HAO - Sole Pressure

The Rotagilla · Post by **The Rotagilla** » 17 Aug 2008, 22:34

patafix wrote:Isn't there some MAX1044 in this ???

The PCB glued and gooped to the footswitch makes me think of a voltage doubling circuit.

Nope. At least not in the one I just got. TL072 op-amp, red LED's for clipping and not my cup of tea. Anyone need any pics before I flip this?

nooneknows · Post by **nooneknows** » 18 Aug 2008, 10:38

smanq wrote:From some posts and what we can see from the guts, the schematics could be like this
sp draft.jpg

if the Sole Pressure is a variation of the Rust Driver circuit and this schematics for the Rust Driver is correct:
https://i14.photobucket.com/albums/a303 ... IVER-1.jpg

the diodes appear to be in a wrong position.
Anyone can confirm?
thx

jaydawg · Post by **jaydawg** » 25 Aug 2008, 18:12

The Rotagilla wrote:
patafix wrote:Isn't there some MAX1044 in this ???

The PCB glued and gooped to the footswitch makes me think of a voltage doubling circuit.
Nope. At least not in the one I just got. TL072 op-amp, red LED's for clipping and not my cup of tea. Anyone need any pics before I flip this?

Hey, I bet you made a trade for that Sole Pressure didn't ya. And the board was already de-gooped when you got it?

Funny meeting you here.

The Rotagilla · Post by **The Rotagilla** » 25 Aug 2008, 19:58

jaydawg wrote:
The Rotagilla wrote:
patafix wrote:Isn't there some MAX1044 in this ???

The PCB glued and gooped to the footswitch makes me think of a voltage doubling circuit.
Nope. At least not in the one I just got. TL072 op-amp, red LED's for clipping and not my cup of tea. Anyone need any pics before I flip this?
Hey, I bet you made a trade for that Sole Pressure didn't ya. And the board was already de-gooped when you got it?

Funny meeting you here.

Oh snap!

It's on its way down the road again.

rhandy gaye · Post by **rhandy gaye** » 23 Mar 2011, 10:09

hi,

i only quickly read this thread but there seems to be confusion about the the use of a max1044.

the links to pics at the start of the thread are of a modded sole pressure by a japanese fx mod/tweaker (soul power instrumnents).

cheers.

new_anuzzerone · Post by **new_anuzzerone** » 15 May 2013, 20:39

patafix wrote:Isn't there some MAX1044 in this ???

The PCB glued and gooped to the footswitch makes me think of a voltage doubling circuit.

sorry for continuing an old thread:

Opened my sole pressure and there was only a drop of goop on the IC, it came of with a pocket knife

underneath there is a: ST (http://www.st.com) --> manufact. --> TL0720N

tried to find some datasheets, but negative.
some chinese salesmen seem to sell these.

Maybe it helps.

FiveseveN · Post by **FiveseveN** » 15 May 2013, 21:02

I think it's TL072CN, C indicating normal temp range and N DIP8.
http://www.datasheetcatalog.org/datashe ... s/2298.pdf

IvIark · Post by **IvIark** » 15 May 2013, 21:23

This has reminded me that I've got one of these somewhere that I haven't had a proper look at yet. I'll do it over the next few days and post a schematic.

new_anuzzerone · Post by **new_anuzzerone** » 16 May 2013, 15:28

FiveseveN wrote:I think it's TL072CN, C indicating normal temp range and N DIP8.
http://www.datasheetcatalog.org/datashe ... s/2298.pdf

Yep, you´re right. Was difficult to see, coz the goop nearly stripped of all the script / paint of the TL.
With daylight, it´s easier. It´s an 072CN

added a quick gut shot of mine

cheers

new_anuzzerone · Post by **new_anuzzerone** » 16 May 2013, 19:26

Homework? DONE!

Here´s some other pics.

The values given, are the ones I measured from the resistors (no, this isn´t a 22k / 5% resistor...)
The 2 diodes on the bottom are just difficult to read: 44R and 5B (I don´t know, if that´s right...)

the pots are:
level:
10 4B
35 1V

Drive:
50 4C
33 6V

whatever that means (100k B and 500k C ??)

the switch is a on-off-on

the board, where the FS is mounted, holds only the LED on the other side, no parts there
ok, here´s the pics:

sorry, for the blurry pics

regards

Manfred · Post by **Manfred** » 27 Jul 2013, 02:00

smanq wrote:From some posts and what we can see from the guts, the schematics could be like this
sp draft.jpg
The supply filter seems a 100uF cap.
I suppose the VR is half supply from classic 2 resistors and a filter cap (values?).
Where are placed the 22K and 100K resistors we can see in photos?

Please try to comment or complete it (errors, values, missing components, ...)

I excerpted follwing schematic from the shots and the schematic from above.

Corrected schematic HAO Sole Pressure

The LEDs are seriell connected to a large 100k resistor,
this leads to the conclusion that the LEDs must be low current types.

What are the values of the potentiometers?
I suppose that the unidentified part of the schematic act as noiseless indicating LED switching.

Manfred · Post by **Manfred** » 27 Jul 2013, 09:10

I was wrong.
Here the corrected Schematic:

Corrected schematic HAO Sole Pressure

smanq · Post by **smanq** » 27 Jul 2013, 10:18

Very strange the choice of 100K resistor before the LEDs, I've never seen a such high value in this position.

For the pots, I think the Drive is C500K (rev log) and the Volume is A100K (log).
You can delete the other components from the schematics: they are for the switch.

Manfred · Post by **Manfred** » 27 Jul 2013, 14:44

smanq wrote:Very strange the choice of 100K resistor before the LEDs, I've never seen a such high value in this position.

For the pots, I think the Drive is C500K (rev log) and the Volume is A100K (log).
You can delete the other components from the schematics: they are for the switch.

It is indeed an extraordinary high resistance.
The expected current value which feed the LED while the maximum signal half-wave is about 40 Microamps.
I don't know how the LED clipping in this case is.
Maybe the main clipping comes from the OP-Amp.
I modified the schematic following your recommandation:

Corrected schematic HAO Sole Pressure

fanela · Post by **fanela** » 06 Jun 2014, 15:50

Hello everyone, excuse my ignorance but this schematic is not missing more components. I see some pictures around and do not match.
Sorry for my bad english.

Manfred · Post by **Manfred** » 07 Jul 2016, 22:06

I bought a second hand one and dissected it.
So I could I traced the Clipping LEDs Curves.
The LEDs are matched.
I verified the circuit and found that the capacitor in seriell with the drive pot has a value of 0.47uF.
I add some oszilloscope shots.
I fed the input with a sine wave of 50 Millivolts 1000 cps.
The Clipping LEDs flatten the sine wave soft so as a slightly overdriven tube power amp.
The clipping starts at the 3 o'clock position of the drive pot in that signal input.
The Op-amp clipping starts a bit greater than the 3 o'clock position.
The Op-amp clipping has been read on pin 1.

Corrected schematic HAO Sole Pressure

box · Post by **box** » 08 Jul 2016, 07:37

Manfred wrote:I was wrong.
Here the corrected Schematic:

HAO_SOLE_2.JPG

Hi,
Please check IC pins are not correct.
TL072 is dual OP-amp :
pins 1,2,3,4 are correct(4-Gnd).
pins 5,6,7 -NC
pin 8 --Vcc.
Rgds,
box

Manfred · Post by **Manfred** » 08 Jul 2016, 11:50

Hi Box,

thanks for the hint.

lemonengine1 · Post by **lemonengine1** » 12 Aug 2016, 14:35

Great thread, lots of info on this pedal here, thanks!

So let's say, hypothetically, one had a pedal such as this (I have this friend...lol) with the TL072CN, is there a way to brighten this thing up a bit? I know, I know...it's supposed to sound like a BASSman, but good gawd, ya'll! Too dark!! Would using a "brighter" IC do the trick? I know the TL072 can be a little dark and gritty (part of its charm). Would the BB or more hi-fi equivalent achieve the desired objective? Not trying to start another opamp debate...

However, any thoughts and/or feedback would be greatly appreciated!!! Thanks!

Manfred · Post by **Manfred** » 12 Aug 2016, 16:20

lemonengine1 wrote:Great thread, lots of info on this pedal here, thanks!

So let's say, hypothetically, one had a pedal such as this (I have this friend...lol) with the TL072CN, is there a way to brighten this thing up a bit? I know, I know...it's supposed to sound like a BASSman, but good gawd, ya'll! Too dark!! Would using a "brighter" IC do the trick? I know the TL072 can be a little dark and gritty (part of its charm). Would the BB or more hi-fi equivalent achieve the desired objective? Not trying to start another opamp debate...
However, any thoughts and/or feedback would be greatly appreciated!!! Thanks!

Try by reducing the input capacitor (100nF).

HAO - Sole Pressure [traced]