EHX Bassballs Clone Build - Help Needed! (Constant tone when engaged)

[steveyraff]

Check your switch with the blue wires isn't shorted while your messing with the machine that goes beep.
😀

its about to be the machine that goes thud...against the wall.

[Kipper4]

I hear you mate been there. I don't want to add to your stress levels.

[steveyraff]

I hear you mate been there. I don't want to add to your stress levels.

You most certainly are not adding to my stress - if anything, you are greatly helping. I appreciate your time. I am sure its stressful trying to deal with noobs like me.

Well, after a great deal of effort, I ripped out IC1 and replaced it. I checked under it to make sure all the links and cuts were ok, and there was no solder bridges.

Still the same issues.

I literally have no idea what to do with this anymore. Never quite been stuck as badly.

[Kipper4]

Maybe step away for a day or two. Give yourself time to think.
Probe the input op amp upto the inverting input of op amp2 so pin 2 or 6 of the 4558.

[Mark Hammer]

It's headaches like this that keep me far away from veroboard.  I far prefer perfboard, where all the connections are ones I deliberately made.

[duck_arse]

I'm with the fish on this one, there is something not right around IC1B, those voltages don't add up. can you repost the volts around that ic, perhaps a nice clear photo of that area, and then back to the beeps, check resistance between the traces in that area.

[steveyraff]

I'm with the fish on this one, there is something not right around IC1B, those voltages don't add up. can you repost the volts around that ic, perhaps a nice clear photo of that area, and then back to the beeps, check resistance between the traces in that area.

Yea. I actually replaced IC1 so I will repost what the voltages of this one are. I'll try to take a clear pic of both sides of that area for ya too. Any help is much appreciated. Gimmie a few minutes and I'll post that...

[duck_arse]

ahh, well, now I'm not so sure. I just put a 1458 on the bb w/ 2 resistors, and got 1V92 at pin 6 and 2V12 at pin 7.

so, do you know if the envelope envelopes? what voltage do you get on the R7//Q1 base with no signal? what happens when you give a strum? that voltage should start 0V, and rise with signal. then Q1 will turn on and put volts on the T1//T2 to put more volts on the Q2//Q3 to turn them on to keep stevie happy with whoosh.

Q2//Q3 bases should be at 0V until the envelope outputs, then they'll go as high as those pots allow them.

I think.

[steveyraff]

IC 1 :
1= 4.4
2= 4.4
3= 4.4
4= 0.0
5= 0.0
6= 1.9
7= 1.9
8= 8.8

All the same.

The transistor beside the +9v is the only one I get a reading from. 1.4v at base.

The other two have 0.0. The one closest to that output wire has 0.1 at the base sometimes.

I presume I am doing this correctly, I have the meter set to DCV 200 and then a croc clip on the black lead attached to the case and touching the parts with the red lead tip. I checked it by touching the power supply at got 8.8v so I presume my method is correct. Its as I seen it done on a few video demos. I can't actually touch the transistor legs so I am touching the solder point under the Base leg.

[duck_arse]

dc 200V or dc 20V?

1V4 at the base, what is at the emitter? and when you stum, does it cahnge anywhere along here?

[steveyraff]

dc 200V or dc 20V?

1V4 at the base, what is at the emitter? and when you stum, does it cahnge anywhere along here?

DCV 200.
At the emitter for that transistor beside the +9v wire, it fluctuates between 0.9 and 1.0.

There is no difference in readings when I strum.

When I strum, NO guitar signal can be heard at all. When the pedal is bypassed, i hear my guitar clearly.

[duck_arse]

so, do you know if the envelope envelopes? what voltage do you get on the R7//Q1 base with no signal? what happens when you give a strum? that voltage should start 0V, and rise with signal. then Q1 will turn on and put volts on the T1//T2 to put more volts on the Q2//Q3 to turn them on to keep stevie happy with whoosh.

Q2//Q3 bases should be at 0V until the envelope outputs, then they'll go as high as those pots allow them.

I think.

oh, dear, while I have the red face I may as well quote myself. your IC volts look good, they match what I got on the bb today. with respect to this diagram:



the ~2V at pin 7 appears at the base of Q1, which is an emitter follower, just buffering the C4//R7 time constant/filter for the rectifier. and T1/T2 just tap some volts following the envelope ramp for those 2 transistors, so there will be some small volts along here all the time. if you don't get a change in voltage (1V9 ~~3V) at R6//R7 when you strum, with the P1 pot at max, you need to find why not.

audio probe all along from input to D1, see where you loose the good stuff. then check voltages on your Q1. which type # transistors did you use (my new favourite question)?

[steveyraff]

so, do you know if the envelope envelopes? what voltage do you get on the R7//Q1 base with no signal? what happens when you give a strum? that voltage should start 0V, and rise with signal. then Q1 will turn on and put volts on the T1//T2 to put more volts on the Q2//Q3 to turn them on to keep stevie happy with whoosh.

Q2//Q3 bases should be at 0V until the envelope outputs, then they'll go as high as those pots allow them.

I think.

oh, dear, while I have the red face I may as well quote myself. your IC volts look good, they match what I got on the bb today. with respect to this diagram:

the ~2V at pin 7 appears at the base of Q1, which is an emitter follower, just buffering the C4//R7 time constant/filter for the rectifier. and T1/T2 just tap some volts following the envelope ramp for those 2 transistors, so there will be some small volts along here all the time. if you don't get a change in voltage (1V9 ~~3V) at R6//R7 when you strum, with the P1 pot at max, you need to find why not.

audio probe all along from input to D1, see where you loose the good stuff. then check voltages on your Q1. which type # transistors did you use (my new favourite question)?

Hey duck_arse, I appreciate all the time you've invested in trying to help me out. Thanks a lot for looking into this for me, I really appreciate it.

For the transistors I used exactly as it stated on the layout, all 2N5088's.

[steveyraff]

To be honest, I'm so pissed off with this build, I'm seriously considering ripping the circuit out, and wiring the Kraken into the same case - I can use all the same drill holes and it looks like a slightly more simplistic build. Then again, if I do that and IT doesn't work, I'll really lose my patience lol.

http://tagboardeffects.blogspot.co.uk/2013/11/madbean-kraken.html

[duck_arse]

audio probe first, wake the kraken second.

[Kipper4]

What happens to the voltage at the base of q1 when you turn the response pot all the way down and strum?

[steveyraff]

What happens to the voltage at the base of q1 when you turn the response pot all the way down and strum?

Geomagnetic reversal of the earths poles.

Seriously though, as far as I recall, the Response pot does nothing at all. I'll check the readings later for you though.

[Kipper4]

The effective gain range of the op amp IC2a is ~15 at one end of the pot. ~47 at the other end.
Which should make a difference in the output voltage and open the q1 switch.
This in turn opens the other Q which alters the resistance in the feedback loops of IC2a and IC2b (the filters) the thing that goes waaaaah.
If I understand the circuit wrong guys put me right.
Have you checked the connections to the pot? 10k response.

[steveyraff]

The effective gain range of the op amp IC2a is ~15 at one end of the pot. ~47 at the other end.
Which should make a difference in the output voltage and open the q1 switch.
This in turn opens the other Q which alters the resistance in the feedback loops of IC2a and IC2b (the filters) the thing that goes waaaaah.
If I understand the circuit wrong guys put me right.
Have you checked the connections to the pot? 10k response.

Cool, thanks for the explanation Kipper.

Yep, I've checked all connections to all pots, over and over. No joy.

[Kipper4]

If your only getting 1.9v at pin7 of ic2 then by the time you take into account the diode drop 0.7v then you will end up with a theoretic of ~1.2v. At the base of q1.
I'm thinking. It won't be enough to open all the switches (q1, q2, q3)