I've seen resistors before, but nothing like these. Anyone have any ideas?



I know the round, light blue ones are tantalums and there's a diode and some caps in there... but the resistors? What about the square caps? anyone have a "cross-reference" to see what the numbers mean?

Hmm... what's wrong with the caps? mybe you're confused with the Euro way of notation. There are some nice conversion tables on the net form Euro to US notation, but I can't remeber where. Someone will surely know around here. Guys?

Anyway: In brief:
1µ = "1.0"
1n = "0.001"
1p = "0.000001"

I don't know what to say about the resistors? Try some color decoding.

If it helps at all, this is a H&k Red Box HKII... so German resistors might be different? :?

R = STD. 5-band code - 6 = tolerance
C = self healing metalfilm caps - STD. coded

1uK200 = 1 uF - 5%tol  - 200V DC
1nK400 = 1 nF - 5%tol  - 400V DC

JHS

So I should read the colors "after" the red band? :?

the last red = 2% (metalfilm res)

edit: I stand corrected - always something left to learn....

Hmm... ok, I think I've got it...

--[|Y|V|B|O|C|R|]--

Yellow
Violet
Black
Orange
Copper <-- Self Healing
Red      <-- 2% Metalfilm

(I'm talking about the resistor between the 2 1/4 jacks). Am I close?

what pedal is that by the way?  It looks interesting

5 band resister coding ?

Go to Aikenamps.com -> tech info -> resister color codes.

The fat band is the tolerance.

Caps are from the VALVO comp.

JHS

Quote from: bobbletroxwhat pedal is that by the way?  It looks interesting

It's a Hughes & Kettner Red Box HKII... I've been on a quest to build one, and it seems that this one is easier to build than the RedBox Pro.

JHS, thanks for the info... you've been a lot of help.

(I just noticed a resistor hidden behind the jack on the right... anyone with guesses what value it might be? I'm thinking that I should just go out and buy one of these boxes

Check this out, 4,5 or 6 band resistor calculator.
http://samengstrom.com/elec/resistor/6band.html

Quote from: RLBJR65Check this out, 4,5 or 6 band resistor calculator.
http://samengstrom.com/elec/resistor/6band.html

Whoa! That is one COOL page!!!
Thanks!!!

you'll eventually just get a "feel" for which end to start reading the bands from, until then it can be frustrating.

Look really closely, usually the temperature coefficient band has a larger gap between it and the rest of the bands.

4 band;
two significant figures, one multiplier and a tolerance.

5 band;
three significant figures, one multiplier and a tolerance.

6 band;
same as 5 band, but add a temperature coefficient band.

Anything with a yellow temp co and a purple tolerance is bitchingly fantastic quality! 25ppm @ 0.1%!

The caps are just as you see them. 1n = 1nF etc. the number on the end is the voltage rating.

I once wanted to make a schematic based on the pcb, and I seem to remember I read somewhere that it was supposed to be the same configuration than the Cream Machine. But I never had time to check that.

http://www.amptone.com/images/schem_cream.gif

Btw, nice info page about 6 band color codes. It helped me find the following.

I checked on my pcb and the partially hidden resistor has the same value as the one close to it: 10K 1% 50 PPM/oC, Brown, Black, Black, Red, Brown, fat Red. All resistors have the same temp coeff (fat Red bar).

The 3rd one close to them is a 470K, and the one close to the red wire is another 10K.

Good luck,

Gilles

Thanks for the additional info, Gilles. I'm trying to get it all drawn out with the pics you sent. I was actually trying to build the RedBox Pro, but the problem is locating the transformer.

I hope you're able to check back to this thread when you can; in case someone has a question about the box.

I sent you an updated pic with the resistors and some caps values added.

One thing I'm not sure is the values of the 3 small caps identified n22 and n10.

Does anyboby knows for sure if it's for 22nF and 10nF?

I will try to add more when time permits.

But being on vacation for the next 3 weeks means that I should be away from home most of the time. And I'm sure that my wife will be glad if I stay away a bit from electronics the following days.

Gilles

small... as in those ceramic monolythic types? (yellow and purple ones in top right of O's photo?)

My money is on 220pF and 100pF. The 'n' acts as a decimal point.

Yes, the 2 yellow and the purple ones.

Yeah, I think you could be right.

That's the feeling I had about one of the blue caps identified u1J100 while another one is identified as 22nK250 for example. It could be a .1 uF (or a 470nF)

So the 220pF and 100pF values would be correct. I didn't see it as clearly that time.

Thanks niftydog.

We (me and my wife) decided to do a quick 1 day trip today, and come back home tonight to be able to go to Ottawa and maybe to go south to US a little bit this week.

So beeing at home tonight permitted me to work a bit on the circuit.

Having the pcb out of the box, I might as well help O with his project when I can (or when I'm home).

Gilles

Added: a cleaner scan of the layout, and what I think is the correct layout. I had to clean the flux with some solvant to be able to see some traces...

http://www.finitesite.com/gtechblues/Files/Scan.jpg

http://www.finitesite.com/gtechblues/Files/Traces.jpg

http://www.finitesite.com/gtechblues/Files/Scan1.JPG

One is upside-down

hey , why don't you post a picture of the trace side of the circuit ? we could make a schematics out of this ! thanks!
domenico

oooopsss!!! )
thanks!