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Messages - JackSkellington

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1
General Questions / Re: Charge Pump: a bit of confusion
« on: September 16, 2018, 02:26:59 AM »
Just because I got a piece of stripboard slighly smaller than what I need for this layout I drawn the it again.
I moved the jumper that make to go the pin 3 to the ground and I moved a cut.

None of these two layouts are verified, but they shoud be ok because the original one is really similar.


2
General Questions / Re: Charge Pump: a bit of confusion
« on: September 14, 2018, 08:10:10 AM »
Here's the modded layout with a jumper makes even the pin 5 grounded.



Thanks! ;)

3
General Questions / Re: Charge Pump: a bit of confusion
« on: September 13, 2018, 01:37:30 AM »
Pin 5 in the GCFX schematic you've shown is also attached to ground -- if you look, it's wired to the same GND point as Pin 3.

Yeah, I meant right this. The veroboard layout has the pin 5 isolated, in the Aeon (Tight Metal) schematic the pin 5 is grounded.

Page 8 of the data sheet, left column: explanation of how the circuit works to use switches on a high-frequency cycle to charge an external capacitor and prevent it from discharging, and discussion of technical considerations of how the switching transistors are biased to avoid latching up. Page 8 right column do's and don'ts, point 7: "User should ensure that the output (pin 5) does not go more positive than GND (pin 3). Device latch-up will occur under these conditions."

In the voltage doubler application, we aren't using the V_out (pin 5) that is used for the negative voltage output. The do's and don'ts clearly suggest that it should be tied to ground. If it floats and is not tied to ground, the circuit may work, until something unexpected happens and it latches up, and then it won't work (and the user will probably say "My charge pump IC is bad," mis-diagnosing the problem).

«If it floats and is not tied to ground, the circuit may work». That MAY worry me a bit. :P

There's even Sabrotone layout:

But this HAS the pin 5 grounded.

It's slightly bigger than the other, and it has the 100uF and 1N4001 extra parts. I assume I can omit them, right? The Tight metal layout already has them.

But I guess I can settle with the tagboard layout and to add just a jumper from the pin 5 and the ground stripe, a shortest jumper in the column between the diode and the cap.
Is that correct?

4
General Questions / Re: Charge Pump: a bit of confusion
« on: September 12, 2018, 02:37:04 PM »
Thanks for the datasheet.
That kind of connection causes the doubt. Why in that layout the pin 5 are isolated? And that layout is verified and used. ???

5
General Questions / Charge Pump: a bit of confusion
« on: September 12, 2018, 02:55:06 AM »
Hi, everybody!

I'm going to build the Amptweaker Tight Metal, but the layout I found doesn't have the charge pump, so I have to build a daugherboard.
I bought some ICL7660SCPA, I want to build something based on it.

I never used a charge pump, but I always thought the following veroboard layout was simple and good:



Of course, I compared it with some ICL7660S layout. Some of them include some extra parts like a 100uF and/or a 1N400X diode, as filter in the power supply. But the layout of the Tight Metal I have to use already has this accessories parts, and I guess I don't need of them.

And now my doubt about the circuit. I see in the charge pump layout that the pin 5 goes nowhere, so it's isolated. But in some other layout, as some schematic, pin 5 is connected (with the pin 3) to the ground. Why in this layout it isn't so?

Here's the schematic of the Tight Metal by Grind Customs with a charge pump section similar to the veroboard layout, except where pin 5 and pin 3 are connected together, and both go to the ground:



Should I consider to put a jumper to connect the ICL7660S pin 5 to the ground like the schematic?

6
General Questions / Re: Phase 90: Matched 2N5952 or just any J201
« on: September 10, 2018, 02:24:24 AM »
I could order the MMBFJ201, eventually, from Tayda, just because they are cheaper than the ones from Musikding.
I'm not talking about my Phase 90, but for any other project.

Meanwhile, I ordered a quartet of 2N5952. Not cheap, but it will work for sure.

7
General Questions / Re: Who knows the real trick to get more bass? (RAT)
« on: September 07, 2018, 01:29:23 AM »
Thanks guys. I knew that BB Mod. I tried a 220R and a 10uF.
The Fat Rat add a 6.8uF in parallel to the 2.2uF. Indeed, I tried to replace the 2.2uF with a 10uF.
I noticed just the usually tame of the highs.

I can't try again all these. Next time I should try harder, or I'll let it go.

8
General Questions / Re: Who knows the real trick to get more bass? (RAT)
« on: September 06, 2018, 01:51:55 AM »
[...]
You can boost the base as much as you're boosting everything else by making C7 220uF. You'll boost literally every frequency. You might as well remove R7 and C6 now as they aren't doing anything. If you turn the treble cut all the way up, ta-da, you have a bass booster. Of course, now you sound like you're playing underwater, but you did ask for a bass booster ...

I would like to increase the bass without cut the treble (or the gain) this is the problem.

http://baritones.tumblr.com/post/92511266453/darrell-rants-about-the-proco-rat-and-the-ruetz

Thanks for the link. I tried some mods like that, but the all of them are pretty subtle about the increasing of the bass. Rather those was a cut treble.

9
General Questions / Re: Who knows the real trick to get more bass? (RAT)
« on: September 05, 2018, 01:03:00 AM »
Thank you very much, I'll try to take a look. ;)
Unfortunately, it's not a very simple solution I was thinking.

10
General Questions / Re: Who knows the real trick to get more bass? (RAT)
« on: September 04, 2018, 05:57:54 AM »
Some clue how I could do it? ???

Please? :D

11
General Questions / Re: Who knows the real trick to get more bass?
« on: September 04, 2018, 01:10:36 AM »
I don't know if I like the blend mod. So the Rat really seems "bass unboostable"?

But the Fat Rat version has a bass boost, some demos show it works pretty fine.
I heard that it adds a 6.8uF in parallel to the C6 4.7uF, thing I tried replace C6 with a 10uF, but... it's not a really bass boost. :(

12
General Questions / Who knows the real trick to get more bass? (RAT)
« on: September 03, 2018, 08:09:04 AM »
Hi! With my second Rat building I tried some tricks I read around here and there to get more bass from this pedal.

I tried with my first Rat the Ruetz mod with the pot control (replacing the R6 47R with a 1k Linear pot).
Now I tried to replace the C7 2.2uF with a 10uF. Then I back with the stock caps.
Then I replace the C6 4.7uF with a 10uF, and even the R7 560R with a 220R.
Nothing of that gets more bass, I got just a slightly dull sound, but this is not a Fat/Bass Boost mod I mean.
I guess it's very hard to get more bass from this circuit!

Who knows the real trick to get more bass?

Thanks!

13
Build Reports / Re: Aion Electronics Refractor/Klon-Centaur
« on: August 23, 2018, 10:12:32 AM »
Form my experience the 1n34s from Tayda have tested on my multimeter have been in the 2.7/2.8 range. Could just be the batches I've received on a few occasions....good luck!

Hi destro. I'm sorry, perhaps I missed something. What do you mean? What is 2.7/2.8 range?

Best thing to do is socket and test with your ears.

Yes, probably I'll do. It's just to know how this pedal works.
Anyway, I bought a pair of D9E from Musikding and, of course, I forgot the 1N34As from Tayda! ;D
So, I'll have wait some weeks to build the Klon and I'll socket the diodes. I'm going to try D9E, 1N270 and... what about 1N60P?

14
Build Reports / Re: Aion Electronics Refractor/Klon-Centaur
« on: August 22, 2018, 06:32:29 AM »
I just want to be sure if the 1N34As Tayda are fine and accuracy for the Klon.

15
Build Reports / Re: Aion Electronics Refractor/Klon-Centaur
« on: August 22, 2018, 04:20:53 AM »
So... the 1N34As are the correct diodes? :o If I already knew it, I forgot it!

I was going to order D9E from Musikding. The 1N34As are more expensive than D9E. Or I could order a pair of 1N34A from Tayda, the low cost choice.

Now, what I have to do? ???
Cheaper D9E from Musikding, expensive 1N34A or cheapest 1N34A from Tayda?
I also have two 1N270s diodes from Tayda bought maybe four years ago.

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