VOGONS


Reply 40 of 50, by Spikey

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InTheStudy wrote on 2024-03-23, 11:06:
That's really, really sweet of you - but I wouldn't be able to accept a $300AU gift from someone even IF I thought it was fair f […]
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Spikey wrote on 2024-03-23, 10:41:

Good luck for sure on all counts. I do have a SC-D70 that I'm unlikely to use again, one of the switching ones, and I can send it to you, if yours is dead.

That's really, really sweet of you - but I wouldn't be able to accept a $300AU gift from someone even IF I thought it was fair for you to "make good", which I don't. We're cool as a Cactuar, Spikey. 😀

I'm optimistic, so let's just see how it goes with the tech next week. In the meantime, I'm gonna take a look at printing a couple of half-rack cases, for the MT-D47 and the World's Worst Recording Studio. 😀

optimism-captain-v0-d2uz8s4dq2x81.jpg?width=640&crop=smart&auto=webp&s=908261bcede7b6b3c1feb60474fefcb727f0c0c2

Optimism, Captain!

Study, are you in AU?

Reply 42 of 50, by Spikey

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Hah, thought I'd ask since you mentioned my currency. Well, let me know if you need the D70, anyway.

Reply 43 of 50, by momaka

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Just some info to pass down to your tech friend: if the fuse is blown and this is a SMPS (switch mode power supply), chances are the MOSFET and its source resistor are dead too. PWM controller also gets damaged sometimes... if there is one in this SMPS (some designs use oldschool 2-transistor self-oscillating circuit.) That being said, if the SMPS has a "standard" voltage output (i.e. 3.3V, 5V, 12V, 24V, etc.), it might be just cheaper to replace the SMPS module with another one that outputs the same voltage and call it a day. Also, in the case of SMPSes, a blowout on the primary rarely causes damage to the secondary, so the rest of the unit should be fine... though I certainly hope I'm not jinxing it by saying this. 🙁

What's indeed puzzling is why the PSU blew after 2 minutes and not instantly. If the SMPS has a 400V (DC) input cap, then it really should be a "full range" 100-240V AC input -capable. Stuff that's built strictly for 110/120V AC for the USA (and Japan) typically carry 200V (DC) -rated input caps only, as they are much smaller and cheaper, and it makes a lot of sense from a manufacturing standpoint to save on costs with a simple part swap right there. So it looks as if it was built as a universal / full-range SMPS, but then wasn't? Again, really puzzling why the PSU manufacturer would do this.

Relating to this... I recently moved from the USA to Europe and brought a few electronics with me. One of them was a surround sound system rated for 120V AC input only and accordingly has only a 200V DC -rated input cap. Being an SMPS, I swapped it with a 400V cap as a cheap attempt at converting it to European voltage system. However, through careful testing, I have found that this is a no-go in the long term, since the US version of the SMPS also lacks some other components in the snubber circuit, making the main switching MOSFET dissipate 2x more power (i.e. 2x more heat). If left this way, it seems like it could certainly overheat and blow. Mine can run for 5-10 minutes, but gets very hot afterwards, so certainly I have to do a bit more work to make it a proper 230/240V AC conversion. But at least I could observe the PSU was built for 120V AC only. In the case of the Rolland SMPS, we still can't get a clear picture if that was the case or not. Thus I also think the possibility of the PSU blowing due to something else is not out of the question quite yet.

Anyways, hopefully we get an answer to this and hopefully your unit will work again with an inexpensive repair.

Reply 44 of 50, by InTheStudy

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Thanks Momaka, I self-evidently have no idea what I'm doing - but my technician does so I'm trying not to get TOO preachy at him.

The latest news is predictably double plus unpositive, once the fuse was replaced; Popcorn was connected to the mains through the step-down transformer and apparently, the line filter coil immediately started smoking. So, investigations continue and your suggestion may very well be on the money. I did find reference to the pinout of a SMPS module used in other synths like the SD-80 which is *apparently* very similar. If that's the case, then (again, assuming no bad voltages made it to the analog or digital boards, in which case I'm just screwed) it should be possible to build a complete replacement - possibly even moving the mains stage out of the unit entirely, which would be nice. But for now; in the words of a great Scottish poet - we wait, with baited breath.

As for Mew, tech doesn't have a 2032 coin cell holder that will fit; so he's going completely overkill and ordering a 2477 holder - which should keep the thing powered till the heat death of the universe.

Reply 45 of 50, by InTheStudy

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Marginal update - still waiting (not Tech's day job!). Tech has indeed found a dead Mosfet; he's replacing it with a much more modern equivalent, and he's found a modern equivalent coil to go on there as well. Still hopeful but not optimistic.

Also waiting on Mew still - the SD-20 is fun in the meantime (and sounds great on FF7's XG Midi files) but it's not quite the sound I was after; so the hold continues while parts are sourced.

Reply 46 of 50, by Spikey

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Yeah, the SD-20 is up there with most disappointing synths I've ever owned, the XV-5050 is the notable other.

Still need to boot up and check out the SD-80 which I got during the pandemic but never tried.

But yeah, keep us in the loop, I'll send you my SC-D70 which gathers dust these days if you need it.

Reply 47 of 50, by InTheStudy

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Spikey wrote on 2024-06-28, 14:12:

Yeah, the SD-20 is up there with most disappointing synths I've ever owned, the XV-5050 is the notable other.

Please don't misunderstand - I actually like the sound of it! It's just more modern than I was going for. The MU is a much better fit for what I was trying to get.

Still need to boot up and check out the SD-80 which I got during the pandemic but never tried.

Well hopefully they don't sound too alike! From what I understood, the biggest difference is the SD-20 is much more limited. computationally.

And again, thank you on the SC-D70 offer. Hopefully it won't come to that!

Reply 48 of 50, by InTheStudy

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Hey, remember THIS thread?

The attachment 200eac2a-9bab-4cb8-95c2-12450a779527~1.jpg is no longer available

Also, remember THIS synth?

After two literal years at the repair shop (it's his side hobby), look at all the blinkenlights! Tested on my Windows machine with Midiplay, and tested on my Linux machine with YouTube because Windows 10 does not like the Vista driver any more for anything other than MIDI. It's fine, considering my actual recording PC is linux-based. (Also ARM-based. I'm so modern!)

It's not a perfect repair - specifically, the new PSU doesn't work with the off-switch; so it's now always-on while connected to the mains, but that doesn't bug me. I'll probably end up sorting out a switched distribution panel now I have all my hardware back. I'll probably also look at finishing the Pi-MT32 too. Or just give up and buy a D110. With this I have an SD (20), an SC (D-70) and an MU (50). If I can pick up something MT-based, I'll have the complete suite of roland sounds plus the bonus Yamaha for that FF7 PC goodness. And now I can hook up the rack of keyboards and finally make some blasted music with all of this.

Goal was all for some lower-fi 80's and 90's sounding backing stuff to go on guitar tracks; with any retrogaming as a bonus. I'm really excited to FINALLY do something with this.

Reply 49 of 50, by Spikey

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Very cool! Please be aware the D-110 won't work as a MT-32 for gaming, but will be fine and excellent for music and backing stuff etc.

I'm glad to hear things worked out. I'd also recommend a SC-55 for authentic sounds for that era, but the SC-55 map in the D70 will be good enough for gaming. The native 8820 map will be great, too. What keys you got?

Reply 50 of 50, by InTheStudy

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I also appreciate all your patience with my heartbreak when this first blew up. You were unimpeachably kind, as was everyone else with one exception and frankly I take responsibility for pissing that person off in the first place. I think it would have been entirely reasonable to have me yeeted from the forum by the start of page two. It was my fault for not sticking to my guns and saying 'no, I will only do this properly.' The "ruined my week" comment was an honest expression of my feelings, but it was also completely uncalled for. I made the call to test it and the responsibility for the fallout rests solely with me. 😀 Which I do note in advance of a bill arriving for the repair... 😁

And yes, I'm aware that the MT32 and D110 have different layouts and some other changes - though to quote a helpful person named Spikey:

> Hopefully you know, but if not - the first Sierra MIDI games, from KQ4 (1988) to KQ5 (1990), can all be played with the D-110.

So there's something I can use if I really want to test it. Thanks for the heads up. RIP the MT-D32 project! The reason to get a D110 is pretty obviously for reasons of copyright. Speaking machiavellially, I could functionally get an entirely comparable musical performance by using Pi-MT32 and doing crime. However unless I also owned a working MT32 (and at that point why would I use Munt for this) I'd be unambiguously pirating my music. Since a working MT32 is currently... *checks* £300+, it makes a lot more sense to spend £80 on a D110, do music on that and leave the working MT32's for the gaming purists that really need them. 😉 And speaking of; honestly, for me the retro-games I'm thinking of are mostly the 2.5D Final Fantasy games. Since I have a MU-50, I'm entirely covered for the sensible way to play them; and the SC-55 maps of EITHER the SD-20 or SC-D70 will be enough for spontaneous other 90's gaming as you say. It would be cool to play Monkey Island with original music too, but... hey, that's what the software emulation is for.

Although this video of the SoMI intro played through a D110 without remapping is pretty hilarious: https://www.youtube.com/watch?v=eye0sGzTc-4

As for the SC-55? It's a good recommendation, but honestly I also think the SC-D70 is close enough for the music side of things as well. I'm not trying to exactly replicate, just get a solid vibe; with the smugness bonus of being able to say I used real hardware. (Also because 4 Cortex-A75 cores are not enough to run multiple DAW's, an amp simulator AND modern midi-engines, SOMETHING had to be moved off-chip). Same story as with the D-110. It'll get me close to video-game-sound without piracy or bankruptcy. 😉 The round playmap is that I have four modules each representing an era - the D110 to represent the late-80's, MU-50 early 90's, SC-D70 for late 90's (Since it's an upsres SC-8820) and SD-20 for early 2000's. It's comprehensive enough for what I want, and I'll never use 99.99% of what I have before adding even more modules!

For controllers, I have a Studiologic VMK-161+, an Arturia The Laboratory and an Akai MPD32. The VMK for the weighted keys, the Lab for the large number of control surface and the MPD for it's pads. I'm sure there's one of those Ableton midi matrix things (one of the early 3-colour ones) around here somewhere too, but I haven't seen it recently. Not surprising as losing the SC-D at the same time as having to send the MU for battery replacement completely killed my mojo for that project. Still, I endured and I'm still here and I can start again!

...in a couple of weeks. I figure at this point I might as well wait a fortnight for Ubuntu Studio 26.04, get that installed on my DAW Pi and start fresh on something stable that has the NUMA patches already installed. There's enough to keep me busy in rewiring the studio for the new kit in the meantime, not to mention thinking up guitar parts and lyrics and such. I'm also considering how to do the audio loops. I'm probably going to end up just using a pile of Alphas for the audio interfacing. They're basically worthless now so are stupid cheap, support 24/48 recording (unlike the Roland AC, which might end up as a dedicated effects processor) and kind of look the part next to the SD-20 to boot. 😉 I'd have just gone 44.1kHz standard to avoid resampling the SD, but I won't drop to 16bps and that's the max that the UA supports. Which means my missing hardware right now is pretty minimal. A £25 Alpha for the MU, a £20 S/PDIF Capture for the SD, and an optional D110 and matching Alpha and USB Midi Cable when I get round to that.

Wait actually scrap that. I also need a USB MTT hub. Pretty sure if I try and run multiple 11Mbps audio interfaces on a STT hub I'm going to face pain and suffering like I would not believe. So, £25 Alpha, £20 S/PDIF, £25 MTT hub. Not terrible. Edit: Counted my USB devices. That escalated quickly. Make that two hubs.

Edit2: Noting the logic before I lose the envelope I worked this out on.

SD (Midi)
MPD (Midi)
VMK (Midi)
LAB (MIdi)
AC (Aud)
α Inst (Aud)
S/PDIF (Aud)

MU/GI (Midi)
D110 (Midi)
Keyb ("Midi")
Mouse ("Midi")
SC (Midi+Aud)
α MU (Aud)
α D110 (Aud)

Puts 4 low-bandwidth and 3 high-bandwidth devices on each of two MTT hubs. Which shouldn't matter since each hub should be able to saturate 42 separate USB1 devices, but still. Probably worth trying to balance them.