FAOW

[Nelson Pass]

It's a slow day. Time for a little entertainment - a micro project!

Someone sent me a request for a simple 1 watt amplifier.

How could I resist?

My answer:

Assuming that your preamp can put out 2 volts (and it should),
a 1 watt design would be the easiest thing in the world.

Attached is an example.

I will put it up on the Pass Labs forum at diyaudio and see
what kind of suggestions it gets for construction and improvement.

Feel free to post questions.

"Zen Mod" will likely be the first to take the bait.

The following draws 1.5A off a 19V computer desktop supply and gets
1 watt into 8 ohms at about .5% THD.

 

[Michael Rothacher]

I love it. Let's have some real flea-power fun! 🙂

 

[MEPER]

I would say…...why not the ACA instead of this?
The idle current is the same so efficiency much better in ACA amp?
So if heat generation is the same as the ACA......what is be benefit other than it is slightly more simple?
How does it sound?

 

[Nelson Pass]

Purely entertainment.

 

[MEPER]

Ok......it looks a bit like a very simple MoFo amp.....but this one has little bit of gain?

 

[Zen Mod]

here's ZM

can' have a gain , being source follower

 

[Zen Mod]

why not doing it as Beast with One Thousand BC109s ?

 

[adason]

BC550...that's what i got (i know bjt)

 

[Dennis Hui]

why not doing it as Beast with One Thousand BC109s ?

Beast with One Thousand 2SJ109 🙂

 

[Zen Mod]

will check what I have of Germaniums , on Monday

 

[Michael Rothacher]

Beast with One Thousand 2SJ109 🙂

I have a couple thousand J113's 🙂

 

[Zen Mod]

have at least 450 of each J271 and J309

though , 1W is sissy

gonna make that with optocouplers

 

[Soundhappy]

1 watt for mighty drivers rated 3~5 watt's max

 

[MEPER]

Ok....but with 2V in it gives 2V out.....it is only 0.5W in 8 ohm?
So the preamp needs to put close to 3V out to have 1W in 8 ohm.
Therefor I concluded it had a little bit of voltage gain 🙂


I throw away a lot of germanium power transistors some years ago. They were paired in some small white boxes. Now I think I should have given them to somebody instead. If was before I thought I would get time for "DIY" audio.....

 

[MEPER]

1 watt for mighty drivers rated 3~5 watt's max

For a 115 dB system 1W is more than enough…….if impedance curve is nice.
I wonder how such a small amp sounds. Is it a 2nd harmonic "beast"?

 

[Soundhappy]

For a 115 dB system 1W is....

Permandur field coils second hand cost ~ 14K, new pair 27K€

Available in France Large bande Voxativ AC-Xp

A dream for watt amplifier

 

[MEPER]

How many do you have of those?


There is also the GIP Lab stuff:
speaker units english


They use drives with field coils…….the big mid horn driver is +40 kg.....and also relative expensive. Think you can build 1W amp systems with those also…..

 

[Soundhappy]

Flea 1250 Miliwatt's don't mean always tiny monoblock's
VinylSavor: 46

 

[Soundhappy]

It's a slow day. Time for a little entertainment - a micro project!

Someone sent me a request for a simple 1 watt amplifier.

Please Mr Pass Lovoltech LU1014D jfet version

 

[wdecho]

One of, if not, the best sounding amplifier I have built is a 1 watt tube amplifier. Using 103db horns.