22-05-2017, 09:02 PM
Hi.
As can be seen in the pictures this project has been built on an old scrap chassis. It is actually built back to front with the output transformers mounted right at the front behind and above the controls. I thought I may have instability so only one channel was made up first. All is well with no problems whatsoever, hum is undetectable and quality spot on.
Some of the components are secondhand and I have not adhered to Mullards values in a couple of places.
The second channel is built but not tested as yet as I will have to change a couple of resistors to bring up the HT to 300v, also the function switch is not connected as yet. An ECC83 has been fitted for a magnetic cartridge which will come later.
So this is an economy amp with 60% secondhand parts and a layout that Mullard would certainly not approve of, it works and as good as any 3-3 should.
One mod that I will need to do is to move the EZ81 elsewhere as it is too close to the mains transformer and it could cause it to get too hot.
