Small Stone Phaser v1 pcb?

[LucifersTrip]

My friend enjoyed the Madbean Kraken (Mutron Micro V) I built for him, so he asked if I could build or help him with a Small Stone Phaser v1.

The closest I could find is the Space Harp:
http://lectric-fx.com/product/spaceharp/

There's hardly any talk of that here and I haven't look for other reviews yet...

Is there anyone else who carries a pcb for a clone?  I rarely build anything from pcbs, so don't know the smaller shops that may be around.

thanx

[jimilee]

The stage fright over at madbean. I have built the spaceharp, sounds just as good as my small stone. Haberdasher is a good guy and an excellent designer.

[LucifersTrip]

The stage fright over at madbean.

It said that it was the Maestro Phaser...though, I didn't compare schematics yet.

I have built the spaceharp, sounds just as good as my small stone. Haberdasher is a good guy and an excellent designer.

sounds cool...thanx alot for the info

[jimilee]

The stage fright over at madbean.

It said that it was the Maestro Phaser...though, I didn't compare schematics

sounds cool...thanx alot for the info
[/quote]
Dammit, you're right, my bad. It sounds kick ass though.

[Scruffie]

The Stage Fright is the Maestro Stage Phaser yeah, the non-ramping model.

The Space Harp is what you're after, don't know of any other PCBs for it.

[LucifersTrip]

The Stage Fright is the Maestro Stage Phaser yeah, the non-ramping model.

The Space Harp is what you're after, don't know of any other PCBs for it.

sounds cool...I'll go for that one.

I did see your name attached to the harp, so I'm sure you know it well.
http://www.madbeanpedals.com/forum/index.php?topic=14400.0

thanx alot

[Blitz Krieg]

is there documentation on the spaceharp?

[LucifersTrip]

at the link I posted above

[Mark Hammer]

UNless you have access to a secret stash of CA3094s, probably the closest you can get is a Tonepad Ropez.  The Ropez duplicates the 6-chip circuit using LM13600s, but subs an op-amp input and mixer stage for the discrete transistor stages the SS uses.  Same LFO, though.

[Scruffie]

UNless you have access to a secret stash of CA3094s, probably the closest you can get is a Tonepad Ropez.  The Ropez duplicates the 6-chip circuit using LM13600s, but subs an op-amp input and mixer stage for the discrete transistor stages the SS uses.  Same LFO, though.

Page 4 is a schematic for the V1 Small Stone using LM13600 (or similar) http://lectric-fx.com/wp-content/uploads/2014/06/SpaceHarp.pdf

The Ropez is a 4 stage OTA phaser that uses 2 OTAs for the LFO but that's about where the similarities stop, the input and output is different as you say, the feedback is different, the sweep width/range is different (well, at least in one of the modes) the filters aren't even set the same. It can be made close enough but stock it isn't anything like it IMO.

[Mark Hammer]

Hadn't seen that circuit.  And yes, it comes closer than the Ropez does, although the phase shift stages seem similar.  What is most different is the manner in which the feedback is routed.

[Scruffie]

The OTAs are set up in a standard OTA All pass filter fashion in both cases, but where the Ropez has 3n3, the Small Stone uses 6n8 so sweeps in a lower range.

The V1 Small Stone also has that low pass filter cap on the LFO to make those nice bubbly tones at higher rates, easily added to the ropez though.

[Mark Hammer]

The OTAs are set up in a standard OTA All pass filter fashion in both cases, but where the Ropez has 3n3, the Small Stone uses 6n8 so sweeps in a lower range.

Easily fixed/modded on the Ropez board if one wants.

The V1 Small Stone also has that low pass filter cap on the LFO to make those nice bubbly tones at higher rates, easily added to the ropez though.

Yeah, I've implemented that some years back, and it works well.  Makes the hypertriangularsweep more triangular at faster speeds.

[LucifersTrip]

Thanx for the replies...

I had a couple questions about the build:
http://lectric-fx.com/wp-content/uploads/2014/06/SpaceHarp.pdf

First, is this a standard dip 3 that will fit the pcb?
http://www.taydaelectronics.com/dip-switch-3-positions-gold-plated-contacts-top-actuated.html

...and just wanted some clarification on the feedback mod.
Instead of a dpdt, a spdt is installed on one "side" and a pot on the other, with a couple resistor omissions/changes.

So, with this mod, what happens in the 2 positions of the switch now that only one "side" is switched and in what setting are you back to the stock circuit?

thanx

[Scruffie]

Thanx for the replies...

I had a couple questions about the build:
http://lectric-fx.com/wp-content/uploads/2014/06/SpaceHarp.pdf

First, is this a standard dip 3 that will fit the pcb?
http://www.taydaelectronics.com/dip-switch-3-positions-gold-plated-contacts-top-actuated.html

...and just wanted some clarification on the feedback mod.
Instead of a dpdt, a spdt is installed on one "side" and a pot on the other, with a couple resistor omissions/changes.

So, with this mod, what happens in the 2 positions of the switch now that only one "side" is switched and in what setting are you back to the stock circuit?

thanx

That DIP should be fine.

The mod means that the switch will switch between the 2 LFO Widths as it always did but you'll have control of the amount of feedback applied is all.