Which lowest distortion reliable DIY AB 60-100W amp would you recommend?

What transformer do you have? or switcher supply? Heat sink? Enclosure to keep out the RF interference?
If no center tap, AX6 and TGM8 are fun and protect your speaker from bad solder joint with a $3 capacitor. I've measured my AX6 at 70 W for 5 seconds at a time. Distortion is down below 1% with only 6 transistors. Retro Amp 50W Single Supply - Page 22 - diyAudio
If no transformer heat sink enclosure fan or RF filters, buy a PV-4c or CS800x for parts or repair on ebay & repair it. Or mixer amps for parts or repair are often cheap, usually need some pots in addition to the usual blown outputs. Schematics are on line.
Don't buy a switcher supply amp or mixer. Mains voltage parts are too dangerous for new people to probe or repair. You can't use a light bulb AC limiter on a switcher supply, either. That gadget keeps transistors from blowing parts up to the ceiling.
 
Last edited:
DestroyerX DX Blame?

Thing is the designs on this forum are so badly documented and kept track of half the time you have no idea what you're making. The DX Blame, however, seems to be popular enough that the design is 'out there'.

So far that's the only 'not too complex' amplifier with good specs I've found that you could trust the design source of.

In all honesty, these days, I think you're better off just going class D. Sound quality isn't really an issue these days and you can get huge amounts of power for not a lot of cash, and everything is documented by a company churning over hundreds of millions of dollars.
 

Ian Finch

Member
Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW
DX's designs, as the "Blame" title might suggest, are far from low distortion by today's linear amplifier design standards. It's no accident, rather it's an intended means of achieving desired sound qualities (IOW, a particular range of audible distortion products).

If we are serious about really low distortion, I'd go along with Mark Tillotson's "Compact Blameless" suggestion or the "Load Invariant" version where the speaker types or power levels might be a concern.