Himmelstrutz - Fitzo

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Himmelstrutz - Fitzo

Postby engineelite » 03 Feb 2019, 23:31

I've got a Himmelstrutz Fitzo (not the more common Fetto) that has become my favorite low gain overdrive pedal over this past year. I build pedals but I'm not experienced at all in reverse engineering circuits... and I definitely don't want this to be my first one as some of the component values are scratched off. I'm willing to mail my Fitzo to someone experienced (and well respected around here) who can draw up a schematic from taking this one apart. I'm willing to pay shipping both ways. My only requests would be:

1. Please don't disassemble more of the pedal/components than you need.
2. Pease put it back together as neatly as you can and in perfect working condition.
3. Mail back to me in timely manner.

Who's up for it?

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mirosol (02 Apr 2019, 19:22), modman (04 Feb 2019, 17:24)
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Re: Himmelstrutz - Fitzo

Postby modman » 04 Feb 2019, 17:24

Great offer, but you can do a lot without sending your pedal out to a stranger. You should try and open the unit, put your digital camera on macro function, get some decent daylight and take some hi res pictures of both sides of the pcb. It might not be a walk in the park if the pots are mounted on the pcb, but well worth the try. Enough people here will gladly assist you in getting it back together again.

It's has happened that two years went passed before some gut shots were traced by an interested 3rd party.

Just had a look at the Himmelstrutz Fetto that was traced a while back -- that unit even contained sort of a layout on the back panel. And pots are not mounted on the pcb

take care,
J

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Re: Himmelstrutz - Fitzo

Postby engineelite » 06 Feb 2019, 01:21

Ok, I'll open it up in the next several days and see if I can make it happen. Thanks.

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Re: Himmelstrutz - Fitzo

Postby engineelite » 16 Feb 2019, 23:57

I got the pedal opened up, removed the black goop, then had to remove white paint, then discovered that all caps and transistors values are sanded off. I'm guessing the last thing to do is measure each component with a meter? How do I go about doing that to find the value of each cap and transistor?
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Re: Himmelstrutz - Fitzo

Postby box » 02 Apr 2019, 05:06

engineelite wrote:I got the pedal opened up, removed the black goop, then had to remove white paint, then discovered that all caps and transistors values are sanded off. I'm guessing the last thing to do is measure each component with a meter? How do I go about doing that to find the value of each cap and transistor?

Hi,
my recommendation is V2.68 Mega328 Transistor Tester Diode Triode inductor Capacitance ESR Meter.
Rgds,
box
box
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Re: Himmelstrutz - Fitzo

Postby gainiac » 02 Apr 2019, 05:46

engineelite wrote:I got the pedal opened up, removed the black goop, then had to remove white paint, then discovered that all caps and transistors values are sanded off. I'm guessing the last thing to do is measure each component with a meter? How do I go about doing that to find the value of each cap and transistor?


Nice work getting the goop off, Himmelstrutz stuff is always an uphill battle to trace. Now if the markings are truly and completely gone from the components, then the only way to get a value for each is going to be measuring with a multimeter. You won't need anything too special, but the meter will have to be able to measure capacitance which besides the very cheapest models, most have this feature and can be bought at a very reasonable price ($50 or less). As far as the measuring itself goes, the most thorough and guaranteed method is going to be lifting (momentarily desoldering) one side of each component before taking your measurement, then resoldering it back after. If you're not super proficient with your soldering/multimeter skills, as was already mentioned there are people here who will walk you through how to do this.

I'm not too familiar with the Fitzo so I don't know if it's op-amp and/or transistor based and I think Himmelstrutz sands off all identifiers on those components so that will be another hurdle to jump but there are ways to figure those out or at least narrow down options based on pinout and what not.

That all said, before you get too deep into this I'd start by taking some close-up pics of what you have to work with right now and posting them up for comments/advice from others. All we are going to be able to help with is generalities until we have some specifics in front of us to look at so you'll find help will be more forthcoming once you posted some images. Often the circuits people are looking to trace end up being based on or very similar to existing circuits and sometimes you can use that schematic as a starting point so it pays to have some experienced eyes take a look . Anyways, feel free to ask questions regardless of what you do.
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