My Own Build PCB on PCB Way

I never build my own PCB ever in my life before.

I always thought making a PCB for my electronic project is difficult. It is simply by the reason that making a PCB in the old ways is troublesome. It was all started by preparing the empty plain copper board and start making the traces on the paper screen, then located and drawing the components size manually. After its done, the layout screen is print to the PCB by using an iron, which often the printing not fully attach to the PCB and need correction manually. The pain is not stopping yet; you need to soak the PCB with the printing on it to the acid (that I also don't know what kind of acid is). The acid function is to peel out the copper on the PCB that not yet covered by the printed screen.

Is it done? Not yet! After it soaked and cleaned, the PCB need to drill for many holes as the components required to put on top of it, then clean it again with fine sand paper. Besides for the trouble when making the PCB, I also found for the finished PCB doing this way always looking cheap and unprofessional. I also worried about the longevity of the PCB, especially for the copper traces are easily oxidize because directly exposed to the air, which effect to the electronic connection overall.

That is why in this post, I will share my experienced design and making my own PCB at pcbway.com

Concerning DC-offset From Vintage Multibit DAC

This post is about sharing my experience for the present of DC offset at the output of a DAC, especially when we build it by our own, we want to make sure it is safe to the equipment after it. Since the DAC is considerably the top-chain in the audio system, so it is important to look this issue in the first place.

DC offset is a nightmare, especially when the equipment after the DAC such as preamp or the power amplifier is not using any capacitor or transformers in the signal path to blocking the DC present at the input. Just a small amount of DC, let's say 100 mV at the input of an amplifier will multiple by the gain from the amplifier, plus its current, will harm to the speaker's driver. In most cases, it will burn the driver's coil.

DC is inaudible, but it moves the driver cone. It creating the heat to the woofer driver coils and burn it. It is safe for the tweeter since the capacitor included in the cross-over network inside the speakers will protect it, act as DC blocking to the driver.

This post will explore the vintage multibit DAC that naturally have DC offset at the analog output and how to solve these problems.

Parasound HCA-1206 Amplifier: Recap & High-bias Setup

I bought this amplifier by the end of last year and I can say this Parasound HCA-1206 is the best sounding solid-state amplifier I've ever heard.

Previously, I've owned and heard many amplifiers in my own audio system. Not on others system to be clear. So, I know the difference in the sound quality. This amplifier is a keep. Although it is very heavy, about 40 kilos, but the weight is equal with its built-quality. The designer of this amplifier is one of the most famous amplifier designs: John Curl. Probably you may know that this guy also designs the amplifier for Mark Levinson.

In this post, I will do some improvement with this amplifier. Let's check it out.

TDA1541A S1 DAC Test With Or Without Asynchronous

This year, I built again a TDA1541 DAC. This is because I still have one DAC IC spare, together with the others parts required.

The main difference is the power supply circuit is now using simple discrete Darlington transistor with Zener diode as reference voltage.

In this post, I will share the finishing build process, continue from the previous post.

I also will compare to listen the music with or without the asynchronous circuit.

Let's take a deep dive.

TDA1541A DAC Build

It is been awhile I am using Parasound DAC-1000 and satisfy with the sound. Moreover, my amplifier is also Parasound and enjoy this combo a lot. But when I look again to my DAC collection and try to find what left from my DIY journey within few years back, I don't have much. They mostly gone already, sold to my friends and fellow that appreciate my built. Their feedback for the sound quality gives me an excitement.

So, since few months back, I started to build another DAC again, from what left in my components bin. With my spares time that already limited, consume by my main professional work, this DAC build is slow.

So, let's share this DAC build.

Crossover For 2-way SB Acoustic Speaker System

About eight years ago, I was built a 2-way speaker system using SB Acoustic drivers. The driver for woofer is SB16PFC25-08 and for tweeter is SB19ST-C000-4. You can visit the post here.

Although this speaker is sound good, but it is not perfect. This is because working on multi driver is challenging. The crossover is the components module to split the frequency range between woofer for low pass and tweeter for high pass. The crossover should make the sound from each of the drivers well blending with the correct phase, so the sound will be coherent. This is not an easy task since the crossover calculation should be made correctly. I made many changes since the day this speaker finished and the last update is on last August here. The goal for those changes is to make the sound enjoyable to listen, less dip and peak especially on the cross-over point, and make the sound fuller and wider.

So, in this post, I made other changes in this speaker system by using the detail parameter on each driver, then I calculate for the correct crossover point and components related to it. The damping materials inside also changed.

Let's take a look.

Parasound HCA-1206 Multi Channel Amplifier, Optimized For Stereo Only

This Parasound HCA-1206 is a multi-channel amplifier that intended for home theater audio setup.

No wonder this amplifier has 6-channel identical amplifier in one chassis, together with the THX certified label, it delivers 120-watt power per channel.

This amplifier is my fresh catch not long time ago after I got the Parasound DAC-1000 before. The condition is like new and I was thinking that this amplifier would be a match pair with my DAC since they are built at the same year.

And I was right! This amplifier is sound wonderful. It really matching with the DAC in term of the style and sound.

That is why, in this post, I will make this multi-channel amplifier optimized for use in the stereo system only.

300B Amplifier Hum Problem Solved

My previous post about the 300B tube amplifier build was a breakthrough. At least for myself. That was my first 300B amplifier build which if I remember, a decade ago, it will never across my mind to build such this expensive amplifier.

I learn a lot from that build and the 300B tube by its nature is direct-heated triode which I read everywhere saying that DHT will always have small hum present at the output, especially when pairing with the speaker sensitivity above 90 db.

My 300B amplifier built intended to drive a headphone. It is also can act as pre-amplifier. Small hum might be a problem for the listening enjoyment. Probably I should accept it.

But when the amplifier is done, the hum is worse than my expectation. It is loud and not at the acceptable level at all. The hum always presents at all time, even with the volume control fully closed.

I think more than a month and I tried to figure it out how to solve this issue. With the help of my friends, now this 300B amplifier is completely free of hum.

Yes, you are read it correctly. No hum at all, it is dead silent.

Only great music.