Small Stone Phaser... SWEET!

killerkev · November 01, 2007, 07:49:29 PM

I have a 1981 Small stone that has been sitting here in need of repair. This version only has 3 IC and I believe the one that is socketed may be the incorrect chip. Does anyone have info on this? Possible what # chip is supposed to be there? Possible Mouser #?

Barcode80 · November 01, 2007, 08:56:09 PM

that is definitely the wrong chip. order the one from the smallbear link i posted earlier and replace with that.

Barcode80 · November 09, 2007, 01:44:10 AM

CRAP!!! I took the small stone out, repainted the enclosure, popped the circuit back in, and now it WON'T PHASE!!! I get only clean signal. hope i didn't fry a chip or something...

Fp-www.Tonepad.com · November 09, 2007, 05:53:01 PM

Could you have messed the pot wires?

Barcode80 · November 09, 2007, 10:44:11 PM

possibly, it was directly soldered to the board, but some traces got damaged when i first built it. i may just remove the opamps and uild another, since the sound was so nice!

Fp-www.Tonepad.com · November 18, 2007, 07:38:38 PM

I hear you. Sometimes troubleshooting is a lot of trouble, specially when you think about a clean fresh build's appeal

GonzoFonts · November 18, 2007, 10:45:12 PM

Not to derail this thread, but...

Does anyone know where I can get copy of the original schematic that uses CA3094's?

I recently got my hands on 6 RCA metal can CA3094's and I want to build the smallstone phaser to see what the fuss is all about.

Thanks.

GF

Barcode80 · November 19, 2007, 12:16:24 AM

Update: Well, i rebuilt it, used the same chips, and BAM! I'm phasing all over the place (I'm really going to need to clean that up)

I also built the Ropez (Ross Phaser) in the same day and it rules too!

lynessmy · January 08, 2008, 08:45:33 PM

I saw LM13600 instead of the more familiar CA3094 in the Small Stone Phase...is that real or the case has been mounted with some other guts.
If it is real, mean LM13600 can be used in place of CA3094 that almost distinct?

Barcode80 · January 08, 2008, 10:46:11 PM

if you saw a 13600, it was probably a rehoused ross. i'm fairly sure the small stone never came with the 13600

RedHouse · January 09, 2008, 12:33:06 AM

Quote from: Barcode80 on January 08, 2008, 10:46:11 PM
if you saw a 13600, it was probably a rehoused ross. i'm fairly sure the small stone never came with the 13600

I don't get what you're saying Barcode80, doesn't the pic posted above show at least two LM13600's in a Small Stone?.

Quote

drewl · January 09, 2008, 03:52:24 PM

Quote from: Mark Hammer on October 30, 2007, 03:17:00 PM

A useful mod is also to replace the 15k feedback resistor on the last stage with something like a 47k resistor and 330pf cap (for hiss control). That will give you about 3x the output of the original. Now, replace the 150k terminating resistor with a 100k log pot and a 47k fixed resistor between the ground side of that pot and the circuit's ground (run a wire from the wiper of the pot to the stompswitch, instead of from the "output" pad on the board). This mod will let you go from a noticeable-but-not-huge boost when the effect is engaged, to something a bit lower than bypass. That way the pedal can be used as a solo effect (with a boost added) OR as a rhythm effect (with a slight volume drop) if you so choose.

Is this for original small stones?

Meanderthal · January 09, 2008, 05:46:31 PM

That pic- are you sure that ain't a small clone instead of stone?

aankrom · January 09, 2008, 07:56:03 PM

Well saying the DOD FX20B is sweeter than making your own Small Stone clone, but the nice thing about DOD effects is that nobody seems to like them so they are easy to snatch up at ridiculous prices. I got mine used & broken at a music store for $5 and it was just a maladjusted switch.

The other thing about DOD effects is that they are SO tweakable. I suppose one could say, "well you HAVE to tweak them to make them usable." This has been true for every DOD effect I have bought, but the end results have been very satisfying and easy on my wallet. I have TWO R-870 Flanger/Doublers. I got the pair for just under $100, but they both needed fixing and tweaking. But now I have two MN3005/SAD512D-based delays with wet/dry controls for two output channels (from one in) that I can moddulate and regen - positive or negative - to my heart's content... But I digress...

The DOD FX20B is a 6-stage OTA-based (LM13600) phasOr. The only mod I have currently done is swap out the stock Mylar 6.8nF caps with 2% tolerance polypropylene ones - with a noticeable difference. I don't care about "true bypass". In fact it's often the case that an FET switched effect with FET buffers on the ins and outs will be much more seamless when switching the effect in and out. I mean you'd never want to put "true bypass" on a Dimension C clone, right? (Yes, I know. It HAS been done...)

The next mod I plan is a 3-position rotary or more probably toggle switch to select from 6-stages to 5-stages to 4-stages like the Small Stone and DOD FX20C (which is a 4-stage phasOr). Nobody thinks about odd-stage phasers, but a 5-stage phaser won't sound the same as a 4-stage one or a 6-stage one, so it MERITS having the option, no?

I guess it's apples and oranges saying a 6-stage phaser is better than a 4-stage one. I also have a Boss PH-3, which for some reason went from 4 to 8 to 10 to 12 stages, never giving a 6-pahser any thought (well the instruction booklet says the 12-stage is 2 6-stage phasers. Huh? Oh well...). But the PH-3 is in a different league, being digital and having a lot of fun options other phasers (or phasOrs) don't have. But I digress...

My point all along is that you can use an LM13600 or an LM13700 or the more pricey dual OTA's with buffers. CA3080's are even becoming hard to come by and there is more consistency between units with the LM13X00, which is very good for phasers. Forget about trying to get a CA3094. It's not worth the bother.

But anyone with DOD effect they don'y want and can't seem to sell, drop me a line...

Anthony

asatbluesboy · July 20, 2011, 11:16:14 AM

And... 3.5 years later someone comes by just to thank Mark a bunch. Did all the mods (I agree with the color control being best applied as a switch) and it does pretty much everything I want from a phaser. The filter switches are really useful--I have them on low-pass position pretty much all the time.

As the thread had already derailed, I have two further questions:
1) Has anyone tried Small Stone values--6n8 for all phase stages? How does it sound?
2) Any tips on how to reduce clock noise? Mine's the black one (not a clone), so could it have to do with some components' (caps) aging? The 3u3 looks pretty damaged.

asatbluesboy · August 02, 2011, 10:34:00 AM

Quote from: asatbluesboy on July 20, 2011, 11:16:14 AM
And... 3.5 years later someone comes by just to thank Mark a bunch. Did all the mods (I agree with the color control being best applied as a switch) and it does pretty much everything I want from a phaser. The filter switches are really useful--I have them on low-pass position pretty much all the time.

As the thread had already derailed, I have two further questions:
1) Has anyone tried Small Stone values--6n8 for all phase stages? How does it sound?
2) Any tips on how to reduce clock noise? Mine's the black one (not a clone), so could it have to do with some components' (caps) aging? The 3u3 looks pretty damaged.

Ahem...

Renegadrian · May 13, 2016, 10:41:33 AM

Quote from: killerkev on November 01, 2007, 07:49:29 PM
I have a 1981 Small stone that has been sitting here in need of repair. This version only has 3 IC and I believe the one that is socketed may be the incorrect chip.

fast reply here...maybe it can help others...have a similar one in my hands right now to be truebypassed and blended and ledded, that chip is correct. lm324n is what I have on it...

News:

Small Stone Phaser... SWEET!