according to the
 manual)
 I have found
 the CS60 tuning manual which tells to set CP2 to 7.6Vpp
 which I can reach, but I'm not sure if it applies to the
 CS80 tuning.
 Maybe someone can
 say something about it?

 Michael









 #yiv2468162440 #yiv2468162440 --