SolderSmoke DCR Audio Amp

I have completed my build of the SolderSmoke-DCR three transistor Audio Amp module. In this video I demonstrate it working with a comparison to my older push-pull 7 transistor amp.
The SolderSmoke-DCR amp provides adequate volume for comfortable listening in reasonably quite room with the speaker within 2 - 3 feet of the listener; however I would not say that it's "room-filling", but it does come close. Now keep in mind that my build uses an audio transformer I removed from an old AM radio I had in the junk box, and may not be the same as Bill's build. My transformer has a DC resistance of 13.7 ohms on the primary, and 0.8 ohms on the secondary (speaker side).
While my build of the amp isn't super loud, it is more than adequate for the first time builder, and in my opinion, would indeed provide may hours of enjoyment exploring the 40 meter band; however, for just a few more components and 5 more inexpensive transistors, I feel the 7 transistor amp provides the better solution for me personally.
Background: Bill N2CQR of the SolderSmoke podcast and blog, has been working on a Direct Conversion receiver project with Dean KK4DAS to be used as a High School Direct Conversion Receiver Project (here: soldersmoke.blo... ). Bill has asked for others to build the DC receiver to help in the testing; so as a result, I have constructed this receiver. I now have 100% of the modules complete:
1.) - PTO (Permeability Tuned Oscillator) a.k.a. VFO
2.) - Diode Ring Mixer / Diplexer
3.) - Attenuator / Band Pass filter
4.) - Audio Amplifier
My build of the project is modular, and I have not made any changes to Bill and Dean's published design other than some very minor component value changes to match what I had in my junk-box, and the addition of an extra bypass capacitor here and there to support my modular layouts.
Schematic (SolderSmoke-DCR original 3 transistor audio amp design):
www.remmepark.c...
Schematic (Alternative 7 transistor design):
www.remmepark.c...
Project page:
www.remmepark.c...
Bill's (N2CQR) blog on the SolderSmoke-DCR
soldersmoke.blo...
73 - Rick - N3FJZ.

[@dadlavinder]

its incredible how good this sounds!

[@M0XFXUK]

Very interesting video, the three transistor amp sounds reasonable but the seven transistor push pull sounds like it has more power and body. I also enjoy building and experimenting. I'm not sure of your mission plan, but I found there are some very cheap audio amp IC's that use minimal components. That being said I guess it's probably more fun making these circuits using more discrete components. Looks like I'm going have to check out your previous videos in this series.

[@Circuit6040]

John, Yes, an audio amp chip would be a good low parts count solution. As you surmised, the goal for this project was to use only discrete components.