Das Lineal - Problems

Hi all! and happy holidays from Norway

I purchased the lineal kit a while back, had some trouble getting it to work and now I'm again trying to fix it (built the DSOTM kit with no problems).

Problem is as follows :

- No sound
- LED lights up when I press the footswitch

I have gone through the pedal and measured the voltages, but since I have no reference values I do not know if these are the expected values :

5.65v - R5

8.57v - R3

7.65v - R6

9.41v - D1

1.75v - LED1

3.62v - leg 1&3

0.60v - leg 1&2

9.40v - leg 2&3

9.40v - input

0.20v - R2

0.80v - R4

0.00v - R1

3.82v - C3

9.42v - C5

0.84v - C1

I have vocational traning in electronics so I'm not a total newbie, however I have not practiced my education for... 10 years so some of it is lost.

Hopefully someone has some idea (I think the voltages for the R2\R4\R1 are quite low.. but they might be as expected).

Zitat von eBernd;351035

O M G :o

what does this mean?!
Is it the transistor? Or the Volume pot?

The most important DC voltages - measured to ground - are the three of the transistor (Vc, Vb and Ve) and of course the supply voltage.

BTW: A notation like "7.65v - R6" doesn't make sense - because a resistor has two legs...

Regards
Bernd

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Hi eBernd! thanks for your reply.

Sorry, I meant to change the names, but I forgot before I posted :

1 = Emitter
2 = Base
3 = Collector

The voltages I measured were between the legs, but I've done fresh readings now for you

Emitter -> Ground = 0.20v
Base -> Ground = 0.80v
Collector -> Ground = 4.00v

Supply voltage 9.40v

In regards to the Resistor values, I measured the values across the transistor with pedal engaged (all values are with pedal engaged \ LED on).

Thanks again for the reply, and hope to hear from you again

Zitat von eBernd;351053

Hi

the voltages around the transistor are ok.

If there is no sound at all, check at first the foot switch wiring. Does the switch have the right orientation?

One method ist to trace (that means follow) the input signal from the input jack through switch and the circuit to the output jack. When it disappears then you found the (solder) errror.
Therefore you need a signal source (a generator or a mp3 player or something like this) and an audioprobe (search for this word) and - for example - your guitar amp.

Regards
Bernd

Hi Again Bernd.

Good to hear the voltages are ok, I have never soldered a footswitch before so I was a bit sceptical at first.

As far as I can see from the diagram

http://diy.musikding.de/wp-content/upl…/linealwire.pdf

The input comes in on the left side, middle pin and should come out in the middle on the middle pin, am I right ?

Zitat von elkulk;351055

Hi,
that's correct.

And: make sure that the orientation of the switch is like in the following diagram - the soldering pins have to form a tunnel from up to below (or below to up; not: left to right/ right to left).

[ATTACH=CONFIG]12939[/ATTACH]

And furthermore: Haven't you swapped the input and output jacks or the input and output of the pcb?

Kind regards
Ulrich

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Hi Ulrich

I have the right orientation on the switch yes, and I have verified I have the input jack and output jack connected exactly like the wiring guide that is posted for the Lineal, I have folllowed the path of the signal with regular beep-multimetermode, and it appears to go where it is supposed to, but I guess I have to make a audioprobe like Bernd suggests to see what happens.

I'm just very confused with the footswitch as searching the web I find many different ways to connect it, like this :

http://home.centurytel.net/flanneldrawers/3PDT-wiring.jpg

-Eirik

Zitat von Magnus;351064

Hello,
maybe you have made a soldering-error on the input-jack...

Take a look at ring and tip, the input has to be soldered to tip,
if you have soldered the input to ring the signal will be connected to ground which causes no signal.

Here's a nice graphic:
http://www.musiker-board.de/attachments/f3…explanation.jpg

There are more than one way to connect a 3PDT-footswitch,
the best way to fix an error is to look how this switch works

And take a look at the wiring of your led,
the short leg of the led (which is the negative pole)
has to be soldered on the right top corner of the switch...
Otherwise there would be 9V DC on the input - not good!
The middle pin on the right side of the switch goes to ground on the pcb.

If anything (input and led) is wired correctly try another transistor, maybe it got damaged...

Good luck

Greetings
Magnus

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Hi magnus.

Thanks for the reply, the jacks are soldered correctly (I know that much :-)) and the LED appears to be working fine since it turns on and off when I press the footswitch..

I just have to find the time to make a audioprobe and actually sit down and fix it I guess... I think the problem is somewhere in the footswitch, but since I have soldered the footswitch as instructed in the buildguide for this pedal I would assume that it would work..

Finally figured it out a few weeks ago, I had made the hole in the chassis too shallow, so whenever I inserted a jack the jack tip would made the plug touch the chassis itself, just twisted the jack a few millimeters and abrakadabra, it worked thanks guys!