[planet10]

Aegir 20W Class A

Aegir is not Class A.

Call it unique Class AB.

dave

[FullRangeMan]

Aegir is not Class A.

Call it unique Class AB.

dave

They are suggesting its Class A, it run hot as Class A.
What if we made a Class A version of the Vidar? No, wait, strike that. What if we made a better-than-Class-A-in-many-respects version of the Vidar? Well, here you go. Meet Aegir.
 
Continuity™: Benefits Beyond Class A
Aegir is our first Continuity speaker amplifier. Technically, Continuity is a way to eliminate transconductance droop outside of the Class A bias region, and extend the benefits of Class A biasing. It also solves the NPN and PNP device mismatch problem, since it uses both NPN and PNP devices on both rails. It’s still a very hot-running amp, though, with over 10W of Class A standing bias.

[planet10]

Continuity is a way to eliminate transconductance droop outside of the Class A bias region

This happens at about 10w according to what Jason said in his tech paper. A 20 w amp so Class AB. But unique.

dave

[FullRangeMan]

This happens at about 10w according to what Jason said in his tech paper. A 20 w amp so Class AB. But unique.

dave

It use various transistors pairs, many AB amps run 10W Class A, in the end it will need a listening test to decide.

[JMW73]

This is all very interesting conversation.  It has made me research lots of other things...

I get that the Schiit (and the Van Alstine) aren't pure class A.  I'd say they are still in consideration, as are any others that aren't.

I appreciate all the suggestions and please keep them coming!  Certainly no decisions have been made.  I have researched every suggestion that has been made and also joined DIYaudio, but that is A LOT to take in as a neophyte.

One thing I'm considering is just building a pair of ACA since they are a kit with well established directions.  And then if I decide to build a more advanced DIY, I'll have that experience under my belt.  I DO like that they are pure class A.  My experience is: I've worked on car audio, including soldering wiring, and building wiring harnesses.  I COMPLETELY rewired a classic car with a Painless Wiring kit, and then had to modify the wiring under the hood when I did an engine swap (which included wiring in a custom electric fan that never existed on this car).  Closest I've come to this type of work was building DIY RCA cables for my main system.  So, I feel pretty confident with the ACA kit with directions, but a more ground up project is unfamiliar to me.

[ssglx]

Monarchy SM-70.
Wonderful little amps.

[Stercom]

I realize many people are strongly opposed to Chi-FI equipment but there are tons of well built, decent sounding mono-block Class A amps with balanced & single-ended inputs available for under $1,000 for the pair.

[JMW73]

I realize many people are strongly opposed to Chi-FI equipment but there are tons of well built, decent sounding mono-block Class A amps with balanced & single-ended inputs available for under $1,000 for the pair.

I'd probably prefer not, but I'd look into it.  Any examples to start down that path of research?

[Stercom]

I owned a pair of these. Never an issue. These have been mass produced for years. I assume Nelson either never had a patent on the design, the patent expired or he simply doesn't want to spend the money enforcing it. What ever the case may be these are solid little amps that are easily upgraded if you wish.

https://www.ebay.com/itm/125318498383?hash=item1d2d90884f:g:5ioAAOSwbxdkbdg~&amdata=enc%3AAQAIAAAA4EwUOcvhzqJ4tPo1vT406LVC5EBgejxbNRAfM%2BbHbjJVWLcZFADQ6ZgSJOdLwVBjdy8gybJDpmuEPLnuL7xAJFgzqbR7UXA%2Fs%2BapOnGBCScHAXa%2BmmLYSburmIXNruA2zCQyL71XWu%2BFcFCHURAfdxt5D7BM%2FGpol1txC4DOP95aHZbKwy1UdQcDIvQgMnXqZ1SybUT3smz070Vc%2Fx6lc%2Bb5qiAA2uMwAs7ezLv5TIl8lG%2F8XIo%2BmGMFNAWYcm2Sx5TLiiZ5%2FRbASqdPSuT9pVrKPtitOvpC4KggVK%2FUrWpr%7Ctkp%3ABk9SR_CpxonBYg

[JMW73]

I owned a pair of these. Never an issue. These have been mass produced for years. I assume Nelson either never had a patent on the design, the patent expired or he simply doesn't want to spend the money enforcing it. What ever the case may be these are solid little amps that are easily upgraded if you wish.

Hmmm; cheap enough to give them a try, or throw them in the system while I build ACA.  It's an option, thanks.

[rif]

If you do decide to go with the ACA, and don't want to read through a thousand posts, here's a concise but detailed guide.  It's written by 6L6, the guru of Pass amp build guides.

I don't know why, but I get the feeling that not many people on diyaudio know about this guides page - they just read through thousands of posts, which are illumating and have some very good discussions, but can be intimidating.

https://guides.diyaudio.com/c/Amplifiers

[JMW73]

If you do decide to go with the ACA, and don't want to read through a thousand posts, here's a concise but detailed guide.  It's written by 6L6, the guru of Pass amp build guides.

I don't know why, but I get the feeling that not many people on diyaudio know about this guides page - they just read through thousands of posts, which are illumating and have some very good discussions, but can be intimidating.

https://guides.diyaudio.com/c/Amplifiers

Awesome, thank you.  And good to know when I'm looking at other future projects. 

No decisions yet, but I did list my first amp for sale with 3 others waiting in the wings!

[planet10]

written by 6L6, the guru of Pass amp build guides

These are essentially on-line assembly guides that walk you thru every step. He has one for many diy Pass amplifiers, in particular boards sold thru the diyAudio store.

His day job is flying a Falcon 9.

dave

[Ericus Rex]

I really liked all of the Monarchy Audio amplifiers I have owned, but FWIW they have always been class A input/driver stages and high bias class A/AB output. Not pure class A. Does that matter? Only if stuck on a topology. How does it sound is probably more important.

IIRC, the very first ones were pure class A.  They ran hot. People complained and they changed the bias. I never heard a cooler unit but the hot ones did sound quite good for the money.

[FullRangeMan]

Class A amps are not suited to hot areas residents, after some years the PCBs and components are fully roasted and may not live much longer, but they are nice to have in Canada or Northern Europe.

[opnly bafld]

 

[opnly bafld]

Class A amps are not suited to hot areas residents, after some years the PCBs and components are fully roasted and may not live much longer, but they are nice to have in Canada or Northern Europe.

    

[FullRangeMan]

   

[ketchup]

Class A amps are not suited to hot areas residents, after some years the PCBs and components are fully roasted and may not live much longer, but they are nice to have in Canada or Northern Europe.

Why?  Aren't inside temps in Canada and Northern Europe the same as inside temps in hot areas?  How much do inside temps actually vary across the globe assuming AC is used?  5-10 degrees F?

[FullRangeMan]

Why?  Aren't inside temps in Canada and Northern Europe the same as inside temps in hot areas?  How much do inside temps actually vary across the globe assuming AC is used?  5-10 degrees F?

Do you mean say with air-c noise and electrical pollution. Last summer we had two heat waves vary from 35 to 42ºC, in these hard conditions inside the amp cover temp are always hot. A few years a go we have 47ºC for two days.