Amptweaker - Tight Metal  [traced]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.

Re: Amptweaker - Tight Metal

Postby J0K3RX » 25 May 2013, 14:57

bajaman wrote:it would be interesting to know what the diodes are - schottky, zeners, ultrafast, general purpose :?: :hmmm: :hmmm:



Diodes are listed on page 1 very first post 3rd pic... only 1 diode on the top side which is 1N4148

All diodes are either one of the following, you can guess which ones are which by either the size or the color...
1N4148
1N4733A
1N4007
User avatar
J0K3RX
Degoop Doctor
 
Posts: 938
Joined: 29 Jun 2011, 02:25
Location: US Florida
Has thanked: 278 times
Have thanks: 431 times

Re: Amptweaker - Tight Metal

Postby J0K3RX » 25 May 2013, 15:41

Some corrected values
You do not have the required permissions to view the files attached to this post.
User avatar
J0K3RX
Degoop Doctor
 
Posts: 938
Joined: 29 Jun 2011, 02:25
Location: US Florida
Has thanked: 278 times
Have thanks: 431 times

Re: Amptweaker - Tight Metal

Postby ggedamed » 25 May 2013, 16:27

Jim, did you use a layer-based software for drawing the traces? If so, is it possible to put somewhere the files containing the separate layers?
I want to make a superposition of the top and bottom PCB layers, it helps me (and maybe others) to better understand what's going on. Also I want to give numbers to the parts in the photos, to have a reference. This together with a drawing containing only the traces and the parts outlines would make the things much clearer on the PCB and they can be done with the traces layers.
User avatar
ggedamed
Resistor Ronker
 
Posts: 319
Joined: 21 Jun 2009, 12:43
Location: Bucharest, Romania
Has thanked: 138 times
Have thanks: 144 times

Re: Amptweaker - Tight Metal

Postby J0K3RX » 25 May 2013, 17:11

ggedamed wrote:Jim, did you use a layer-based software for drawing the traces? If so, is it possible to put somewhere the files containing the separate layers?
I want to make a superposition of the top and bottom PCB layers, it helps me (and maybe others) to better understand what's going on. Also I want to give numbers to the parts in the photos, to have a reference. This together with a drawing containing only the traces and the parts outlines would make the things much clearer on the PCB and they can be done with the traces layers.


Yes, I did use layer based software (Sprint)... I am in the process of redrawing one of the layers (front) to match the back. When I first did it the bitmaps were slightly off, one was larger than the other so, the layers don't fall on top of each other well... they are off by quite a bit and makes a mess if you try to match up the layers. I am correcting... When I get it done I will upload the files if you want them and I will try to overlap them myself as well.
User avatar
J0K3RX
Degoop Doctor
 
Posts: 938
Joined: 29 Jun 2011, 02:25
Location: US Florida
Has thanked: 278 times
Have thanks: 431 times

Re: Amptweaker - Tight Metal

Postby jymaze » 25 May 2013, 19:17

Jim, can you verify the 2nd resistor down from the tone pot (read 3k3 right now). I labeled it 332 on my draft, but I see you only put a question mark there (by the tone pot).
My way of superposing the layers: I just put the 2 sides in GIMP as 2 layers, aligned them the best I could, and was switching from one to the other for 12 million times. I know that PCB like the back of my hand now! Even with both sides aligned it was not an easy trace because of the density and the constant random jumping from one layer to the other.

If we could make sure the values for the resistors are good on the pictures, I can correct on my draft schematic. There are one or 2 I really wonder about.

For this message the author jymaze has received thanks:
J0K3RX (25 May 2013, 21:14)
jymaze
Resistor Ronker
 
Posts: 374
Joined: 06 Mar 2011, 23:19
Has thanked: 87 times
Have thanks: 158 times

Re: Amptweaker - Tight Metal

Postby J0K3RX » 25 May 2013, 19:47

jymaze wrote:Jim, can you verify the 2nd resistor down from the tone pot (read 3k3 right now). I labeled it 332 on my draft, but I see you only put a question mark there (by the tone pot).
My way of superposing the layers: I just put the 2 sides in GIMP as 2 layers, aligned them the best I could, and was switching from one to the other for 12 million times. I know that PCB like the back of my hand now! Even with both sides aligned it was not an easy trace because of the density and the constant random jumping from one layer to the other.

If we could make sure the values for the resistors are good on the pictures, I can correct on my draft schematic. There are one or 2 I really wonder about.


If you are referring to the schematic I posted that was from euronymous0001's Eagle file that I imported so people could read it... not mine, and I saw quite a few unidentified components on it as well.

this is correct and I made sure with a meter.
download/file.php?id=21751&mode=view
When they are marked like 3k32 you can take that as 3.3k or 3.32k, 47k5 = 47k or 47.5k etc...

By the way - That large 1W light blue "resistor" in the bottom left reads 47 ohm exactly.

Still unsure about the gate/gain pot... one lug is not connected to anything for the gate like the gate on the BF or Engl I made.../ jsx noise gate etc..

Also, from looking at the actual board, to me it looks like the gate has 3 diodes (two 1N4148 and one 1N4733) and a 220n cap or, am I seeing things?
User avatar
J0K3RX
Degoop Doctor
 
Posts: 938
Joined: 29 Jun 2011, 02:25
Location: US Florida
Has thanked: 278 times
Have thanks: 431 times

Re: Amptweaker - Tight Metal

Postby J0K3RX » 25 May 2013, 20:32

coldcraft wrote:I tried a noise gate like that once and was disappointed in its performance. I guess I didn't have enough gain before it.


From the ones that I have built they are really only good for high gain and they work quite well, actually very well... This one acts differently for some reason, works much better and doesn't cut the highs at all which is the only gripe I had with the jsx gate? With either one there is absolutely no note clipping or crappy attack... A tiny bit of sustain loss with the jsx but this one not at all!
User avatar
J0K3RX
Degoop Doctor
 
Posts: 938
Joined: 29 Jun 2011, 02:25
Location: US Florida
Has thanked: 278 times
Have thanks: 431 times

Re: Amptweaker - Tight Metal

Postby jymaze » 25 May 2013, 21:18

You are sure about all resistors?

Ok, then I have to correct some values on my schematic.

Will do tonight.
You do not have the required permissions to view the files attached to this post.
jymaze
Resistor Ronker
 
Posts: 374
Joined: 06 Mar 2011, 23:19
Has thanked: 87 times
Have thanks: 158 times

Re: Amptweaker - Tight Metal

Postby J0K3RX » 25 May 2013, 21:30

jymaze wrote:You are sure about all resistors?

Ok, then I have to correct some values on my schematic.

Will do tonight.


Yes, I measured all and except for the 150k brownies all are measuring correct... I figure that something is affecting them making them read 66k to 68k... they look to be 150k but I can lift one and make double sure if you think that would be best? If you read the color bands one way (brown/green/black/orange/brown) you get 150k. If you read them the other way (brown/orange/black/green/brown) you get 13M which is not likely...

The ones you have circled are as follows;

orange/orange/black/black/brown = 330 ohms 1% and measures as such.

orange/orange/red/brown/brown = 3.32k ohms 1% and measures as such.
User avatar
J0K3RX
Degoop Doctor
 
Posts: 938
Joined: 29 Jun 2011, 02:25
Location: US Florida
Has thanked: 278 times
Have thanks: 431 times

Re: Amptweaker - Tight Metal

Postby jymaze » 26 May 2013, 02:24

Ok, values to be inserted in your schematic Jok3rx:

R19 is 3.3k

C14 is 220n

D1 4148

D2 4733

D3 4148

D4 4733

D5 D6 4148

D7 4733
jymaze
Resistor Ronker
 
Posts: 374
Joined: 06 Mar 2011, 23:19
Has thanked: 87 times
Have thanks: 158 times

Re: Amptweaker - Tight Metal

Postby jymaze » 26 May 2013, 02:42

Then here is the PSU, conceptually:

TM-PSU.gif


The last part seems to appears several times around the board.

I am still not totally sure about the replicates of Vref around the board and their decoupling, but having the Vref voltage divider appear only once is probably enough.

Jok3rx, can you check the voltage of the following points (in yellow, disregard the black circles):

TM-VrefPoints.jpg


I think they should be around 5.4 or a little under, all of them.
You do not have the required permissions to view the files attached to this post.

For this message the author jymaze has received thanks:
J0K3RX (26 May 2013, 06:50)
jymaze
Resistor Ronker
 
Posts: 374
Joined: 06 Mar 2011, 23:19
Has thanked: 87 times
Have thanks: 158 times

Re: Amptweaker - Tight Metal

Postby jymaze » 26 May 2013, 02:49

On the Eagle schematic again, values to be inserted:

C11 100n

C12 100n

Tone B10k

Volume B10k


I think that is it! The schematic is complete.
jymaze
Resistor Ronker
 
Posts: 374
Joined: 06 Mar 2011, 23:19
Has thanked: 87 times
Have thanks: 158 times

Re: Amptweaker - Tight Metal

Postby jymaze » 26 May 2013, 02:56

Last thing Jok3rx,

It is normal if the brown resistors read around 62k. The 100k resistors should also read about 62k. Probably you are reading 100k in parallel with 150k, plus the resistor in the low pass in the PSU.
jymaze
Resistor Ronker
 
Posts: 374
Joined: 06 Mar 2011, 23:19
Has thanked: 87 times
Have thanks: 158 times

Re: Amptweaker - Tight Metal

Postby euronymous0001 » 26 May 2013, 05:19


For this message the author euronymous0001 has received thanks: 3
bato001 (05 Apr 2017, 03:20), J0K3RX (26 May 2013, 18:00), modman (27 May 2013, 14:24)
euronymous0001
Breadboard Brother
 
Posts: 87
Joined: 26 Jun 2010, 04:11
Has thanked: 19 times
Have thanks: 29 times

Re: Amptweaker - Tight Metal

Postby euronymous0001 » 26 May 2013, 05:28


For this message the author euronymous0001 has received thanks: 3
J0K3RX (26 May 2013, 06:50), modman (27 May 2013, 14:23), Pruttelherrie (26 May 2013, 11:15)
euronymous0001
Breadboard Brother
 
Posts: 87
Joined: 26 Jun 2010, 04:11
Has thanked: 19 times
Have thanks: 29 times

Re: Amptweaker - Tight Metal

Postby J0K3RX » 26 May 2013, 06:19

jymaze - I can't get voltages just yet... the pedal is all apart and I am still tracing it for a double sided diagram/layout in Sprint.

Great work jymaze and euronymous0001!! This thing is a true nightmare!!! My brain is twisted from looking at this thing! Should be called Twisted Metal :lol:
User avatar
J0K3RX
Degoop Doctor
 
Posts: 938
Joined: 29 Jun 2011, 02:25
Location: US Florida
Has thanked: 278 times
Have thanks: 431 times

Re: Amptweaker - Tight Metal

Postby ggedamed » 26 May 2013, 10:48

1N4733 is a 5.1V Zenner, right? The Zenner clipping is weird, at 9V the op amp will clip before the Zenner on one side of the signal. Given the way Vref is made, the negative side of the signal cannot go lower than 4.25V, even with the best rail-to-rail op amp. At 9V the Zenner could be replaced by a 1N4148 type diode turned the other way around.
Jim, did you tried supplying it with 18V? It should sound somewhat different, as the Zenner will clip the both sides of the signal.
User avatar
ggedamed
Resistor Ronker
 
Posts: 319
Joined: 21 Jun 2009, 12:43
Location: Bucharest, Romania
Has thanked: 138 times
Have thanks: 144 times

Re: Amptweaker - Tight Metal

Postby J0K3RX » 26 May 2013, 17:41

ggedamed wrote:1N4733 is a 5.1V Zenner, right? The Zenner clipping is weird, at 9V the op amp will clip before the Zenner on one side of the signal. Given the way Vref is made, the negative side of the signal cannot go lower than 4.25V, even with the best rail-to-rail op amp. At 9V the Zenner could be replaced by a 1N4148 type diode turned the other way around.
Jim, did you tried supplying it with 18V? It should sound somewhat different, as the Zenner will clip the both sides of the signal.



Haven't tried it with 18v yet. Actually, I only even got to play with it one time before I butchered it for tracing...
User avatar
J0K3RX
Degoop Doctor
 
Posts: 938
Joined: 29 Jun 2011, 02:25
Location: US Florida
Has thanked: 278 times
Have thanks: 431 times

Re: Amptweaker - Tight Metal

Postby J0K3RX » 26 May 2013, 19:50

Ok, here is the front overlay... May be a few mistakes but nothing big, this thing is a brain twister!! Back coming soon..

And yes, that one green trace hangs down and connects to nothing if you were wondering...
You do not have the required permissions to view the files attached to this post.

For this message the author J0K3RX has received thanks: 2
ggedamed (26 May 2013, 22:58), modman (26 Apr 2016, 14:13)
User avatar
J0K3RX
Degoop Doctor
 
Posts: 938
Joined: 29 Jun 2011, 02:25
Location: US Florida
Has thanked: 278 times
Have thanks: 431 times

Re: Amptweaker - Tight Metal

Postby pakrat » 26 May 2013, 20:36

Pretty sick man, good job! :horsey:
pakrat
Breadboard Brother
 
Posts: 54
Joined: 27 Jan 2011, 17:27
Has thanked: 17 times
Have thanks: 30 times

PreviousNext

Return to Boutique Stompboxes dissected...

Who is online

Users browsing this forum: daedelus23, Groovenut, Jan1966, POTL and 22 guests