Solid State Guitar Amp Forum | DIY Guitar Amplifiers
Solid State Amplifiers => Amplifier Discussion => Topic started by: Talkboxert on September 24, 2009, 07:20:23 AM
Hey there,
I have a (newbie) question about my Fender vintage tube headf (PA 100).
Originally designed as a PA system with 2 speakers, this baby has two 8 OHm outputs.
My question: Could it harm the amp when I only connect 1 of those outputs to a 8 Ohm cabinet? Or should I then use a cabinet of a different Ohmage?
A schematic can be found here: http://www.schematicheaven.com/fenderamps/pa100.pdf
Thanx
Those jacks are wired in parallel, so your two 8 ohm speakers present a load of 4 ohms to the output transformer (this is also stated on the schematic next to the output jacks). so if you want to plug in just one speaker you will need a 4ohm speaker.
A friend of mine bought one of those, and ask me to transform it into a guitar amp..
i totally dismantled it and build a 2 channel tube amp with reverb, fx loop, etc.
check it out here:
http://www.youtube.com/watch?v=2muKFCCx5l0&hl=es
i connected it to a 8ohm speaker with no issues..on tubes, impedance mismatch is not as a big deal as with SS.