Hiraga "le monstre"

[neazoi]

Thank you Dan,
Are you able to make any comparisons with a vacuum tube class-A amplifier?

Now that is a little messy cat (they are always like this, so we like them )

[danieljw]

Hi Neazoi I cant compare because i have different speakers since then.

-Dan

[neazoi]

It seems this topic is inactive for quite a long, I guess all of you are in building stages

I am on building stage too, everything ready, just a few connections left for the PSU capacitors, I will post pictures soon.

I have used battery only operation and non-magnetic BNC for the I/O ports in a configuration that I have post here K.Giannopoulos official site

[bluevas]

I am on building stage too

[Lee Knatta]

Originally Posted by neazoi

K.Giannopoulos official site

Thanks for the link to the hilarious website.

[neazoi]

I just tested the amplifier. all the I/O cables are messy but I couldn't wait to give it a go. It works, it amplifies, this means no error on the circuit, but the 1 Ohm resistors get too hot. Mine are 3.5-4W and the schematic suggests 5W.

With the configuration shown on http://www.audio-constructions.com/m...-schematic.png the voltage drop across the resistors is 2.7V!! I have not made any adjustments yet, I just wanted to see that it works for now. maybe that is why the resistors get too hot?

Oh something else I plugged the batteries using cables and no switch and I got a nice spark from the huge initial draw current of the caps.... You wonder if this sparc would exist inside the future added switch? No, if you add a switch there is no spark I have tested it.

Not even adjusted and the sound is very transparent and it seems the bass region goes too low. The middle and highs are just excellent I have not heard anything like this before. I wonder how they will be when adjusted.
The volume is exceptionally high I guess it is much more sensitive than I thought, perfect for a passive preamplifier, as I had to adjust the volume of the internal attenuator of the CD to the minimum and still it was very loud for my room (I have 90-102dB speakers).

An exciting moment to see everything working as expected!

I cannot wait to make the adjustments (and replace the 1 ohm resistors with bigger wattage ones?)

[neazoi]

Originally Posted by neazoi

Not even adjusted and the sound is very transparent and it seems the bass region goes too low.

I mean the frequency, not the volume of the bass

[bluevas]

same as mine, too hot but my working voltage is 17v, need to drop to 12 v.

[FRUGIVO]

hi all fron Burgos (spain)Neaozi tell us more about your final impresiones thanks!pedro

[neazoi]

Originally Posted by FRUGIVO

hi all fron Burgos (spain)Neaozi tell us more about your final impresiones thanks!pedro

I am just building the sides of the box of the amplifier currently, where all the I/O will be attatched.

I added a 2K good quality multi-turn potentiometer parallel to each of the 1K resistor to set the bias for class-A and hopefully to reduce the heat on the load resistors.

I will let you know very soon of the results.
PS. I am running it only from batteries.