Kurzweil K2500 operating system bugs?

[ʝɵʝɵ]

After obtaining a K2500 with OS 2.80 installed, I wanted to install the latest version, 3.02 (for non-KDFX units), which I downloaded from the Kurzweil website. While it seems to work in general, I noticed that now some patches behave strange. For example program 891 - SpaceStation sometimes introduces little noise bursts into the notes that were previously not there. I tried installing both from Floppy and SCSI to rule out bad floppy sectors as a source of this problem. I also re-installed the ROM objects and did a hard reset, with no result.
So for now I reverted to OS 2.80 which came on a floppy with the synth. Is this a known issue? Does anyone have any of the OS versions between 2.80 and 3.02 for comparison?

EDIT: Slightly off-topic, but does anyone have a working download for the VAST Programmer? The original website seems to be down and web.archive.org does not have the downloads, only the website itself...

[Rasputin]

Don't know about the first part of your post, RE: system firmware bugs, but if you are looking for Kurzweil VAST programmer by TangentCats then maybe this will help...

https://drive.google.com/drive/folders/ ... sp=sharing

That's the 0.2.12 beta version (last released version that I'm aware of) including the MIDI patch fix. Also the demos and K2500/K2600 VPO bundle.

[ʝɵʝɵ]

Thanks for the link!

[ʝɵʝɵ]

I found this on ebay: http://www.ebay.de/itm/Kurzweil-K2500-K ... 1438.l2649
"SMCTLV8 - sample memory control version 8.
note: older or faulty versions of these can cause problems in sample memory such as strange
"clicks" or noises, improper recognition of sample memory, or sudden sample memory corruption"

It sounds to me like it should not apply to built-in samples, but maybe it does? I would guess that the chips in my K2500 are not the latest, given that it came with several older firmware disks.

EDIT: Another slightly off-topic question: Some sites suggest that the K2500 PRAM expansion (1MB of additional program RAM) is just regular SIPP memory. It certainly looks like it, but seems to have 45 instead of 30 pins.

[Tekhed66]

Don't know about the first part of your post, RE: system firmware bugs, but if you are looking for VASTprogrammer by TangentCats then maybe this will help...



That's the 0.2.12 beta version (last released version that I'm aware of) including the MIDI patch fix. Also the demos and K2500/K2600 VPO bundle.

Fantastic timing ... I was recently hunting for this programmer but the original host website isn't active anymore... thanks for posting the link.

Stupid question - how do you install the VAST programmer as I can't find an .exe file in any of the zipped folders ... do you need a pre-existing copy of VAST or do you run the Windows batch file? ... I just wanted to ask first before I installed anything as I just paid mega bucks for my computer to be brought back to life after accidentally installing some dodgy software.

Thanks again.

[ʝɵʝɵ]

You need Java to run the JAR file, it's not a regular Windows executable. You can find an appropriate BAT file in VP_0_2_12_Beta.zip that launched Java with the appropriate parameters. So first extract VP_0_2_12_Beta.zip somewhere, and then extract VP_0_2_12_Beta_Patch_1.zip on top of that to replace the JAR file.

[ʝɵʝɵ]

Meanwhile I've found the previous OS versions (and tons of other useful stuff):
http://kurzweil.com/content/migration/d ... ng_System/

[ʝɵʝɵ]

In the meantime I've received those updated chips - I managed to install 340CTLV9 but those PLCCs are so damn hard to remove even with a chip puller that I didn't manage to install the SMCTLV8 yet. I don't want to damage the synth so I have to think of a clever solution for swapping out the chip. Does anyone have hints on what to do with hard-to-remove PLCC chips?

In other contexts I definitely noticed that loading samples from KRZ patches could introduce clicks into the waveforms (even visible in the sample editor, and gone when reloading the patch from the disk), so I think updating to the SMCTLV8 might really fix the issue for built-in patches as well.

In other news, crazy as we are, dojoe and me are working on a cheap PRAM extension remake, as the original one goes for way over 100€ on ebay - if you manage to find one at all. No big production run as for the Roland memory cards this time though, I'm afraid. But if it works out, there might be two spare ones to sell, and the schematics will be open-source of course.

[Rasputin]

In the meantime I've received those updated chips - I managed to install 340CTLV9 but those PLCCs are so damn hard to remove even with a chip puller that I didn't manage to install the SMCTLV8 yet. I don't want to damage the synth so I have to think of a clever solution for swapping out the chip. Does anyone have hints on what to do with hard-to-remove PLCC chips?

I too am scared by PLCC removal, chip puller/extractor or not. That style of socket is such a bad design. The most practical solution is to have multiple styles/models of extractor and try them all to see which one finally fits and can actually grab it properly.

Here's a wild thought though... what if you use high strength epoxy to mount a "handle" to the top of the chip and simply pull straight up vertically? I'm thinking something like a dime sized drop of epoxy on the chip with an inverted nail (head side down) stuck into it. Once the epoxy cures, grip the nail with pliers and carefully increase the upward force. Crazier things have been tried before, I'm sure.

Other ideas are to reinforce the socket by putting a nylon zip-tie around it and hot gluing it in place. Then carefully pry the chip out by the corners (paper clip, jeweler screwdriver, wooden toothpicks, etc.) Sometimes (usually?) the stress will crack the socket, hence the need to strength it externally before applying any levering force.

As for your open-source schematics...

[Tekhed66]

In the meantime I've received those updated chips - I managed to install 340CTLV9 but those PLCCs are so damn hard to remove even with a chip puller that I didn't manage to install the SMCTLV8 yet. I don't want to damage the synth so I have to think of a clever solution for swapping out the chip. Does anyone have hints on what to do with hard-to-remove PLCC chips?

In other contexts I definitely noticed that loading samples from KRZ patches could introduce clicks into the waveforms (even visible in the sample editor, and gone when reloading the patch from the disk), so I think updating to the SMCTLV8 might really fix the issue for built-in patches as well.

In other news, crazy as we are, dojoe and me are working on a cheap PRAM extension remake, as the original one goes for way over 100€ on ebay - if you manage to find one at all. No big production run as for the Roland memory cards this time though, I'm afraid. But if it works out, there might be two spare ones to sell, and the schematics will be open-source of course.

Hi Jojo

Sorry to hear about your problematic K2500.... I had a huge job on my hands simply trying to remove the OS chips from my K2000 and they're supposed to come out really easily... They were the original chips and I think they simply fused to the board over time... they eventually came out with an improvised chip puller (knife/nail file/flat head screwdriver) but it took hours of swearing and nail biting.... I hope that you'll have similar success.

On another note - I am definitely very interested in your P/RAM remake... I recently bought a P/RAM board (not the original Kurzweil board... it was made by someone else... am I allowed to say who on this forum??) ... anyway, to cut a long story short, I installed the board and the synth completely cr*pped itself ... it was a total meltdown... some of the things that happened:

Boot-up loop (startup... works for a while - sometimes seconds and sometimes minutes... shuts down...reboots.. repeat)
Shutdown on program change (assuming it would stay on long enough to change programs)
Blown fuses on startup (flicking the switch ON)
Hangs on startup (if it didn't loop, it would 'white out' the LCD screen and just hang)

I took it to a tech and paid good money for him to say the synth was too old for him to worry about and that he personally hates Kurzweil synths.... The synth wouldn't read the board at first but when the tech switched it on, it powered up and seemed to read the PRAM board OK... He left the synth switched on for hours but didn't access any of the commands... it just sat there and it seemed to behave (he didnt do anything to the synth but he did check my soldering though and said all was fine - big deal!) so I collected it, took it home, switched it on and tried to use it and all of the problems were still there ... In the end I snipped out the board... the synth returned to normal and I'm back to square one.

Soooooooo... yes I'm interested in your board if/when it happens... if you need a K2000 mule to see if your board works, I'll put my hand up

OK - enough of my rant.... good luck with your K2500.... let us know how you went.

tekhed

[ʝɵʝɵ]

Thank you both for your inputs on removing the chips.

Tekhed66, I'm afraid the K2000 PRAM option is physically very different from the K2500's PRAM2 option. It certainly looks a lot more complicated, which could explain the issues you were having with the possibly faulty remake. The K2500's PRAM is really not much more than some SRAM chips and a PAL, so hopefully there is little that can go wrong for us. Incidentally, I just found this (also for the K2500), which is much more hack-ish in nature than our design: http://kurzlist.yahoogroups.narkive.com ... sion-us-20
I should also mention that our design will probably not work with a KDFX board installed, due to the differently-sized SRAM chips - If the KDFX board overlaps the area where the PRAM would be located, it would no longer be able to sit on top of the daughter board, unless you use a right-angled connector for the PRAM board. It might be a tight fight, though.

[Tekhed66]

Thank you both for your inputs on removing the chips.

Tekhed66, I'm afraid the K2000 PRAM option is physically very different from the K2500's PRAM2 option.

Ahhhh ... yes I remember reading about that when I ordered my PRAM board ... mine was definitely for the K2000 so there may be a fault in the board itself ... oh well

Anyway - good luck with your sticky chips ... I've found that a simple 5 minute job usually ends up taking several hours when it comes to servicing my old synths... nothing ever goes smoothly and it always ends with me promising/screaming 'no more vintage synths... next time I'm buying something NEW!!!' .... to give you an idea just how well this works, just have a look at my equipment list

And to ask you a question you're probably sick of hearing - how are the multibank memory cards coming along????? (sorry - just had to ask )

all the best
t66

[ʝɵʝɵ]

And to ask you a question you're probably sick of hearing - how are the multibank memory cards coming along????? (sorry - just had to ask )

It won't take much longer, but I cannot give you an exact estimation when they will be available.

[ʝɵʝɵ]

Still haven't gotten around replacing that darn PLCC, but 64MB of SIMMs just arrived (found an amazing deal on Amazon - half the price of those crazy ebay sellers) and the custom PRAM expansion is working as well!

Memory-wise, I'm all settled now.

[ʝɵʝɵ]

Update to the click issue: The noise bursts seem to be caused by the LP2RES filter, and in particular by increasing the filter cutoff by large amounts (decreasing is fine) as done by FUN4 in patch 891. According to Jean from Kurzweil support, the clicks are not a known issue.