From tmoravan@netcom.comFri Feb 10 09:19:01 1995 Date: Fri, 10 Feb 1995 05:46:21 -0800 (PST) From: Tom Moravansky To: analog Subject: MKS-80 differences Scanning through the MSK-80 service manual, I noticed that Roland made some major changes to this unit between Rev 4 and Rev 5. Mainly, they replaced the Curtis CEM 3340 VCO with a custom Roland VCO (IR3R03), replaced the venerable IR3109 filter and CEM 3360 VCA with another custom chip (IR3R05 filter / VCA chip). The stated reasons for doing this were that waveforms clipped when playing in Unison mode with high resonance and fast decay rates on the VCA (non-linear gain characteristics). I was wonderiung if anyone had doe an A/B comparison of the earlier MKS-80 with a later one. BTW - the 'new' IR3R05 is also used in the MKS-70. Also - to check the OS version: Hold down the Auto Tune and Write buttons and power the unit on. -- _______________________________________________________________________________ Tom Moravansky tmoravan@netcom.com still looking for a Synthex From fischer1@student.msu.eduSun Feb 12 14:20:37 1995 Date: Fri, 10 Feb 1995 15:51:22 -0500 (EST) From: Michael Fischer To: analogue@magnus.acs.ohio-state.edu Subject: MKS-80 Rev 4 and Rev 5 A/B comparisons... Tom, I used to own both a Rev4 and Rev5 MKS-80 ( I kept the Rev5, sold the Rev4 )... The following I noticed : 1) I looked at the logic boards in the two units, the Rev5 was distinctly more "orderly", with a much "nicer" looking A/D / D/A board.... The one on the Rev4 looks like a "hack". 2) As far as sound goes.... With both units using the EXACT same patch data... and using the EXACT pair of headphones on the main outs/headphone jack... the Rev4 was distinctly noisier, however it had a "brighter" sound... the Rev5 was ( even at highest volume ) not showing this residual, always present noise...even at maximum position... Being one to prefer the absolute latest ROM/versions, etc., et.... I chose to keep the Rev5.. The "brighter" sound of the Rev4 was not "bright" enough ( IMHO ) to justify its level of line output noise. Furthermore, there are ( unquestionably ) "bug" fixes in the version 5.0 ROMS that are not in the Version 4.0 ROMS... The next question, logically, is : "Well, just put version 5 ROMS in the version 4 logic board one.... ) WELL, the ROMS are NOT interchangeable between the different logic board revisions... Sincerely, Michael Fischer fischer1@student.msu.edu P.S. Tom, J.L. at MusicTek knows quite a deal about the MKS-80 vers 4 / vers. 5 ROMS/VCO's, etc.... you might want to talk to him about it...