Simple DIY Stereo Tube Amp with around 20W

[GentryBa]

Hello!

I was asking me if there is a very simple (and maybe cheap) tube amp to build somewhere?

From september last year till may this year I built a dual mono F5:

...and equipped it with some µC stuff to check all the values:

rest of the pics:
http://www.diyaudio.com/forums/pass-labs/166784-pictures-your-diy-pass-amplifier-125.html

it was a very nice project, I learned much about all the stuff...

the next project should be completely analog- and tubes are very fascinating for me, too.
but I don't want to build a tube amp as long as the F5's.

Is there a simple to build tube-amp with a nice sound and cheap cost?

Regards,
Matthias

 

[Eli Duttman]

Is there a simple to build tube-amp with a nice sound and cheap cost?

Yes! Build an "El Cheapo". It's will yield approx. 6 WPC with triode wired O/P tubes and about 12 WPC with ultralinear mode "finals". A priori, tubed amps cost more per watt than SS. It a matter of magnetics.

 

[yoaudio]

Or check out Tubelab's Simple P-P tube amp.
$108 for the board and parts to populate the board,
then add your iron and tubes.

This amp produces about 5 watts in triode mode,
or as high as 20 watts in pentode mode.

George is updating his web site, so use the internet
archive-wayback machine to view the assembly manual.

http://web.archive.org/web/20100613...om/AssemblyManualSimpleP-P/StartHere_SPP.html

 

[percival007]

Mullard Amps, start simple!

For people new to Valves (like me) I don't think you can go far wrong with the Mullard designs:-

Articles Contents Page

the 20Watt Amp being here:-

Twenty-Watt Amplifier

I started with the 3-3, here:-

Mullard 3-3. Three Watt Amplifier (see attached Pics) a very simple Amp but taught me a lot. I 'advanced' on to a 3-3 based on the EL33 (see second pic).

Best wishes,

James.

 

[costis_n]

What kind of speakers are you planning to drive with this? Sensitivity?
How big is your listening room and your desired sound level?
What you liked and what you disliked in the F5 ?

These would help people give you more meaningful recommendations.

 

[GentryBa]

Hello everybody and thank you very much for all the answers!

Speakers I use in the moment:
SB 18 | Lautsprecherbau

They sound soooo nice, and are cheap to build, too...

The F5 sound is very clean and smooth, I love it. You can hear a big difference to all my bought receivers before.
I have heard a tube amp on the bigger brother of the SB18, the SB36:
SB 36 | Lautsprecherbau
This is the tube amp:
EL34 plus MKII

The bass was much deeper, but I think the main reason for this is the bigger loudspeaker?

Its hard to describe my listening, because of my bad english...

The first thing I see is, that a tube amp is not sooo easy to build.
But with your links and tips maybe I can do it!

Thanks again for all the help!
Matthias

 

[Salectric]

If you are building from scratch, I would highly recommend the E-Linear design from Bandersnatch, a/k/a PakProtector a/k/a Douglas. You can find the schematic on this thread in Message #6:

http://www.diyaudio.com/forums/tube...-build-25-30-wpc-push-pull-amp-need-help.html

I built a pair of monoblocks using this circuit but on Douglas's recommendation, I used 6AC7 pentodes instead of the 6AU6 shown on his schematic.

Don't be deceived by the circuit's simplicity. Amps using this design are pretty much as good as it gets, in my opinion.