So indeed, that is an expansion port 😀 .

But before we get to that I should mention one bad bit about this synth. Despite Roland's claims, it is pretty much useless as a master keyboard because it cannot send program change messages for changing patches other than those generated by the button matrix on the synth itself. That's right, you can't send specific MSB, LSB, and program numbers from the synth 😠 . The manual skirts around this by not actually expanding on MIDI control and only talking about controlling the JV-35/50 itself via MIDI. So it's more like a sound module with a keyboard tacked on, where the keyboard is only present for playing the sound module part directly. I will have to check whether controlling another Sound Canvas (that isn't a SC-55 Mk. II) is still possible, but anything not-Roland looks like it's absolutely out of the question because of this dumb implementation issue.

Back to the expansion port. Of course, the port is to be expected, as it says so on the front of the synthesizer: "Expandable synthesizer". 😉

So what goes there?

Roland manufactured two expansion boards that are exclusive to the JV-35/50/90/1000: the VE-1GS and the VE-1JV. It's useful at this point to mention that the JV-35 and 50 are GM/GS synthesizers, while the JV-90/1000 are actually part of Roland's real JV synthesizer range.

Each of the expansion boards is actually a synthesizer on a board:

• the VE-GS1 contains the whole VJ-35/50 synth engine and patch set.
• the VE-JV1 contains the JV-90/1000 synth engine and the complete patch sets for the JV-80 and JV-1000 synthesizers as well as the PN-JV80-04 Contemporary Composer expansion card patches (for a then massive 512 patches total).

So adding one of these cards to your JV-35/50/90/1000 actually adds the basics of a whole new synthesizer to your existing synthesizer. What it does not do, is what Roland claims it does, namely expanding the number of voices to 56 voices by doubling the polyphony. Instead, it makes the polyphony 28 + 28 (28 voices per synth engine).
When using the expansion board with the same synth engine as the one already in the synth, it's possible to obtain extra fat sound by playing the voices in unison via a loop-back MIDI cable.

But, well, that's not really what interested me. OTOH, using an expansion board that let me experience some of the richness of the professional JV range did.

Enter this little box:

Contents:

I find it highly amusing that Roland pads the contents of the box with an exclusive screw driver with a bog standard philips head and a bog standard flat head:

This makes it pretty cool 😎 :

Quite nifty, actually. At least I can now claim I own a Roland screwdriver, even if they didn't go as far as including their logo on the plastic. 🤣

The board itself together with the installation tool that's also included:

Really not much to see.

(slightly delayed continuation due to having way too much fun with the expansion board patches... 😁 )

Thar she goes into the synth, that little expansion board:

The VE-JV1 board offers 512 patches + its own effect block (chorus + reverb) + 8 drum sets, all editable from the front of the synth together with a rather limited subset of the editable parameters of the board. All available parameters of the JV90/1000-engine on board can be edited via MIDI sysex though...
A review I found online about this expansion board mentioned it was not possible to save edited patches when using the expansion board on the JV-90/1000. Fortunately, it is actually possible to do so on the JV-35/50, but only for the parameters that can be directly accessed via the front panel. This has the same memory limitation as for the standard JV-35/50 patches, except that it's slightly worse due to having 512 patches in four banks while there are only two banks to save patches to.

The patches vary in quality, with some being rather mediocre (and one patch panned entirely to one side for some reason). The standard synth pads and strings are all quite good. There also are quite a few excellent evolving pads, especially in banks three and four, and many seem perfectly suited for moody and/or cinematic music, possibly with a pinch of scifi.
The overall patch quality is miles above that of the standard JV-35/50 GM patches, with much less artifacting and generally having fuller sound.

What you also get with this expansion board is the JV-80/90/1000 filter. In my first post I raved about the GM patches devolving into aliasing at times, but after experiencing this expansion board they seem outright boring. Its low-pass filter brings out massive aliasing and digital noise at high settings, sounding positively dirty and rough. Although I suspect some people will think it's just sounding broken... 🤣

Just wanted to quickly reply and say thanks for posting. Being somewhat knowledgeable about Roland's different PCM synths, this was really interesting 😀 I am curious if the SC-55mkII patches sound the same, and curious how they sound with different reverb/chorus also.

yawetaG wrote:

• Dual allows the stacking of two voices, with the choice of patch for each of the two voices completely free. Therefore it is possible to stack two drum sets or two regular patches or a regular patch and a drum set.

This can be exploited to layer up to 32 patches into a single sound played from the keyboard, despite the JV-35 only supporting 16 MIDI channels and performance mode being limited to 16 patches!

Now the maximum polyphony is 28 for the JV-35 itself and 28 for the expansion card, so if using only one of the two the maximum is actually 28 patches. However, when you assign one dual voice to the JV-35 itself and the other to the expansion card, 32 is possible.

How it works:

Dual mode sets up two patches to be played together. Each set of two patches are assigned to their own part - by which I mean the upper patch is assigned to 1 part of 16, and the lower patch is also assigned to 1 part of 16, and the two part ranges are independent of each other. So that gives us 2 x 16 patches = 32 patches total.
To make them sound at the same time, all of the patches for the upper patch setting must be set to the same MIDI channel, and all of the patches for the lower patch setting must be set to the same MIDI channel.
Now effects are set per part. So each part (2 x 16 parts) can have its own effect settings, which then apply together to the whole layered set of patches.

However, the really cool thing is that as long as you don't change to another patch for a given part, in dual mode the keyboard will remember what changes you made to the patch (despite never explicitly saving the patch) and reapply those settings on next power up - hello undocumented feature!

yawetaG wrote:

But before we get to that I should mention one bad bit about this synth. Despite Roland's claims, it is pretty much useless as a master keyboard because it cannot send program change messages for changing patches other than those generated by the button matrix on the synth itself. That's right, you can't send specific MSB, LSB, and program numbers from the synth 😠 . The manual skirts around this by not actually expanding on MIDI control and only talking about controlling the JV-35/50 itself via MIDI. So it's more like a sound module with a keyboard tacked on, where the keyboard is only present for playing the sound module part directly. I will have to check whether controlling another Sound Canvas (that isn't a SC-55 Mk. II) is still possible, but anything not-Roland looks like it's absolutely out of the question because of this dumb implementation issue.

I'm currently testing with my SC-88VL and the JV35 being a wonky MIDI master keyboard is pretty much confirmed. The currently selected part indicates the MIDI channel on which data is sent. Program change works as described, with the additional caveat that when you change part the currently active patch setting is automatically sent out (with no option to disable that behaviour 😵 ). This means that to be able to use this keyboard as master keyboard you have to add a MIDI message filter in between the JV35 and the controlled synth to avoid accidentally changing the patch you're on. Of course, only SC-55 patches can be selected from the JV-35. The behaviour of the variation button is a bit strange, in that it does not cycle through the variations on the SC-88VL, but only through the patches that are variations on the JV35 (some of which are not variations on the SC-88VL, but separate patches).
The dual and split keyboard modes work, as do the +1 and +2 octaves modes, transpose, and solo/portamento.

Unfortunately I haven't been able to get the SC-88VL to react to the effect and patch editing buttons. Some further testing with my Yamaha TG-300 seems to confirm that these buttons only affect the JV35's internal sound. In the case of the effect buttons, this might be because the JV35 basically has presets for the effects, while on the modules these presets are absent.

Another thing I noticed is that the JV35 has a much fuller sound than the SC-88VL (on the headphone out). The SC-88VL sounds bland.

Edit: Gah, there's another way to select patches and control external devices from the JV35, except that Roland 'helpfully' spread the information over multiple paragraphs with non-indicative titles...will come back on that later.

yawetaG wrote:

Edit: Gah, there's another way to select patches and control external devices from the JV35, except that Roland 'helpfully' spread the information over multiple paragraphs with non-indicative titles...will come back on that later.

So it has a MIDI Master controller mode, that allows control over MIDI Continuous Controllers 0-9, 12-31, and 64-95 via an assignable slider (that can be modified live and therefore can be used to change multiple settings in a row - not documented), and also 10 and 11 except that those two each have their own slider. Unfortunately, it cannot send MIDI CC 32 except via the stupid implementation I already mentioned that inconveniently resets the part's settings too. The workaround of using NRPN numbers also cannot work because the JV35 also cannot use the associated CC numbers...

Using the MIDI Master controller mode also temporarily disables the functionality of the Oct 1, Oct 2, Dual, and split keyboard buttons (that is, until you quit MIDI Master controller mode).

I've tested whether using CC 0 together with the patch selection matrix was possible, and it isn't. Using the buttons that select the banks appears to send a combination of MSB and LSB, while CC 0 sets the MSB - there's no way to set LSB separately. The patch selection matrix ought to send the Program Change value.
The manual states that setting a specific option lets one send User Patch information (basically the Tone selection + custom settings) for custom patches that were previously saved. It also states that the JV35 should send NPRN data if the option is disabled, but this does not appear to happen when manipulating the parameters that should send that data (or my SC-88VL doesn't react to it).
What mystifies me is that it is possible to send CC 0, 6, and 38 values, but not custom values for the Continuous Controllers (32, 98, 99, 101, 102) that are supposed to precede those Continuous Controllers. Yet at the same time the MIDI specification indicates the JV35 can transmit those non-user-accessible Continuous Controllers... 😕
I guess that means either (i) there is an undocumented and hard to find way to use those CCs, or (ii) it is a left-over of a feature that was not implemented.

Since it is possible to disable the logical connection between the internal sound module(s) and the keyboard section, I also tried whether it was possible to access the various parameters using a MIDI loopback cable from MIDI OUT to MIDI IN port. It is, but the parameters do not react in the same manner to the values I set. This implies that directly editing a patch from the keyboard sets certain parameters to certain values in the background, parameters that are not directly user-editable and that need to be separately set when using the MIDI IN port.

Interesting bits of information from the Service Notes:
- the JV35/50 has a battery.
- it should be possible to convert a JV35 to a JV50 by adding the JV50 bits, as all the other parts are common.
- the expansion module and the internal sound generator have their own separate DACs.

As an aside, it turns out that Roland's MIDI spec for the SC-88VL is incomplete, as mine reacts to CC numbers not mentioned in the manual (e.g. CC 74).

So despite Roland claiming the opposite, using the MIDI controller feature with an external module without first disconnecting the internal sound generator and the keyboard does change (some) settings for the internal generator (that also get saved). Otherwise I cannot comprehend how changing the panning via the MIDI controller mode also changed the panning for the internal generator...

Also, I will have to check out what filter is used by the JV-35 for its internal sounds and the expansion board (they share the filter). It clearly is different from my SC-88VL's filter (and I presume the SC-55). The headphones out is also much better on the JV-35.

JV35/50 DAC = JV1080 & SC-88VL DAC (UPD63200GS-E2).
Custom Sound Generator chip = SC-55Mk. II (TC6116AF (GP4)), but for some reason it also uses a separate gate array.
CPU = SC-88 CPU (H8/510)
One of its op-amps is the same as one of the op-amps in the SC-88VL, the other two are different (one is for the headphones).

So it's not really a SC-55Mk.II in keyboard form, rather more a SC-88VL in keyboard form with the SC-55 Mk. II PCM ROM. And since the expansion board has the JV-90/1000 synth engine on it, but DAC and op-amps are shared with the JV-35/50 itself, the sound from the expansion board will also be different compared to the full-sized JV-90/1000 because those use other ICs.