Dating fender transformer code
To see embedded text comments, go to video on Youtube. If you want cleaner and spankier preamp distortion charcteristics, you may replace the V1 or V2 12AX7 preamp tube with 12AT7 and 12AY7.These tubes have different frequency responses than 12AX7, particurlarly when distorting.You’ll have to increase the volume setting to achieve a similar volume as before.The reason is that 12AX7 tube has a voltage gain factor = 100, while 12AT7 = 60 and 12AY7 = 45.People describe these tubes to have less harsh and buzzy distortion.
This mod does not change the amp’s clean headroom but increases the preamp gain and preamp distortion.It has the same 2×12″ speaker configuration as the Twin Reverb but has a less powerful amp.It has half the number of power tubes, smaller transformers and a tube rectifier in stead of diodes.A set of Celestions give you a Britsh Marshall color with strong mids, while traditional Jensen-style speakers give you the classic Fender tone.Speakers are very difficult to recommend since the tone experience is nothing but personal taste.
If you pull one tube the other channel’s tube will be hotter biased and offers more gain.