I rebuilt a Fender Princeton for a friend

[HamishR]

A friend of mine bought a ltd Fender Princeton to use in his surf band - it's in blonde tolex and looks very nice indeed. After playing my rebuilt Deluxe Reverb RI he wanted to get the Princeton Reverb rebuilt with Sozos, tagboard etc - but with a twist - this one now has upgraded transformers, a choke and runs 6L6s. You could probably use 6L6s in a stock Princeton Reverb but it wouldn't really be any louder because of the plate voltage.

It was actually quite tricky because there's a lot crammed into a Princeton Reverb and I had to allow room for the choke. So rather than cut a large circular hole for the cap can I just laid it on its side in the chassis so the choke could take that space on the outside. As a result it's not my neatest build which bugs me more than it should! But it's nice and quiet and the result sounds bigger than a Princeton should. He also bought a Celestion 10" Gold for it which sounds amazing in this amp.

So it's a big sounding small amp with plenty of headroom - in fact you have to go past 9 to get significant distortion. As we're not really big fans of BF Fender distortion that's fine. And the tremolo even works - it probably shouldn't with 6L6s. It's not as loud as my KT77 amps but it's loud enough for its intended purpose I'm sure.

 

[Harry Klippton]

That looks fun! Nice work

 

[fig]

Bravo! That is definitely a lot of doodads. Great idea on the cap & choke. Is the can secured or suspended?

 

[Gordo]

That looks really nice. So this was a circuit board tear out? Tasty workmanship there.

 

[HamishR]

Yes this was a PCB amp, so there's not much of the original amp left there! I used the original filament wiring and the reverb transformer... Thanks for the kind words fellas.

The filter cap can is held in place with silicon. It's solid but will be able to be prised loose one day for replacement when necessary.

The trickiest bit was working out the bias. The transformer has a bias tap where the original didn't, so there was a bit of trial and error getting the bias sorted.

 

[Barry]

Looks great! Amps are on my one day list, I've modded a couple of Blues Juniors for friends, but that's about it so far.

 

[HamishR]

I've been lucky this year. I have had a few jobs working on amps for friends and also I found a bunch of left-over bits from when I was building amps more frequently so have really been able to get into this year. And once I get into my amps I lose interest in building pedals. Still, I really rate having built some of these pedals - I have learnt a huge amount and been able to develop some of my own ODs which has been incredibly satisfying. Obviously the two things go hand in hand.

 

[Chuck D. Bones]

Very clean build.

 

[SillyOctpuss]

Sorry for the necro bump but can I ask what the choke does?

 

[Chuck D. Bones]

Sorry for the necro bump but can I ask what the choke does?

It's part of the B+ (plate voltage) filter. Low power amps usually use an R-C filter to remove ripple from the DC supply. L-C filters are more efficient. Hamish replaced the 1K 1W resistor with a choke for less voltage drop. That's the short answer.

 

[SillyOctpuss]

It's part of the B+ (plate voltage) filter. Low power amps usually use an R-C filter to remove ripple from the DC supply. L-C filters are more efficient. Hamish replaced the 1K 1W resistor with a choke for less voltage drop. That's the short answer.

Thank you and thanks for the short answer in a format I could understand