Assistance in Choosing Plans for a DIY High-End Mono Power Amplifier

[Damnati]

Hello everyone,

I hope you can help me with my first DIY HiFi project. I'm looking for recommendations for plans for a high-end mono amplifier that delivers performance
and sound quality similar to the Purifi 1ET7040SA or the Neurochrome Modulus-686. My goal is to build an amplifier that can deliver up to 200W into 8Ohms.
The AMP class doesn't matter to me.

This will be my first project, but I want to build something worthwhile that I'm willing to use.
I don't want to produce junk. I'm very skilled in manual tasks, trained as an electrician, and I learn quickly.
I'm fully aware of the scope of such a project and would not like to expand on this further.

I'm ready to invest in this project, both time and financially, and aim for an amplifier that's not just powerful but also durable.
Any tips or advice you have for a beginner like me would be immensely helpful.

Thank you in advance for your support!

Kind regards,

Damnati

 

[restorer-john]

I remember the time I decided to build a 200wpc (300w@4R) power amplifier. It was in the late 1980s and I went dual mono (two 350VA transformers, a 19" rack mount 3 unit case etc) and built the thing. It was a beast. And it looked good (or so I thought)...

Went through a few aluminium front panels before being able to perfectly fit a large neon-lit rocker for the power switch. One square hole for a young man with a hand drill, a file and 3mm black anodised aluminium...

It's still going in a church for PA all these years later, so I did good.

I would go for a bulletproof design, using off the shelf parts that can be easily replaced or repaired at a component level. That completely rules out the Purifi in my book. The Modulus-686 will be able to be rebuilt, repaired at low cost with excellent datasheets and support for basically ever.

With the Purifi- you get nothing, no schematics, no parts lists, no available parts and no help. It's a plug and play module. Realistically, a plug, fail, and throw out module. Is that the amplifier you want to build?

No brainer. Go with the commodity parts and a proven, excellent design, from a stand-up guy, @tomchr

 

[SIY]

I'm looking for recommendations for plans for a high-end mono amplifier that delivers performance
and sound quality similar to the Purifi 1ET7040SA or the Neurochrome Modulus-686.

Getting the same sound quality is easy; nearly any modern amplifier (outside of the very cheapest and the very most expensive) will be transparent. Equaling bench performance may not be. I have had excellent experience with modules from Hypex and Purifi, and despite the anti-Class D jihad by two vocal members here, great reliability and load-driving performance. They run cool, efficient, dead silent, and clean. @orchardaudio has some interesting-looking modules as well, but I have only tested the complete units from them; the owner/designer is active here and in other forums and gives great support to users and integrators.

Last generation Class AB amps will look more impressive and can get excellent performance as well, but they will be bulkier, more expensive for the performance, and run hotter. If that's what appeals to you, you might think of building a tube amp to maximize those qualities.

 

[Damnati]

I remember the time I decided to build a 200wpc (300w@4R) power amplifier. It was in the late 1980s and I went dual mono (two 350VA transformers, a 19" rack mount 3 unit case etc) and built the thing. It was a beast. And it looked good (or so I thought)...

Went through a few aluminium front panels before being able to perfectly fit a large neon-lit rocker for the power switch. One square hole for a young man with a hand drill, a file and 3mm black anodised aluminium...

It's still going in a church for PA all these years later, so I did good.

I would go for a bulletproof design, using off the shelf parts that can be easily replaced or repaired at a component level. That completely rules out the Purifi in my book. The Modulus-686 will be able to be rebuilt, repaired at low cost with excellent datasheets and support for basically ever.

With the Purifi- you get nothing, no schematics, no parts lists, no available parts and no help. It's a plug and play module. Realistically, a plug, fail, and throw out module. Is that the amplifier you want to build?

No brainer. Go with the commodity parts and a proven, excellent design, from a stand-up guy, @tomchr

Hello,

Thank you very much for your detailed response and for sharing your experiences. Your insights into the construction and long-term use of an amplifier are undoubtedly valuable. However, I believe there has been a misunderstanding regarding my original request.

My question aimed at getting recommendations for plans to build a high-end mono amplifier that performs and has sound quality comparable to the Purifi 1ET7040SA or the Neurochrome Modulus-686. The specific technology or brand was less important to me, rather the performance and quality I wish to achieve.

I am looking for guidance or resources to start a project that can deliver up to 200W into 8 Ohms, regardless of the amplifier class. My goal is to build an amplifier that is not only powerful but also durable. Your advice to focus on a design that is easily repairable and consists of easily replaceable parts is certainly useful. However, I was seeking concrete plans or suggestions for such a project that match my request.

Could you or someone else in the forum share specific recommendations or resources for building plans or designs that meet my requirements? Any help in this direction would be enormously helpful and greatly appreciated.

Thank you again for your time and efforts to help me. I look forward to more advice and recommendations that could assist me with my project.

Kind regards,

Damnati

 

[Damnati]

Getting the same sound quality is easy; nearly any modern amplifier (outside of the very cheapest and the very most expensive) will be transparent. Equaling bench performance may not be. I have had excellent experience with modules from Hypex and Purifi, and despite the anti-Class D jihad by two vocal members here, great reliability and load-driving performance. They run cool, efficient, dead silent, and clean. @orchardaudio has some interesting-looking modules as well, but I have only tested the complete units from them; the owner/designer is active here and in other forums and gives great support to users and integrators.

Last generation Class AB amps will look more impressive and can get excellent performance as well, but they will be bulkier, more expensive for the performance, and run hotter. If that's what appeals to you, you might think of building a tube amp to maximize those qualities.

Hello and thanks for you fast reply,

Putting amplifier modules into a case is not DIY for me. I want to actually do some of the work myself, see and understand the circuit diagram, and experiment around. I'm looking to dive deeper into the project.

That's why I'm explicitly searching for a plan or circuit diagram, or a tutorial with explanations and ideas. Something to tinker with that will also turn out well in the end.

So if you have some considerations or Links or resources that can provide what im looking for, I would be really happy.

Kind regards,

Damnati

 

[restorer-john]

+

Hello and thanks for you fast reply,

Putting amplifier modules into a case is not DIY for me. I want to actually do some of the work myself, see and understand the circuit diagram, and experiment around. I'm looking to dive deeper into the project.

That's why I'm explicitly searching for a plan or circuit diagram, or a tutorial with explanations and ideas. Something to tinker with that will also turn out well in the end.

So if you have some considerations or Links or resources that can provide what im looking for, I would be really happy.

Kind regards,

Damnati

If you want to actually desgin a PCB, lay it out, have it produced and truly build an amplifier from scratch, none of these pre-built modules-in-a-clown-suit will do it for you.

Some of the best Silcon Chip/ETI/EA/AEM or Elektor designs may do it for you, but they will need dragging into the 21st century. Do some research, dredge the archives and see what floats your boat.

Pissing around with a prebuilt Class D module is hardly "creating" anything.

 

[Doodski]

Hello and thanks for you fast reply,

Putting amplifier modules into a case is not DIY for me. I want to actually do some of the work myself, see and understand the circuit diagram, and experiment around. I'm looking to dive deeper into the project.

That's why I'm explicitly searching for a plan or circuit diagram, or a tutorial with explanations and ideas. Something to tinker with that will also turn out well in the end.

So if you have some considerations or Links or resources that can provide what im looking for, I would be really happy.

Kind regards,

Damnati

I read @restorer-john's comment about PCB design and having one made or several made due to the expense of making multiples the multiple PCB price gets kinda attractive rather than a single PCB order. This... This is a excellent project. There are many companies online that can do this for you and they are very fast on turnaround time. You may design the schematic or copy one yourself or they can do it for you. You may design the PCB layout yourself or they will do it for you. I have used maybe 3 different free softwares that I downloaded from the PCB supply companies and I must say I was digging it big time, was up and operational within minutes laying out a schematic and a PCB too. It really is that efficient, easy to get into and effective. It does not require a high power PC but a larger monitor size is desirable so you don't need to fuss about moving the screen around. Good Luck!

 

[Mnyb]

Buy some good books about amplifier design "dough self blameless amplifier" is what comes to my mind but I'm not an experienced DIY guy .

I'm sure that John or SIY can recommend tons of good reading about this .

I just know that Dough Self has written a literal book about amp design that many says is very complete on the topic .

Good luck with the project .

 

[JayGilb]

Start with a discrete amp kit. Build it, test, modify and measure it. Learn how each component works in the scheme of amplifying an audio frequency signal.
At the very least purchase a DVM, signal generator and oscilloscope.

From there you can start designing your own amplifier.

 

[DVDdoug]

The AMP class doesn't matter to me.

Class A/B is probably the only way to go unless you want to use a chip . Class-A is "dumb" and difficult & expensive, especially at higher wattage.

I wouldn't attempt Class-D "from scratch" with discrete components. I could probably do it, but it would take me months and I'd probably fry a few MOSFETs during development. Plus, I don't own an oscilloscope... I've built lots of audio circuits without one, but a class-D amplifier would require it.

TI makes some high-power class-D chips and that looks manageable.

For PCB design I've used Design Spark. (I wasn't building amplifiers.) The free version has some limitations but nothing that limited me as a hobbyist (no limits on board size or number of layers, etc.). I Tried KiCad but I got frustrated trying to made a custom part that wasn't in the library.

I had the boards made by Seeed Studio/Fusion who has them made in China. I was able to get 10-20 small boards (smaller than a power amp) for less than $100 USD, including about $30 for DHL shipping from China.

...I've made two boards (in the "modern computer era"). Both had errors and I had to go to "Rev 2". (In my case, PCB layout errors not circuit design errors.) That was extremely disappointing because I tried to be extremely careful and double-check everything! But it didn't really surprise me. I work in electronics (not as a PCB designer) I don't think I've ever seen a board come back prefect the 1st time. So, I was financially prepared and somewhat emotionally prepared. If you design your own boards, I recommend allowing time and budget for a revision.

....I wouldn't actually build a power amp these days, at least not a high-power one. It's not economical.

 

[Speedskater]

for more on DIY amplifiers see:

Forum list

The diyAudio Community

www.diyaudio.com

 

[SIY]

Buy some good books about amplifier design "dough self blameless amplifier" is what comes to my mind but I'm not an experienced DIY guy .

I'm sure that John or SIY can recommend tons of good reading about this .

I just know that Dough Self has written a literal book about amp design that many says is very complete on the topic .

Good luck with the project .

Doug Self and Bob Cordell both have designs that are impeccable if you want a last-generation product with excellent performance.

If you want to go the tube route, Morgan Jones is the go-to.

 

[MCH]

@Damnati please keep us updated of your progress. I am very curious about what people recommend and how the project end up performing. (I am thinking of building a chip one myself).
I cannot help you with your questions buy my recommendation as someone who started building PCBs recently is to start learning kicad or your software of choice in parallel. That and general PCB layout. I would even start with a simple small project first just to practice. Order the PCBs and learn from your mistakes. Good luck!

 

[voodooless]

I want to actually do some of the work myself, see and understand the circuit diagram, and experiment around. I'm looking to dive deeper into the project.

I think you’ll have to specify very well what you are willing to do yourself, and what not. Given that you want close to SOTA performance, an existing design would be the best bet unless your actually know how to design, simulate, and measure complex circuits. Even PCB layout can be tricky, because the devil hides in the details. Sure you can learn some of this, but not all (at least not in a reasonable amount of time). So you’ll have to compromise to do the things you are comfortable with.

 

[Doodski]

Even PCB layout can be tricky, because the devil hides in the details.

Am I correct in thinking that the better schematic software and it's mating software suite for the PCB layout are now good enough for auto PCB layouts? When I downloaded from several PCB manufacturers websites and test drove the software packages they where incredibly easy to figure out. The intuitiveness of operation was very impressive and so good that I was up and drafting stuff within minutes. The major advantage that one manufacturer was stating is that their free software suite used the schematic and parts list to layout the PCB and create a electronically stable and suitable PCB layout. Not for RF operation I think but good enough for other electronics circuitry designs? Was I reading more than is reasonably capable? Was a it all hogwash or was this the state of the industry?

 

[voodooless]

Am I correct in thinking that the better schematic software and it's mating software suite for the PCB layout are now good enough for auto PCB layouts? When I downloaded from several PCB manufacturers websites and test drove the software packages they where incredibly easy to figure out. The intuitiveness of operation was very impressive and so good that I was up and drafting stuff within minutes. The major advantage that one manufacturer was stating is that their free software suite used the schematic and parts list to layout the PCB and create a electronically stable and suitable PCB layout. Not for RF operation I think but good enough for other electronics circuitry designs? Was I reading more than is reasonably capable? Was a it all hogwash or was this the state of the industry?

Good auto routing PCB software is costly. I don’t know how good KiCAD (free) is? It’s quite a good tool overall and can be used for complex projects, but requires some learning (as do all the others). I still think you’ll need to do the critical bits yourself. An amplifier isn’t a massive task layout wise. You’ll just have to know what you’re doing.

AI will be a major game changer in this area I assume. Will be interesting what it can do (more).

 

[Damnati]

Thank you all for your valuable insights and suggestions so far. I appreciate the depth of knowledge shared and your willingness to assist. However, I would like to clarify my original request to ensure I'm moving in the right direction with my project.

I'm specifically looking for a hands-on DIY experience that goes beyond assembling pre-made modules. My goal is to deeply understand the circuit design and actively engage in the building process, which includes soldering components, working from a schematic, and possibly even PCB layout if necessary. I'm keen on a project that challenges me to learn and grow, culminating in an amplifier that boasts both excellent sound quality and power output.

Could you provide:

1. Specific plans, schematics, or resources tailored to constructing a high-end mono amplifier from scratch, similar in performance to the Purifi 1ET7040SA or the Neurochrome Modulus-686?
2. Guidance on how to approach the project as a beginner with a strong desire to learn, including any educational materials or tutorials that might help me understand the intricacies of amplifier design and construction?
3. Recommendations for tools and components that are essential for a project of this caliber, especially considering my background in electrical work and manual skills?

I'm fully committed to making this project a success and am prepared to invest the necessary time and resources. Your further advice and recommendations would be incredibly helpful.

Looking forward to your continued support and thank you again for the help provided thus far.

Kind regards,

Damnati

 

[HoweSound]

for more on DIY amplifiers see:

Forum list

The diyAudio Community

www.diyaudio.com

I was going to make the same suggestion - see the link to class D amp and design at DIY Audio forums:

Class D

Switching Power Amplifiers and Power D/A conversion

www.diyaudio.com

 

[Doodski]

I'm specifically looking for a hands-on DIY experience that goes beyond assembling pre-made modules. My goal is to deeply understand the circuit design

The calculations and math systems used to understand and explain analogue electronics circuitry are complex and require constant honing of the skills and foundations of mathematics to keep it fresh in the mind and reflexive. Do you have a very strong background in algebra, calculus, complex number systems etc? I say that because I found them combined with the electronics concepts to be very challenging although it was @ a rate of study and information flow that was unflinchingly relentless and without rest other than coffee breaks and lunchtime. It is a big deal for many people.

which includes soldering components

This is the easy part. Pretty much everybody can learn solder thru hole PCBs within days at the most. Get a old PCB from some gear and use it to practice or buy a practice kit and learn to solder. I used old gear destined for the garbage and hacked away on that for practice. Surface mount devices (SMD) soldering is much more technical and requires a lot more stuff/ability/control/muscle stability than thru hole soldering. So stick with thru hole at first and then when you need a challenge go for SMD soldering and see what cool soldering is about.

working from a schematic

If you study electronics circuitry operation and analysis schematics are part and parcel of that so you will be able to read a schematic within a short period of time. It comes pretty fast and is ingrained pretty much permanently.

possibly even PCB layout if necessary

This can be very technical stuff because of the reactance of capacitance and inductance and current flow. I am not up to speed on how to design this layout stuff and I understand that it can be pretty complex and require some serious amounts of ability to really do it properly based on solid principles of electricity.

Guidance on how to approach the project as a beginner with a strong desire to learn, including any educational materials or tutorials that might help me understand the intricacies of amplifier design and construction?

I would go to a college, technical institute or university library and borrow the hard cover textbooks from a library or go to the college/technical institute/university bookstore and buy the textbooks they use for teaching the courses. Avoid those new format yucky and tacky poorly constructed laser printed modules that they now offer to students. Go for the real hard cover textbooks written by standards in electronics education. I particularly enjoy and prefer the author, "Thomas L Floyd." But that's just me. Some textbooks are designed for electronic technicians, others are intended for engineers and some for physicists. So find what works for you.

Recommendations for tools and components that are essential for a project of this caliber, especially considering my background in electrical work and manual skills?

Wow.. That's a personal thing and a big topic. Tools brands like Wiha, Weller, Cooper Tools and Xcelite are all good stuff for electronics hand tools and some of them are expensive but you get tools for life and others from them are amazingly affordably priced.

 

[SIY]

Guidance on how to approach the project as a beginner with a strong desire to learn, including any educational materials or tutorials that might help me understand the intricacies of amplifier design and construction?

Again, the books by Self and Cordell. They both have documented projects.

You won't likely get the performance of the Purifi in a diy effort. But the performance you can get will be far better than you could detect by ear. Purifi gets you another decimal place in distortion and source impedance (which are of more interest to an analyzer than a user), not to mention a ton of power.