21-08-2016, 07:23 PM
Hi.
Well the amp is finished. I have fitted the new cathode resistors that arrived early. I had to move the centre tap for the HT winding from the mains transformer to a different point on the busbar due to hum.
The cheap Chinese 6550's are far from good with them being wildly out in spec. Four brand new GEC KT88's make this amp rock........ totally amazing!!!
I don't think the customer will pay the £800 I could sell them for though.
I have suggested that two new 6550's would do the trick.
I have changed the cathode bypass caps for different values with an RC network to give a little bottom end boost.
Overall a magnificent outcome that is well within budget of the customer. Mind you I have been building valve amps for 50 years!
Well the amp is finished. I have fitted the new cathode resistors that arrived early. I had to move the centre tap for the HT winding from the mains transformer to a different point on the busbar due to hum.
The cheap Chinese 6550's are far from good with them being wildly out in spec. Four brand new GEC KT88's make this amp rock........ totally amazing!!!
I don't think the customer will pay the £800 I could sell them for though.
I have suggested that two new 6550's would do the trick.
I have changed the cathode bypass caps for different values with an RC network to give a little bottom end boost.
Overall a magnificent outcome that is well within budget of the customer. Mind you I have been building valve amps for 50 years!
