EA Tremolo

Hi!

I've been trying to build a tremolo I found a schematic for.

**broken link removed**

When I power it up I get a pulsing LED, although fairly faintly, but the output audio is terrible. Almost as if the signal is too strong, It's pretty much only the lower tone strings that get me some sound. Higher tone gets me a click here and there.
The schematic says it should be trimmed to 4.5 - 5v. I can only get 1.26 - 2.55v. Maybe I'm doing it wrong. I've used a 2N3904 instead of the 2N5088 and a 220k pot instead of the 250k.
I'm guessing this might have something to with it. But I have no idea.
Maybe someone knows where I'm going wrong?

I can post pictures of my rather chaotic breadboard if it will help.

There is nothing in the circuit to boost low frequencies or cut high frequencies. It has a very high output impedance (if its volume control is halfway) so keep its output cable short because the capacitance of a long output cable cuts high ferquencies.
The "trim" adjustment should easily set the bias at half the supply voltage. Maybe you should try another Mosfet.
Your parts changes are insignificant.
Make it neatly on stripboard or on a pcb, not on an intermittent chaotic breadboard.

Thanks.
I'm going to try this and see what difference it makes. I'm using the breadboard because I wanted to make sure it worked before soldering it up.
Could I make some changes to the schematic so it would get good sound no matter what length my output cable is?
When I measure the voltage at the drain of the BS170 I can't get any more than the 2.5v. Could this be because of wrong wiring?
And if I didn't have enough questions, what would be a good replacement for the BS170? Would any Mosfet do?

A long output cable (high capacitance)and a high output impedance cuts high frequencies.
A low output impedance is not affected by the high capacitance of a long output cable.

Every Mosfet is different. Even different BS170 Mosfets are different.
Maybe the circuit was poorly designed so that it does not work with some BS170 Mosfets.

I'm still trying to build this thing.
I was wondering if someone could tell me exactly how the transistors should go in.
For example, I'm pretty sure that Q1 has it's gate towards the 1M resistor, the drain towards the 4K7 and the source towards the 180.
I'm thinking that I'm wiring Q1 and Q2 wrong. I'm getting the pulsing LED, but the sound isn't very loud and it doesn't seem to be affected by the tremolo.

Jakobberry said:

I was wondering if someone could tell me exactly how the transistors should go in.
For example, I'm pretty sure that Q1 has it's gate towards the 1M resistor, the drain towards the 4K7 and the source towards the 180.

Click to expand...

Correct.

I'm thinking that I'm wiring Q1 and Q2 wrong. I'm getting the pulsing LED, but the sound isn't very loud and it doesn't seem to be affected by the tremolo.

Click to expand...

Look at the datasheets for Q2 and Q3 to see which pin is which.

One final question. Just to make sure I'm doing it right. When I measure the voltage at Q1 drain I connect the negative lead of the multimeter to ground and the positive to the Q1 drain. Is this correct?