Tap Tempo LFO Chip

[MoltenVoltage]

Hi everyone.

After many grueling months, we have finally finished developing a precision Tap Tempo Low Frequency Oscillator (LFO) chip, MV-53.

By outputting an ultra-clean analog signal (from an internal Digital Analog Converter), MV-53 can control Phasers, Wahs, Tremolos, and any other type of circuit that relies on low frequency oscillation.  All this is done using extremely precise digital controls.

What's more, MV-53 allows the pedal user to program and save sequences of up to 16 LFO and Playback Rate combinations!

Check out the video on this page and see for yourself:
http://www.MoltenVoltage.com/mv-53.html

The three circuits in the video are a modified Script Phase 90, a modified Dr. Q (Dr. Quack) and a custom tremolo.  We'd be glad to give you details on how to incorporate MV-53 into those pedals.

Features include:
    * Analog waveform generation at a 1.23 MHz sample rate, output by an on-board Digital Analog Converter [DAC]
    * Four different waveforms: Square, Sawtooth Up, Sawtooth Down, Sine
    * Four different playback rates: 1:1 [real time], 1:2 [double time], 1:3 [triplets], 1:4 [quadruple time]
    * Wide playback speed range of .033 seconds [1818 bpm] to 13 seconds [4.6 bpm]
    * Waveforms, rates, and speeds can be switched seamlessly "on the fly"
    * Programmable with sequences of waveform and rate combinations of up to 16 steps, stored in nine (9) non-volatile memory locations
    * Simple to program
    * Switchable between two different speed controls:
      - Tap Tempo ~ accurate to better than 1/1,000th of a second
      - Potentiometer-based
    * Dual simultaneous waveform output (one is inverted)
    * Duty Cycle Control with 11 different musical ratios that can "swing": 1/8, 1/6, 1/4, 1/3, 3/8, 1/2, 5/8, 2/3, 3/4, 5/6, 7/8
    * Real-time LED interface
    * Easy to defeat unwanted features

The datasheet, which contains a basic schematic, is available on this page as well:
http://www.MoltenVoltage.com/mv-53.html

Samples are available for $20 each + shipping.  Send an email to questions@MoltenVoltage.com

Just to be clear, although we are offering samples, we don't have time to troubleshoot your one-off circuits. If you don't already have a good idea of how to replace the LFO in a circuit, please don't order!

One very critical piece of information: MV-53 runs on 3.3 volts - not 5!

The datasheet schematic shows how to convert the MV-53 output into 0-9 volts using a rail-to-rail op amp.

Please let me know if you have any questions that aren't covered in the datasheet.

Thanks!

[Processaurus]

For the program mode, to get this right, steps you program are the LFO shape+ Rate, for one cycle?  Like, if I programmed in a quarter note squarewave, followed by 4x 16th note squarewaves, the program cycle would last 2 quarter notes, like this ?

_____l¯¯¯¯¯l_l¯l_l¯l_l¯l_l¯

Looks fun in any case, neat chip, thanks for making it available to us!

[earthtonesaudio]

It was hard to tell from the datasheet, are there any sort of data/digital or switched outputs available, or any pin that could be used as a clock sync with other chips?

Looks pretty cool, good luck!

[MoltenVoltage]

For the program mode, to get this right, steps you program are the LFO shape+ Rate, for one cycle?  Like, if I programmed in a quarter note squarewave, followed by 4x 16th note squarewaves, the program cycle would last 2 quarter notes, like this ?

_____l¯¯¯¯¯l_l¯l_l¯l_l¯l_l¯

Looks fun in any case, neat chip, thanks for making it available to us!

That's exactly right.  The point of programmability is to add a more interesting rhythmic element to the effect.

MV-53 can store 9 programs and switch between them "on the fly".  It also has a free-running mode that just loops whatever rate/waveform combination is selected.  If you don't want to use the program mode, just leave all the program select pins unconnected.

It was hard to tell from the datasheet, are there any sort of data/digital or switched outputs available, or any pin that could be used as a clock sync with other chips?

Looks pretty cool, good luck!

No there isn't, but its simple to buffer the LFO output and send it to multiple chips.  I have a schematic for that if you need it.  It also has a second output that is identical to the first, but the waveform is inverted.

We can customize the chip with a minimum order of 100.

Thanks for the feedback!

[MoltenVoltage]

I'm posting this MV-53 Tremolo schematic in response to a question in another thread.  It's simple but sounds decent.

http://www.moltenvoltage.com/downloads/MV-53_Tremolo_Schematic_v1.jpg

[aziltz]

looks pretty cool!

is the tap triggering on this the same as the delay time/tap you are also working on?  it would be really cool to link delay and tremolo/modulation in time, but have different subdivisions and control over the waveform, etc...

[MoltenVoltage]

looks pretty cool!

is the tap triggering on this the same as the delay time/tap you are also working on?  it would be really cool to link delay and tremolo/modulation in time, but have different subdivisions and control over the waveform, etc...

MV-53 is a straight up LFO, but, its funny you should ask, I was thinking the same thing after looking at a lot of manufacturer websites the last couple weeks.  Lots of delay pedals also have an LFO modulation feature.  I have to assume most people use the PT2399 chip, and we were about halfway done with the code on that anyway when we decided to pursue MV-53.  Will certainly let you know when MV-53D is ready!

I am also going to work out the voltage range for each rate/waveform combination setting so you can target specific settings if you don't want to use all four rates or all four waveforms in your pedal.  There will be 16 different target voltage ranges (4 rates * 4 waveforms).  Will post it here in the next day or so and add it to the Datasheet.

Thanks for the feedback!

[Mark Hammer]

You know, for me, the most fascinating component of all of this, and the aspect that has been surprisingly overlooked here, is the answer to the question: How the heck do you get a custom chip made?

I've been on this forum since its inception, and with the exception of Karl/Molten none of us here has ever announced that they had developed a chip and gotten it produced for them.  Maybe some of you have, albeit in non-musical contexts, but no one has ever mentioned it, or hipped us to what's involved in the process.

So, to heck with tap tempo.  I wanna know how you get a tap tempo chip made.  No requirements to spill corporate secrets or present financial figures.  It's the steps and the thinking that interest me.

[JKowalski]

So, to heck with tap tempo.  I wanna know how you get a tap tempo chip made.  No requirements to spill corporate secrets or present financial figures.  It's the steps and the thinking that interest me.

I thought it was just a microcontroller that they pre-programmed.

[Unbeliever]

Be aware that Molten Voltage claim they are patenting this tap tempo LFO chip of theirs, and refuse to make it clear if they will sue 'infringers' of their 'patent' or not:
http://www.diystompboxes.com/smfforum/index.php?topic=78836.0

'Infringers' could well include your fellow DIYers who develop their own 'tap tempo LFO chip' (yes, which is indeed just a pre-programmed uC).

[kvb]

I've been on this forum since its inception, and with the exception of Karl/Molten none of us here has ever announced that they had developed a chip and gotten it produced for them.

A few months back someone said they were working on a chip that could output maybe 10 or so waveforms. I'm not sure if anything came out of that. Maybe he ran into a snag.


The "patterns" on the MV-53 seem interesting but I think that more waveforms to choose from is also a good idea.

[octfrank]

You know, for me, the most fascinating component of all of this, and the aspect that has been surprisingly overlooked here, is the answer to the question: How the heck do you get a custom chip made?

Actually having designed chips and had them produced for a couple of companies, I've been deep in this area. There is no simple answer to this question, it depends on how deep you want to get into the design flow. So here is an overview going from easiest method to most complex. Note that after you choose the path to take you need to find a fab to actually make the chip. Note that costs are big!

1. FPGA -> Gate array
This is the easiest path, a number of fabs can take an FPGA netlist and make a gate array from it. Think of a gate array as a complex FPGA, the transistors are already there and are wired up according to the netlist. Good path for medium volume.

2. Logic design -> Gate array
Design the circuit using schematic and/or synthesis and send the netlist to the fab. Will usually result in a denser design than above since you will use the fabs library and not have to translate from the FPGA to the fabs library. Also good for mendum volume.

3. Logic design -> standard cell
Design the circuit using schematic and/or synthesis and send the netlist to the fab. This path results in a much denser die as only transistors used are actually in the design. This is a much more expensive path, for gate arrays you only need to pay for metal and via layers to connect the transistors because the transistor are already placed, in a standard cell you need all mask layers. You provide the final netlist and the fab will do the layout. Good for higher volume.

4. Full custom
Not only will you design the circuit using schematic and/or synthesis, you will also do the layout. You may use the fabs cell library or you may design your own (as a note, FV-1 was done with a custom library, not the fabs) but you send the fab the GDSII (GDS2) files, think of them as gerber for a chip, separate layers for wells, N, P, gate poly, metal layers, vias, etc.

So, choose the path you wish to take, select a fab that supports your desired path, select s/w (commercial or open source) that supports that path and fab, get an estimate from the fab on costs, design the chip, send to fab.

[slacker]

Be aware that Molten Voltage claim they are patenting this tap tempo LFO chip of theirs, and refuse to make it clear if they will sue 'infringers' of their 'patent' or not:
http://www.diystompboxes.com/smfforum/index.php?topic=78836.0

'Infringers' could well include your fellow DIYers who develop their own 'tap tempo LFO chip' (yes, which is indeed just a pre-programmed uC).

Seems to me there's not a lot to worry about, there's already DIY and commercial multi waveform "LFO" chips out there, and tap tempos on a chip, simply combining the 2 on one device ain't something you could patent. Even if you did it wouldn't be worth the paper it's written on.

If they want to try and patent the whole "sequencer wave" bit then fair play to them.

[MoltenVoltage]

Be aware that Molten Voltage claim they are patenting this tap tempo LFO chip of theirs, and refuse to make it clear if they will sue 'infringers' of their 'patent' or not:
http://www.diystompboxes.com/smfforum/index.php?topic=78836.0

'Infringers' could well include your fellow DIYers who develop their own 'tap tempo LFO chip' (yes, which is indeed just a pre-programmed uC).

Seems to me there's not a lot to worry about, there's already DIY and commercial multi waveform "LFO" chips out there, and tap tempos on a chip, simply combining the 2 on one device ain't something you could patent. Even if you did it wouldn't be worth the paper it's written on.

If they want to try and patent the whole "sequencer wave" bit then fair play to them.

I'm glad somebody gets it.  Thanks Ian.

Like I said on the other thread, nothing we have filed patents on has even been suggested on this forum.  That's the bottom line.

[M0n0mania]

This sounds great, I'll be ordering samples! Any chance we could get a look at the mods you did for Phase 90 & Dr Q?

[loss1234]

does the price go down on these for orders over 100?

I am seriously interested

thanks

(too bad there is no SYNC in)

[MoltenVoltage]

does the price go down on these for orders over 100?

I am seriously interested

thanks

(too bad there is no SYNC in)

Quantity pricing is on this page:
http://www.moltenvoltage.com/mv-53.html

We can customize the chip with a minimum order of 100.  Additional programming charges will vary based on complexity.  Send us an email and let us know what you have in mind.

Thanks for the interest!

We will get the Phase 90 and Dr. Q schematics posted as soon as we can.

[gena_p1]

8 bit pwm? that's suxx

[MoltenVoltage]

8 bit pwm? that's suxx

Not sure what you are talking about, MV-53 does NOT use Pulse Width Modulation at all.  Instead it has an on-board Digital Analog Converter [DAC] that has 16-bit resolution and the output sample rate is well over a million samples per second (1.23 MHz).

The output is so clean, even at a 13 second interval, it will bring tears of joy to your eyes!

[doc_drop]

I for one am just waiting for a schematic for the Dr. Q to buy one of these. Then maybe a tremelo circuit?.... I just built a phaser (Frequency Central's Phase Evolution adoptation of  RG Kean's take on the Phase 90 ) so I am not up for doing another one for a while.

But of course we are all hungry for a tap tempo delay circuit!

Thanks for developing this chip and letting us know about it. I wish I had the skills to encorporate it into a circuit myself, but I'm not at that point yet. Maybe once I see how it gets added to a circuit I know.