Phase-Locked Loops for multiplying multiple frequencies

Hi, I've been trying to research PLL's online for a few days now and I'm having trouble finding enough information about them. I'm working on a project where I'm taking a mixed signal of frequencies and converting them to higher multiples of themselves.

For example, an analog signal with frequencies 456Hz, 780Hz and 932Hz are mixed together and I'm trying to retrieve a signal with 912Hz, 1560Hz and 1864Hz. I know that PLL's can take in a frequency and multiply it by a divider but is it possible to multiply multiple frequencies?

If a PLL isn't capable of this are there any other IC's that may be able to accomplish this? Also if they can accomplish this, are there any good websites about actually using PLL's in circuits and what their pins are used for.

Thanks

Re: Phase-Locked Loops

You won't be able to do that with a PLL.
You could use 3 notch filters to get at the individual components, and then multiply them with 3 PLL's and then sum them, but that is pretty messy.
I haven't worked much with mixers, but your answer may lie in there. I'm not sure about that though. Some RF guy's will hopefully be along in a minute to confirm or deny.

Re: Phase-Locked Loops

I was thinking about using some sort of filter before to send the separate frequencies through their own PLL's to multiply their freq. and then mix them back together, but the frequencies being used are not static and vary between 20Hz and 20,000Hz.

Ive been trying to figure out a way around this: maybe a variable filter depending on input (if possible)? Or using something to lock into 1 frequency and then subtracting it to leave the other frequencies in the signal, and then repeating. At most, 5 - 6 main frequencies will be sent at a time.

Re: Phase-Locked Loops

Do you have to do it with an anlog circuit?
When not, you could think about a DSP System.
First digitize the signal then make the filtering and the multiplicaiton and finally convert the digital signal back to an anlaog.

Re: Phase-Locked Loops

I'm planning on making a custom guitar pedal that takes in a set of notes, splits the input and then adds on signals containing harmonics to give it a more full sound.

Would DSP have enough bandwidth to make a close enough model to the original signals at at decent price per chip?

I'm not exactly sure of the types of DSP's or the main functions that they are capable of, but would this be possible:

-Take and input of a signal.
-Convert the analog signal to digital.
-Take the bits and put them into a set length buffer. (A Set Osc will set the
freq. of the bits being taken. Say 20Khz.)
-Another Osc set at twice the speed or higher takes the bits from the buffer and
sends them out at twice the rate, multiplying the frequency.
-The signal being sent out is repeated and attached to the end of the first bits to
fill in the time gap.
-The digital is then converted back to analog at a multiple of the original signal

Re: Phase-Locked Loops

Good questions.
Unfortunately I'm not an expert in DSP.
I think you should ask the questions in the DSP board.