Search found 21 matches

by 1way2life
Tue Jul 09, 2019 5:18 pm
Forum: HELP!
Topic: Jupiter 6 Filter frequency reversed
Replies: 0
Views: 1033

Jupiter 6 Filter frequency reversed

Have a Jupiter 6 that I'm restoring... The problem is the filter frequency slider... it's reversed (fully open is on the bottom in LPF mode), and also the linearity is off greatly.. full cutoff is in the middle of the slider. I swapped IC1 (4067) with the left panel, but same result. Also, this is n...
by 1way2life
Fri Mar 01, 2019 4:22 pm
Forum: HELP!
Topic: Yamaha CS40m Sample & Hold mod, plus patch write not working
Replies: 15
Views: 4679

Re: Yamaha CS40m Sample & Hold mod, plus patch write not wor

Glad to hear! Enjoy the Yamaha. I guess the Sample & Hold module could be nicknamed the Vangelis module. Because it functions as a channel from which music emerges from the chaos of noise, and you had to replace la FET sauvage :lol: HA! Indeed. :lol: Yea, been playing it quite a bit... love it. The...
by 1way2life
Fri Mar 01, 2019 2:29 pm
Forum: HELP!
Topic: Yamaha CS40m Sample & Hold mod, plus patch write not working
Replies: 15
Views: 4679

Re: Yamaha CS40m Sample & Hold mod, plus patch write not wor

Mooger5, Got the FETs last night. This morning, I desoldered both from the MOD board and tested them. Sure enough, FET3 was shorted. Replaced it, and the 0.039uf cap (used a MLCC) and it produced the cleanest S/H I've seen to date :-) Now the CS40M is totally restored! Thanks for your continued help.
by 1way2life
Thu Feb 28, 2019 12:03 am
Forum: HELP!
Topic: Yamaha CS40m Sample & Hold mod, plus patch write not working
Replies: 15
Views: 4679

Re: Yamaha CS40m Sample & Hold mod, plus patch write not wor

Hi Mooger5, I'm still waiting on the 2sk15a FETs, however I decided to start on restoring my CS30, and low and behold, a nearly identical S/H circuit!. I popped it open, and started scoping its FETs. Sure enough, the S/H signal is right at the first FET, where on the CS40m just passed the pulse from...
by 1way2life
Sun Feb 24, 2019 7:31 pm
Forum: HELP!
Topic: Yamaha CS40m Sample & Hold mod, plus patch write not working
Replies: 15
Views: 4679

Re: Yamaha CS40m Sample & Hold mod, plus patch write not wor

Thanks... I ordered the replacements to try. Was a bit hard to find the 2sk105a FETs.

I'll let you know how it turns out!
by 1way2life
Sat Feb 23, 2019 4:14 pm
Forum: HELP!
Topic: Yamaha CS40m Sample & Hold mod, plus patch write not working
Replies: 15
Views: 4679

Re: Yamaha CS40m Sample & Hold mod, plus patch write not wor

No heat, seems normal. I Swapped 2 of the 4558s and same issue. Really weird.
by 1way2life
Sat Feb 23, 2019 2:33 pm
Forum: HELP!
Topic: Yamaha CS40m Sample & Hold mod, plus patch write not working
Replies: 15
Views: 4679

Re: Yamaha CS40m Sample & Hold mod, plus patch write not wor

Yes it is! I was dreading tracing through all the logic, as Im not very good at it. But then I saw the broken trace, fixed, and all was good with the patches. Very satisfying! So, from your description of the S/H circuit, I suspect the FETs or the 0.039 cap, as the pulse that comes through Tr8 and D...
by 1way2life
Sat Feb 23, 2019 12:14 am
Forum: HELP!
Topic: Yamaha CS40m Sample & Hold mod, plus patch write not working
Replies: 15
Views: 4679

Re: Yamaha CS40m Sample & Hold mod, plus patch write not wor

Hi Mooger5, Always great advice from you... thanks! I have traced it to a point. I am NOT getting the S/H random square waveform out of the MOD 1/3 section where the other LFO waveforms appear. Instead, I get a steady ring pulse, with no variation. I am getting noise out of the noise generator and i...
by 1way2life
Wed Feb 20, 2019 11:56 pm
Forum: HELP!
Topic: 80s synth bass
Replies: 7
Views: 2297

Re: 80s synth bass

Yes, could be a number of synths... but could easily be replicated on a Roland Juno 1, 60 or 106.
Sounds like a saw wave, with a half amount of sub octave underneath. Filter has slight resonance, medium cutoff and some envelope applied, with a medium decay.

Hope that helps.
by 1way2life
Wed Feb 20, 2019 4:39 pm
Forum: HELP!
Topic: Yamaha CS40m Sample & Hold mod, plus patch write not working
Replies: 15
Views: 4679

Yamaha CS40m Sample & Hold mod, plus patch write not working

Hi all, I have a CS40m that I am restoring to the best of my ability. Power supply rebuilt, and all caps replaced. Got most of the unit working. However, the sample and hold modulation isn't working. When selected on a VCO, and depth increased... pitch just decreases and stays, no change in pitch fr...
by 1way2life
Sat Feb 16, 2019 1:30 pm
Forum: HELP!
Topic: yamaha CS-10 stuck LFO!
Replies: 17
Views: 4766

Re: yamaha CS-10 stuck LFO!

Same here,

Cant seem to find any replacement ICs.
by 1way2life
Tue Feb 12, 2019 12:49 pm
Forum: HELP!
Topic: Yamaha CS 40m Help!
Replies: 12
Views: 3758

Re: Yamaha CS 40m Help!

Well, found the issue... and it certainly was the 0.47 fusible resistor on the +15v rail. It was noticeably dark in color, and was reading at 5k ohms. Although these are still available, I'm going to look into an alternative solution, as fusible resistors IMO are just a bad idea, and are rarely used...
by 1way2life
Sat Feb 09, 2019 7:00 pm
Forum: HELP!
Topic: Yamaha CS 40m Help!
Replies: 12
Views: 3758

Re: Yamaha CS 40m Help!

Same issue here, get an under-voltage on the +15 rail, with no boards connected. I get 14.58v.

Anyone ever figure this one out?

I'll have to trace through, and swap some pairs on the board to try to figure it out.
by 1way2life
Thu Dec 20, 2018 4:38 pm
Forum: HELP!
Topic: Juno-60 Hold Button is Broken
Replies: 2
Views: 1824

Re: Juno-60 Hold Button is Broken

This place is great... ordered from them in the past, and they have the juno-60 plastic button tops:

https://syntaur.com/roland_juno.html#6
by 1way2life
Sun Dec 16, 2018 12:02 am
Forum: HELP!
Topic: Juno 106 - wierd distortion fault
Replies: 69
Views: 17717

Re: Juno 106 - wierd distortion fault

Listed as NOS. Pic looks spot on.
I'll let you know for sure :-)