Build This MoFo!

Actually have a 6yr old who knows all about electrical safety and even about electronics and amps already, and he has even soldered his own F5.

That's great! :)
Now Nelson can add a line to the F5 article: "An amp that even a 6yr old can assemble" :)
Joking a bit, but that's really cool. Wish he further develops the talent and becmes better than his father. I have a 6 yr old too, but he's more interested in math :)
Regarding "caseless" amps, there's a certain minimalistic appeal in running electronics on just a piece of wood. Once you put them in a nice shiny case, they don't sound as good :p
 
Yes, SE Class A amps have dominant 2nd harmonic distortion with descending higher orders and that is why it sounds pleasing to the ears. The zero global feedback keeps the correct phase relationships, along with single full range driver - so that the soundstage and imaging are very accurate. An ultralow distortion amp with a typical balanced front end and lots of negative feedback will not sound the same beccause of the harmonic profile and phase relationships. Some people prefer dominant third order distortion and lots of negative feedback though. I agree that the MoFo with a fullrange speaker sounds great. It is my daily player in the kitchen with Amazon Dot (Alexa) as source and an Aksa Lender preamp, then 0.53x scale Karlsonator full range speakers with dual 3FE25-16's. Superb combination.

how would be the harmonic profile (H2 vs H3 and phase) using 2 mofos bridged for each channel?
Input form each mofo per channel fed by the + and respectively the - output of a balanced DAC
 
you need a gaped transformer to avoid saturation with DC

coming back to bridged MOFO do you think that H2 will go lower and maybe H3 increase?

the advantage of bridged mofo is to use an output transformer without gape because the DC magnetic flux will be cancelled. No need for gaped transformer, just a 12+12v transformer like this input transformer can be omitted if feeding from balanced source (XLR) and using the MoFo bias network
 
You are reinventing Sue Parker's Zeus Amp. Read up and learn the finer points she and others have shared over the years.

Marconi118;
The answers you seek to the push-pull amp you displayed are in the Zeus Amp thread and the Zeus Amp web pages.

Jolntsai;

For a SE transformer, I would consult a transformer manufacture.
All output transformers are a compromise. Having low impedance drive is a big plus.
One thing for sure, its going to be heavy if you want more than a few watts.
I would guess 20% more than the inductor required for the equivalent MOFO.

HTH
 
Can you all hear a bit of white noise from the tweeter when a preamp is connected to MoFo and the ear is 3-4 cm from the tweeter (94 dB tweeter in my case)? …..with volumen turned down? with MoFo only connected with shorted input the white noise is almost inaudible but with preamp…..in my case BA3 pre the white noise is a bit more audible. At a distance of 30 cm from ear the noise is inaudible. I use a Khozmo 50k shunt attenuator for BA3 pre. So a 50k resistor is always in serie with signal and with 47 k Rin of BA3 pre the signal is only half even at full output. Step 0 is gnd. Step 1 is -60 dB and I am able to hear the music through the white noise with ear close to tweeter. So I guess I should be ok regarding noise? …..or what is normal? …..I hear no "buzz or hum". Would I be able to hear a bit of white noise from tweeter even with the most expensive Pass Labs amps connected?
 
Founder of XSA-Labs
Joined 2012
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Finally, MOAMOFO playing in stereo. Dual mono setup with independent 37v @ 4.5amps provided by a pair of Antek AN-3232 powering JK-MrEvil Cap Mx's, and voltage gain provided by Aksa-Lender Melbourne preamp. Good for 50wrms into 6.8ohms. Quick test at loud levels and sound is not congested - nice sounding and can get loud. Now also fitted with Noctua silent PWM fans pushing air through CPU coolers to maintain air temp at 45C.

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