Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Amplifier Discussion => Topic started by: dan6896 on February 02, 2011, 12:01:20 AM

Title: Noisy Cricket problems!
Post by: dan6896 on February 02, 2011, 12:01:20 AM
Ok, so i built a noisy cricket following the schematic on beavisaudio.com,turned it on and plugged my guitar in it sounded pretty good. but when i turned the volume up and started playing it made this horrible fuzzy sound, same with the gain pot. :grr  when i turned the boost switch on it sounded absolutely terrible :grr :grr. its really hard to describe the sound that it makes. Whenever i play a note it makes the same fuzzy farting sound but it is dead quiet when nothing is being played. I have checked the schematic to my layout and it is all connected fine. i have tried many different speakers and it all sounds the same

any ideas on how to fix this.

in advance thanks for the help, ;)



Title: Re: Noisy Cricket problems!
Post by: DJPhil on February 02, 2011, 04:20:29 AM
I'm not entirely sure what your trouble is, but I have something you can try. I made a Ruby (similar 386 amp) for a friend, and he found that it sounded horrible if his guitar's volume wasn't turned down a good bit. He's got an axe with an (my opinion) absurd amount of pickup options on it, and it ran a bit hot for the Ruby.

The Ruby's volume and gain controls are very, very interactive and require a lot of tweaking. In the Ruby we'd often turn the volume up, the gain down, and slowly bring up the gain until it started breaking up at about 1/3. With the volume at half the gain would go to about the same. Exceeding that brings the clipping on hard and the sound gets horrible.

If you dink with it a while and have no luck you might consider trying to post a sample of the audio, as it'd be really useful if it turns out to be a bugger.

Hope that helps. :)
Title: Re: Noisy Cricket problems!
Post by: joecool85 on February 02, 2011, 05:53:10 AM
I haven't built the Noisy Cricket, but I did build the Little Gem which is a more basic LM386 design at runoffgroove.com.  The only time mine got "farty" was when the batteries were low or I had a grounding out issue.
Title: Re: Noisy Cricket problems!
Post by: J M Fahey on February 02, 2011, 07:51:23 AM
Please post the schematic here, so we all refer to the same one.
A picture would also help, to see your layout.
Never built a Noisy Cricket , but the simple 386 one (similar to the Smokey), and had no farting problems.
Yes, it overdrives easily, but in a pleasant way.
In fact there even is a distortion pedal based on it.
Title: Re: Noisy Cricket problems!
Post by: dan6896 on February 03, 2011, 01:59:39 AM
ill try and post a picture in a couple of days. i was gonna post a sound sample but my mic screwed up :grr

schematic attatched:

ps: im using an lm386N-4

thanks everybody :tu:

Title: Re: Noisy Cricket problems!
Post by: J M Fahey on February 03, 2011, 10:58:44 PM
Well, with no volume and minimum gain, what's the DC voltage on LM386 pins   6 and 5?
What's Q1 (Fet) source voltage?
In that schematic, C3 should be 10uF and don't know what C4 is supposed to do.
I would not use it at all.
Title: Re: Noisy Cricket problems!
Post by: dan6896 on February 03, 2011, 11:21:38 PM
from what i believe c4 is  switchable to get extra grit.

ill post the voltages soon.

i tried it on 12v power and it sounded much better but it has the same kind of farty sound
Title: Re: Noisy Cricket problems!
Post by: Alexius II on February 04, 2011, 03:04:43 AM
Have you tried it with a battery?
By your description, this could be caused by a "bad" power supply (and/or a ground loop), as joecool already stated.

Try a battery or another power supply  :tu:
Title: Re: Noisy Cricket problems!
Post by: dan6896 on February 04, 2011, 03:15:31 PM
i used it with a 12v power drill battery which had about 13.8 volts
Title: Re: Noisy Cricket problems!
Post by: Dimi Pana on October 25, 2011, 05:39:16 PM
Quote from: J M Fahey on February 03, 2011, 10:58:44 PM
Well, with no volume and minimum gain, what's the DC voltage on LM386 pins   6 and 5?
What's Q1 (Fet) source voltage?
In that schematic, C3 should be 10uF and don't know what C4 is supposed to do.
I would not use it at all.

Hello, JMF !!!

Are you absolutely sure this C3 should be 10μF instead of 100nF ? What is the reasoning behind that? I am not questioning your input -on the contrary- I am just curious why, just want to learn.

Also, when jumpering pins 1 and 8 of the LM368, should n't a capacitor be in there as well? I read somewhere about this but unfortunately do not remember any specifics.

Thank you!
Title: Re: Noisy Cricket problems!
Post by: joecool85 on October 26, 2011, 02:01:22 PM
Quote from: Dimi Pana on October 25, 2011, 05:39:16 PM
Also, when jumpering pins 1 and 8 of the LM368, should n't a capacitor be in there as well? I read somewhere about this but unfortunately do not remember any specifics.

On all three LM386 amps I've built I jumpered 1 and 8 directly, no cap or resistor.
Title: Re: Noisy Cricket problems!
Post by: J M Fahey on October 26, 2011, 05:25:42 PM
Fact is, LM386 was designed with *extreme* simplicity in mind.
So much so, that it includes the gain setting negative feedback resistors.
To provide you an option, one of them is connected between pins and 8.
Open: "normal" gain, good for most uses.
Shorted: quite a lot more.
But there is some DC voltage betwen those pins, so if you add a pot there to vary the gain, you need a cap in series with it or it will scratch.
If you add a gain switch, it will pop when activated.
If the connection is fixed, no problem, can use or not the 10uF cap at will.
a 100nF cap is too small and, best case, will work as a bright control.
Title: Re: Noisy Cricket problems!
Post by: Dimi Pana on October 26, 2011, 11:20:18 PM
Quote from: joecool85 on October 26, 2011, 02:01:22 PM
Quote from: Dimi Pana on October 25, 2011, 05:39:16 PM
Also, when jumpering pins 1 and 8 of the LM368, should n't a capacitor be in there as well? I read somewhere about this but unfortunately do not remember any specifics.

On all three LM386 amps I've built I jumpered 1 and 8 directly, no cap or resistor.

OK, I am getting a little confused, but that's normal for a novice, right?

So, the LM386N-1 datasheet http://www.national.com/ds/LM/LM386.pdf (http://www.national.com/ds/LM/LM386.pdf) says:

"With pins 1 and 8 open
the 1.35 kΩ resistor sets the gain at 20 (26 dB). If a capacitor
is put from pin 1 to 8, bypassing the 1.35 kΩ resistor, the
gain will go up to 200 (46 dB). If a resistor is placed in series
with the capacitor, the gain can be set to any value from 20
to 200."

First the 1.35 kΩ resistor from the datasheet, where is it on the NC schematic?

Second, regarding the pin1-8 gain thing, what is the difference between the two approaches? What are the benefits or simply the rational behind each design?

I guess if I want max gain without a gain pot I do it like you Joe, otherwise if I want to vary the gain from 20 to 200 then the original NoisyCricket design is correct right? But there is no capacitor in the NoisyCricket. So what's going on?

Also, that C3 cap is connected to pin 7 which is labeled as "bypass". Bypass, of what? The way I see it pin 7 is also connected to pin 5 (Vout) via the the "grit" switch and C4. I mean pin 7 is there for a reason, so why is it labeled "bypass".

So that C3 what is it doing there and is the NC value correct or should it be changed to 100nF instead of 10μF and why?

Thanks!
Title: Re: Noisy Cricket problems!
Post by: Dimi Pana on October 26, 2011, 11:38:51 PM
Quote from: J M Fahey on October 26, 2011, 05:25:42 PM
Fact is, LM386 was designed with *extreme* simplicity in mind.
So much so, that it includes the gain setting negative feedback resistors.
To provide you an option, one of them is connected between pins and 8.
Open: "normal" gain, good for most uses.
Shorted: quite a lot more.
But there is some DC voltage betwen those pins, so if you add a pot there to vary the gain, you need a cap in series with it or it will scratch.
If you add a gain switch, it will pop when activated.
If the connection is fixed, no problem, can use or not the 10uF cap at will.
a 100nF cap is too small and, best case, will work as a bright control.

In my case, the 386 being simple is good.

So since I do want a Gain control, do I follow the NC design exactly or do I add the extra 10μF cap in series with the variable resistor between pins 1 - 8? And what designation do we give that cap so I do not confuse it with C3. And what is the purpose of C3 ???

Thanks!

Title: Re: Noisy Cricket problems!
Post by: J M Fahey on October 27, 2011, 09:34:05 AM
This Forum tries (and does !!) help, but it's not Electronics 101.
We try to answer most questions, but when *every* part of a circuit has to be explained, the effort does not justify the result, mainly because we try to offer answers which are useful for as many users as possible.
Explaining in great detail *one* circuit to *one* user is not the idea.
What about the thousands others who follow us?

Am I implying everybody has to be an Electronics Engineer to participate here?
Not at all, quite the contrary, the Forum is based on "regular" musicians which have depeloped an interest on how the Electronics they use all day long happen to work.
You do not *need* to know any Electronics theory to build one of these projects, such as the Noisy Cricket, just need to follow building instructions, play, and be happy.

The published circuit and instructions *do* work, the project is popular and has been built by thousands, just build it as-is , play, and then share your experience with us.
After that, you can continue advancing, the Sky is the limit.
Meanwhile read datasheets, suggested application notes, they provide a wealth of information.
Good luck.
Title: Re: Noisy Cricket problems!
Post by: joecool85 on October 27, 2011, 10:03:14 AM
Quote from: J M Fahey on October 27, 2011, 09:34:05 AM
The published circuit and instructions *do* work, the project is popular and has been built by thousands, just build it as-is , play, and then share your experience with us.
After that, you can continue advancing, the Sky is the limit.

This is also what I recommend.  Also, if it turns out the gain knob is "scratchy" then we can advise you on what to do etc, otherwise, enjoy it as is!  Good luck and keep us posted  :tu:
Title: Re: Noisy Cricket problems!
Post by: Dimi Pana on October 27, 2011, 01:04:07 PM
Sorry, but all of a sudden I do NOT feel welcome anymore.

When I registered in this forum it did not state anywhere that the minimum requirement should be electronics knowledge higher than 101. How am I supposed to know which of my questions is above or below level 101 if I have never taken the 101 class? I never said or even implied that I am an expert, on the contrary. When I see a schematic like the NC (noisy cricket) I can identify all the components but I am not 100% sure why they are there and what exactly they do.

Yes, I want to learn BUT NOT at the expense of your time or whatever. So, since I am not afraid to use a solder gun, if I am given CLEAR instructions and non-conflicting advice I can build a circuit as simple as this. I guess, my response is, if you find my questions TOO basic, by all means PLEASE do not bother answering them. Perhaps, a few others more experienced than me but definitely less knowledgeable than you, will chose to "waste" some of their time to do so. I personally, never took this forum for granted, sharing is caring, YES, still no one forces any one to do anything, right?

I do fall under the description of a " ... *regular* musician who has developed an interest on how Electronics they use work, etc..." however with all due respect it is not fair to be treated like the village idiot because I have never taken -YET- a 101 electronics class. I am a foreign graduate student at UI of Chicago in Information Technology Management and I tutor younger students on Math, Computers, etc. What do you think will happen, if my students asked me a basic question and I told them to go -first- take the 101 class?   

So, what do you want me to do? Keep posting or basically "get the heck out" until I have a better understanding of 101 electronics? I mean this is basically what your message is Mr. JM Fahey, and I am sorry if you feel I imposed on you and the rest of the members. That was not my intention. However, knowing myself, you will be surprised how fast I learn, with the right teacher, so if you stick with me now, I will be soon asking more challenging questions. If not, we're still friends...

In all fairness if you all go back in this thread, to previously posted messages, you will notice some conflicting advice and comments from various members that contradict each other or -especially- what the datasheet is saying. Yes, I did read the datasheet and understood most of it. I am assuming the datasheet is right, right?

Also, as matter or fact in JMF's last message paragraphs #1 and #2 state two exactly opposite positions. How am I to respond to that? If I say I agree, I am basically excluding myself from this discussion and I should probably un-register. If I say I disagree, I am being ungrateful to ALL this great feedback JMF already gave me. I am sorry, this is getting unnecessarily complicated, I just can't comprehend where this is coming from. Did I say something to offend you? If I did, I apologize.

-

Now to the original point, there is some confusion (at least to me) as to:

1) What exactly C3 is doing attached to pin-7 then going to ground (if pin-7 is a bypass), what is its optimal value and WHY?

2) Pin-7 is also connecting to pin-5 via the "grit" switch and C4. But, what will the effect be trying different C4 values?

3) Finally, is an extra capacitor -indeed- needed across pins 1-8 as the datasheet suggests (and as a matter of fact in series with a resistor) or NOT, and WHY? If you say YES, what are the optimal R, C values and WHY?


--
Thank you very much!

PS: I am attaching the PDF I am following for building the NC.
Title: Re: Noisy Cricket problems!
Post by: joecool85 on October 27, 2011, 02:03:16 PM
Quote from: Dimi Pana on October 27, 2011, 01:04:07 PM
Sorry, but all of a sudden I do NOT feel welcome anymore.

...


3) Finally, is an extra capacitor -indeed- needed across pins 1-8 as the datasheet suggests (and as a matter of fact in series with a resistor) or NOT, and WHY? If you say YES, what are the optimal R, C values and WHY?

Dimi, I'm sure Juan didn't mean to offend and just came off as a little harsh - his first language isn't English either so maybe that is part of it?

I can't help with most of your questions, but as to #3 I can.  Build it as in the NC schematic (w/o a cap), it should be 100% fine.  The cap is there to remove "scratchy" noises that can happen as you adjust the gain with the potentiometer.  If the scratches are there you might want to use a cap in series to remove that noise.  From what I gather the cap size isn't terribly important as long as it's at least 2-3uF in size, bigger wouldn't be an issue.  That said, I've always built mine with an on/off switch that either connects the pins or disconnects them, no resistor, no cap and they work fine.
Title: Re: Noisy Cricket problems!
Post by: Dimi Pana on October 27, 2011, 04:14:22 PM
Τhanks for your reply, Joe. I now understand the pin 1-8 configuration and any additions (or not) to it.

I am building this with Volume + Gain + Tone controls, I just wish it did not have the "grit" switch.

From what I have read, "grit" switch augments the distortion. E.g. with this switch OFF the the gain control will still produce distortion, turn it ON and you get more body in the distortion. Perhaps you can put it in better more electronically correct terms.

Anyway, if anyone else cares to answer queston #1 and #2, it would be greatly appreciated.

As far as JMF, I am highly appreciative for all of his advice to date and -hopefully- in the future. I am not offended at all, on the contrary, I am concerned about myself NOT to offend anybody. My first language is not English either.  :tu:

Thank you all!
Title: Re: Noisy Cricket problems!
Post by: J M Fahey on October 27, 2011, 05:45:01 PM
OK, do you want the full Monty?
Here it is.
*Only* problem is, each answer creates 2 or 3 *new* questions, which in turn, when answered,  create *each* 2 or 3 .... I think you imagine what follows.

QuoteAre you absolutely sure this C3 should be 10μF instead of 100nF ?

Short answer: YES

Longer (although still incomplete) answer:

yes, because its function is to bypass the current source which feeds the (unmarked) transistor which through a current mirror modulates the (unmarked) transistor which has 3 functions I recognize, probably more:
1) inverts again the phase of the signal present in (unmarked) transistor collector
2) receives signal from the non-inverting input, and substracts it from the input signal. making a conventional negative feedback loop possible (like in any Op Amp).
Usually this one is not used, because the network of 15K/1K35/150r does that, but the possibility exists, if a more "conventional" circuit is needed.
3) being symmetrical and built in the same chip, at the same time, allows 2 wonderful things to happen (hail to its designers)
3a) sets the quiescent DC voltage at the output rail to sit quite close to ideal 1/2 +V rail.
3b) being in *real* close contact, compensates thermal drift very well
4) drives the (unmarked) transistor which is the main gain cell in the entire amplifier, as in all Lin architecture amplifiers.

Now to the "mod".
5) using a too small cap (100 nF) makes it behave poorly.
Even 10uF is low, and was chosen because it´s a cheap low power amp which will probably drive a 2" radio speaker; imagine a capacitor 100 times smaller.
6) the "grit" mod, which if you read earlier posts I wrote against, yes, probably adds some distortion to the sound .... in a way similar to slitting the speaker cone with a razor blade, or some other poor way.
In my opinion, just overdriving this little amp with your guitar, full volume, will provide more (and better) distortion.

Well, all of this for just 1 question, imagine the others, plus answering the *new* ones which appear.

I did not mean to disrespect you or any other, never did,here or anywhere else, and in my opinion I gave you a good Friend's advice: go and build it.

PS: the fact that National does not identify parts in their schematic, such as Q1, Q2 , R1, ... etc. , only adds to the confusion.
In fact, since it´s an integrated circuit, you shouldn´t even care as to what´s inside it, just use it as suggested.
Modern ICs do not supply internal circuits any more; at most functional block diagrams.

QuoteWhat is the reasoning behind that? I am not questioning your input -on the contrary- I am just curious why, just want to learn.
Well, you had a small sample of the reasoning involved.
Congratulations on your wish to learn, please keep doing so.

You never stop, I'm still learning a lot 43 years after having started with this ..... and even worse, giving up on a LOT of things which I know I won't learn in a reasonable time.
Does it mean I won´t be able to do anything at all in those areas ?
No, but I´ll be happy in "following the book/standard rules/datasheet examples"

If I haven´t said so before, good luck. :tu: :tu:

PS2: just as a personal curiosity, what would your first language be?
I speak quite a few, yet my last addition, Chinese, is driving me crazy.
Title: Re: Noisy Cricket problems!
Post by: Dimi Pana on October 27, 2011, 09:11:07 PM
Hello JMF -

Thank you for the long explanations, most of that is obviously way above me, but I was able to follow your reasoning.

I tend to be fast when I get infatuated with something, that is my shortcoming, I need to learn to curb my over-enthusiasm. I realize I have agitated you, and I apologize for that.

Regarding the NC, I have collected all the parts and I will build it as is. I want to hear how it will sound into a bigger cabinet. Eventually though I think I will try a non "grit" version, exactly per your advice. It sounds like for such a simple design a Volume and Gain control should yield a sufficient range of clean and "dirty" sound.

So, if I decide to NOT use the "grit" switch do I just remove SW2, jumper the gap, and leave everything else as is, or do I remove C4 and C3 as well?

--

I would have never attempted to learn Chinese, so -really- I admire your courage. I speak decent English, average French, basic Spanish and Italian. I can "fake it" in German as long as I keep my responses to an absolute minimum ;D.  Finally, I am fluent in Hellenic since I was born and bred in Athens, Greece.

Best regards!
Title: Re: Noisy Cricket problems!
Post by: J M Fahey on October 28, 2011, 06:25:19 AM
Hi Dimi.
I would skip the Grit Mod and just use the 10uF capacitor as suggested in the Datasheet.
As a simpler explanation, it works like some kind of Tremolo (volume modulation), but instead of using an external oscillator to drive it (causing the typical up-down-up-down volume) it uses the speaker output itself to do such modulation.
It does not sound as a tremolo but as a funky, synthesizer type waveform, very "plastic" or "cheesy", not nice at all to my ears.
Since it can´t go "more up" than its limited power, it won´t, so it can only go down, losing power, which in a 1/2W amp isn´t the best option.
If , on the contrary, you overdrive it with a strong signal, it will clip like any overdriven amplifier and provide almost 1 W (squarewave).
As a couple free samples of what an LM386 can do, just as the datasheet application (pins 1-8 shorted) and *nothing* else, not even a humble transistor buffer (not even a volume pot .... which you already have in your guitar)
This one is even simpler than the NC.
Hear for yourself:
Note: here you will clearly hear the base of a myth, that Tube Amps are fat and sweet, and SS amps are thin and buzzy.
Truth is, cheaper SS amps usually come in small cabinets and with small/cheap/poor speakers, which don't exactly help them, while expensive Tube amps "justify" big expensive speakers.
Hear for yourself what happens when the cheapest simplest SS amp gets plugged into a 4x12" Marshall !!!!
http://www.youtube.com/watch?v=og_RiEB-74U&feature=player_embedded

http://www.youtube.com/watch?v=j9VqN0Kna0U

Here again plugged into a "real" speaker
http://www.youtube.com/watch?NR=1&v=7VaxzLjWcRU

PS: when I arrived in Greece, I said, watching the street signs, "wow ! , at least now I feel I'm travelling" ... which I had not felt in Spain (obviously) Italy, France or England.
The sensation quickly faded when I realized I understood most of what was written, and quite a lot of what was said, just by getting the root of any word, which is often the root of one (or more) of our Spanish ones.
Oh well.
For example: I went to a book shop to buy a Greek copy of Antoine de Saint Exupery's "The little Prince".
The shop owner didn't understand what I needed, until I spotted on a shelf the "Mikrós Prinkipós" (or something like that).
Of course!!, The Micro Prince !!! Clear as water !!
The language institute in front of my Hotel offered to teach languages from "Gallia", "Germanía" and so on.
At the market I pointed to some flat bread, the salesman asked if I wanted "pitzá". Well, pizza, of course!
So I found I already understood *a lot* of Greek, without even trying.
Now you understand why I´m getting into Chinese ! :lmao:
Title: Re: Noisy Cricket problems!
Post by: Dimi Pana on October 29, 2011, 01:41:54 PM
Hola Juan, muy encantado de conocerte! Cómo está el tiempo hoy en Argentina?

Well, I won't attempt any more of my broken Spanish, all I know is from the guys I play fútbol with.

I am pleasantly surprised that you have visited my country, especially because after landing in Athens, most people "hit" the beaches and the bars/night-life in the islands. But you -instead- went into a bookstore and then a bakery shop. And as much as I can understand the bakery (cuando viajas te da hambre y tengo que comer, no?) shopping for a copy of Antoine de Saint Exupery's "The little Prince" is definitely remarkable!

Modern Greek (or Hellenic as is the proper term) is the direct descendant of Ancient Greek, simplified and adapted to people's ever-changing needs over the last 2,500 years. Still it is a language that is -according to my favorite saying- unnecessarily complicated, definitely not for the fainted at heart. However your approach makes a lot of sense and speaking a latin based language yourself clearly gives you an advantage. The only simple thing about Greek is that we say what we read and we write exactly as we say it. Sounds and letters do not change between words, i.e. like in English. One other thing is that Greek and Spanish have pretty much the same sounds that -say- Americans are not used to. My soccer buddies make fun of me when we play because when I get mad I start yelling at them in Spanish and actually my accent changes depending who I am yelling at. :grr  I play goalie, (y porteros suelen ser locos) so I get to yell at them a lot, you get the picture :duh  

OK, I am grossly abusing the terms of this forum. So back to business, I read your post, here's my take:

1. I am skipping the "grit" switch but keeping the variable R and C between pins 1-8 to adjust my gain and keep it scratch free. I am posting a modified schematic. Please comment if you see any mistakes.

2. I would have never thought using the speaker output itself to do such modulation can a Tremolo effect. WOW!

3. I heard the YT samples and I was blown away! If appears that a great amp will sound bad through a small/cheap speaker, while a basic amp will sound OK via, if not good enough, via a nice 4x12" cabinet.

4. In Greek the book you were looking for is "Ο Μικρός Πρίγκηπας" (o Mikrós Prínkipas) and the bread you asked for was not pizza but probably some kind of "πίττα" meaning some kind of variation of the famous "pitta" bread widely found in in the USA in those fast-food places selling gyros. BTW, "γύρος",  means when something goes around completing full 360 degree revolutions. You've seen how they cook "gyros", right?

5. I still have not made the connection why you are "torturing" yourself with learning Chinese but since I cannot help you with that I can only wish you "good luck", I admire you! If you ever want to brush-up on your Greek, you know who's your tutor gonna be! :tu:

Ηasta la próxima vez!

--
Δημήτριος Παναγιωτίδης του Γεωργίου
PS: Τhat's my full name, so now you know why the abbreviated Dimi Pana
Title: Re: Noisy Cricket problems!
Post by: J M Fahey on October 29, 2011, 02:25:13 PM
Well, let´see by heart, not cheating by looking it up anywhere (and forgive the mistakes)

Δημήτριος would be Dimitrios

Παναγιωτίδης would be Panationis

του ??? this one beats me

Γεωργίου would be Georgiou

..........
close enough?

I´m just using the "Spanish built in" Greek I used to read road and shop signs, menus, and deciphering newspaper headlines.

A special mention apart for Greek women: for a Classic tastes (in the literal way) guy like me, I was blown away by having classic beauty statues ... *alive* , moving around, clad in jeans and t-shirts.
Only problem? ... they tried to be "too American" ...... fine but didn´t fit them as well as Classic clothes would.
Oh well.
And when they speak .... oh my God .......
Title: Re: Noisy Cricket problems!
Post by: Dimi Pana on October 29, 2011, 02:58:37 PM
Quote from: J M Fahey on October 29, 2011, 02:25:13 PM

Δημήτριος would be Dimitrios

Παναγιωτίδης would be Panationis

του ??? this one beats me

Γεωργίου would be Georgiou

..........
close enough?

You got 3 our of 4, that's impressive!

The "του" word is a declension of the singular form of the masculine article, in the genitive case (i.e. possesive). It basically means "of the". Thus my name is: 1st name Dimitrios (meaning, I was named after the Christian orthodox Saint Dimitrios), 2nd name Panagiotidis (that's my family name which -simplified- means the decendants of Panagioti who was my great-great grand father) and 3rd name (of the) Georgios (meaning that my father's 1st name is Georgios). According to Greek culture we name our children after their grand father/mother's names, which -you guessed- creates ever more complicated combinations.

I agree about the external quality or the greek women, and I am with you 100% on their pointless and futile desire to look less "Hellenic" and more American. But what can you do? Nothing... Can't live with can't live without them. Luckily, for the time being I am taking a hiatus from Greek women. Living in the US -definitely- gives one the advantage to be ethnically more ...selective.

--

BTW, any comments on the modified schematic? Let's not forget what we're here for eh!  8|

'Till later!   
Title: Re: Noisy Cricket problems!
Post by: J M Fahey on October 29, 2011, 04:19:01 PM
Thanks.
Do not join pin 7 to 5 *at all* and use 10uF instead of 100nF.
You´ll be able to get or surpass the You Tube sounds.
The tone control will have little if any effect, because it has a 100K pot working against a 10K volume pot.
It will do nothing most of the way, and suddenly work in one end, more like a switch than a potentiometer.
The tone pot in your guitar will work much smoother and better.
Good luck.
Title: Re: Noisy Cricket problems!
Post by: Dimi Pana on October 29, 2011, 04:38:10 PM
C3=10μF and no pin7-5 circuit at all.

Shall we say this is FINAL?

(at least for today?) :D
Title: Re: Noisy Cricket problems!
Post by: J M Fahey on October 29, 2011, 07:37:07 PM
Yes, it´s fine, it will work as intended.
Now you build it and post MP3s and pictures to help others in the future.
Good luck.
Title: Re: Noisy Cricket problems!
Post by: Dimi Pana on October 30, 2011, 02:47:27 PM
Hello all!

Ι was building the NC today and I think I got a little impatient (i.e. careless) towards the end, I believe I "fried" the MPF102 with too much soldering heat. I wish I'd bought a socket for it, just like I did for the LM386 IC. I mean there is a socket for this part, right?

I bought my parts from RS (radio shack) and that particular store did not have a socket for the transistor. I mean the attendant in the store I went (Rt. 83 in Des Plaines) probably knew less about electronics than -even- me... I don't know, from the first time I stepped into a RS, it did not feel right somehow.

So, anyone from the Chicagoland area? Do you know a decent and novice-friendly (yes, that's me!) retail electronic parts store?

Thank you!     
Title: Re: Noisy Cricket problems!
Post by: J M Fahey on October 30, 2011, 05:53:46 PM
Unfortunately most shops (not only Electronics) are like that, they hire the cheapest help available.
Don´t worry about the socket, solder a new Fet there.
Or do what Phatt suggests, buy a protoboard and experiment there; commit the project to PCB (or perfboard) only after you are happy with it.
Title: Re: Noisy Cricket problems!
Post by: Dimi Pana on October 31, 2011, 07:10:06 PM
Hey, how about this:

Looking in the NC schematic (RadioShack build or PCB build):

VR2 is the Gain pot, rated for 1KΩ

VR3 is the Tone pot, rated for 100KΩ

However...

Looking at the parts list (in both builds) it appears that these values have been inadvertently reversed:

Gain is still VR2 but rated at 100KΩ

and

Tone is still VR3 but rated at 1KΩ.

--

So which is correct? The Schematic or the Parts List?

(Pls, see attached!)
Title: Re: Noisy Cricket problems!
Post by: phatt on November 01, 2011, 04:28:13 AM
I'd just go with a 10 K pot as 1k seems a bit silly.
Phil.
Title: Re: Noisy Cricket problems!
Post by: J M Fahey on November 01, 2011, 07:13:10 AM
QuoteGain is still VR2 but rated at 100KΩ
No, look again, in the layout just above the parts list, VR2 *now* is Tone.
Its *value* and *function* match the schematic, its *designation* (VR2) does not.

QuoteTone is still VR3 but rated at 1KΩ.
Same as above, VR3 now is gain and still 1K.

So in a nutshell: schematic and layout both work, but their "labels" (for lack of a better word) do not match.

*BIG* famous companies have errors greater than these (sometimes even on purpose), so I am eager to forgive Beavis Audio which very probably is a one man operation.
Nothing against that, of course !! ;)

Which version are you building?
Didn´t check the PCB transfer one, but it probably works.
The Radio Shack version looks very confusing even for me, much more so for a beginner, because they use a PCB which was designed with a very different use in mind, I find it very easy to make wiring mistakes with it.
I think I will design and post a perfboard (which is really universal) version of the Smokey amp, which as you already heard sounds impressive, has no pots, and about 5 or 6 parts total.
Check here tomorrow.
Title: Re: Noisy Cricket problems!
Post by: Dimi Pana on November 01, 2011, 02:04:30 PM
ΟΚ, this is probably a waste of time for you all, it was a good exercise for me.

Here's what's going on:

There are two build versions posted by BeavisAudio. One is a PCB based one the other is the RadioShack (RS) version. BTW, I am building the RS version since at this point I do not have what it takes (knowledge and tools wise) so I cannot print and etch my own PCB.

Each version includes (at least) the following:

1. Parts List

2. Schematic

3. Parts Layout


Here's what the error is (regarding the V, G and T pots):


In the PCB version:

The "Parts List" agrees with the "Schematic" and both disagree with the "Parts Layout"


In the RS version:

The "Schematic" agrees with the "Parts Layout" and both disagree with the "Parts List".

---

Of course, all this is immediately recognizable by all you experienced people, unfortunately in my case it is a "show stopper" since I realize the discrepancy but I am unable to distinguish between RIGHT and WRONG.


---

However, by reading your posts and doing some research myself, here's what I will do:

VR1 = Volume = 10KΩ

VR2 = Gain = 1KΩ (*)

VR3 = Tone 100Ω

---

Νow, because, RS do not carry a 1KΩ pot, and since phatt(*) already suggested to change it with a 10KΩ,  is it OK to use -instead- a 5KΩ ( just happen to have one)  so I do not have to buy it? I do not want an explanation why (to save you time) just a YES or a NO.  ;)

---

Last question for today: This design calls for a 100nF "poly film" capacitor at C3. JMF suggested I change it to a 10μF (right?). I cannot find this value in film but I can in electrolytic. Can I substitute film with electro? Again, I am asking for a YES or NO answer, obviously I'm interested in the WHY, please answer only if you have a short and simple one, anything longer just post a link on the net, let me then do the reading.  :tu:

---

How am I ever going to pay you all back for your patience, kindness and your hard-acquired knowledge offered for free? My family owns a small "Bed & Breakfast" motel in the Greek island of Santorini, so if you ever visit my country, please drop me a line, I might (actually for sure) be able to work something out for you. But please hurry, given the current financial instability and judging by the (poor) quality of the Greek politicians, I am not sure if in the near future Greece will still belong to the Greek people or owned by some big, inconspicuous financial conglomerate.  :'(   
Title: Re: Noisy Cricket problems!
Post by: J M Fahey on November 01, 2011, 04:37:51 PM
QuoteΟΚ, this is probably a waste of time for you all, it was a good exercise for me.
Friend, don´t worry about that, it´s not a waste of time and we take it as going to the Gym (another Greek word, of course) and working out our minds.
QuoteThere are two build versions
QuoteΝow, because, RS do not carry a 1KΩ pot, and since phatt(*) already suggested to change it with a 10KΩ,  is it OK to use -instead- a 5KΩ ( just happen to have one)  so I do not have to buy it?
Yes. It will not be as "smooth", as the big gain change will be cramped towards one end, but it will work.
QuoteLast question for today: This design calls for a 100nF "poly film" capacitor at C3. JMF suggested I change it to a 10μF (right?). I cannot find this value in film but I can in electrolytic. Can I substitute film with electro?
Sorry for not being clear, my mistake.
The original 10uF was an electrolytic; when Beavis changed that into 100nF, we are in ceramic/polyester, etc. area, not electrolytics, so he changed the spec.

QuoteHow am I ever going to pay you all back for your patience, kindness and your hard-acquired knowledge offered for free? My family owns a small "Bed & Breakfast" motel in the Greek island of Santorini, so if you ever visit my country, please drop me a line, I might (actually for sure) be able to work something out for you.
WOW !!!!!!!!! SANTORINI !!!!!!! One of the paces I HAVE to know in my life !!!
The (real, historical) origin of what we know as Atlantis, the Universal Deluge, amd many of Bible´s catastrophes.
Just hold a loose reserve for a room , ***someday**** I´ll be there.
WOWWWWWWWWWWWW !!! SANTORINI !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
QuoteBut please hurry, given the current financial instability and judging by the (poor) quality of the Greek politicians, I am not sure if in the near future Greece will still belong to the Greek people or owned by some big, inconspicuous financial conglomerate.  :'(
Don´t worry, Greece will survive, as it has for the last 2500 years.
And your politicians are MUCH BETTER than ours (ours meaning the rest of the World)
They are asking People to VOTE about their economic future and how their money will be spent.
Unbelievable !!
Except, of course, in the land that INVENTED Democracy 2500 years ago.
Not to mention Science, Art, Psychology, Logic, Geometry, Ethics, and 10000 other things, as we know them.

PS: for those curious about it, Santorini *was* a round island, which housed a very advanced (Minoan) civilization.
In 1600 BC, it showed its true face: it was a volcano which exploded with the power of a few atomic bombs
This picture shows a satellite image.
The land you see is what remains of the volcano, all that water in the middle is filling the explosion´s crater.
Imagine the explosion.
(http://upload.wikimedia.org/wikipedia/commons/thumb/1/14/Santorini_Landsat.jpg/250px-Santorini_Landsat.jpg)
The Tsunami it created flooded coast areas up to a lot of inside land, from Spain to Egypt, Israel, Iraq, (Greece of course) and most of the ancient world known to us.
We have 3 versions of that historical terrible, remembered with awe for ages, fact.
Of course, each of them tells his own version, and thinks it only happened to them as punishment for something. (Very reasonable assumption considering nobody knew lands beyond a few hundred miles from their own)
1) Noah . Israel. <-- this one we know.
2) Deucalion (Greek) "Zeus loosed a deluge, so that the rivers ran in torrents and the sea flooded the coastal plain, engulfed the foothills with spray, and washed everything clean. "
3) Gilgamesh (Sumerian/Babylonic/Iraq)
   "1. Early in the morning at dawn a black cloud arose from the horizon.
...
   4. The thunder god Adad rumbled in the cloud
......
   7. There was stunned shock at Adad's deeds which turned everything to blackness. The land was shattered like a pot.
   8. All day long the south wind blew rapidly and the water overwhelmed the people like an attack.
   9. No one could see his fellows. They could not recognize each other in the torrent.
  ..........
  14. The flood and wind lasted six days and seven nights, flattening the land.
  ....................
   2. The terrain was as flat as a roof top.

As we can see, all three are telling the same story, in their own words.
All three lived around 1500/1600 BC.
The Santorini explosion happened (measured by scientific expeditions, including a National Geographic team) between 1400 and 1600 BC.
It was 4 times as powerful as that of Krakatoa (around 1880) which was seen all over Asia, the volcanic ashes reached Europe and America.