Rare Angel's Breath

[67plexi]

I had a chance to work on this amp in 2014 I turned it down. It rent's out at $7500.00 per day.
First time I have seen a bi polar bias.

 

[ivan H]

Interesting, very interesting. Ultra linear output stage too. Seen a few ultra linear guitar amps but it's not overly common. Cheers

 

[ivan H]

Another interesting feature is the 12AX7 phase inverter followed by 12AX7 cathode followers driving the KT88's. This is good practice as it drives the KT88's from a low impedance source. I've seen this in old Aussie Holden Wasp 200 watt (4 X KT88) amps (I have previously posted a pic of a very young Angus using one). Early versions used 12AX7's for both phase inverter & cathode followers/driver's while later ones used the better suited combination of a 12AT7 phase inverter & 12AU7 cathode followers/driver, however in the Holden Wasp design the cathode followers/driver's were R/C coupled to the KT88's. This design has the cathode followers/driver's direct coupled to the KT88 control grids. Very nice ddesign work, especially the way the bi polar bias supply & cathode follower balance circuit is applied. Cheers