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Messages - ghoshsubha444@gmail.com

#1
Quote from: J M Fahey on April 25, 2013, 11:51:12 AM
That's what Enzo means  :cheesy:
The "schematic" is a footswitch shorting or not an 1/4" guitar plug.
What's the FSW supposed to switch?
Channel/dist/gain/boost/reverb?
Plug a stereo plug into the FSW jack and alternatively ground one or the other terminal (tip or ring) with a piece of wire ... any change?
Once you've confirmed this, the pedal wiring is using 1 (or 2) switches to duplicate the shorting previously tested "by hand".

EDIT: *some* pedals are more complex than that, such as Fender, which have internal Leds and a diode matrix so 1 wire controls 2 functions (clever) but afaik "small" Marshalls use simple generic switches.

Now, say, the one in an MF350 uses a 15 pin connector, multiwire cable, has some 5 switches , Leds, etc. ... but thanks God it's not the case here.

no its suppose to switch between clean and dirty channel
#2
Quote from: Enzo on April 24, 2013, 07:24:44 PM
It's a switch in a box.

resolder the footswitch jack, make sure the cutout contacts on the jack are making well.  Check the solder and contact resistance on the panel switch.

hello enzo,

thank you for your kind reply. actually this amp contains a dedicated input only for footswich. and i was asking for schematic of that box. so that i dont have to open the chassis of the amplifier and to modify the existing board.

according to the manual supplied with it says it uses P801 footswitch and which is unavilable in my local place in india

I am uploading a picture of this amp for the reference..

Thanks

#3
hello,

a friend of mine owns a marshall mg30dfx amplifier. He is quite frustrated with the manual switching between clean and dirty in the middle of a song while he is playing something. so it would be a great help if some one can post the schematic for marshall 30dfx foot switch. any kind of idea is helpful for me..

:)  :)

thanks in advance
#4
hello ssguitar users

I am little busy with my exam...will start the project as soon as my exam is over..

Have a nice day!

see you later.
#5
Schematics and Layouts / Re: Phatt-stuffRevisited
March 19, 2013, 07:40:56 AM
Dear Phil,

can you Explain us about phabtone and ddc please :) :)
#6




:lmao: :lmao: :lmao:
Ha ha!!
#7
compressor
#8
hello..

I dont know about if I am doing any mistake on other things but I can 500% assure you that mains earth is first attached to the chassis and from there to the common ground.


I have really messed a lot with wires and colors but when I will be done with the experimentation I will definitely set up the whole thing with proper color wires with neat arrangement.

Mains Voltage:220V @ 50Hz
Thanks for the care <3) <3)

#9
Quote from: phatt on March 17, 2013, 06:58:58 AM
OK good cheap metal case,,, But Why is that ground lug that (I assume) comes from Earth pin from the IEC socket floating in space? (The Green Yellow wire with eyelet) 8|

Yes I do see where the earth for psu and common for circuit all join up but You MUST have it all tied back to the ground plug as well otherwise you have a floating Zero volts that is not grounded to EARTH pin and it will likely hum like mad.
Phil.

Edit,, whoopsy. yes I now see that the Mains socket is not in use,, but still the mains EARTH must connect to the case otherwise hum.

Thanks for examining...

The Blue color wire is the main earth which is first attached to the chassis with a screw and from there a short black wire goes to Com ground where several wires are tied together. Similarly all +25v -25v +9v are all tied together and connected to their respective position as a single point.. Please refer to  my earlier attachment.
#10
Amplifier Discussion / Re: Fahey Amplifiers
March 17, 2013, 02:59:34 AM
Quote from: J M Fahey on March 16, 2013, 09:05:56 PM
Thanks, very interesting, but please "translate" to U$, so we all can compare in an easier way :) :) :)

Then I am posting Price is us$ in india  based on 1us$=55 INR

Western digital 1 TB hard disk               90.90 $

Kingstone pendrive  16gb                      10.96 $

Fender Frontman 25R                           147.27 $

Squier Hot rail Guitar                            381  $

nokia asha 311 mobile                          109

mobile calling charge                            0.54$/hour

3G 10mbps Broadband                         4$/GB

Plane fare (2000kms)                           100 $

Train fare (2000kms) First class             60 $

Staying in a 5 star Hotel                       100$/night

Electricity meter                                 0.1$/Kw

Petrol                                               1.36$/ltr

Diesel                                               0.95$/ltr

Resistor                                            1.1 $/50 dozen
5%-250mw

Capacitor                                         2.5$/50 dozen
20-25v small ceramic

solder                                              1.4 $/50 gms
Good Quality

Admission fee in University                   45.45$/year
including tuition(Govt. Sponsored)
for Engineering study

Admission fee in University                   1800$/year
including tuition(private)
for Engineering study





Food and Vegetables:
In India

Potato  0.36$/Kg

Milk    0.45$/ltr

chicken 3.27$/kg

Cocacola  1.1$/2 ltrs

Salary of School Teacher/Freshers Software Engineer/Bank Employee:545 $/mon



Indian President Salary :2727 $/mon + 4000000 $/Year for additional Expenses,So hey can buy 2560 bottles of Cocacola  with his monthly salary :) :)

We are really Football crazy..we were quite mad about maradona and now mad about messi... :) :)
But our country is very poor. Poverty is everywhere. But it is progressing very rapidly..

What about yours..     
#11
Amplifier Discussion / Re: Fahey Amplifiers
March 16, 2013, 04:07:01 PM
Quote from: J M Fahey on March 15, 2013, 05:08:33 PM
I'll probably send you one, will ask for address and other data when I do it.
I'm wondering about making an smps version, freight by the pound is murderous and a deal killer.
The regular post 9 Kg rate (what a 100W head weighs) is murderous U$155  :loco :duh :grr
Through EMS, the USPS "courier" it costs U$165  :( :grr
*Maybe* I can lower it to <3Kg, which means around U$80.
Not cheap but more reasonable.
Oh well.
Check http://www.correoargentino.com.ar/precios/encomiendas/internacionales and divide by 5.1 , the U$/$arg exchange rate.

Hi Fahey, I was trying to compare Argentine vs Indian Economy...

Here is a price list for Both Argentina and India...May be the prices are lower in local store

Goods                  Ars         Ars from Rupees(India)ruppee/10.65

Western digital 1 TB hard disk         599         469

Kingstone pendrive            90         59.40

Fender Frontman 25R            1461                 760.56

Squier Hot rail Guitar            4,317         2065

nokia asha 311 mobile            1499         563

Reference  http://listado.mercadolibre.com.ar

Food and Vegetables:
In India

Potato 2 ARS/Kg

Milk    2.4 ARS/ltr

chicken 17.5 ARS/kg

Cocacola  5.5 ARS/2 ltrs

Salary of School Teacher/Freshers Software Engineer:3000 ARS/mon

Indian President Salary :14084 ARS/mon + 2,06,57,277 ARS/Year for additional Expenses,So hey can buy 2560 bottles of Cocacola ;) ;)

What about yours.. :) :) :) :) :)
#12
Quote from: phatt on March 16, 2013, 09:45:06 AM

my proto cases are reused many times over and they end up full of holes for knobs.
Yes plus 1 on Old VCR stuff. they also often have a lot of shielded cable just perfect lengths for small audio wire ups.

Some years back I built a 6V6 Amp from old transformers that where given to me and that chassis had so many modifications during the build that I had more holes than metal on the front.
I had to make a new case before I finally mounted it all in an Amp head. :cheesy:

Keep at it chum, it will all become clear to you in the end. It took me a long time to get my head around circuit layout which is not as simple as it first looks.
Have fun, Phil.

I am 200% agree with you. Till date i have spent almost double money on this than I presume. With this money I could have purchased a decent amp for sure! But who cares.  Its my money and DIY spirit that I care.

BTW, according to your suggestion I have somehow managed to find a spare SMPS case[photo attached]. Where I put PSU circuit. Do I have to put entire circuit on the case. If so, then I have to look for some bigger case like OLD VCR. But as the noise is concern, no improvement yet. Even I have tried to connect a 0.1 cap between +ve and -ve pin of the opamp.

Today i did a connection from computer to Amp with master volume almost set to 0. Its awful. But as I already know that guitar amp dosen't sound like hi-fi speaker.

Made a connection with keyboard too. Sound not bad. But not so good like the inbuilt speaker of the keyboard.

#13
Amplifier Discussion / Re: Rod Elliott's P27 Project
March 15, 2013, 03:59:12 AM
Ok Sir. I will give a look into my old SMPS.

I have tried to draw a new PCB for power supply but it is quite a headache  :o

So, I have tried to draw an image to depict the order of components in my earlier homemade PCB.

Please check my attachment.. and suggest if my earlier arrangement was wrong..If something seiously wrong then have to redraw it :(
#14
I am not sure but I heard something that Bass notes draw more current than higher pitch notes. Besides We will not get good response from normal guitar speaker. The cabinet construction is some what different. And you may cause permanent damage inside the speaker. But you can play in comparably less volume. i think that will do no harm. 
#15
Amplifier Discussion / Re: Rod Elliott's P27 Project
March 13, 2013, 03:00:15 PM
Thanks Roly..

Quote from: Roly on March 13, 2013, 08:58:28 AM
well we are half way there.  The green earth/ground/common is radial as it should be, but you show the red and orange +/-25V daisy-chained.  These should also distribute radially like the green ground side.  Buss connection of +ve and -ve is not permissible (for exactly the same avoiding "resistance-in-common" reason).


Understood.

Quote from: Roly on March 13, 2013, 08:58:28 AM
The "other earths" are your green wires (the mains earth being your blue wire).

ok.

Quote from: Roly on March 13, 2013, 08:58:28 AM
Looking again at your a222.jpg it looks like you are using on-board regulators for each board (can't see all of the Phaser board but I assume it also has a 3-pin regulator out of frame).  If this is the case then you can simply daisy-chain the supply because each board will be isolated from unwanted supply signals by their respective regulators.
yea for complexity i ignored drawing 9v line. i run effects boards @9v :)

Quote from: Roly on March 13, 2013, 08:58:28 AM
I have spotted one other thing; on your p27 board one of the zeners is cuddling up to an electrolytic cap, and this isn't a healthy relationship for either of them.  Zeners get hot and like free air around them to keep cool, and electro caps don't like getting hot.  In general I try to give components that are going to get a bit hot, zeners, their series resistors, 3-pin regulators, etc., a bit of "breathing space", and also mount them so that they are a few millimetres up off the board rather than hard down on it (because over time they will also bake the board).

Eagle eyed!! 8|
I am modifying my pcb drawing and will obviously allow more spaces between hot items.


I am again drawing my power supply pcb to rectify earlier error. Will post here as i am done.

1.I am encountering a problem something known as bouncing. whenever i am changing/twisting my ceiling fan regulator I am getting heavy popping sound. Start up popping is not possible since i have used relay delay in my power amp?

2.whenever i am disconnecting the mains earth from the ground the noise is increasing hugely. Is this usual or is this because of noise in power line? if this is usual then how amps like Roland cube 15 with 2 pin in the plug exist?(apart from they are well isolated).

My current psu picture is attached..