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What I have is a Fender build that began as a 5E3 and it's in a 1971 music master amp chassis so all I had to work with were one vol and one tone pot and 2 inputs so I just used one triode of the preamp 12AY7 . I didn't like the sound to much gain so what I did was wire the vol and tone pots just like a 6G2 fender princeton which brough me less gain and the tone and vol pots did not interreact like they do on the 5E3 . The rest of the amp including the phase inverter and power section and no NFB is the same as the 5E3 all I did change is I removed the cathode bias and installed an adjustable fixed bias .
The tubes are V1 12AY7 . V2 12AX7 V3 & V4 JJ 6V6s and a 5Y3 rect since that was what the 5E3 used as well as the 6G2 . some may know the 6G2 is basically a 5E3 with a different tone stack and fixed bias and has a NFB loop and has the added tremlo which I didn't add.
So here is what is a bit confusing to me. The PT is a bit more than the stock 6G2 would normally use and a bit less than the 5E3 would use . I got it from Allen Amps and it is a beefed up replacement for a champ or all princetons I also used an Allen amp OT which is a beefed up model for a princeton all models that are push/pull . The PT fits right in the PT cutout for the SF champ and MM fender bass amp since they share the same chassis . It is rated at 325-0-325 HT @ 180mA and after the 5Y3 I have a 30 uf reservoir cap and a 5000 ohm dropper then a 16 uf cap and a 22K dropper then another 16uf cap . With those values in mind I have a 410 volt plate . With a bit smaller PT like the 6G2 has a 325-0-325 ht @ 70mA yet it has a 30 uf reservoir then a 1000 ohm dropper another 30uf cap then a 10k dropper and about 320 volt plate.
Ok here is the weird part . I look at the AA964 princeton same PT as the SF champ and 6G2 princeton yet it uses a GZ-34 rect tube has 420 volts plates and one more filter stage 20 uf then a 1K dropper another 20 uf cap then 18K dropper another 20uf cap and a 18k dropper . Now even though the AA964 princeton has the extra filter stage both the build I made and the 6G2 and the AA964 all have the plate run right from the pin 8 of the rect tube to the OT center tap , the first dropping resister is after the reservoir cap before the 6V6 screen all set up the same way so how can my build have almost the same plate using a 5Y3 as the AA964 have using a GZ-34 rect ? Is it because mt PT has a 180 mA instead of a 70 mA secondary . They all have the same output tubes and all use two 12A--7's on my build I just use one triode of the 12AY7 but that does not draw that much more if I used both triodes . Could it also have something to do with the Allen amps OT I used ? With both his PT and OT I got they can run a pair of 6V6's a 5Y3 and easy two 12AX7's or a pair of 6L6GC with a GZ-34 and easy two 12AX7's . The OT is really just a higher watt OT and a larger sized OT than a stock push/pull princeton and the PT is an inch taller with higher mA rating on the HT secondaries.
The tubes are V1 12AY7 . V2 12AX7 V3 & V4 JJ 6V6s and a 5Y3 rect since that was what the 5E3 used as well as the 6G2 . some may know the 6G2 is basically a 5E3 with a different tone stack and fixed bias and has a NFB loop and has the added tremlo which I didn't add.
So here is what is a bit confusing to me. The PT is a bit more than the stock 6G2 would normally use and a bit less than the 5E3 would use . I got it from Allen Amps and it is a beefed up replacement for a champ or all princetons I also used an Allen amp OT which is a beefed up model for a princeton all models that are push/pull . The PT fits right in the PT cutout for the SF champ and MM fender bass amp since they share the same chassis . It is rated at 325-0-325 HT @ 180mA and after the 5Y3 I have a 30 uf reservoir cap and a 5000 ohm dropper then a 16 uf cap and a 22K dropper then another 16uf cap . With those values in mind I have a 410 volt plate . With a bit smaller PT like the 6G2 has a 325-0-325 ht @ 70mA yet it has a 30 uf reservoir then a 1000 ohm dropper another 30uf cap then a 10k dropper and about 320 volt plate.
Ok here is the weird part . I look at the AA964 princeton same PT as the SF champ and 6G2 princeton yet it uses a GZ-34 rect tube has 420 volts plates and one more filter stage 20 uf then a 1K dropper another 20 uf cap then 18K dropper another 20uf cap and a 18k dropper . Now even though the AA964 princeton has the extra filter stage both the build I made and the 6G2 and the AA964 all have the plate run right from the pin 8 of the rect tube to the OT center tap , the first dropping resister is after the reservoir cap before the 6V6 screen all set up the same way so how can my build have almost the same plate using a 5Y3 as the AA964 have using a GZ-34 rect ? Is it because mt PT has a 180 mA instead of a 70 mA secondary . They all have the same output tubes and all use two 12A--7's on my build I just use one triode of the 12AY7 but that does not draw that much more if I used both triodes . Could it also have something to do with the Allen amps OT I used ? With both his PT and OT I got they can run a pair of 6V6's a 5Y3 and easy two 12AX7's or a pair of 6L6GC with a GZ-34 and easy two 12AX7's . The OT is really just a higher watt OT and a larger sized OT than a stock push/pull princeton and the PT is an inch taller with higher mA rating on the HT secondaries.
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