Spitfire vs Marshall 18 watt

[xtian]

I have parts for an 18 watt build. Comparing schemos for Spitfire and 18 watt lite. Very similar topologies, but very different component values.

How do these amps sound? I guess the Spitfire is cleaner, the Marshall meaner?

[xtian]

I have a Hammond 125E output transformer. How do I figure the best primary impedance? I've read anything from 4.4 to 8k.

[rdjones]

The original Marshall had up around 8.5k a-a.
I don't know about the Spitfire.

rd

[Gee]

They are very similar and for identical builds next to each other, you might not hear a difference for a big part of the control settings IMO.

The Spitfire is more Vox AC15 with a bit less gain, more jangle and the 18Watt is more classic rock but can end up being a big ragged and fuzzy which some like and some don't.

I built a Spitfire with an 18Watt OT and a switch for 4 or 8 ohm and preferred the 8 ohm setting - more volume and crunch to my ears - which was what I wanted at the time.

Both are really good amps and are easy to convert between each other.

[M Fowler]

The big differences are in the resistor values in the PI and power amp grids.

[Darkbluemurder]

The tone controls in the 18W are different, too - both in the Normal and in the Trem channels.

Just build it - it's easy to convert one into the other by just swapping some part values.

Cheers Stephan