Stas

I plan to make a series of recordings to show some of the features of the wal circuitry. Zobel filters play an important role in forming the frequency response, and my friends' opinions differ greatly - it's almost 50/50 for and against their use. However, I believe that they have found application due to the protruding lower midrange, since the wal pickups are located along the string, and this will inevitably lead to amplification in the lower frequency range. In addition, there are at least 2 nodes in the circuit that introduce distortion, and I think it would also be very nice to show how each block works separately. I hope that today I will be able to make simple sound examples!

Thanks a lot!😃

That is, mentally draw a line between these two colored sinuses, and you will see that the resulting signal will be neatly flattened at the maximum

In simple words, in guitar limitation, symmetrical limitation is pleasant. When both half-waves have the same limitation. If you compare several limitations, such as a lamp, or a jfet, or a bipolar transistor - they will differ in the smoothness of this limitation. That is, ideally, the sine should be smoothly pressed from above, if you speak figuratively in the case of wal, both channels with the maximum open tone knobs give the maximum possible distortion, and in this case, both channels add up to form a very soft, and at the same time growling sine wave.

Dear friends, I just now quite by accident noticed that the signal on both channels is simply perfectly distorted! Now I understand why both channels were processed with different filters! This is simply an ideal mix of two signals into a common sine! Blue bridge pickup, green neck pickup

I suggest going even further and let's look at the waveform? The first picture shows the input signal. The second picture shows the signal at the distortion control point. The third picture shows the output signal. The fourth picture shows the output signal with peak attack enabled.

The wal preamp does indeed have distortions, but they are not caused by the slew rate Here is the frequency response of the non-original, my clone, and below is the frequency response of the original wal preamp. The top graph is single jazz bass pickups, and the bottom is the given diagram of the wal pickups.

The low slew rate of the op amp will realize the roll-off at high frequencies, but it will not give you the desired sound color. For the sake of experiment, you can put a capacitor in the feedback circuit of the output op amp, and I doubt that you will get wal.

That's right - if you move the resonant peak beyond 7 kHz, the controlled range will be flat.

Thanks for your attention! It will take a little more time, and I will be able to supply them as a complete set. In my opinion, it would be interesting to make a complete set of pickups. Now I am developing a prototype of a pickup.

Thanks for your attention! I originally planned to play this with setting #1🙂

Continuing with the post, let me share the sound options. Which sound did you like? videoplayback.mp4

Tl064 is not a complete analogue of Tab1043. Current consumption of the whole circuit is about 500mA, if my memory serves me right) to be specific, the op amp model does not play a key role, except for the noise level. This circuit does not require high fast action, so I put TL06x. With the same success I could have put LF44x, and the result would have been the same. Half of the circuit is a copy of the original circuit, except for the input stages, which are my commercial development, which of course I can not share with you. But I am ready to answer your questions regarding the original circuit, timbre formation, no problem. Sorry for my English, it is not my native language

Thanks a lot! I plan to make some circuits in the near future to send out to musicians for testing. I have three prototype boards, but they are large enough to be used without problems. Perhaps I could send you one of them for testing, but I need some time to finish my personal affairs and fully finish soldering them. You and I have different units of measurement, so I’ll attach a photo on a sheet of squared paper. If this topic is relevant to you in the near future, then I think we would do it without any problems.

Thanks a lot! I am very pleased to receive such feedback! In fact, the pickups play a very mediocre role here. The whole point is for the pickups to be able to have a frequency response of at least 7kHz. If the pickups have a lower response, the sound will be muddier and the pick attack will not produce the same sound. In the wal circuit, the pickups are fed to a Zobel filter to filter out low frequencies at the input. I took a different path and developed my own input stage, which creates conditions under which the pickup does not have a load, and its maximum frequency spectrum can be obtained. This allows the wal clone to run with most pickups on the market.

Hi all! I'm probably getting pretty fed up with my posts, but today I finally finished building the pick attack, and I want to show you what happened. I apologize for the poor performance, I am not a tool player, the sound is not processed in any way, there is no vst. I am ready to answer any questions regarding the wal amplifier. tutu.mp4

Hi all! I recently posted examples of the sound of a wal clone preamp with cheap Chinese pickups. I decided to go ahead and wound the pickups to approximate the specifications of the original wal pickups. I made a series of calculations and determined the characteristics of the original sensors, after which I made low-impedance coils of 1k6 and 1k9 resistance. Since the resonant peak of the original sounds determines the maximum only for the pick attack function, I decided to correct the peak on the spot. The pick attack frequency is in the range of 6300-6700Hz, so I simply adjusted the resonant peak of my sounds after taking measurements. I'm planning to make full-length multi coil pickups soon. As an example of the sound, I attach a small cover. I apologize for my English, and for the cover - this is the only track that was played nearby, which I decided to play there are two modes in the first and second verses, respectively 5555555.mp3

https://www.youtube.com/watch?v=Vb8KHBcWRq8 Hello, friends! I did a short review of my Wal based preamp. Sorry for my terrible slap, it doesn't work for me. The preamplifier has 2 input stage modes. Here is the first version, the second version could not be recorded. The second version has more presence. Thank you for watching!

I assembled a prototype to test and build on site.

You're right my friend. I studied the data in this thread and designed an equivalent circuit for the wal pickups. I corrected for deviations, and designed the amplifier's input stages so that the connected pickups were corrected for the frequencies of the original pickups.

Hi gues! Sorry for my English. I was very interested in the information from this thread, and I tried to make my own version of the wal amplifier. I had to change the input stages to be able to adjust the original frequencies of the pickup. I made a test recording yesterday on jazz bass P. S. : Don't judge my performance too harshly, I tried to record this quickly, I haven't played tool band covers before www.mp3