Small Stone (Tonepad) problems (volume drop, oscillating)

[Del Pedro]

Hi,

I have a few problems with my Small Stone. It is built according to the Tonepad layout.
It works quite well and sounds really good but displays a volume drop. This volume drop is noticeable in both positions of the color switch but stronger and really annoying when color switch is ON.
In addition there's some oscillating, again stronger when color switch is on.
I wanted to solve both problems with these tips. So I tried 10k  for R11 and R42 (and values between 3,3k and 10k für R11), but to my ears this doesn't change anything.
Any ideas what to do? Try higher values than 10k?

Kind regards
Peter

Here's a picture of the effect (with it's twin   )
http://forum.musikding.de/attachements/Small_Clone__Stone.jpg

[Del Pedro]

Oops, I changed the wrong resistor  :oops: , R7 instead of R42. So I will try if increasing the correct resistor solves the volume drop problem.
But I guess that doesn't affect the oscillating, so if someone knows a solution for that I'll be very grateful.

Kind regards
Peter

[bryantabuteau]

I may have had a similar problem on my build.  

I changed R11 (the 3k3 resistor off the emmitter of Q10) to 10K.
I think this was labeled as an anti volume drop mod, but also fixed my oscillation when the colour switch was engaged.

Something to try.

[Del Pedro]

I may have had a similar problem on my build.  

I changed R11 (the 3k3 resistor off the emmitter of Q10) to 10K.
I think this was labeled as an anti volume drop mod, but also fixed my oscillation when the colour switch was engaged.

Something to try.

Hi,

that's what I already did. I changed R11 (originally 3k3) to 5k6, 6k8, 8k2 and 10k. I can't hear any difference, the volume doesn't change, nor does the oscillating.

I changed R42 to 10k, now there's no volume drop if the color switch is off. If the color switch is on volume still goes down.
Any ideas what to do?

Back to oscillating:
The effect is a little bit noisy, a bit noisier than I would like.
I tried to record a short soundsample of the oscillating. But on the sample the noise level is considerably lower than it seems to me while playing.
So here's just the phaser with an overdrive box (as on clean settings there was no audible oscillating on the record). I first hit a chord with just the distortion on (for level comparison), then turn down the guitar volume and add the phaser. First with color switch off, then it is turned on.
What do you think, is this normal noise or should it be lower? (probably you'll have to turn up the volume of your speakers a bit).

http://delpedro.gmxhome.de/soundsamples/smallstone.mp3

Kind regards
Peter

[bryantabuteau]

I'll have a look sometime within the next day and post some voltages that might help you track down where it seems to be breaking.  I'm not really overly good at troubleshooting myself, but If I can help, I will.

My small stone build is not very noisy, I use a humbucker equipped guitar though so it may be different with single coils.   I have a slight volume difference between having the color switch on and off, but not much.

[Del Pedro]

Thank you very much in advance for your help!

[bryantabuteau]

I'll try and do that tonight, sorry, my weekend was a little bit too busy.

[bryantabuteau]

Okay, My speed pot is on 8 on a 1-10 scale and is a 1M log pot

IC1-4 (approx) (/=low high oscillating)
1- 0
2- 2.49/2.67
3- 2.5/2.8
4- 0
5- .61/.68
6- 3.2/3.8
7- 6.3/7.1
8- 0

IC5
1- 0
2- 2.0/5.8
3- 2.0/5.8
4- 0
5- .47
6- 1.6/1.9
7- 6.2/7.0
8- 0

I have made the following mods -
R42 10k - was 4k7
R11 10k - was 3k3

I'll try and get the trannie voltages later, but gotta get dinner

[Del Pedro]

Hi,

Okay, My speed pot is on 8 on a 1-10 scale and is a 1M log pot

Is this slow or fast modulation?
This question may seem dumb but I used a 1M log pot, too, with not so good results. I wired it like shown in the tonepad pdf but it work counterclockwise. So I thought that I made a mistake with the wiring and changed the wiring but now the type of control was terrible (I hope it can be understood what I mean, I don't know the correct technical terms ).
Now I use a 1M rev. log. pot.

IC1-4 (approx) (/=low high oscillating)
1- 0
2- 2.49/2.67
3- 2.5/2.8
4- 0
5- .61/.68
6- 3.2/3.8
7- 6.3/7.1
8- 0

IC5
1- 0
2- 2.0/5.8
3- 2.0/5.8
4- 0
5- .47
6- 1.6/1.9
7- 6.2/7.0
8- 0

I have made the following mods -
R42 10k - was 4k7
R11 10k - was 3k3

I'll try and get the trannie voltages later, but gotta get dinner

Thanks very much for your effort. I'll compare my values later (I'm not at home right now).

Kind regards
Peter

[Del Pedro]

Ok, here are my voltages in comparison to yours (mine following yours). Speed was quite low.

IC1-4 (approx) (/=low high oscillating)
1- 0           -            0
2- 2.49/2.67 -           2.7/3.0
3- 2.5/2.8      -        2.7/3.0
4- 0                -     0
5- .61/.68         -    0.62/0.69
6- 3.2/3.8          -    3.76/4.08
7- 6.3/7.1           -  6.8/7.5
8- 0                    - 0

IC5
1- 0                     - 0
2- 2.0/5.8           -  2.3/6.2
3- 2.0/5.8            -   2.1/6.3
4- 0                    -   0
5- .47                -   0.56
6- 1.6/1.9           -     1.66/1.87
7- 6.2/7.0            -    6.8/7.5
8- 0                     -   0

I have made the following mods -
R42 10k - was 4k7
R11 10k - was 3k3

So did I.


The voltages seem rather normal to me, they are all a bit higher than yours. Maybe that's because of the power supply (I had 8,86V).

[bryantabuteau]

looks all about the same.  I can't get reverse log pots over here, so I have a crappy range on my 1meg log.  I plan to reverse the wires so i get a more usable range sometime soon, but I havn't got around to it.  The speed I get at 8 is not real fast, but a steady pulse.  
My thoughts would be to experiment with layout of your input and output wires, keeping them away from each other, and after that, I'm not to sure.   Double check your wiring on the color switch.   My oscillation was changed dramatically with the R11 mod, so maybe you've got a solder bridge somewhere thats bypassing some components in that area.  I'm really clutching at straws here.   If you need certain trannie voltages just give me a yell and I'll grab them.  Theres just lots and lots of them

[Del Pedro]

My thoughts would be to experiment with layout of your input and output wires, keeping them away from each other, and after that, I'm not to sure.   Double check your wiring on the color switch.   My oscillation was changed dramatically with the R11 mod, so maybe you've got a solder bridge somewhere thats bypassing some components in that area.  I'm really clutching at straws here.   If you need certain trannie voltages just give me a yell and I'll grab them.  Theres just lots and lots of them

Thanks for your tips! Unfortunately I couldn't find any mistakes (what doesn't mean that there none   ). So I decided to stop the debugging attempt now and use the effect as it is. Because first I will probably use the phaser most of the time with color switch off, and second I don't want to bother you any more.

Kind regards
Peter