Fulltone - 2B  [traced]

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

Fulltone - 2B

Postby Bside2234 » 21 May 2019, 17:57

I have one of these here for a week or so. I'm kind of working on a schematic but any help would be appreciated. I'll take pics of anything you want and try and help with any values/info you need.
Here are some pics. If there is interest in this I will continue with the schematic and post it. Don't really want to post a unverified, unfinished schematic. I'll try and post some values later.
20190510_105853sm.jpg

20190510_105900sm.jpg

20190521_093222sm.jpg

20190521_093226sm.jpg

20190521_093230sm.jpg

20190521_093234sm.jpg

20190521_093258sm.jpg

20190521_093302sm.jpg

20190521_093304sm.jpg

20190521_093306sm.jpg
You do not have the required permissions to view the files attached to this post.

For this message the author Bside2234 has received thanks: 6
287m (21 May 2019, 18:25), Intripped (22 May 2019, 00:31), karul (28 May 2019, 01:44), modman (31 Jul 2019, 11:01), okgb (26 May 2019, 16:44), Zokk (22 May 2019, 14:47)
Bside2234
Solder Soldier
 
Posts: 236
Joined: 30 Jul 2007, 20:35
Location: Kennewick, WA
Has thanked: 5 times
Have thanks: 69 times

Re: Fulltone 2B

Postby Bside2234 » 22 May 2019, 04:31

Here are the values I came up with. I think I got everything. If not, let me know and I'll get it. The IC is sanded so I don't know what it is. It's a single op-amp. I don't see any value markings on the Gain pot.

R1 10K
R7 3M3
R15 10K
R20 3M3
R22 10K
R23 10K
R26 100E
R27 100K
R29 4K7
R30 1K

C? 0.1uF (Bigger reddish cap in the middle. No reference that I can see)
C7 100uF/25v
C13 100uF/25v
C14 10u/35v
C15 10uF/35v
C16 100pF

D3 1N4005
D4 1N5818
D5 5mm LED
D9 1N750A
D13 Germ
D14 Germ

U3 ? Sanded Single Op-Amp
Q4 BS250

DYNAMICS B-250K
GAIN ? Measures 60K In Circuit
Bside2234
Solder Soldier
 
Posts: 236
Joined: 30 Jul 2007, 20:35
Location: Kennewick, WA
Has thanked: 5 times
Have thanks: 69 times

Re: Fulltone 2B

Postby Bside2234 » 22 May 2019, 15:49

In the parts/values list above I wrote R20 and it should be R28. I didn't have my glasses on and the 8 looked like a 0. :D
Bside2234
Solder Soldier
 
Posts: 236
Joined: 30 Jul 2007, 20:35
Location: Kennewick, WA
Has thanked: 5 times
Have thanks: 69 times

Re: Fulltone 2B  [traced]

Postby Bside2234 » 22 May 2019, 18:12

Here's the schematic. Maybe this will spark more interest in this. I'm pretty sure it's correct but I have the pedal for a few more days so if you have any doubts/questions I'll check them.
2Bv1.0.pdf
You do not have the required permissions to view the files attached to this post.

For this message the author Bside2234 has received thanks: 5
dtp (31 Jul 2019, 16:12), Intripped (23 May 2019, 03:08), karul (28 May 2019, 01:43), Manfred (23 May 2019, 21:45), modman (31 Jul 2019, 11:02)
Bside2234
Solder Soldier
 
Posts: 236
Joined: 30 Jul 2007, 20:35
Location: Kennewick, WA
Has thanked: 5 times
Have thanks: 69 times

Re: Fulltone 2B

Postby Intripped » 23 May 2019, 03:36

Hey, thanks for your work!
the gain pot value: you should be able to measure it, if you lift one end of R30; but I see they have bent the legs of all components under the PCB, and this could result in some complications in the desoldering process.
You could try and unbend the component legs while desoldering, but probably the safest way is to just cut the legs and then use a new resistor.

Good to know, that this pedal is not true bypass, and that it becomes a buffer when bypassed.
A nice test that you could make, is to hear and evaluate the "transparency" (or tonal influence) of this buffer.
Intripped
Cap Cooler
 
Posts: 495
Joined: 25 Aug 2009, 02:03
Location: Italy
Has thanked: 606 times
Have thanks: 216 times

Re: Fulltone 2B

Postby Bside2234 » 23 May 2019, 04:47

Intripped wrote:Hey, thanks for your work!
the gain pot value: you should be able to measure it, if you lift one end of R30; but I see they have bent the legs of all components under the PCB, and this could result in some complications in the desoldering process.
You could try and unbend the component legs while desoldering, but probably the safest way is to just cut the legs and then use a new resistor.

Good to know, that this pedal is not true bypass, and that it becomes a buffer when bypassed.
A nice test that you could make, is to hear and evaluate the "transparency" (or tonal influence) of this buffer.


It's not my pedal so I didn't really want to mess with it too much. I'll see if I can lift the leg of that resistor and see what I measure. It didn't seem like there was much resistance in series or parallel with it so I didn't think too bother too much
with it.
Bside2234
Solder Soldier
 
Posts: 236
Joined: 30 Jul 2007, 20:35
Location: Kennewick, WA
Has thanked: 5 times
Have thanks: 69 times

Re: Fulltone 2B

Postby Intripped » 23 May 2019, 06:13

Bside2234 wrote:It's not my pedal so I didn't really want to mess with it too much. I'll see if I can lift the leg of that resistor and see what I measure. It didn't seem like there was much resistance in series or parallel with it so I didn't think too bother too much
with it.


Pay attention, you could damage the PCB, because of that bent leg.
Resistor substitution it's the safest way, if you really want to do it.
Intripped
Cap Cooler
 
Posts: 495
Joined: 25 Aug 2009, 02:03
Location: Italy
Has thanked: 606 times
Have thanks: 216 times

Re: Fulltone 2B

Postby Bside2234 » 23 May 2019, 19:24

The Gain pot measures 100K exactly with R30 removed.

For this message the author Bside2234 has received thanks:
Intripped (24 May 2019, 09:02)
Bside2234
Solder Soldier
 
Posts: 236
Joined: 30 Jul 2007, 20:35
Location: Kennewick, WA
Has thanked: 5 times
Have thanks: 69 times

Re: Fulltone 2B

Postby ahauser » 21 Jun 2019, 02:00

Hi Bside,
Were you able to identify the Germanium Diodes?
Thanks.
ahauser
 
Posts: 4
Joined: 17 Jun 2019, 01:55
Has thanked: 0 time
Have thanks: 2 times

Re: Fulltone 2B

Postby ahauser » 21 Jun 2019, 03:29

I had a look in the FD 3 as the boost is apparently the same. The 2 ICs in it are
2072C and AD711J

For this message the author ahauser has received thanks:
bossman (18 Jul 2019, 18:47)
ahauser
 
Posts: 4
Joined: 17 Jun 2019, 01:55
Has thanked: 0 time
Have thanks: 2 times

Re: Fulltone 2B

Postby Bside2234 » 21 Jun 2019, 04:45

ahauser wrote:Hi Bside,
Were you able to identify the Germanium Diodes?
Thanks.


No. There weren't any markings on them.
Bside2234
Solder Soldier
 
Posts: 236
Joined: 30 Jul 2007, 20:35
Location: Kennewick, WA
Has thanked: 5 times
Have thanks: 69 times

Re: Fulltone 2B

Postby Bside2234 » 21 Jun 2019, 04:49

ahauser wrote:I had a look in the FD 3 as the boost is apparently the same. The 2 ICs in it are
2072C and AD711J


Not familiar with the 2072C. Is that the TLE2072? Link to a datasheet?
Bside2234
Solder Soldier
 
Posts: 236
Joined: 30 Jul 2007, 20:35
Location: Kennewick, WA
Has thanked: 5 times
Have thanks: 69 times

Re: Fulltone 2B

Postby ahauser » 22 Jun 2019, 12:24

It has a texas Instruments logo on it so im assuming its this one.
http://www.ti.com/product/TLE2072

For this message the author ahauser has received thanks:
bossman (18 Jul 2019, 18:47)
ahauser
 
Posts: 4
Joined: 17 Jun 2019, 01:55
Has thanked: 0 time
Have thanks: 2 times

Re: Fulltone 2B

Postby Bside2234 » 22 Jun 2019, 14:51

ahauser wrote:It has a texas Instruments logo on it so im assuming its this one.
http://www.ti.com/product/TLE2072


So then we can assume the 2B uses the AD711J since it's a single op-amp in there and the TLE2072 is a dual.
Bside2234
Solder Soldier
 
Posts: 236
Joined: 30 Jul 2007, 20:35
Location: Kennewick, WA
Has thanked: 5 times
Have thanks: 69 times

Re: Fulltone 2B

Postby ahauser » 09 Jul 2019, 07:20

Hi BSide,
Re the IN750A diodes can I substitute with a 4.7V IN5230B? I cant find any IN750A's.
Also what do you suggest for the Germanuim Diodes?
Adrian
ahauser
 
Posts: 4
Joined: 17 Jun 2019, 01:55
Has thanked: 0 time
Have thanks: 2 times

Re: Fulltone 2B

Postby Bside2234 » 09 Jul 2019, 13:55

ahauser wrote:Hi BSide,
Re the IN750A diodes can I substitute with a 4.7V IN5230B? I cant find any IN750A's.
Also what do you suggest for the Germanuim Diodes?
Adrian


I would assume any 4.7v would work in this application. For reference the 1N750 is a 0.5W/4.7V zener diode. I'd probably start with a 1N34A for the Germanium diodes. Probably socket them and see if there is any difference between others.
Bside2234
Solder Soldier
 
Posts: 236
Joined: 30 Jul 2007, 20:35
Location: Kennewick, WA
Has thanked: 5 times
Have thanks: 69 times

Re: Fulltone 2B

Postby okgb » 09 Jul 2019, 15:25

Yep he's looking for his own magic diodes so he can be better than Bill! , Doe's this remind anyone of Jack & the bean stock ?
okgb
Diode Debunker
 
Posts: 792
Joined: 16 Mar 2010, 04:58
Has thanked: 209 times
Have thanks: 42 times

Re: Fulltone 2B

Postby dtp » 31 Jul 2019, 05:37

Yay! I've been wanting a schematic of this for a long time! I love to the boost section of my FD3, but the rest of the pedal is only kinda meh...

Thanks for posting this!
dtp
 
Posts: 1
Joined: 26 Apr 2014, 01:21
Has thanked: 1 time
Have thanks: 0 time

Re: Fulltone 2B

Postby Optical » 31 Jul 2019, 10:50

Cool, the VFE dragon uses a clipping/compression circuit just like this but with BS170 body diodes as instead of the germaniums
Optical
Breadboard Brother
 
Posts: 83
Joined: 28 Jul 2016, 23:44
Location: Auckland
Has thanked: 11 times
Have thanks: 14 times


Return to Boutique Stompboxes dissected...

Who is online

Users browsing this forum: jalmonsalmon, pc3326 and 12 guests