CP-251 build quality???

[donato]

I have a Voyager and the VX-351. I recently picked up a CP-251 and noticed quite a drop off as far as build quality and design. The knobs don't turn smoothly and are mounted a bit raised from the surface as opposed to the knobs on the Voyager and 351 that are almost flush with the surface. Is there something wrong with my unit or are all of the 251's like this?

[monads]

Mine is the same. I noticed the knobs don't turn as smooth as on the VX351 and Voyager.

[peacefrog]

When I bought mine brand new and brought it home one of the circuits didn't work. While on the phone with their tech support we found that a wire was connected wrong and I couldn't fix it on my own. I shipped it back to them, they fixed it and shipped it back. (They could have fit a teach shirt in there for the inconveinence.)

[Jebus0000]

just a though...the CP-251 doesn't handle any audio so the pots they use may differ and may not be to the standard of the pots used in the pedals where audio quality is a concern. I don't know too much about electronics but I don't see how a better pot would affect performance of something that only handles CV.

Also, the knobs are different on the CP-251...that may account for them not being flush.

I don't really think the pots not turning as smoothly really amounts to build quality and design problems...unless there's other things you've noticed?

[MC]

I have both the VX351 and CP251 and have noticed the same thing. The VX has pots that are damped more - that's not a quality issue, they probably just changed to a different style pot for a certain run of units.

I wouldn't worry too much about them. I'm an EE. One, the VX and CP cases are sealed as are the pots. Two, the change may have been done to facilitate assembly without affecting quality. The pots in all of Moog's stuff are excellent quality, I have most of the MFs and a Voyager SE.

[vintageabuser]

one of the attenuator pots on my control processor turns all the way around if you push down on it a little while you max it. but not when you turn it all the way down. it still works fine though. they do seem a little crappier than the other mooger knobs.

[basscracker]

The knobs are mounted a bit raised from the surface as opposed to the knobs on the Voyager and 351 that are almost flush with the surface.Is there something wrong with my unit or are all of the 251's like this?

the knobs have spacers in them.pull the knobs off carefully and most of the spacers will fall out,some get stuck.i just tapped the knob on the table and the stuck spacer fell out.

[godzilla]

just a though...the CP-251 doesn't handle any audio so the pots they use may differ and may not be to the standard of the pots used in the pedals where audio quality is a concern. I don't know too much about electronics but I don't see how a better pot would affect performance of something that only handles CV.

Also, the knobs are different on the CP-251...that may account for them not being flush.

I don't really think the pots not turning as smoothly really amounts to build quality and design problems...unless there's other things you've noticed?

As yet i only have an etherwave but i thought the cp 251 could handle audio and cv.
i thought that you could use the attenuators as a volume control of an audio signal and use the cv mixer as a audio mixer as well, and use the four way multi on an audio signal to use on three things at once, and use the noise generator and the lfo (in it's higher freq) as an audio source.
. I thought the range of the circut was extended to handle cv not shifted.

[Impossible Sound]

The CP-251 does handle audio. Most of its features work on both audio and CV, as you pointed out.

[godzilla]

few, i thought so
it would be such a shame if it couldn't handle audio.

Are analog audio signals the same as cv signals but just in higher range, and if so can you output audible CV direct into an amp (just to hear, and the VCA just adds control over its level) or do you need a VCA to make it audible?
if not then i take it a VCA changes the CV into audio?

I always asumed that CV and Audio were basically the same, only some CV contains vibrations imperceptable by the human ear (below 20hz).

[Impossible Sound]

>Are analog audio signals the same as cv signals but just in higher range,

Not exactly. Without getting too technical (I'll leave that for the experts) Audio is AC and CV is DC. Audio is typically in the ±1V range, at whatever frequency (Hz) the sound is at. Control Voltage is at 0Hz, and with Moog equipment is typically in the 0 to +5V range. There are standards of 0 to +10V and ±5V with other equipment.

>and if so can you output audible CV direct into an amp (just to hear, and >the VCA just adds control over its level) or do you need a VCA to make it >audible?

CV is not audible, but you can view it with a Volt meter.

>if not then i take it a VCA changes the CV into audio?

The CV controls the level of whatever kind of signal is at the input. It can be either audio or CV.

Hope that helps explain things!

Mike Fun

[godzilla]

>Are analog audio signals the same as cv signals but just in higher range,

Not exactly. Without getting too technical (I'll leave that for the experts) Audio is AC and CV is DC. Audio is typically in the ±1V range, at whatever frequency (Hz) the sound is at. Control Voltage is at 0Hz, and with Moog equipment is typically in the 0 to +5V range. There are standards of 0 to +10V and ±5V with other equipment.

But what about the carrier out on the 102 that's an audio and a CV out, how can they be different if they are combined in the same jack on the 102?

>and if so can you output audible CV direct into an amp (just to hear, and >the VCA just adds control over its level) or do you need a VCA to make it >audible?

CV is not audible, but you can view it with a Volt meter.


but the carrier out is audible, i thought that any cycle that repeats between 20 and 20000 times a second would be audible

>if not then i take it a VCA changes the CV into audio?

The CV controls the level of whatever kind of signal is at the input. It can be either audio or CV.

ok so if you plug an LFO into a VCA CV in then the volume of the audio input on the VCA would vary to the rate of the LFO, but what happens if you plug the LFO into the AUDIO in on the VCA
as far as i can make out a square wave will make a series of audible clicks (in the low range) and the normal clarinety sound that square waves make ( in the high range)

but what i wnat to know is the difference between say the output of a self contained synth (producing a patch of an unfiltered VCO) and the output of a VCO module.


Hope that helps explain things!

I need more explaining less confusing.

[OysterRock]

Without getting too technical (I'll leave that for the experts) Audio is AC and CV is DC.

This is not true. Much of the CV signals you use are AC. Carriers, LFOs and oscillators are all AC. The thing to keep in mind is that, whether audio or CV, its all just voltages. The only difference between an audio signal and any other is that one is coming out a speaker.

Any AC voltage in the audible frequency range will produce sound if connected to a speaker. That is what a speaker does, it converts voltage to audio. Now, the reason why you shouldn't hook up random CV voltages to a speaker is that if you don't know what the max rating on the speaker is, you could damage it.

BTW, never connect a DC voltage to a speaker, it will damage it.

[godzilla]

Without getting too technical (I'll leave that for the experts) Audio is AC and CV is DC.

This is not true. Much of the CV signals you use are AC. Carriers, LFOs and oscillators are all AC. The thing to keep in mind is that, whether audio or CV, its all just voltages. The only difference between an audio signal and any other is that one is coming out a speaker.

Any AC voltage in the audible frequency range will produce sound if connected to a speaker. That is what a speaker does, it converts voltage to audio. Now, the reason why you shouldn't hook up random CV voltages to a speaker is that if you don't know what the max rating on the speaker is, you could damage it.

BTW, never connect a DC voltage to a speaker, it will damage it.

Hang on, wait does this mean that you could use the audio output of a NON-MODULAR synth (or any audio out that has a frequency ie: a periodic waveform, even a voice form a microphone) to FM modulate a modular VCO?

Where's the distinction between "normal" audio signals (like giutars and microphones and things like that) and CV/audio signals like VCOs and Carrier oscillators, and noise generators?
now i know the output of a guitar has a more complex waveform than a square wave but what if you just play one note at a time and what about a mic'd up clarinet in a reverbarent free (sound proof) room, that would have a very similar wave to a VCO producing a square wave, and anyway you can use noise as a CV and that's about as complex a waveform as you can get.

ok if its not the wave or freq that stops you from using "normal" audio as a mod source (if there is indeed anything stopping you from using "normal" audio as a mod source) then it must be the amplitude of the output, and couldn't you boost or attenuate that anyway?

Has anyone ever tried using "normal" audio as a mod source?

Hmm after thinking about this i have come to the conclusing that the answer (if indeed anyone does answer) will have something to do with pitch to CV converters, or that what i have been talking about is the basic theory behind pitch-CV converters.



just realised
this has nothing to do with the CP-251 build quality.

[OysterRock]

Hang on, wait does this mean that you could use the audio output of a NON-MODULAR synth

Yes and no. Just because you can doesn't mean you should. With out some sort of converter, the voltages from other gear might hurt you CV gear. Plugging a guitar into CV probebly woun't do anything because of the high impedence of guitar output. The signal isn't strong enough. You need something like this:

http://www.synthesizers.com/q118.html

If the signal isn't strong enough, it amplifies it. It also makes sure the signal never goes above 5V, which is the max rating ov the voyager and moogerfoogers.