Does anyone know where to buy OP275 op-amps?

[RDV]

I wish Small Bear had them :wink:  :wink:
I want to build a "Freddy Fuzz".

Regards

RDV

[smallbearelec]

Noted for next year. I have spent a godawful amount of money in the last few months stocking my shelves with staples. I will be adding new items, too, but slooowwly.

SD

[aron]

I wish Small Bear had them :wink:  :wink:
I want to build a "Freddy Fuzz".

Go ahead and build it with the "normal" chips and then sub the OP275 later.

BTW: I played a real one a month or so ago and I found it had rather low distortion levels - I was amazed.

[RDV]

I understand that to buy enough of anything to get the price that makes it profitable you have to make a fairly serious commitment $-wise & space-wise.

Regards

RDV

[RDV]

Go ahead and build it with the "normal" chips and then sub the OP275 later.

You mean like a 4558 or something?

Regards

RDV

[Paul Marossy]

When I built my Freddy Fuzz clone (AKA Black Cat OD-1), I just asked for samples of the OP275 directly from Analog Devices, the manufacturer of that opamp. They sent me some very quickly.
I have also tried a JRC4558 and a NTE928M, and they worked fine. The OP275 did seem to sound the best of the three that I remember trying. I'm sure there are many others you could use - NE5532, LF353, KA358, MC1458, LF412 and others.

[RDV]

When I built my Freddy Fuzz clone (AKA Black Cat OD-1), I just asked for samples of the OP275 directly from Analog Devices, the manufacturer of that opamp. They sent me some very quickly.

That's the route I've gone also.

Regards

RDV

[RDV]

When I built my Freddy Fuzz clone (AKA Black Cat OD-1)

Hey Paul, I've put one together, but mine sounds kind of grainy, any tips for a better sound?

Regards

RDV

[Paul Marossy]

What kind of caps did you use? I used ceramic caps in mine and it sounds pretty good, actually. It will sound a little grainy/rough with a humbucker in the neck position, but it still sounds good IMO. I think it was probably designed more for a Strat w/ single coils.
I incorporated a tone control on the input and the output, which really helps to shape the tone. I didn't use very big caps or pots on the tone controls, just enough to smooth it out a little bit. It was a little too bright for my tastes when I first built it. I like it quite a lot, it's been on my pedal board since I built it a couple of years ago.
According to AnalogMan, "The OD-1 is a very sensitive distortion pedal, housed in a small black MXR distortion+ sized box. This pedal can go from clean, slightly crunchy tone to all-out saturated fuzz. It is unique in that it is VERY sensitive to the guitar- like a good fuzzface it cleans up well when you roll back the volume on the guitar."
Mine does clean up pretty well when I roll back the volume knob, but not quite as well as my Boutique Fuzz Face will. The Freddy Fuzz has considerably more gain, though.
One other thought... you could try messing with the 100pF cap that is in the second feedback loop. Maybe a 120-150pF cap may smooth it out a little bit without affecting the frequency response too much.

[RDV]

The .1uF caps are all poly. The smaller ones are ceramic. The larger ones are electrolytics.

I've been using it with the Les Paul, which could explain some of the graininess. Is the schem(I used the one from your site) copied from an original, or does it contain your mods?

I also haven't boxed it or tried it with the Marshall yet either. It may have a somewhat different character through the stage rig.

Regards

RDV

P.S.
Have you looked at the Si Tonebender I have in Schematics 2 ?
It is a great sounding pedal for what it is :wink: .

[Paul Marossy]

The schematic on my site is a redraw of one the Gilles C. drew up a while back. I just added the footswitch wiring to the schematic. I used ceramic caps throughout, it was the first thing that I built. In my case, it seems to have worked out well. The tone pots were an afterthought, so they are no on the schematic. I'm glad you found something on my website useful.

Hmm... I haven't really looked at the Si Tone Bender yet, I'll have to check it out.

[RDV]

The Blackcat OD-1 seems to work best to boost an already distorted amp. It doesn't stand on it's own too well(similar to MXR Dist+).

My faves so far as distortions go are:

Rocket(maybe the best sounding FF deviant ever)

Si Tonebender(like a FF on steroids)

Obsidian(transistor version)(can't really make it work on stage, but a whole lot of fun at home)

Regards

RDV

[Paul Marossy]

Well, my Freddie Fuzz clone has a lot of distortion all on it's own, about as much as my Boutique Fuzz Face does with some higher gain Ge transistors in it... a little more than my Blue Magic, but not quite as much as my Boss Metal Zone. It may have to do with the ceramic caps.

I've heard a lot of good stuff about the Rocket. I built the Rev. B MOSFET version of the Obsidian Overdrive, which sounded great, but was too noisy to really use it much. I've heard that the transistor version sounds good, too.