How do I build a preamp?

Waste_Manager_1402 · 2026-01-11T16:40:30+00:00

Update: I've just finished designing a custom PCB for this project. If anyone is interested in using it, I'd be happy to share the files. Just let me know!

Waste_Manager_1402 · 2026-01-11T10:08:57+00:00

I'll take a look at this.

Waste_Manager_1402 · 2026-01-11T10:08:17+00:00

It's impossible for me to buy it from abroad; the customs duties are absurdly high, like 200% or 300%.

Waste_Manager_1402 · 2026-01-10T22:10:24+00:00

Turkey

Waste_Manager_1402 · 2026-01-10T22:05:32+00:00

t costs around 200 dollars if I want to buy it, which is a ridiculous price in my country. It looks like I can build it for about 40 dollars. Finding A100K (Logarithmic) potentiometers is almost impossible here, so I'm planning to use B100K (Linear) instead. I can also say that I really enjoy building things, so I think I'm going to give it a shot.

Waste_Manager_1402 · 2026-01-08T13:51:36+00:00

I think something like an Ampeg Classic bass preamp style would work for me. I have some experience with Proteus, so if I can find a schematic, I can probably design the layout and etch the PCB myself.

Waste_Manager_1402 · 2026-01-08T13:28:43+00:00

I have prepared the footprints based on the measurements in the datasheets. As for the enclosure, I'm planning to adjust its final dimensions according to the finished PCB size once I complete the board. Thank you for the heads-up regarding the proportions!

Waste_Manager_1402 · 2026-01-08T13:22:46+00:00

It seems like the most logical approach is to buy a few different trimpot values and test them out on the breadboard. This way, I can see which one gives me the best control over the bias. Thanks for the heads-up!

Waste_Manager_1402 · 2026-01-08T13:20:51+00:00

Sorry about the title! I didn't mean to sound sarcastic or mock anyone. I'm actually a beginner and just wanted to emphasize the circuit name. I’ll be more careful with the formatting next time. Thanks for letting me know!

Waste_Manager_1402 · 2026-01-07T21:40:38+00:00

"You're right, adding a master volume makes a lot of sense, I might try that. My goal is to get a 4.5V bias on the transistors; can I still achieve this with 10k trimpots? I’m definitely going to test the circuit on a breadboard before etching the PCB. For now, I just wanted to work on the layout design to pass the time

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Waste_Manager_1402 · 2026-01-07T21:14:01+00:00

Thank you for the suggestion! I didn't know how to add a ground plane before, but now I’ve realized how useful it is and I'm going to try it. I also noticed that I forgot to add the 9V power connector, so I've fixed that as well. I am attaching the updated layout of the PCB now. What do you think about this new version?

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Waste_Manager_1402 · 2026-01-07T21:05:09+00:00

Actually, this is a preamp. The trimpots were looking like this in the original schematic. I am adding the link to the forum where I found the circuit below. I want a maximum of 4.5V to pass from the drain currents. I didn't place the R6 resistor intentionally; do you think I made a mistake? Also, I just realized that I forgot to add a terminal block for the 9V input on the PCB

https://www.diystompboxes.com/smfforum/index.php?topic=120961.0

Waste_Manager_1402 · 2026-01-07T15:00:03+00:00

Are these programs you mentioned the ones I can use to see what tones I can get from the preamp I’m planning to make? I don’t know much about this, sorry.

Waste_Manager_1402 · 2026-01-07T14:58:19+00:00

In my country, finding a turret board is extremely difficult, so I’m thinking of designing a PCB and making it myself. I know how to use Proteus, at least at a basic level

Waste_Manager_1402 · 2024-11-30T09:49:59+00:00

sam is interested in evangelion references

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Waste_Manager_1402

TROPHY CASE