Jumping into Class A

[lawbadman]

Hello guys,

I'm thinking of diving into the class A world, being that all I have is class a/b amps.
I'm looking for a simple amplifier to build that will drive a 8 ohm load to around 50watts or more.
I already have big heat sinks and a 35-0-35 500va torroid.
Can anyone suggest a nice sounding amplifier?

 

[ColinA]

Simple!
F5 Turbo3. F-5T – diyAudio Store

It don't get no better.

 

[MASantos]

35 AC secondaries? That is a bit too high for a simple class A, you'll have to get into the "less than simple" ones! 🙂

The f5 turbo or maybe a BA3 (with the input stage on a separated lower voltage) are good canditates.

 

[aspringv]

When you say 'big' about the heatsinks, how big do you mean? Because at that voltage secondarys you're going to be pushing a lot of bias current, which equals a -lot- of dissipation.

Actually, I don't believe that a 500VA transfo would be enough...

The jump in hardware required for class A can be ...surprising. 🙂

 

[aspringv]

On a tangent though, I'd you downgrade your power output expectations, you could use that kit for a Zen v9. Or if you went for an active ground (ala Quad) any of the bipolar supply first watt designs are possible.

Just a thought. 🙂

 

[2 picoDumbs]

Well using the transformer you have, the most sensible solution would be something like the following.
Cascoded BA3 front end with source follower output stage biased at 1A.
Will give you 16 W Class A then over 100W into Class AB

 

[aspringv]

Hey 2picodumbs, I was just this morning thinking about something similar... ba-3 front-end and the mu- monster... using SiCFET's so I didn't need quite as much heatsink. Probably as mono blocks using Conrad's biggest heatsinks.

Just once I get done with all the other amps 🙂

 

[Nelson Pass]

I'm thinking of diving into the class A world

Come on in. The water's warm.

😎