Planning my first project

[bob243]

Hello,
I am planning and locating parts for my first project. After months of reading and searching different sites, I think I am going to give this project a try..

EL34 Ultralinear power amp


Has anyone else tried this one?

It looks like there was enough info included for my to be able to do this.

There is a couple bits of info I was wondering..

First, In the power supply there is 2 .002uf 6kv caps, I havent found these anywhere, anyone know where to get them? or is a 2,200pf an ok substitute?

Also I am guessing that normal 18awg is fine for alot of the wiring, however what should I use where the voltage exceeds 600v Ive found some places that manufacture 1kv rated wire, but no places to get a 25 or 50ft roll of it. Any suggestions??

Thanks in advance
Bob

[SY]

I think you might want to try something simpler and lower powered your first time out.

[Mikie]

Ouch! I tend to agree, and not just cause this one is complicated, the output transformers alone will cost megabucks...

[frank754]

That's for sure, even the basic Hammond 50w OPT's are over $80 each.
It'll be $300+ just for the iron & chassis (incl the power xfmr), and if you have a short that's all down the drain.
Anyway, I'd just like to say, since there are new members all the time, (and I'm fairly new in audio, but not radios & ham stuff, and these guys here are brilliant), please state your experience, maybe we won't be as discouraging. Have you done work in Ham Radio or other tube areas?
I find these discussions to be fascinating. Actually, audio is a whole lot simpler than radio, but on the other hand to get into audio is to strive to be a perfectionist and it's been refined down over the decades to be an art, and a sort of fixed art like math at that, since the basic topologies are old, tried-and-true, and a fine-tuned design creates a work of beauty.
Even if you've built umpteen radios & heathkits, etc, over the years, it's best not to jump into something big ("I want a 50 watter"), etc., but do a small project first, every one is a joy to work with and there's a totally different style and mindset with audio. By seeing what these guys write, you get familiar with a lot of the "trade" jargon and all of that.
There are all kinds and types of amps and amp stages like there are varieties of cats, you get a feel for these, what each does, and where the component values are strict, forgiving, etc.
I just wanted to put in my 2 cents.
As far as parts go, if you get a schematic and don't have a whole lot of experience, naturally you'd want to find an exact match or a step-by-step walkthrough. If you have good soldering & layout skills, can keep everything tight and have an eye for tolerance, ratings, and the unforeseen (good bench equipment etc.), that's a good start. Power supplies are somewhat forgiving, bias is more strict. Components in the signal path need to be close, but in many cases 10-20% off won't spoil all the joy. Basically it's gaining the confidence (to know where & when & with what) before jumping. To learn enough to have a bit of ease in the playing field, instead of peering through thick goggles & thinking: "ok, Mr Frankenstein, should we power it up?"....

[cbutterworth]

I'm inclined to agree with the other postings. My own experience started with things such as a lightning detector, 35W HAM amp, followed by CMOY and Meta42 headphone amps. My power amp was a kit (excluding chassis and transformer) - the AKSA is well designed and comes with extremely well-documented material.

After all that, I thought that a tube project would not be too difficult. Well, I was wrong. My Aikido preamp has beared witness to anguish and tears. Thankfully, I finally believe that I've got it licked.

You may want to rephrase your post to ask for suitable tube amp projects for a beginner tube person. I would certainly do that for a main amp. I'd even go so far as to look for one that at least comes with PCB's. I am sure that as far as tube amps go, simpler and easier is not necessarily inferior, and I reckon that you'd still be amazed with the sound.

Of course, this forum is excellent and the members polite and extremely knowledgeable.

Just my two cents' worth.

Charlie

[Audio_idiot]

Hi Bob,

That is a complicated and demanding construction. Success rate is not high and discouraging.

I agree with the others that you should start with something small and simple. Something like the Simple EL84 from diyparadise.



Cheers

[dsavitsk]

Another option is a nice kit. A well documented kit is a great way to learn proper layout and soldering and get your feet wet in the process. Welborne labs and Bottlehead are both good for this. In both cases, you should be able to sell the assembled amps for at least as much as the cost of the kit if they are not your interest.

[Audio_idiot]

One of the member tubelab has something really caught my eye.

http://www.tubelab.com/SimpleSE.htm

Very flexible for further tweaks.

Hope this help.

Ken

[bob243]

Thanks for all the replies.

As far as experiance, from about 95 to 98 I worked at various shops repairing mainly consumer electronics and some PA equipment. Got out of it as a job, but kept doing stuff as a hobbie. Aside from a few table top radios I havent done much with tubes.


I will keep looking... Iv'e seen a couple 2a3 builds that caught my eye, however none really had much info about them..

[jduffy]

I think your first project should be something that you can build with little difficulty so that you can listen to it as you plan your next builds.

I went that route in getting a Bottlehead amp, building a Gainclone from scratch, now moving on to building a preamp from scratch. In my dreaming/listening to my amp process I've now decided to build a phono preamp as well.

It's enjoyable to get the first build out of the way with 100% success. Now I feel like I can move up to some more difficult builds.

Good luck with your search.