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Crumar Mojo 61 Review - (LONG)


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I don't think a UPS or caps or something will solve your problem: first of all, and first thing to look at, are your accessories, I'm thinking about volume pedals "in primis". What are you using? if the variable resistor inside this pedal is not compatible or the brush is not in perfect shape, the problem you experience is possible.

I would like to suggest you to check this.

The external power supply of your mojo61 doesn't need additional precautions in 99% of cases.

 

Please, let me know, better and faster using the support section in our web pages :-)

www.crumar.it

info@crumar.it

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Thanks for replying , I just got mine few days ago . I can only say I love it and I hope it works without major glitches. I have an Fc 7 which works fine now but should I get a replacement?

I bought a DMC with gemini btw if that makes any difference

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I'm thinking about volume pedals "in primis". What are you using? if the variable resistor inside this pedal is not compatible or the brush is not in perfect shape, the problem you experience is possible.

I would like to suggest you to check this.

I would say that if the Mojo freeze due to a FC7 expression pedal in a wornout condition you should not blame the pedal.

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The external supply is a switcher, so it should respond to voltage variations but perhaps not quickly enough. I'm wondering if a big fat electrolytic cap would do the trick.

 

That's a good point. Switching PSUs have the advantage to accept a wide range of input voltage, have a stable DC output and a low cost. Even though we use mostly MeanWell PSUs, that aren't cheap at all (and whoever is into electronics can confirm this), still they're not perfect.

 

Should we use a linear PSU? Really? Something with a 5 pound transformer for a 2 Ampere output?

Should we build our own PSU? Really? Do we have more expertise in PSU electronics than MeanWell?

 

We just do the right thing, we use high quality external power supplies made by a well known leader in this field. And we always use standard ratings, and standard hookups, the Mojo61 runs on 9V 2A, and uses a standard 2.1 DC socket, so a faulty PSU can be replaced with a new one or equivalent at any time, even with a Wallmart spare.

 

Unfortunately, a switching PSU isn't fast enough to compensate for drastic voltage drops, and some of the internal CPUs (yes, there's more than just one!) may brown out before the voltage stabilizes again. I have a Mojo61 next to me in my office that is on almost 20 hours a day since the first days of 2016 and it has never frozen, because the power in my home is stable. But I've been a gigging musician for quite some time before I started making instruments myself, and had similar experiences with my keyboards that occasionally froze during a gig and most of the times it was because something was turned on that caused a voltage drop, something like big aircons or fridges in the bar or light equipments on the stage. The only thing that never froze was the PC because it ran on battery as soon as power went off.

 

 

As a side note... a new firmware update for the Mojo61 will be released during this week.

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I would say that if the Mojo freeze due to a FC7 expression pedal in a wornout condition you should not blame the pedal.

 

Oh right. If you put kerosene in a car tank you should not blame the fuel.

Biting is seldom a good support strategy. I have only experienced a single freeze on my Mojo61, lets hope that not was caused by the rewired MJ-EXP2.

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On the original Mojo, the recommendation for the expression pedal was their own branded Crumar long throw, with a potentiometer rating of 10K. The FC7 has a pot rating of 50 K.

 

Assuming that the Mojo 61 and the DMC are the same as the original, it makes sense to me to use the pedal that the manufacturer says that you should use.

 

Just a thought.

Occasionally, do something nice for a total stranger. They'll wonder what the hell is going on!
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Agree completely, this is common sense. As it is to design the expression pedal input circuit and system sw to handle the markets most common expression pedal and handle when «the brush is not in perfect shape» without freezing. My humble suggestion was to try to isolate from this instead of blaming the real world happenings :cofee:
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I have 2 FC 7 that came with a KX88 I bought used , 1 rewired to be used with a nord ekectro . Used that combi for probably 10 years now . The pedal was really mistreated on some gigs and there have been countless open air festivals with " suboptimal " power conditions . Never any problem . The other pedal which is not rewired seems to work now just fine with the DMC but I know what to look for now . Which other pedals are compatible ? ( No info in the manual)
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It's not the 10K vs 50K pot value. The problem resides in how the pot is scanned inside the pedal along its 270 degree rotation. The Crumar pedal (that is actually made by Fatar) scans almost the whole range, leaving only a 10% at the edges that is compensated by the software; the Yamaha FC-7 is one of the very few pedals that is able to scan the whole range or most of it. Other pedals scan only a small part of the range, and since there are dozens of them, we can't support them all so we only support our Crumar branded pedal officially, and a few others non officially, one of which is the FC-7.

 

On the other hand, the FC-7 tends to wear out pretty rapidly, it's a great pedal with great ergonomy but I myself had to buy 3 of them in the past 7 or 8 years. A cheaper option is the Behringer FCV-100 that is perfectly compatible as well, but it will last even less than the FC-7. The cause is probably the fact that the potentiometer inside it has the open side towards the top, from where dust coming off the shoe gets in.

 

I'm not sure if you're completely aware as to how an expression pedal works in a digital keyboard... Its resistance value is applied to a fixed voltage so the pot functions as a variable voltage divider, in other words the resistance is converted in voltage, that is later read by an ADC (Analog to Digital Converter) and then converted into digital data to be elaborated by the software. A very wearout pedal can either be completely innocuous or be a big problem according to its role into the circuit. With a generic workstation where the expression pedal is only used by a few patches, having a wearout pedal connected would probably be unnoticed most of the times, but with a clonewheel organ the pedal is a very important part of the instrument and is constantly scanned and applied to the sound, so having a wearout pedal in this case is a problem that the software can't handle because all the software does is reading the data coming from the ADC, and the ADC transforms into data the voltage coming from the voltage divider. If this voltage is continuously drifting over time, the result is unstable digital data that can cause problems either to the software or to the general operation of the instrument.

 

I think what I've just explained can be applied to ANY digital keyboard because we've not reinvented the wheel, this is exactly how an expression pedal works in every digital instrument, since the invention of the ADC.

 

 

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This explanation makes no sense to me, Guido.

 

This is a topic that came up in another thread, and here's what I said there. Missing from that explanation is that, yes, in software you generally map your ADC values in such a way that you have a little bit of a dead zone at the extreme ends of the wiper's travel.

 

Nothing you've said explains why an instrument should crash if the wrong pedal is attached.

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This explanation makes no sense to me, Guido.

 

This is a topic that came up in another thread, and here's what I said there. Missing from that explanation is that, yes, in software you generally map your ADC values in such a way that you have a little bit of a dead zone at the extreme ends of the wiper's travel.

 

Nothing you've said explains why an instrument should crash if the wrong pedal is attached.

 

I think he did Dave - you just might not like the answer ;) .

 

...the result is unstable digital data that can cause problems either to the software or to the general operation of the instrument.

 

 

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This explanation makes no sense to me, Guido.

 

This is a topic that came up in another thread, and here's what I said there. Missing from that explanation is that, yes, in software you generally map your ADC values in such a way that you have a little bit of a dead zone at the extreme ends of the wiper's travel.

 

Nothing you've said explains why an instrument should crash if the wrong pedal is attached.

 

Hi Dave. Excuse me but I don't read all the posts on the forum and wasn't aware of a similar explanation you did in a different thread. I was just replying to someone else wondering why a wearout pedal should cause problems to an instrument.

 

The reason why your Mojo61 didn't boot up at all at the gig might be due to power problems, but this is a different matter that requires some deeper investigation. And, as you know, a problem can be addressed and resolved only if it's replicable at any time.

 

 

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Not a Mojo owner but I do wonder why folks will spend $1,500 on a board and plug a 10 year old expression pedal in to it rather than spend $100 on an expression pedal from the same manufacturer which is guaranteed to work with board. And if it doesn't its on the manufacturer to fix it.

A misguided plumber attempting to entertain | MainStage 3 | Axiom 61 2nd Gen | Pianoteq | B5 | XK3c | EV ZLX 12P

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Recently posted on FB by Crumar:

 

Mojo61 new firmware release v.1.25

 

Changes in firmware v.1.25:

 

- Added: the optional lower manual can now send velocity according to the global settings

- Added: sends MIDI Program Change messages with values from 0 to 7 according to the Instrument selection

- Added: Clavi EP note-off is now engaged at the lower key contact, resulting in a "snappied" feel just like the real Clavinet!

- Fixed: notes playing on the lower manual could hang if the octave shift was enabled while in split mode

- Fixed: notes could hang if switching between Upper & Lower in Single MODE while playing rapid passages

 

Feel free to download, install and enjoy your Crumar instrument!

 

Link

 

dB

:snax:

 

:keys:==> David Bryce Music • Funky Young Monks <==:rawk:

 

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Not a Mojo owner but I do wonder why folks will spend $1,500 on a board and plug a 10 year old expression pedal in to it rather than spend $100 on an expression pedal from the same manufacturer which is guaranteed to work with board. And if it doesn't its on the manufacturer to fix it.

The discussion was about the claim from Andrea from Crumar that connecting a pedal with a defective potentiometer (may also happen with the original Crumar pedal) or 50k instead of 10k potentiometer as a reason for the problem with Mojo 61 locking up, «freezing». On the other side I recommend the original Crumar expression pedal I bought with my Mojo61. Sturdy with a solid and firm movement, but heavy. I leave it at home when going for rehearsal, there I connect the Mojo to a FC7....

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Another pedal issue to consider: I have the Crumar long-throw pedal, but I prefer the FC7 only because it sits lower to the ground. The Crumar pedal is high enough that you have to raise your foot an extra inch or so. As a long-legged person who frequently ends up banging his knees into the bottom of keyboard rigs that work just fine for other people, this is significant for me.
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A cheaper option is the Behringer FCV-100 that is perfectly compatible as well, but it will last even less than the FC-7.
Does anyone have any experience with these two to compare? I'm curious about how they feel and the length of the throw. The closer to a real Hammond swell pedal the better.

"I'm so crazy, I don't know this is impossible! Hoo hoo!" - Daffy Duck

 

"The good news is that once you start piano you never have to worry about getting laid again. More time to practice!" - MOI

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The FC7 has the long throw; the FCV-100 is substantially shorter. Not good for Hammond playing. I think I am going to give this Fatar pedal a try:, I think it is only $40, about the same cost as the FC7 but 10K as required by my Kurzweil:

 

http://www.fatar.com/pages/FP_50.html

 

57 Hammond B3; 69 Hammond L100P; 68 Leslie 122; Kurzweil Forte7 & PC3; M-Audio Code 61; Voce V5+; Neo Vent; EV ELX112P; GSI Gemini & Burn

Delaware Dave

Exit93band

 

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no , it is clear so far .the clavia in use is not much different , used it 90 percent for organ and 10 percent for pedal wah clav with the before mentioned pedals . Maybe the quality has diminished , I am pretty sure my 4 FC7 are still from the 80' s , all work fine still , one has a replacement cable. I will get a spare part now
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