Messages

I know the vol stage Opamp is an internal set and forget, but I would like to have some form of control over the CL high end output as it is very trebly on my set up (yes, I know this is like the EM it is moddelled afeter   )

Can anyone offer any guidance as to the best place/type of treble cut control to the 2015 circuit ?

The output stage is a simple opamp buffer/gain set up, so am not sure whether to put another simple low pass pot/cap filter before that or after it (like a rat) ?

I was thinking about that 100pF feedback cap and trying to figure out if that could be made variable ?

Solved

Another symptom of what turned out to be the problem was the Control Voltage coming off Pin 2 of the LM311 only varied between 1.0v - 2.2v (9v supply) or 1.3v - 3.1v on a 12v supply), giving very little sweep.

After reading various threads on the EM3207 etc on DIYSB forum from the brilliants guys there, I tracked it down to the builder using a 10k Lin pot for the Range control instead of a 100k Lin pot !!!!

Swapped it out now, and the LM311 Pin 2 CV now reads 1.1v - 8.8v  (on a 12v supply) during flanger sweep (not static matrix mode)

After Clock trim adjustment I can get the lowest 4013 Pin 1 clock rate at 70khz on the knuckle , high is about 1000 khz (yes 1 Mhz!!)* with no chirping or drop outs, giving a delay range of 0.51 - 7.31ms, perfectly in Electric Mistress territory.

Whether or not the MN3001 can provide a signal at that speed re gain and fidelity is another matter, but I am impressed the signal doesn't "click" out and back in at the top at that speed 

The one thing left I can't yet investigate without a scope would be to look at the clock rate (Or better "delay time") sweep in terms of VCO / MN3007 in terms of shape. I know the EM LFO is triangular, and I know the EM "perfect" shape for the resulting delay time perception is "hyper triangular" (sharp at the top, rounded at the bottom).

Does anyone already know what the Current Lover and/or EM3207 sweep shape is vs the Electric Mistress ?

Listening to this now really shows the greatness of the whole circuit, with the added volume stage tacked on the end and, to my ears more crucially, the retention of the high end of the signal through the pedal, stunning!

Hi all,

I have a new Madbean Current Lover 2015 and the sweep didn't sound very "sweepy", so have got my multimeter out that is capable of frequency measurement and have the following at the *lowest* point of the Clock trim, ms times are worked out using "ms=stages/(freq in khz * 2)"

High: 620 khz = 0.82ms
Low:  170 khz = 3.01ms

These numbers go through the LM 311 Pin 7 and into the MN3007 Pins 2 and 6, and the low side freq of 170 khz seems a bit high, leading to a very narrow sweep of 0.82 - 3.01 ms.

With Filter matrix on I get even worse on the low end, but I know that the circuit LFO and "Filter/Matrix" are different

Range Fully CCW: 600 khz = 0.85 ms
Range Fully CW:   266 khz = 1.92 ms

I was expecting something more .8ms  - 7ms or so, freqs 70khz - 600khz for a MN3007 1024 stage bbd

I also have a Boss HF-2 as well and that seems to operate "by the book", with sweeps from 40 - 500 khz so I know my multimeter is ok.

Voltages measured today with a 9.2v Battery, pdf figure is first, my figure is second. I have put a * next to the ones I think are "dodgy":

IC1   4558   
1   4.59   4.46
2   4.59   4.47
3   4.18   4.05
4   0   0
5   4.51   4.38
6   4.55   0
7   4.53   4.42
8   9.13   8.87

IC2   MN3007   
1   9.13          8.86
2   ~4.45   4.27
3   ~4.85   4.75
4   41mV   380mv *********
5   0   
6   ~4.45   4.37
7   ~4.2          4.87
8   ~4.2          4.9

IC3   CD4049   
1   9   8.8
2   4.5   4.38
3   4.5   4.38
4   4.5   4.38
5   4.53   4.38
6   4.5   4.35
7   4.5   4.36
8   0   0
9   4.5   4.36
10   4.5   4.36
11   4.5   4.36
12   4.5   4.36
13   ignore   
14   4.5   4.28
15   4.5   4.33
16   ignore   

IC4   CD4013   
1   4.53        4.34
2   4.53        4.34
3   varies   4.7-5.3
4   0   
5   4.5        4.35
6   0   
7   0   
8   0   
9   0   
10   0   
11   0   
12   9        0  ****** are these two a typo ?
13   0        8.75  ***** are these two a typo ?
14   9        8.75

IC5   LM324   
1   varies   7.46
2   ~4.2   4.07
3   varies   4
4   9   8.69
5   0   
6   0   
7   7.8           0   **********   Looks very odd!
8   varies   2
9   varies   2
10   varies   2
11   0   
12   ~4.2       3.9
13   ~4.2           3.9
14   varies   4

IC6   LM311   
1   0   0
2   varies   
3   varies   
4   0   0
5   9.14   8.69
6   9.14   8.69
7   varies   
8   9.14   8.69

IC7   4558   
1   4.55   4.36
2   4.55   4.36
3   4.55   4.36
4   0   
5   4.51   4.3
6   4.55   4.3
7   4.55   4.3
8   9.14   8.67


I have checked some components around those areas but all seem ok, I will continue to check values, but any guidance would be appreciated.

Thankyou

Update - I posted this on diystompboxes, and got some great info from DrAlx, all fixed now.

http://www.diystompboxes.com/smfforum/index.php?topic=114014.0

R30 in the 2015 build is in line with the Range pot and sets the lower limit, the Orig EM has 22k-39k.

I now have mine at 37k , and with the bias and clock correctly set there is now no cutout at the top of the sweep

OK, more investigation today:

IC4: all voltages are fine, but Pin 1 moves to 0v between the pops, Pin 2 moves to 8.7 between the pops.

Pin 3 (input from the clock/LFO) varies between 0.66-7.7v when rate min and range Max.

Pin 3, again, with range min and rate shorter only varies between 3.1-6v with no pops

Best guess position for Pin 3 min voltage with no pops is 2.3v

So I reckon the feed from IC3 into IC4 is varying too much, lowering the low end too much below the value needed to keep IC4 "alive".

Tracing back to the Rate pot (1MOhm reverse taper C) it is in series with R27 which must sets a Minimum r in that path.

The 2015 PDF schematic shows this as 3k9, but my board has  3k3 in.

Doesn't look as though this could make much difference though.

Haven't traced any more yet

Ok, done some more testing.

Bias resistor swapping made no difference to the pops, except that a 20k R10 (2015 build) means i now get 3007 cutoff at low and high pot settings, that seems "better" to me so will keep it.

Voltages on IC2, 3007, pins 2 and 6 both cut out to 0v as the pops occur, ie something cuts out going up to the top of the sweep and cuts back in off the top of the sweep.


If I bias the 3007 off, then the LFO is still working and the pops are still there, so to me this isn't a bias buy something in the LFO not being able push out the sweep signal correctly.

As I say, if the rate gets faster and/or the range decreases then it is fine and sweep works through its cycle.

Any clues?  LFO cap values or something?

I also am having this trouble with my 2015 version; also an ebay buy so I did not put it together myself.

Range pot on max clockwise, Rate at slowest, I get a double pop at the top of the sweep.

If I increase the Rate (turn CW) or narrow the range (turn CCW) sufficiently, eventually it will go away, but I do not get the full range of control then.

Feedback T1 does not affect this, and it does not matter when the Bias trimmer is; the Clock trimmer either speeds up the sweep or slows it down (ie the two pops are closer or farther apart) but they don't go away at max or min Clock trim.

Tried on 9v and 12v, tried many variations of the pdf instructions


Help.....

Many thanks, that is good to know.

I have a picture of the pedal guts but as it is top down I can't make out any Cap markings easily so will wait until it arrives.

Search hasn't thrown up anything conclusive hence the question.

I have bought a premade *2015* Current Lover which does not appear to have a Road Rage built in.

So it is the MN3007 only version that as standard runs on 9v.

Just to see/hear the difference (if any) is it OK to run the pedal from a dedicated 12v wall wart ?

If so them does it need to be  a Regulated one, or will a standard pedal type one be OK ?

My thoughts are that a normal 12v supply straight into the jackshiuld be fine, as the MN3007 is rated for 15v and the unregulated 12v supply gives a bit of leeway - but I would appreciate confirmation of that !

Many thanks

(Edited to remove earlier mention of 15v as I have now found and read the 2015 pdf!)