• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

First project, need guidance

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Disabled Account
Joined 2005
Several years ago I had a dream of building my own amplifier. After letting the dream subside for a while, I am finally ready to pursue it.

Of the past 48 hours, I believe I spent more than 30 reviewing this subject. Although I have learned a great deal I still believe I am a novice. I would like to build a system from the ground up. I've recently moved from my folks home into my own, giving me the perfect opportunity to pursue my dream.

With all the introduction aside my questions are as follows:
1. In order to obtain high-quality sound, what will my budget needs to be?
2. I prefer to build this by myself, not a kit. Are there any recommended schematics?
3. I enjoy listening to all kinds of music, from jazz to rock. Are there amplifiers that can handle such a wide range?
4. Would you recommend me building a simple, cheap amplifier first in order to gain some experience?

I would love to hear any advice. Feel free to ask questions that would help guide me to a decision. I hope you can help me from drowning in all this information.

Thanks,
Eitan Waks
 
Do you have any previous experience with electronics?
Do you understand what all the symbols mean on a schematic?
Do you have the basic tools to build from scratch?
Can you use basic equipment such as a multi meter and a soldering iron?

If you are new to diy electronics, it can take some time and expense to equip yourself with the tools to build an amplifier from scratch, and a little experience to source a problem if your circuit won't light up first time.

Don't let this put you off though, as there's no better sounding amp in the world than the one you just finished building!

I started off with a book, and built a circuit from there, then looked around on the internet for new projects.

A kit is a great place to start, as you don't need to spend hours ordering loads of different bits from different places, and the circuits will have been well tried and tested and you get all the transformers and chassis in some.

Doing it from scratch is time consuming and tricky.
 
Hi Eitan,

A piece of advice - stop. Looking around at schematics without understanding, or perhaps even worse - reading the incoherent ramblings of hi-fi reviewers teaches nothing. If this is what you are doing, you are just making things difficult for yourself. Once you know the basics, looking at as many schematics as possible is a good thing to gain a feel for how other people design amps, but is useless before.

There are several very good resources out there on the internet like John Broskie's TubeCad Journal - the Grounded Cathode Amplifier article is worth a read. Steve Bench's Of Loadlines, Power Output and Distortion series is similarly worth reading. Actually both sites are worth reading in their entirety if you have the time ;)

There is also a certain book by someone hailing from 'near London' which is well worth a read, but I've reccommended it so many times I'm starting to sound like a broken record, or perhaps a free publicity department. Post again if you're willing to buy it or go scouring the libraries to borrow a copy like I did. Books tend to be more 'complete' than websites, and hold fewer distractions - so I would start here with a book if I were you.

48 hours is not a long time to study the design of amplifiers. I've been at it for several years and really have just begun to scratch the surface.

Building completely from scratch isn't really that hard. It just requires lots and lots of patience. Firstly you have to take enough time to learn and understand the basics, then you have to source all the parts - some of which may have been out of production for decades, others may be difficult and/or expensive to source. It takes me a few months to find all the parts for an amp even though I might have quite a few in the scrap box. A case in point is Hammond transformers. They are very cheap and easily available in North America, but are not that easy to source and very expensive around here. Much cheaper to get the transformers wound locally, but this takes time. I suspect the situation will be similar in Israel.

If this seems too hard, then a kit might be an option, but in my opinion it takes the fun out of making an amp - part of which is designing it yourself! I didn't start with a kit simply because I can't stand building something I don't understand at least on a basic level, and was too fiscally rententive - but that is just me. What I would recommend is that you spend some time to study the basic design and workings of valve circuits first, then you probably will be able to answer most of the questions yourself. What Bob posted above is true - there is no better sounding amp in the world than the one you just finished building!

Originally posted by eitanwaks
1. In order to obtain high-quality sound, what will my budget needs to be?
As large as it needs to be. I know this is a totally useless answer, but the price and availability of parts varies so much that no one can really tell you this (unless you order all the parts over the internet at well known sites). Some people manage to get enough old parts from scrap which cost next to nothing and make a wonderful amplifier, while others could spend a fortune on making a complete mess.

Originally posted by eitanwaks
2. I prefer to build this by myself, not a kit. Are there any recommended schematics?
The best schematic is the one you draw up yourself which has been checked over by someone more experienced to make sure it will work. :D A little more seriously, there are some quite good original ideas out there, and a whole lot of stuff which claims to be groundbreaking but is just a rehash of an old idea. You should be able to sort the wheat from the chaff when you understand how these things work.

Originally posted by eitanwaks
3. I enjoy listening to all kinds of music, from jazz to rock. Are there amplifiers that can handle such a wide range?
Yes.

Originally posted by eitanwaks
4. Would you recommend me building a simple, cheap amplifier first in order to gain some experience?
Most certainly. This can be like a disease - your first amp almost certainly won't be your last! Start with something simple first which you understand, then work up to more complex endeavours.

:att'n: Obligatory safety warning - as you probably would have noticed from checking out a few schematics, valve amplifiers operate at several hundred volts, which can make you very dead. A healthy respect for high voltages is a good thing.
 
Disabled Account
Joined 2005
Thanks for advice - followup q's

Mr Hayes, thanks so much for the prompt and thorough reply. With regard to your questions:
(1) I have previous experience with both electronics and engineering.
(2) Yes, I am well versed in the symbols on electrical schematics.
(3) I have the range basic tools (soldering iron, wicks, voltameter, etc) but they are not the highest quality. What tools will I need to build the amp? What are some good brands and which tools is it a good idea to invest in?
(4) I have limited experience using most of the basic tools...

As a student of engineering, a kit doesn't interest me as much as building the amp from scratch - I am more than willing to invest the time (and money) it takes to do that. I get a certian sense of accomplishment from understanding and working with electronics anyway.

I recently purchased two books: Building Valve Amplifiers and Valve Amplifiers, Third Edition both by Morgan Jones. They were recommended on various forums (including this one). What do you think of these two books? Do you have any suggestions for some additional texts?

Jason:

Thanks for taking the time to write such a helpful and informative response. I will certianly take your advice seriously. Also, thanks for the referral's to the sites - I'll look them up tonight! Feel free to market the book you referred to - I'd like to know the title and author. :)

With regard to the amount of time I've spent on amp's - I certianly don't claim to be an expert by any measure but i have a good deal of experience with engineering and electric circuitry! Admittedly, I have no experience with valve design.

Do you think you'd be able to recommend some reliable internet dealers for the parts I'd need? I can get parts from North America as I have family in the USA.

Regarding the costs, which components are important to get high quality and which are less crucial? How much would you recommend spending on my first amp? I understand its a very subjective question but any guidance you could offer would be much appreciated.

Do you think I should go with a PP, SE or some other design for my first amp? Pros and cons?

Anyway, thanks so much for all your help. I really appreciate it.

-Eitan Waks
 
It sounds like your about ready to get stuck in then?

The Morgan Jones book is the one I started with, and the first amp I built was a slightly modified version of his EL84 PP amp...(bevois valley I think he named it), driven by E88CC.

I used an alternative driver/splitter valve as I couldn't get E88CC cheap enough, and silicone PSU.

This is a great performing little amp, although quite complex for a first project, but it plays any music with plenty of grunt and clarity.

You might prefer to have a go at something else though.

Good luck with it, and keep posting on here as you progress.
 
Re: Thanks for advice - followup q's

eitanwaks said:
I recently purchased two books: Building Valve Amplifiers and Valve Amplifiers, Third Edition both by Morgan Jones. They were recommended on various forums (including this one). What do you think of these two books? Do you have any suggestions for some additional texts?

Those were the ones I was thinking about :cool:
 
Re: Thanks for advice - followup q's

eitanwaks said:
Do you have any suggestions for some additional texts?

As an engineer you may be able to appreciate the Radiotron Designer's Handbook - 4th Ed. (also known as the Radio Designer's Handbook.) 2nd hand copies are usually available on eBay and there may still be reprints available new. It is not a substitute for the other books and makes dry reading, but it is a fantastic reference. A lot of new discoveries are actually shown to be re-discoveries by this tome.

eitanwaks said:
Regarding the costs, which components are important to get high quality?

Output transformers.
 
Re: Thanks for advice - followup q's

eitanwaks said:
...(3) I have the range basic tools (soldering iron, wicks, voltameter, etc) but they are not the highest quality. What tools will I need to build the amp? What are some good brands and which tools is it a good idea to invest in?...

I recently purchased two books: Building Valve Amplifiers and Valve Amplifiers, Third Edition both by Morgan Jones.... Do you have any suggestions for some additional texts?
-Eitan Waks [/B]


One nice thing about tube circuits is that they are very forgiving. Once you have it together if voltages etc. check out within 10% of the values on the schematic it will probably work just fine. Better, more accurate tools are nice but you can do this with very basic tools at first.

I think one of the most important tools I've purchased (and I know have a DVM, oscilloscope, SPL meter, tube tester and more) was my inexpensive soldering station. It is so much easier to do quality soldering than with the station than with my old firesticks!

Another book I would like to recommend is Beginner's Guide to Tube Audio Design by Bruce Rozenblit. It explains, step by step all the terms and uses lots of schematic examples for each amp component.
 
frugal-phile™
Joined 2001
Paid Member
As mentioned, it is not likely you will only build one amp...

a friend was pondering building a scratch amp for sometime... one of the EL34s in his Jolidas expired so i loaned him a console spud amp (ELL80) i had lieing around to keep him in tunes. Before i could blink an eye he had rechassied it and gussied it up. With that under his belt, he had the confidence to go on. he started with an "as close as he could get to a Decware ZEN" (because a couple of ZENs thru his house had impressed him). That -- with a bit of encouragement -- quickly progressed thru 3 or 4 amps plus variations until he ended up with something quite different, and quite a bit better (map below). He now has a stunning little amp -- not a lot of power mind you -- and the confidence to attack a re-working of his Jolida. He built it all with recycled iron (from my basement) so it cost him very little out-of-pocket. (well under $200 CAD i believe).

dave
 

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