Introducing my DIY amps.

[johnnyreece]

It really is art. Just fantastic!

[syscokid]

I’m seriously blown away from the talent and effort that is shown on your thread. Thank you, psychepool…

[psychepool]

I’m seriously blown away from the talent and effort that is shown on this thread. Thank you, psychepool…

I started DIY around 2008 with make a stompbox.
I also focused on making the stompbox small. I think it was just my nature.

I started making amps around 2010, and when I got used to it, I focused on making them small.
As I continued making them, I ended up making them in the same style as now, through the Dumble I made about 12 years ago.

It feels really good to be able to bring the plan I had in mind to fruition without compromise.

It really is art. Just fantastic!

Thank you! Actually, I am not an electrical engineer, so I don't have the ability to make something better in terms of functionality or sound, so I worked on it with the idea of ​​making the exterior looks good.

Actually, I wanted to make the internal build really nice, but it wasn't easy because of the high density.
Every time I build, I think I'm doing pretty well in the beginning when there aren't that many parts, but as I go into the latter part, it becomes increasingly difficult to handle the density.
Especially when you start using shielded cables, the wiring becomes very messy. Since they are all high-gain amplifiers and the density is not suitable for them, I use enough shielded cables as insurance, but if I make it next time, I think it would be good to reduce the shielded cables a little.

[pdf64]

...
Even if I wanted to make a new one after selling it, it's legally difficult to sell a DIY amp in the country I live in.
I have to pass the safety certification conducted by the country to sell it, and if I sell it without safety certification, I' ll be punished.
...

What's your country?
One option might be to offer the amp for sale as 'for spares or repairs', rather putting it up for retail sale as a consumer ready product.

It would be interesting to know how small builders in the EU / EEA / UK go about managing regulatory compliance.
eg Modulus primarily sell amp kits, but also offer a prebuilt service.

Very impressive amp builds!

[psychepool]

What's your country?
One option might be to offer the amp for sale as 'for spares or repairs', rather putting it up for retail sale as a consumer ready product.

It would be interesting to know how small builders in the EU / EEA / UK go about managing regulatory compliance.
eg Modulus primarily sell amp kits, but also offer a prebuilt service.

Very impressive amp builds!

I live in South Korea.

When I first started DIY, there was a lot of second-hand trading of DIY amps and stompboxes.
However, about 10 years ago, I heard that people in the musical instrument community were reported for selling DIY amps and were investigated by the police.
The charge was 'Electrical Safety Act'. It means that we cannot sell products that have not undergone safety inspection.
Since the original purpose of the law was not to crack down on DIY amps, I know most people in the case ended with a suspended indictment.

Whether the law is understandable or not, there is no reason to continue this hobby while breaking the law, so I have not traded second-hand DIY amps since those incidents.
In fact, those who have made vacuum tube amps themselves will know that they can be quite dangerous if made incorrectly, so I also acknowledge the purpose of the law.

However, last year, I sold a few DIY stompboxes that I had not used for a long time and was reported. After about 6 months of police investigation, I also received a suspended indictment and the case was closed.
I thought the 'Electrical Safety Act' was the problem and stompboxes did not have safety issues, so I did not think there would be a legal problem.
However, this was a violation of the 'Radio Wave Act', not the 'Electrical Safety Act'.
This is a law that states that products that generate 'radio waves' must be sold with a permit.
The relevant laws were written in great detail, but the gist of it was that products with active devices cannot be sold without a permit.
Simply put, if there are active devices such as OPAMPs and several components attached to them, a permit is required.

The interesting thing is that products with chip-type components such as OPAMPs were problematic, but components such as TRs or Jfets were not.
I asked why there was a legal difference between the two, which are the same active components, but the people in charge could not explain the reason. They were not at all professional and I was not professional either, so it was difficult to have a deep conversation and they also expressed skepticism about having to waste their energy on dealing with such cases.

There must be a reason why laws are made, and making exceptions is something that must be done carefully, so I did not want to look into trivial reasons. However, I was curious about how other countries handle second-hand trading of DIY amps and stompboxes.

[chuang_weike]

Fantastic build, and an excellent approach. I once attempted to create a high-gain amplifier myself, but the various types of noise present inside the chassis eventually led me to abandon the idea. To this day, all those components are still sitting in a corner of the warehouse.

[maxkracht]

These are killer! Nicely done and thank you for sharing!

It's a shame those laws don't seem to have much nuance. I have seen plenty of dangerous electronic devices that are mass produced. One would think regulatory agencies would focus on limiting the flow of these common items instead of small scale DIY projects... To be fair, I have also repaired a large number of dangerous items from other DIYers or unscrupulous techs. I think an affordable certification process for techs and hobbyists would be my preference to deal with these issues, but no one is putting me in charge of anything.

[psychepool]

Fantastic build, and an excellent approach. I once attempted to create a high-gain amplifier myself, but the various types of noise present inside the chassis eventually led me to abandon the idea. To this day, all those components are still sitting in a corner of the warehouse.

Needless to say, the biggest difficulty in building a high-gain amplifier is the noise problem.
In the case of a general build, this can be solved by right grounding, isolating areas where noise may occur, and using shield cables appropriately.
However, in the case of high-density build, the options for component and line isolation are greatly limited.
In fact, many problems occurred during the build process.
However, in the end, I found solutions and were able to build an amp without serious noise problems.
In the process, the build look became a little ugly, but it is not something to worry about because it is not visible when placed in a cabinet.
Have to be careful not to move the isolated areas due to impact, etc.

In fact, to put it extremely simply, the structure of a tube amp is only the difference in the value of the parts soldered around the tube.
Therefore, a method that does not cause problems in a particular amplifier build should not cause problems in other amplifier builds, but interestingly, even if I build it the same way, another problem occurs every time.
For example, the lines from the cathode follower to the EQ did not cause any problems with the adjacent parts in other amplifiers, but in the VH4, this line caused very serious noise.
I had a lot of stress trying to figure out the cause because I did not think this would be a problem.

Since the build difficulty is not easy, I kept saying this while making it.
"If I had failed to make Dumble back then, I would not be suffering like this."

These are killer! Nicely done and thank you for sharing!

It's a shame those laws don't seem to have much nuance. I have seen plenty of dangerous electronic devices that are mass produced. One would think regulatory agencies would focus on limiting the flow of these common items instead of small scale DIY projects... To be fair, I have also repaired a large number of dangerous items from other DIYers or unscrupulous techs. I think an affordable certification process for techs and hobbyists would be my preference to deal with these issues, but no one is putting me in charge of anything.

As I said, this law has its original purpose anyway, and making an exception for a small number of DIYers would be close to a waste of administrative power.
Those who investigate and make judgments are also very tired of their labor being consumed by this kind of work.
The people who reported probably also know that this is not an issue that requires reporting.
Except for those who reported it just for fun, I guess they are probably people in related industries.

Since the possibility of the sale of DIY amps or stompboxes becoming a social issue is close to zero, it does not seem like the situation will change.