Weber Copper Top

[John Dowden]

So I just recently bought a Princeton Reverb Reissue off of CL for a steal and have been using it for low volume gigs (I'm a fiddle player) instead of lugging my Twin. The amp sounds absolutely amazing at low volumes (yes I know its only 15 watts) but I still feel like I can get a bit more headroom and usability out of this thing with a few mods. I'm sticking with the 10 for the time being because I think they just have more punch for fiddle than a 12 or 15.

Has anyone ever used a Copper Top solid state rectifier in place of the tube? From what I've gathered I can either go with the replacement (WZ34) which will give the same amount of sag as the glass but with increased reliability or I can go with the WS1 which has the diodes and limiter only and no sag which will give me slightly higher headroom.

I'm also looking into updating the speaker from the flubby Jensen to either a Weber 10F150H or the Cali Alnico...unless you guys have some better suggestions that will give me more headroom and not the brightness of the Jensen.

[Dave Mudgett]

I use smaller Fender amps, including Princeton, Deluxe, and Vibrolux Reverbs quite a bit. I haven't used a Weber Copper Cap rectifier, but I have used solid-state rectifiers. IMO, a solid-state rectifier is pretty much a solid-state rectifier - lots of people have offered them and they're pretty easy to make yourself. My take on advantages/disadvantages of tube rectifiers vs. solid-state replacements:

Rectification: for any of the smaller Fender amps, it's pretty easy to get either a tube or solid-state rectifier with sag or without it. Advantage: neutral.

Controlled Warmup: remember that a Princeton Reverb doesn't have a standby switch, so the gradual warmup of the rectifier tube is a good thing, not a bad thing. I realize that the Copper Cap does slow down the warmup a bit, as compared to a typical solid-state rectifier. But warmup time is nowhere near as long as a typical rectifier tube. Advantage: tube rectifier.

Reliability: I've seen dud rectifiers before I put one in an amp, but I have rarely if ever myself had a tube rectifier fail in-circuit in 40+ years. I have seen solid-state rectifiers fail fairly often. So I don't really see a significant advantage to solid-state in reliability, except the potential for breakage. Advantage: neutral.

Availability: there's also no particular problem getting either 5U4 or 5AR4 tube rectifiers, as long as you're not hung up about getting something like a Mullard GZ-34 or something like that. 5U4 will have a bit of 'sag', but a 5AR4/GZ-34 will have very little, and both were used at various times on Princetons. So at least for now - Advantage: neutral.

On balance, I think the controlled warmup of the tube rectifier wins the day on a Princeton.

I currently use an MI-series JBL 10" speaker in my Princeton and a Weber 12F150 12" speaker in my Deluxe Reverb, and they're both great. I'm especially impressed with the efficiency of the 12F150 and how it holds together for pedal steel. I had another Princeton with an older 10F150, and it had that same type of efficiency and headroom. I'd say offhand that the 10F150 and 12F150 speakers I've used have been more efficient than any JBL I've used, but the JBLs certainly have something special if you're into that kind of thing. I think it comes down strictly to personal preference, and I don't know any way to judge that except to try them.

I would never cut out the baffle on an old Princeton for a 12" speaker. If the baffle is removable, trying a 12" in a repro baffle is a reasonable choice. I have had Princetons with 12" speakers already in them, I guess I think the smaller box likes a good 10" better, to my tastes.

[John Dowden]

Dave, thanks for that wonder response. I guess I need to start looking around for a reasonably priced Mullard...as if such a thing exists.

What effect have you found the solid state rectifier has on tone compared to a tube? I know its not running an audio signal path through it but it still has to have some effect on overall amp tone.

I read an article....probably the main argument for some people in favor of SS rectifiers that SRV's amp tech did away with all of the rectifier tubes in his amps because of how after being turned on for extended periods of time (in my case four hour gigs) the rectifier starts to cause some unwanted distortion that wasn't there at the beginning of the gig with the same tone/volume settings. I actually found this to be the case for the first time at a gig I played last night.

Was the 10F150 you played through paper or hemp coned? I've read up on all three different offerings Weber offers and it seems like for fiddle ( to tame brightness) the hemp cone would possibly be the best solution but I've never played on a hemp cone speaker so not really sure how it responds compared to paper/cloth.

[Ken Metcalf]

+1 for the Weber 10F150 in my Deluxe.
I also had a Princeton which I put a JBL MI 10 in and was very happy with.
My deluxe was sort of dead sounding and a new set of power tubes really brought it to life.
The Weber 50 watt added sparkle to the sound and the amp is very fun to play now.
I like to replace my power tubes every couple years of hard use when clean headroom is the goal.
I just use JJs and do not hunt for exotic NOS.
Fresh strings, fresh tubes and good speakers are a better mod than most PU swaps or effects.
20-30 year old, well used speakers start to loose clarity.
People that want fuzzy guitar sag prefer old tubes and old speakers.

[John Dowden]

Ken, is the JBL MI-10 different from the old JBL D110 or K110?

[Olli Haavisto]

A good speaker for Princeton is the Jensen Neo 10.
Clean and efficient, will probably add up to 6 db of loudness compared to the stock speaker. Light as a feather, too.

[chris ivey]

the only practical mod for using a princeton with a steel is a powerful microphone in front of it.

[John Dowden]

I wouldn't be using this amp for pedal steel. Just fiddle.

[John Billings]

How about the power supply/phase inverter mod? Change it to the design in a Deluxe. My PR is now almost 20 watts.

[Donny Hinson]

IMHO, if you're just using the amp for fiddle, you'll likely notice very little difference with any kind of rectifier swap/change. The sag and bloom characteristics of rectifiers that some players obssess over are largely noticed only when playing distorted guitar. In normal (clean) playing, there really isn't a vast change in raw power output experienced by using different rectifiers. The amp sound with a fiddle, with it's inherently softer attack, will likely remain basically unchanged.