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electrospeaker
Joined: Jun 30, 2006 Posts: 49 Location: Norway
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Posted: Sat Mar 15, 2014 7:25 pm Post subject:
"Ensemble" effect circuit similar to Roland VP-330 vocoder? |
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I'm in the process of building a rack-vocoder, and having previously owned a Roland VP-330 vocoder I really want to incorporate that "ensemble" (chorus) effect as IMHO it made half the vocoder sound.
It should be small enough to fit inside the vocoder's 19" rack enclosure and I can do fine with just a few preset settings (as opposed to multiple adjusting potmeters which there won't be any room for anyway).
As I'm not an engineer but more of a practical hobbyist I can't design it myself, so it should be a circuit board I can order, a functioning circuit layout Eagle etc. file (which I can make a PCB from), a kit or even a ready made board.
The best solution would be a clone of the VP-330 ensemble section but I haven't found that yet. I did however find the Oakley stereo ensemble project which seems very cool, but too big and with too many knobs for my use.
I read somewhere that the Roland RS-505 Paraphonic keyboard uses the same ensemble section as the VP-330 which in turn is based on the Roland Dimension D chorus effect unit (there's a Dimension-D clone available from TB-audio gear but it's a bit on the pricey side and I can probably do with a simpler unit.
I've also read comments about how the Boss Dimension-C pedal (Boss DC-2) and Boss DC-3 works wonders. Behringer's CC300 pedal has also been suggested -possibly a clone of one of the Boss pedals.
I don't have any experience with any of the above so any suggestions are very welcome. |
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StephenGiles
Joined: Apr 17, 2006 Posts: 507 Location: England
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Posted: Sun Mar 16, 2014 5:48 am Post subject:
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The sample on the Oakely site is brilliant, using chords to demo the chorus sounds - unlike those on Youtube for the Buchla 297 Infinite Phaser which use sequenced staccato sounds and demo nothing at all!! |
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Wed Mar 19, 2014 6:11 am Post subject:
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You could get a second hand Boss SE70… The "Wave Chorus" algorithm is the one you want as it gives a perfect 3 phase chorus effect, just like the VP and other stringers.
The annoying thing is, that I recently completed JH's Triple Chorus not realising that I had access to the same rich ensemble effect in the SE70 that's been languishing at the back of my cupboard for the past 10 years |
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electrospeaker
Joined: Jun 30, 2006 Posts: 49 Location: Norway
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Posted: Thu Apr 03, 2014 4:38 am Post subject:
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So your digital SE-70 chorus setting sounds similar to the analog Jürgen Haible Triple chorus?
I've located both the Roland VP-330 vocoder and RS-505 Paraphonic service manuals online which contain the schematics, but as I'm not competent enough to design my own stuff from that I was hoping someone else had beat me to it. I just heard an RS-505 demo on Youtube and its ensemble sounds more powerful (and versatile with its 3 settings) than the VP-330, but I guess either (or other similar ones) will make a huge difference in the vocoder anyway. |
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Broadwave
Joined: Feb 16, 2007 Posts: 347 Location: Manchester UK
Audio files: 6
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Posted: Thu Apr 03, 2014 9:50 am Post subject:
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I've just taken a look at the VP & RS schematics - The VP ensemble FX has two delay modulation circuits, one fast and one slow, quite basic from what I can see.
The RS on the other hand has 4 delays (one more stage than most ensemble effects), which would account for the richer effect.
The SE-70 is a Boss/Roland unit, and now that I know about it, I'm not surprised they incorporated that particular chorus algorithm - it's very nice, as you can use 2 or 3 mod LFO's. I just wish I'd stumbled across it sooner. |
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electrospeaker
Joined: Jun 30, 2006 Posts: 49 Location: Norway
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Posted: Mon Sep 29, 2014 1:15 am Post subject:
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Trying to revive the thread..
As you're saying the VP-330 and RS-505 schematics seem quite basic, do you have any suggestions as to how I could duplicate one of them as a stand-alone board without first taking an engineer's degree?
From what you're saying it seems the RS-505 would be the better one to go for, but as I have no experience with it but was perfectly happy with the VP-330 this would probably suffice as an effect for the vocoder if it would be easier to make. |
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Oakleysound
Joined: Sep 16, 2010 Posts: 10 Location: Cumbria, UK
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Posted: Mon Sep 29, 2014 5:22 am Post subject:
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The RS-505, RS-09 and VP-330 all use four delay lines and all connected in a very similar way. They have two BBDs per stereo side each with their own modulating LFOs. The VP-330, also has a real time vibrato section too as well as a VCA based noise reduction, which the other do not.
I'd check out the later RS-09 circuit if you are going to clone any of them. Early versions of both the RS-09 and VP-330 both contain hard to get BBD devices. In all cases the circuitry is not trivial.
You may want to try out the Behringer CC300. It not the same as the four stage ensemble, being a clone of the Dimension C pedal, but it does make a nice ensemble sound.
Tony _________________ Oakley Sound Modular Synthesisers
My Music |
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electrospeaker
Joined: Jun 30, 2006 Posts: 49 Location: Norway
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Posted: Mon Sep 29, 2014 7:37 am Post subject:
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Why do you recommend the RS-09 ensemble over the VP-330? Noise reduction certainly sounds useful to me.
Here's the ensemble circuitry of the VP-330 with its surrounding components:
... and a closer look at just the ensemble section:
.. and finally a block diagram of the VP-330's modulation board:
Having found the above I was hoping for a circuit with a simple input and two outputs (stereo) but apparently, to a non-engineer hobbyist as myself it's a lot more complex. As someone who obviously has a lot more knowledge in this field than myself, saying that the circuitry is not trivial: is it not just a matter of following the schematics and "tapping into" the input and outputs, and eliminating all the other (non-ensemble) components of the VP-330?
I do have two Panasonic MN-3004 ICs if those were the BBDs you're referring to. I suppose the other components are pretty standard and easy to get hold of.
As for the Behringer CC300: as pointed out elsewhere it doesn't do well with line-level signals, being a guitar-pedal, and lowering the signal only to amplify it again after the ensemble stage has me worried that I'd end up with significant added noise. |
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Oakleysound
Joined: Sep 16, 2010 Posts: 10 Location: Cumbria, UK
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Posted: Mon Sep 29, 2014 9:58 am Post subject:
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electrospeaker wrote: | Why do you recommend the RS-09 ensemble over the VP-330? Noise reduction certainly sounds useful to me. |
Yes, it is useful but the noise reduction on the VP-330 is particularly tailored to the sounds it makes. It's not as good as could be for general music program material.
The noise reduction parts are not shown on those schematics in full - only the expander section based around the BA662 on the far right. You'll need to look further left on the full schematic to see the compression part of the NR - also based around another BA662 VCA.
Remember only one channel is shown there, you'll need to build another identical one for the other side of the stereo pair.
Quote: | Having found the above I was hoping for a circuit with a simple input and two outputs (stereo) but apparently, to a non-engineer hobbyist as myself it's a lot more complex. |
The VP-330 is particularly complex and the way the schematic is drawn doesn't help. That's why I suggested the later RS-09 - it's a better drawn diagram and it's simpler too.
Quote: | I do have two Panasonic MN-3004 ICs if those were the BBDs you're referring to. I suppose the other components are pretty standard and easy to get hold of. |
That's the later one. The earlier ones used the rare SAD512D in the ensemble. And you will need four MN3004s not just two.
Tony _________________ Oakley Sound Modular Synthesisers
My Music |
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electrospeaker
Joined: Jun 30, 2006 Posts: 49 Location: Norway
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Posted: Thu Oct 02, 2014 4:24 am Post subject:
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Too bad about the noise reduction, but if it's not suited for general music material it's really of no use in this case.
I had a look at the RS-09 schematics and they use the SAD512 BBD chips which you say are hard to find, so that pretty much rules it out as well. Since I already have two MN-3004 chips, is there anything useful I can use them for?
What other options do I have for line-level signals if I want a not too complex VP330-like ensemble effect to be mounted inside the vocoder? |
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