Square waves

There is a pictorial of a Stereo 70 build shown on both Bob's and Roy's websites. There is a picture of a 10khz square wave from an old MkIII and a new ST120.
The difference is dramatic. What accounts for it, wider bandwidth OT, better power supply, better driver stage? Would a new MkIII do any better against a ST120?
I'm thinking about MkIIIs (M70s actually), or a ST120.

ramon68 wrote:There is a pictorial of a Stereo 70 build shown on both Bob's and Roy's websites. There is a picture of a 10khz square wave from an old MkIII and a new ST120.
The difference is dramatic. What accounts for it, wider bandwidth OT, better power supply, better driver stage? Would a new MkIII do any better against a ST120?
I'm thinking about MkIIIs (M70s actually), or a ST120.

You can build a set of Mark IIIs to the same specs, Ramon68 - here is a link to the VTA driver board version for the Mark III: http://www.tubes4hifi.com/MK3.htm

I have gone that route by building two Mark III amps using the VTA drivers ( https://dynacotubeaudio.forumotion.com/t514-dynaco-mark-iii-build ), however up-front you need to know that it is not as cost-effective as the single chassis ST-120 approach though. You do gain a bit in physical separation by going with monoblocks - you have to decide for yourself which option you can live with (without causing Wife Aggro too much ;-) ).

-- JunkyJan