Question about BOSS NF-1

[onelife]

Hello, I am new to this forum, so I am begging the moderators to move my post if it at the wrong place.
Anyway, I am planning of making a replica of the BOSS NF-1 Noise Gate. I found the schematics on the internet, but I am not very familiar with USA conventions of electrical schemes and I can't understand something.
Where do these black arrows connect to?
What are they connected to?
I would be glad if anyone could help me, or give me some information about the USA conventions for electronic components, so I could understand the schematic.
I would also like to ask about the notes for the capacitors - what does 1/50 mean? - 1uF/50V? Something like that?
And if it is so, is it the same for the other capacitors - 100/16,2.2/50, etc

[Heemis]

The black arrows indicate a connection to +9vDC.  If you look just to the right of the adapter input, you'll notice a black arrow that's labeled "9v".  This means that all black arrows are connected together.

You are correct about the capacitor markings.

[onelife]

Thank you very much for you reply. Now it is really more clear to me.
I would also like to ask something more about the capacitors - in what dimension are these - 0.1, 0.047, 0.033. In some pose through the net(I couldn't remember where that was) I read that this is measured in Farads, so it should 0.1F, 0.047F but this way of giving the dimensions is really unfamiliar to me, and I am not sure how should I read it.
I guess that this is some old fashioned way of giving the values, thus the schematic is made in the early 70's
Any help on that would be appreciated/

[slacker]

I would also like to ask about the notes for the capacitors - what does 1/50 mean? - 1uF/50V? Something like that?

Yes, this means 1uF 50 volts. You do not need to use the same voltage capacitors, they should just be at 9 volts or more.

The capacitors with no dimensions are in micro Farads (uF).
10 = 10uF
0.015 = 0.015uF = 15 nano Farads

Welcome to the forum

[PRR]

> in what dimension are these - 0.1, 0.047, 0.033.
> I read that this is measured in Farads, so it should 0.1F, 0.047F

In 1970, there was no 1 Farad cap and 0.1 Farad was the size of a small trash-can.

If you study many schematics, you see that 10uFd, 1uFd, 0.001uFd are VERY commonly used.

Next to Q7 Q8 are some "470p", 470 picoFarad.

Since 1970 there is a trend to use "nF", nanoFarad.

Pico, nano, micro, milli are standard Metric-system decimal units.

1,000 pFd = 1 nFd
1,000 nFd = 1 uFd
1,000,000 pFd = 1 uFd

It was common for schematics to have a note "all caps in uFd unless otherwise noted." This may have been trimmed-off the image you posted.

[onelife]

Well, these are really more complete answers than I expected, which is highly appreciated by me I am glad that I found that forum.
For the future I would remember that about:
"all caps in uFd unless otherwise noted."
I just didn't knew it but it is really useful, and I would look for that if it is specified in the schematics for the future
Thanks for the warm welcome.
OK, my next question is about that part "SDT 1000". I found in the net that this is a thermister but I could find it anywhere in my country, so I could buy it.
Any ideas on what is its function in that schematic, or where should I buy it from, or any equivalent of that?

[PRR]

> question is about that part "SDT 1000".

That's very fussy Japanese engineering. The JFET Q3's threshold voltage varies with temperature. When too-thorough Japanese engineers use precision meters and test at extreme temperatures, the action changes a little bit.

Replace the whole network 4.7K SDT1000 and 10K with one 3.6K resistor, adjust VR4 in normal playing conditions. That will be fine until you do a gig so cold you have to play with gloves on, or a noon concert in the desert. Then you may need to nudge the Sensitivity knob a bit. (But you probably have to fine-trim Sensitivity for almost any change of gear or venue anyway.)

[onelife]

Ok, tha past I was trying to know the elements and the schematic itself.. and it going well.
But I can't understand something about the adjustments. Here are the instructions:

Adjustment procedure:

1) Set the Sens knob fully counterclockwise and the Decay knob fully clockwise.

2) Connect an oscilloscope to the effect's output through a millivoltmeter. Feed a 1kHz -45dBm sine signal to input.

3) Adjust VR3 and VR4 for the values shown in Fig.3.

The only problem who produces the sine signal with these parameters. Probably a sine generator, but how should it be adjusted, so that it provides signal with -45dBm, which is 100nW.
And how could I find this generator, or how could I make it. I am interested in that because I first want to make the schematic in some software - pSpice or Proteus so I could make a simulation and try to adjust the guitar effect as it is shown.
Please help with this generetor.

[PRR]

> provides signal with -45dBm, which is 100nW.

0 dbm is 1mW.

100nW is -40dBm. 

-45dBm is 0.031uW.

But in small audio we don't think in Watts.

dBm is "power"; but in audio if not specified otherwise it means "power in 600 ohm resistor".

And the easiest way to measure audio power in a resistor is by Voltage.

-45dBm is 0.00436 Volts, 4mV.

> how should it be adjusted,

If you mean a physical signal generator: adjust output to a convenient level, say 1 Volt. Compute a voltage divider to give 0.00436V in 600 ohms.

Bottom resistor may be 600 ohms. Top resistor is 1/0.00436 times higher, 137,600 ohms.

620 and 140K are convenient standard values.

If you mean a simulated signal generator-- the "-45dBm" assumes RMS value of a Sine. Some simulators do all work with Peak values, 1.414 times higher.

> I first want to make the schematic in some software

Limiters are VERY hard to simulate. You need a rapid sample rate to get the audio wave right, but you need a much-much longer total time period because the compressor action is slower than the audio. In this case you also have Q5 Q6 slamming through zero current, which requires the simulator to slow-down to capture the very small currents (even though we really do not care). Simulations which slam parts through "zero current" are also very likely to fail, convergence problems.

[onelife]

Well, I just tried some simple simulation of previous discussed things. It is made in Proteus 7.
There is an option of putting generators there. So I put Sine generator which provides 1V, 1kHz sine wave and to its output I connected the mentioned Voltage Divider.
According to the Voltage Probe = 0.0044V and the oscilloscope it looks like this is the way that I could try the BOSS-NF1 when its schematic is ready.
There is just one thing. Physically I have to make a sine wave generator which could provide nice sine wave or something that approaches to it. Yesterday I found one solution but when I attached it to the oscilloscope it didn't provide sine, but instead of that something like "pulse-shaped" signal.
Please tell me your opinions of my simple simulation.
I am going to search for appropriate schematic for this generator. Any ideas are welcomed

[onelife]

Due, to the fact, that stereo and mono jacks are not included in the Proteus software, I am wondering how could I replace them. May be with just outputs or something like that, which simulated correctly the jacks.
Could you give any opinions on that, may be someone with more experience in board design than me

[PRR]

> didn't provide sine, but instead of that something like "pulse-shaped" signal.

Looks sine to me:



> stereo and mono jacks are not included in the Proteus software

You don't need jacks to _simulate_ a circuit. It may be a problem when you finalize a PCB layout.

[onelife]

Yes, that's a sine but I wanted to make a real simulation oscillator, because this is integrated in the software and it is ideal.
I think I found one solution using Wien-bridge oscillator but I post it in another post. You can check it here if you are interested:
http://www.diystompboxes.com/smfforum/index.php?topic=96413.0.
Also you can give your opinion, it would be useful for sure
As to the PCB design then I am not sure how could I make the 1,2,3..etc. points in the schematics, so that they appear when making the PCB, I guess it would be done
the hard way (manually

[PRR]

> this is integrated in the software and it is ideal.

What's wrong with that? The Boss NF-i does not have an oscillator. What you really want is a simulated guitar. But for all realistic simulation you use an ideal sine wave.

[onelife]

But where should I get this ideal wave from, so I could simulate a guitar signal. What is the device. I thought that the oscillator is the device that creates sine waves.
May be something else?