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DIY Stompboxes => Building your own stompbox => Topic started by: Mark Hammer on January 21, 2015, 11:25:49 AM

Title: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: Mark Hammer on January 21, 2015, 11:25:49 AM
EHX is releasing a new über-tremolo, that has not only a very usable interface, but a broad assortment of interesting and creative features, many of which are illustrated in this video demo from the ever-enviable Bill Ruppert.  Including ALL of the features undoubtedly requires gobs of digital assistance, but some of the features are undoubtedly do-able in the analog domain, and it's nice to hear them in action.  One of the rather different features we don't often see is the use of an expression pedal input to sweep from the sub-audio (tremolo) into the audio (ring-modulation) range.  Neat!  Hearing the two forms of envelope control is thought-provoking as well.  This thing brings new "zip" to the world of tremolo.  Kudos to the designer or design-team.


Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: samhay on January 21, 2015, 11:44:22 AM
It indeed does look like a nice piece of kit. Pretty much covers all the tremolo bases in some form or other. Is it time for a forum tremolo work-a-like?
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: StephenGiles on January 21, 2015, 02:23:17 PM
Utterly amazing!
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: deadastronaut on January 21, 2015, 02:31:42 PM


;)

needs more leds.. ;D
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: Kipper4 on January 21, 2015, 03:03:03 PM
Wow Hours of fun in that.

"Needs more leds"
Almost as many as Robs robot  :)

Now how do I mod my Tremulus Lune to do this? :icon_biggrin:
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: midwayfair on January 21, 2015, 03:05:48 PM
It's going to be OTA based. You could use the TAPLFO with enough filtering presumably as long as you don't need the presets. The envelope shouldn't be too hard to wire in, with a rotary to alter what it controls, basically just make a little envelope generator running on 5V (so that it doesn't generate too large a voltage and kill the chip) and you feed it to the pin of the TAPLFO to override the control voltage set by the pot. Expression control is easy.

Used you should be able to pick it up for under $200, though, and it might be worth it considering parts could easily run over $100, plus who knows how much time trying to emulate the features with analog circuitry.

EDIT: One very cool thing you can do with this is set the expression to volume, and use a preset with 0 depth to make your expression pedal a volume pedal. Saves space on your board but still lets you get expression controlled tremolo.
Title: Re:
Post by: thehallofshields on January 21, 2015, 04:11:42 PM
I am in love.
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: StephenGiles on January 21, 2015, 04:43:52 PM
Quote from: midwayfair on January 21, 2015, 03:05:48 PM
It's going to be OTA based. You could use the TAPLFO with enough filtering presumably as long as you don't need the presets. The envelope shouldn't be too hard to wire in, with a rotary to alter what it controls, basically just make a little envelope generator running on 5V (so that it doesn't generate too large a voltage and kill the chip) and you feed it to the pin of the TAPLFO to override the control voltage set by the pot. Expression control is easy.

Used you should be able to pick it up for under $200, though, and it might be worth it considering parts could easily run over $100, plus who knows how much time trying to emulate the features with analog circuitry.

EDIT: One very cool thing you can do with this is set the expression to volume, and use a preset with 0 depth to make your expression pedal a volume pedal. Saves space on your board but still lets you get expression controlled tremolo.

1.  How do you know it's OTA based?

2.  I don't think EH "just make little envelope generators" for their new pedals!!
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: midwayfair on January 21, 2015, 05:24:27 PM
Quote from: StephenGiles on January 21, 2015, 04:43:52 PM
Quote from: midwayfair on January 21, 2015, 03:05:48 PM
It's going to be OTA based. You could use the TAPLFO with enough filtering presumably as long as you don't need the presets. The envelope shouldn't be too hard to wire in, with a rotary to alter what it controls, basically just make a little envelope generator running on 5V (so that it doesn't generate too large a voltage and kill the chip) and you feed it to the pin of the TAPLFO to override the control voltage set by the pot. Expression control is easy.

Used you should be able to pick it up for under $200, though, and it might be worth it considering parts could easily run over $100, plus who knows how much time trying to emulate the features with analog circuitry.

EDIT: One very cool thing you can do with this is set the expression to volume, and use a preset with 0 depth to make your expression pedal a volume pedal. Saves space on your board but still lets you get expression controlled tremolo.

1.  How do you know it's OTA based?

2.  I don't think EH "just make little envelope generators" for their new pedals!!

1. The original Pulsar is. It's reasonable to assume that this is an OTA-based dry path with an extensive digital LFO. We know that the dry path is analog, and it can do ring modulation, so the variable resistance element is extremely fast and therefore it's a solid bet that it's not optical, even if EHX would bother with an optical pedal in the first place (due to the ROUSs ;) ).

2. It has a knob labeled "envelope." Unless you're contending that the control voltage generator is digital, I'm really not sure what you're taking issue with here. And besides, I'm describing how a DIYer could reproduce some of the functionality, not describing how it's done in the SP.
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: Mark Hammer on January 21, 2015, 07:00:19 PM
I think it's a really nice user interface.  Very usable, and no bloody screen.

If one goes back a decade here, we had some discussions about better and worse visual indicators for tap tempo, when the cycle time is very slow (>1sec), and the 8 LED display nicely fills the bill for something that can provide useful feedback about very long sweeps.
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: Tony Forestiere on January 21, 2015, 08:04:49 PM
Absolutely impressive amount of control (and loss of control, should one desire). In Bill's hands, a thing of beauty. Thanks for the link(s).  ;D

*edit* Looks like the perfect amount of LEDs.
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: tubegeek on January 21, 2015, 11:21:31 PM
"How Soon Is Now" riff sounds great - I think it needs more JACKS.
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: StephenGiles on January 22, 2015, 01:52:00 PM
Quote from: midwayfair on January 21, 2015, 05:24:27 PM
Quote from: StephenGiles on January 21, 2015, 04:43:52 PM
Quote from: midwayfair on January 21, 2015, 03:05:48 PM
It's going to be OTA based. You could use the TAPLFO with enough filtering presumably as long as you don't need the presets. The envelope shouldn't be too hard to wire in, with a rotary to alter what it controls, basically just make a little envelope generator running on 5V (so that it doesn't generate too large a voltage and kill the chip) and you feed it to the pin of the TAPLFO to override the control voltage set by the pot. Expression control is easy.

Used you should be able to pick it up for under $200, though, and it might be worth it considering parts could easily run over $100, plus who knows how much time trying to emulate the features with analog circuitry.

EDIT: One very cool thing you can do with this is set the expression to volume, and use a preset with 0 depth to make your expression pedal a volume pedal. Saves space on your board but still lets you get expression controlled tremolo.

1.  How do you know it's OTA based?

2.  I don't think EH "just make little envelope generators" for their new pedals!!

1. The original Pulsar is. It's reasonable to assume that this is an OTA-based dry path with an extensive digital LFO. We know that the dry path is analog, and it can do ring modulation, so the variable resistance element is extremely fast and therefore it's a solid bet that it's not optical, even if EHX would bother with an optical pedal in the first place (due to the ROUSs ;) ).

2. It has a knob labeled "envelope." Unless you're contending that the control voltage generator is digital, I'm really not sure what you're taking issue with here. And besides, I'm describing how a DIYer could reproduce some of the functionality, not describing how it's done in the SP.

Well you may be right, but you may also think that the Enigma Qballs is OTA based, but I understand that it's opamp based, and in fact there appears to be a lot of opamps in that unit, so it would tend to suggest that EH are going for top notch circuitry these days, rather than simplicity.
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: samhay on January 22, 2015, 03:05:32 PM
Quote from: midwayfair on January 21, 2015, 03:05:48 PM
It's going to be OTA based.

You may be correct, but by a similar argument, it could also be using PWM to control some sort of analogue switch - like Ray Ring's PWM compressor.
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: Mark Hammer on January 22, 2015, 03:22:59 PM
Whatever forms the variable gain element, it is clearly - at the least - microcontrolled-assisted, though given how much EHX has been migrating toward DSP of late, my own money is on mostly DSP or microcontroller.
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: Ice-9 on January 22, 2015, 04:05:40 PM
My guess would be that not a lot of analogue stuff will be in that, mostly digital DSP , I would like to have a look inside one all the same. EHX are making some canny stuff these days.
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: kaycee on January 23, 2015, 05:39:21 AM
That's impressive! Sounds great, even the Repeat Percussion sounded right.

There's no way I'd try and DIY something like that, it would take me forever and more brains that I'll ever posses, plus it's well worth the price I think. EHX are really coming up with some cool stuff, more power to them. Still gassing for the B9 organ machine they brought out last year, even though I can't think of any song I play I'd use it for!

Well done EHX
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: Mark Hammer on January 23, 2015, 02:24:38 PM
Just to be clear, I wasn't suggesting that anyone attempt to replicate the entire thing.  Rather, there are a bunch of great functions all rolled up into the one pedal, which a person might want to ponder adding on to an existing design, individually.  Think of it like a "tremolo's greatest hits" compilation.
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: StephenGiles on January 23, 2015, 04:53:17 PM
Quote from: Mark Hammer on January 23, 2015, 02:24:38 PM
Just to be clear, I wasn't suggesting that anyone attempt to replicate the entire thing.  Rather, there are a bunch of great functions all rolled up into the one pedal, which a person might want to ponder adding on to an existing design, individually.  Think of it like a "tremolo's greatest hits" compilation.

Like using the envelope function to fire up the LFO in a flanger or phaser for instance.
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: amptramp on January 23, 2015, 07:46:00 PM
I think our typical way of stringing effects together in a linear stream does limit things.  For example, suppose you have a fuzz or compressor followed by something that needs envelope information.  Once you have crushed the envelope in the fuzz or compressor, that information is no longer available in the audio stream.  You have to have some way for the original information to exist further down the pedal chain so you could, say, vary your tremolo or phaser frequency from the input envelope.

In a systems engineering sense, the most general type of interconnection allows any pedal to talk to any other.  If you have a number of functions in one enclosure, you no longer need separate interconnect cables, so you don't have parallel runs of cable.  This goes along with a number of things that have been grandfathered down to us - the 9 VDC supply with positive shell, side jacks for cables where top edge cabling would allow denser packaging and plain boxes that do not provide for protection of the control knobs from the guitarist's foot.  I think EHX is pointing the way for future builds and it will be interesting to see just how much the amateur and low-production entrepreneur will follow suit.
Title: Re: New EHX Super Pulsar a compendium of interesting ideas for DIY-ers
Post by: cloudscapes on January 23, 2015, 08:13:01 PM
DSP would be overkill, a micro does this just fine. I built a few tremolos who's LFO was generated by microcontroller.

the pattern trem can be achieved via other means, too. like using cmos 4017 step sequencer