Holy Grail of Valve Amps

[fdegrove]

Hi,

Just received this message from Bruce Rozenblit:

Later this spring, watch for a new OTL. I am going to develop a super-high power model, quite possibly the most powerful OTL amplifier in the world. It will be available in kit form.

Watch your counter...
This seems like his Festivus statement....

Cheers,

[DVDHack]

I'm in Australia where we had high 30s last week (deg Celsius) so I'm not realy looking for a Tube Radiator

I have done a fair amount of research on the web now and found many suppliers of Valve Amps and they all say their is better than anything ever sacraficed to the valve god. Can someone answer the following:

Do home built kit amps sound as good as bought ones?

Which designs are up to those holly grails listed in the replies?

I deliberately asked the holly grail question first, none of the replies talk about that great kit amp they bought !!!

[fdegrove]

Hi,

I deliberately asked the holly grail question first, none of the replies talk about that great kit amp they bought !!!

Maybe that's because we don't actually buy kit amps but design our own?

Do home built kit amps sound as good as bought ones?

They can...

In short it all depends on you really...
Once you understand what you actualy need and want from it, I feel it's rather easy.

Cheers,

[DVDHack]

OK

I accept the challenge. I have wanted a valve amplifier since I was about 14 years old when I bought my first Luxman integrated amp from a guy who had just purchase a pair of Luxman valve mono-blocks. That was 25 years ago.

I've dabbled with high-end audio for all that time and never got into valves - now is the time.

I would like to build a realy great amp. I've read numerous experiences of people building their own.

Can someone point me to references for basic techniques eg

Importance of Layout
Valve specific contruction (I have been an electrician and have work in elecronics in power stations (controls)
Component choice
Etc

How do I choose a design to reach that Holly Grail?

Thanks for staying with me, as you can see I'm new to valves. I'm in Australia and there seems to be little by way of easy access to stuff so I must order things from overseas so I want to get it right first time.

[DVDHack]

Forgot to mention.

I'm going to build a 300B SE design of some sort. Seems to be the popular choice and I had a listen to one at the local HiFi store. I loved the sound.

This is for another room so I get to buy what ever speakers work best with the amp.

[Mike C]

DVDHack asked:
< Do home built amps sound as good as bought ones?>

No, they don't.

We could do this, if we wanted to. By,say:
Using the cheapest components that work well, rather than finding the best.
Compromising on output transformers as these are expensive.
Skimping a bit on power supplies; mains transformers that are just up to the job rather than over-spec'd; minimum chokes (they are expensive and ugly); trying to compensate using large electrolytic caps.
Paying as much (or more) attention to looks as to performance; getting a sale has a lot to do with visual appeal!
Trying to match all tastes and all connected equipment, rather than designing for our own systems and our own tastes.

Yes, if we did all that, I guess we could drag our standards down to that of bought equipment.

So no, home built do not sound as good; they sound a bloody sight better.


Please do have a go at a 300B SET. I suggest you research this for at least 2 months, looking into the driver stage, PSU design and output transformer choice. Er ... that's all there is in a 300B SET.
If you can learn how to design a good 2 pi PSU, model it in PSUD, check and optimise its poles and Q, you will be AHEAD of nearly all the so-called professionals out there. With a good driver stage (needs to swing +/- 150V in my opinion) and good output transformers (don't penny pinch!), results can match all but the most exotic gear.

Have a go, have fun, it is.

We'd all love to help!

[Coulomb]

Here is a link where you download several PDF Documents for some very fine Designs by Satoru Kobayashi. He has publishe in Glass Audio many times and has built a few 300B designs around the Plitron series of specialty toroids for tube amps.

http://www.plitron.com/pages/Product...o/publicat.htm

Regards

Anthony

[DVDHack]

Thanks a lot for all the help.

[agent.5]

Just a couple links (with schematics) that may interest you:

http://www10.big.or.jp/~dh/work/power.html


http://www.diyparadiso.com/index1.htm

[SHiFTY]

< Do home built amps sound as good as bought ones?>

No, they don't.

So no, home built do not sound as good; they sound a bloody sight better.

Thanks for staying with me, as you can see I'm new to valves. I'm in Australia and there seems to be little by way of easy access to stuff so I must order things from overseas so I want to get it right first time.

You can buy some parts from www.evatco.com.au
www.retrovox.com.au

Jaycar sells ok high voltage capacitors to get you started, and some valve sockets.

If you look around, ask some Ham radio dudes, you should be able to scrounge a decent power tranny for free or next to nothing... I bought one off an old engineer that is capable of 900VCT @ 450mA plus loads of 6.3V windings and a 5V winding. Also lots of them have huge stocks of loose tubes lying around, I have scored plenty of used but good tubes this way.

The output trannies are the things to spend money on...

Also if you like visually striking stuff, consider the mesh plate tubes now being made in china, they look crazy!

Cheers from over the ditch...