anyone used these as indicator led?

[grolschie]

Argh.... I tried various resistors from 1.5k down to 360ohm. At 1.5k it switched only a few colours and stuck on one. Somewhere along the way down to 360ohms it switched 6 colours then stuck on the last one. I tried ~200ohm by paralleling a 470 and a 360. 6 colours then stuck, for a few tries as before, and now it cycles only through to colour 4 then stays there. I tried jumpering the resistor, still stuck on colour 4. I might have killed it perhaps....

[oskar]

I might have killed it perhaps....

Not likely. I don't think undercurrent will kill it. Maybee bored it to death?   
Remember, there is more factors involved in determining the current for the LED ( or what that thing really is... )
On the schematic I linked to, the LED series resistor is R88/10k.
The transistors base current however is determined by R72 which is 1M. That is a bit to high.  Try sticking another 1M in there in parallel with R72. You may need to go even lower but remember. It could provoke the on/off switching action if you take out too much current, but hardly with the modest currents we're talking about here.

[grolschie]

Thanks for the reply.

On the schematic I linked to, the LED series resistor is R88/10k.

Don't you mean R62?

The transistors base current however is determined by R72 which is 1M. That is a bit to high.  Try sticking another 1M in there in parallel with R72.

I will give another 1M a go. What is the purpose of this transistor in this setup? Thanks. 

[oskar]

Don't you mean R62?

Yes indeed!

I will give another 1M a go. What is the purpose of this transistor in this setup? Thanks. 

More likely something like a total resitance of ~200k. I looked up the datasheet for the 2sc1815 and it has an amplification between 70 and 700. So if you're lucky you'll get away with a resistor big enough not to interfere with the switch. Witch in this part is fed by... R88
You just might get away with it. Start with 1M though.

TR13 amplifies the signal on TR12 so the LED doesn't interfere with the switching action

[grolschie]

Ok. I paralleled a 1Mohm. Colours stop cycling on the last colour. I paralleled another 1Mohm and success! So currently, the series resistor is 360ohms and I think that the R72 value is 333k (3x 1Mohm in parallel). The LED works. The LED cycles through all colours. Signal cuts out when LED is on - because I guess that the tone circuit not connected back up yet, so I am guessing that the switching still works. Many thanks Oskar! 

Final questions. What values should I settle with for R62 and R72 to ensure switching works and LED colours cycle, but LED won't suck too many milliamps? LED seems to work off a Boss PSU and a new battery. Many thanks.

[oskar]

Ok. I paralleled a 1Mohm. Colours stop cycling on the last colour. I paralleled another 1Mohm and success! So currently, the series resistor is 360ohms and I think that the R72 value is 333k (3x 1Mohm in parallel). The LED works. The LED cycles through all colours.

Great!

Signal cuts out when LED is on - because I guess that the tone circuit not connected back up yet, so I am guessing that the switching still works.

Ok. I didn't get that...    -Your main focus is still making noise so make sure it turns on/ off properly...   

Final questions. What values should I settle with for R62 and R72 to ensure switching works and LED colours cycle, but LED won't suck too many milliamps? LED seems to work off a Boss PSU and a new battery. Many thanks.

Well. R62 regulates the current through the LED really and the LED at minimum current will at least double the total current drawn by this circuit.
You are mainly going to use PSU's from now on, probably?! My main concern is that the proportionally small current we take from the switch, to turn TR13 on enough for the LED's operation, is going to upset the switch or make it unstable with intermittent problems when switching it on/off or perhaps turning off if it gets hot or something like that. Now we decreased R72 enough to feed TR13 but earlier you diminished R62 pretty much.
Just maybee you can settle on 1k.
If you don't want to starve it and give it the rated 20mA( ~220R), and it works off 360R so perhaps 470R - 1k maybe could work.

If the switch gets restless or go on a strike or whatever I'ld like to hear about it. OK?

Thank you, it's been a pleassure


Oskar

[Sir H C]

In a high gain circuit

[grolschie]

Thanks Oskar. The tone circuit is on a separate board which connects up to the main board when assembled in the case. It is easier to work on the circuit outside the case. :-)

I measured the current draw at the battery (without tone/gain/level board connected) and I am sure it read 8.9mA. When replacing R62 with a 1K (which works by the way), it draws 8.7mA. Should I try a bigger valve?

Will measure the current draw when it's all back together. The pedal belongs to a friend who uses a PSU. 

Actually, after seeing the video Sir H C posted, I had better put her back together for a listen. Yikes.

[oskar]

And that was LED'ish for "Feed me!!!"?     
Yep. We haven't really adressed the issue of noise but I believe it was mentioned earlier in the thread.
We'll get there...

[grolschie]

Thanks. I will try it in the case soon. :-)

[grolschie]

Ok. It seems to work in its case.

However, one question: being not sure how this transistor switch arrangement works, would there ever be an scenario where both the dry and wet signal are being blended together i.e. clean signal leaking through when pedal engaged?

I didn't have a decent play with the pedal prior to changing the LED, but it sounds like on the loudest bass notes that I can hear the clean sound mixed in real loud. Or is that how a TS-7 supposed to sound like? Lower gain pups don't seem to have same effect, only high gain ones and when they are played hard. It's more noticable with high gain on full and hot switch also engaged. When the sound is supposed to be compressed and distorted (which it is when I play gently), there seems to be clean mixed in. This is quite a cool effect, because I can still hear twang. But I suspect it's not how it supposed to sound. 

[oskar]

However, one question: being not sure how this transistor switch arrangement works, would there ever be an scenario where both the dry and wet signal are being blended together i.e. clean signal leaking through when pedal engaged?

Yes there is.
http://www.diystompboxes.com/smfforum/index.php?topic=73099.0
But this guy was parachuting without an instructor ( or parachute ). The LED in that circuit is driven directly by the switch without amplification so it's more difficult to tweek.

I didn't have a decent play with the pedal prior to changing the LED, but it sounds like on the loudest bass notes that I can hear the clean sound mixed in real loud. Or is that how a TS-7 supposed to sound like?

Never touched one of those things... I know, my DIY credibility just took a severe dive.
But I don't think it's supposed to sound clean when you go full on.
Measure J401 pins on and off. They should take turns to be high/low and hold comparable values.
It's still doable if you're having troubles with leak but as you might have figured out allready it could take some work.
One fix would be to again increase R72 and instead change TR13 to one with higher gain. R88 is also a possible target here but that is off limits as far as my experience goes. You could try and lower it a bit, again with another resistor stuck in parallel ( for a total R of perhaps ~2/3 of it's present 56k... just guessing here! ). But take readings on j401 first.

Lower gain pups don't seem to have same effect, only high gain ones and when they are played hard. It's more noticable with high gain on full and hot switch also engaged. When the sound is supposed to be compressed and distorted (which it is when I play gently), there seems to be clean mixed in. This is quite a cool effect, because I can still hear twang. But I suspect it's not how it supposed to sound. 

When it starts clipping it really does that. It get's more distorted but the level won't increas considerably. The level of your playing is however so it really sound like something could be leaking through here ( actually the clean switch could be fully open... )

[oskar]

Done thinking. The transistors in the switch is set up with slightly different component values. I think that is because them japanese wanted the unit to be allways the same state when you put a cable in the input (off ). All we need to do however is make sure the collector voltage is the same on both of them trannies and that is what you're about to measure on either the collectors directly or on j401 ( via 1M resistors ). R88 has to be lowered like I said before. A 100k in parallel will probably do it.

[grolschie]

Hi Oskar.

I put the postive end of multimeter on a ground i/o jack plate and the negative end on the collectors of TR12 and TR13. Here are the voltages:

TR13 ON: 1.66v, 1.66v, 2.2v, 2.02v, 2.05v, 2.27, 2.36 (approx, as the values change fast, with dips below 1v while changing)
TR13 OFF: 6v

TR12 ON: 5.2v
TR12 OFF: 0.02v

Taking readings from the reverse side of the board from the solder produces lower readings (approx 0.5v lower).

[oskar]

TR11? We need to know that one rather than TR13.

[grolschie]

TR11 ON:   0.05v
TR11 OFF: ~7.0v

The collector is the middle pin right?

[oskar]

So. Decrease R88 untill TR12 is ~7V also...      Were enginering!!! Whooopieee!
A 100k over R88 is a good start!

[grolschie]

Paralleling a 100k makes it read 6v now.

[oskar]

  ...lower! R88 stick another 47k - 100k in there... and boldly so!
EDIT! 47k is a bit low perhaps!

[grolschie]

6.58v now with another 100k tacked on. This is looking like Frankenstein's latest creation.