Fender Special Run Princeton

edited February 2015 in Root
Hi everyone. I've been listening to Jim for around two years now and love the way he plays . I also enjoy reading through the forum and hearing what you all have to say on the various discussions that come up. I've decided to post something as I've just purchased a FSR Princeton. It's the "Sparkle Blue" model and it's certainly a looker. I'd been on the lookout for a PR for sometime and this one came up second hand. The price was right so I went for it. It's the model with Celestion G10

My question is whether anyone else has had problems really getting the PR to break up? The amp is much louder than I expected but when cranked to 10 it still doesn't carry that breakup we all know and love from Princetons. Does anyone have any ideas on why this might be? I also find the reverb to be over the top and washed out sounding past 3; sounding almost like a digital reverb pedal with the mix too high.

The seller told me the amp was as it arrived new and from what I can see it is. I've played Fender amps all my playing life (17 years or so) but have never used the Groove tubes Fender are supplying these days. Could it be this? I'm aware Jim runs his bias very hot, I wonder if this maybe isn't the case and it's hurting the tone? I should also mention that I'm running a Gibson 335 into it just now and I'm feeling it's maybe not the best combination with the Princeton. If anyone has any thoughts it would be much appreciated. Thanks for taking the time to read and good day to you all.

Martin
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Comments

  • How much breakup are you looking for? With the volume on 10 it should be ratty as all get-out LOL. If it's not, it sounds like something's wrong... IDK how the headroom on the G10 compares to the stock Jensen P10R, but I don't think the G10 is a totally clean speaker, so......
  • Did you check the bias? I've heard that Fender factory bias setting is way too cold.
  • Hi ruger9 and Tak.

    I agree ruger9, if anything I was concerned of too much break up from the G10 compared to the Jensen. Add a 335 (mine is customised with a P90 between the two stock PU - and I've tried all 3) and I was expecting alot of breakup. Odd indeed! I was hoping for the perfect amp and what I've got is a conundrum

    Hi Tak, no I've yet to get to grips with the amp to that level. I am thinking the bias could be the problem. I've played a Twin all my days thus far that I got used and it's always sounded great. I'm considering getting the bias tweeked to address the breakup issue on PR; I'm sure what else it could be.

    Currently, with the PR on 10 it gets to a bit of breakup and you can hear some compression coming through. Compared to what I hear from my favourite PR players (Jim and Marty Stuart spring to mind) it's nowhere even close. Now I like clean tones but so far this FSR PR is reminding me of the 65 Deluxe reissue, as Jim has mentioned somewhere on the forum I believe, they seem reluctant to break up or compress and I'm getting no hint of "bloom". 'tis a puzzle.

    Thank you for the feedback gents; your ideas and suggestions are much appreciated.
  • Definitely something wrong.... could be the bias, but it would have to be WAAAAAAY off. Unlikely. Verify all the tube positions have the correct tubes in them (no 12AU7s where a 12AX7 should be, for example). Including the phase inverter and the reverb tubes. The only other thing I can think of is maybe the power tubes, but they don't usually loose power permanently- they fluctuate from full power (breakup) to lower power (less breakup)...

    Check the tubes, check the bias. Replace the power tubes.
  • edited February 2015
    deleted- sorry I misread something lol
  • Hi Ruger and thanks for your comments.

    I've had a look at the preamp tubes. I have the following moving left to right from behind the amp:

    GT-12AX7-R.
    GT-12AX7-R
    GT-12AT7
    GT-12AX7-R

    I can't see into the rectifier and power tubes but the manual lists them as: 5AR4. 6V6. 6V6.

    I've never used Groove Tubes before and am wondering what the "R" is about. The manual states the amp should have 12AX7A instead of R. Looking on the Groove Tubes website they describe the 12AX7-R as being low gain and slightly harsh when overdriven - a good choice for higher gain amps and for keeping over the top overdrive under control. I wonder if these guys could be my problem....



  • Those are all correct. The "r" just means it was manufactured in Russia- likely a Sovtek. The "X" is the important part.... 12a_7... ax7, at7, au7, ay7. Looks like all the tubes are correct. Puzzling.

    Well, if it were me, I'd replace every tube in the amp except the rectifier (rectifiers either work or they dont), but that's because I have a bunch of tubes on hand. I would also check and adjust the bias. It's not hard, but you do have to know what you're doing, and remove the chassis to do it. Other than those 2 items, I can't imagine what is wrong.
  • edited March 2015
    As an aside you can buy bias measuring devices that mean you don't have to pull the chassis out of your cabinet. The one I have fits between the power tubes and their sockets and has a switch so you can see the measurement for both tubes.
    However, to be totally accurate you need to know the plate voltage of the amp. For this I bought a probe that attaches to my multimeter. You will also need to know the plate dissipation of your power tubes. Then you need to do a bit of maths.

    If this is already sounding a bit complicated you are probably best going to an amp tech.

    The reason I mention it is that I bought the right tools and am confident I understand enough to correctly bias my Princeton Reverb Reissue. It is reasonably straightforward and I'm sure with a bit of self education most tech minded people could learn how to do it.

    However, tube amps are dangerous and easy to damage so always exercise extreme caution and if in any doubt whatsoever leave well alone.
  • Hello ruger9 and AndyJ and thanks for the informative replies.

    I'm fairly certain the biasing is (at least part of) the problem. Tak is on the money; for my money!

    I've known Fender amps to come out the shop biased low from friend's experiences. Mine wasn't touched by a technician under its previous owner so I am assuming this is the issue.

    I do a fair lot of my tech stuff myself and wouldn't mind doing the biasing as from what I've looked into it's fairly straight forward. However, as I understand it the Princeton does not have a bias pot in the circuit. I'm aware it's a common mod. So I may put the amp into have a tech install a pot to adjust the bias. From there on I would happily do it myself. I work with a bunch of different projects and frequently go from needing headroom to not. I'd like to be able to this adjustment myself and without needing to change components regularly.

    So, I wonder if anyone has any experience with mod to a PR to include a biasing pot?

    Thoughts and ideas are much appreciated. Thanks again guys :)
  • edited March 2015
    It DOES have a bias pot; it's behind one of the transformers..... there is a hole in the chassis (actually it's nut- it looks like a jack) that you can stick a screwdriver up thru to adjust it, BUT- this only works if you have a bias reader that plugs into the power tube sockets.... otherwise, you'll have to use the internal bias test points, which requires removal of the chassis. Then the bias pot is plainly visible.

    Let me see what I have in my files.....

    OK, I do have some directions on how to check and set the bias using a multimeter... BUT: the standard disclaimer: there are high voltages inside a tube amp THAT CAN KILL YOU. Unless you know what you are doing, and know how to safely discharge the filter caps, do not work on your own amp.

    Rather than posting the directions here, if you would like me to send them to you, I will... my email is ruger9two _at_ yahoo.com

    Here is a pic of the bias pot, you can see it behind the transformer:




    image
  • Here's an underneath shot of the bias pot.
    image
  • One potential wrinkle I'll throw in as far as accessing the bias pot from below the chassis: In some versions of the PRRI (like mine which is one of the two-tone orange and white FSRs), Fender added and extra strip of wood across the inside top of the baffle to stiffen it up a bit and reduce unwanted vibrations. The problem is that the strip of wood blocks the bias pot.

    But if that's the case with yours, it's not the end of the world. You can either 1) pull the chassis completely from the cabinet and adjust the pot from the inside of the amp or 2) you might be able to simply pull the chassis a half inch or so towards the back (after removing the 4 top screws of course).

    I ended up doing #1. So I don't know how stable the chassis will be within the cabinet after pulling it back slightly. But it may work. Has anyone here tried this?
  • Unless you have a bias tester that plugs into the power tube sockets, you have to pull the chassis anyway. If you're using a multimeter to check the bias, you have to pull the chassis. It's not a big deal to pull the chassis.
  • Hi Guys!

    So, I have located the nut to access the bias pot without removing the chassis. As BlueCajun says, the FSR have this extra strip. I am luck in that a skinny screw driver can get up there.

    Here's where you might all get annoyed with me. I slid the screwdriver and had a little fiddle without having a multimeter or bias tester to see if it makes difference with my problem. It does! The amp is sounding better already.

    I guess the question now is how important is it I get a meter on it to check I've not turned the bias pot too far and putting too much through it. Or, is the amp made in such a way that I cant damage but rather only reduce valve longevity. And of course, is getting a meter on it and getting to an exact value likely to improve tone further.

    There's definitely progress guys and thank you for your assistance! :)
  • The reason getting an actual bias number is important is: biasing tubes too hot (which Jim does and I do as well), will wear out power tubes faster. I'm fine with that. But you don't want to bias them too too hot- power tubes generate alot of heat, and increasing that heat causes wear & tear issues elsewhere as well.

    In the "old days" (lol) guys biased by ear (which is what you did) all the time. Worst case, a power tube blows and takes something else with it, in which case you'd have to take it to a tech for repair.

    ALSO: JJ 6V6s will handle a hotter bias better than others (Tung Sols, Sovteks, whatever). The JJ 6V6 is almost like a mini 6L6. I don't prefer then JJ's for tone (they have a slight bit more headroom and stiffness than the other 6V6s), but they can't be beat for durability.
  • Hello again and sorry for the delay in replying; a few weeks back someone drove their car in to my driver door and I've been laid low more or less since.

    Before all this - which seems like a long time ago - I had cranked the bias and was getting some nice tones. However, I was using a boss blues driver (not too much to be fair but a little) to get a decent amount of break up. I've been having a look on the Fenderguru site and the clips posted there have much more break up than I get. I know they're using vintage amps but yeah, I guess I'm still surprised at how little break up I'm getting.

    I'm thinking of changing out the tubes. I can't imagine the groove tubes are particularly good anyway. I have mesa boogie in my twin which are very good work horses. Thinking of trying the TAD tubes as getting NOS isn't easy in the UK - anyone any experience with them. besides that I'm thinking drop it into my local tech and see if they can make the bloody think distort more.

    I should say - I'm largely a pretty clean tone kinda guy. I'm not looking for modern day levels of break up. But even at 10 with a stock Gibson 335 I can't get half the level of break up that other PRs get. 'tis strange.

    Anyway, I hope you've all been and playing lots!

    Martin
  • Something is wrong with the amp. Take it to a tech. Seriously. You have exhausted your options: tubes and bias.

    There is a slight chance you power tubes are on their way out, or a preamp tube is faulty, the only way to know is to replace ALL the tubes with new ones. But to me, it sounds like there's something else going on. A qualified Fender service tech will be able to verify everything is to spec, and if its not, fix it.

  • Thanks for your help ruger9. I'll let you know of any developments; I think a tech will indeed be the next port of call. Cheers for your help!

    Martin
  • You guys really know your amps! Would anyone be able to recommend an amp with a nice, clean jazz sound for a hollow body (Guild A-150?) Do you think a Princeton would fit the bill?

    I'm currently using a VOX VT40+. It's OK with the tele and even my Epiphone 339, but with the Guild, I have to turn up the gain too much and I get a lot of humming and feedback.

    Thanks,
    Nick
  • Nick,

    The Princeton would work, but only at low volume. It doesn't have a lot of headroom.... a hollow body can certainly sound gorgeous thru one, just depends on how much volume you need. For home? The Princeton would be perfect. IMO.

    Keep in mind- there is no "gain" control. The Princeton is a "NMV"- "No Master Volume"- amp. It has one control for gain and volume (called volume). Depending on your guitar, it starts to breakup around 3-5... I don't know anything about that repro Dearmond "monkey on a stick" pickup that comes on the Guild....
  • Ruger9,

    Thanks for the feedback. You are absolutely right, the guitar has a DeArmond reproduction, which has a nice mellow sound.

    I'm not sure what you mean by "headroom."

    The guitar tends to feed back on the low strings when I increase volume, which I assumed was caused by increasing the gain, the main volume already being maxed out.

    I am not playing in large places and I am playing mostly with unamplified horns and piano - sometimes miked. So I don't need to be very loud, but - especially on the ensemble parts - I need some volume to cut through the horns.

    I guess the best thing to do is go to the store and play a bunch. Not a bad way to spend a day.

    Thanks again,
    Nick

  • edited April 2015
    Headroom is how high you can turn the amp's volume up before it starts to breakup... a "high headroom" amp is very clean, all the way up. A "low headroom" amp starts to get dirty quickly, by about 3 on the volume knob. And how hot the guitar's pickups' are plays a roll.... which is why I'm not sure if the PR will be loud enough with that Guild... maybe? If the Guild's pickup is low-power, then the PR may be all you need...

    So it all comes down to: how clean do you need to be, at what volume? Playing with unamplified horns? If you want to be dead clean IDK if the Princeton, as it comes with the stock speaker, will do that or not. I know it'll be loud enough, just don't know if it'll be clean enough. there are also "tricks" to get more clean volume... cranking the amp to 10 and using the guitar's volume very low (this is what Jim does, works great on a tele.... I have found for some reason it doesn't work as well on my hollow body guitars).

    Just my opinion, but "I sometimes need volume to cut thru the horns"... I personally would look for more wattage than a Princeton... maybe a Deluxe Reverb, or the new 68 Deluxe Reverb, or even better- the new 68 Custom Vibrolux. The new 68 vibrolux has more headroom than the old one, and 40 watts.
  • Ruger9

    This is really great - thanks for all the info.

    I'll let you know how it goes.
    Nick
  • You should have my Princeton, Nick, it won't break up!

    A few wee things to suggest if feedback is the problem. Don't face the amp when playing. Feedback is when a sound signal basically gets caught in a loop. When facing your amp the sound is going into your hollow body and being picked up again by the pick ups. Try facing away from the amp and any other speakers if you have them.

    Also, feedback usually happens with a particular frequency. Of course pulling volume back will solve the problem typically. But try to identify if it's a high, low, mid frequency feedback and then try to EQ this frequency a bit. Usually turning the low back a bit if it's a low frequency feedback will help etc.

    I looked up the Vox amp you have and I see it has gain, vol and master dials. Ensure none of these are running hot. Feedback is more common when something in your settings is cranked high. Keeping everything in its comfort zone can help avoid feedback.

    I see the amp has a bunch of onboard effects. If you're using these try taking them all off and see if you can get it to work without feedback. You can then reintroduce them slowly. Effects such as reverb can help feedback do its dirty work .... I say that, but there's times when FB is brilliant :)

    Good luck!
  • Martin,

    Appreciate the info. I am not running much - just reverb - but I'll give it a try and see what happens. I do keep the bass up pretty high and the treble rolled off. That setting gave my tele a nice fat jazz sound on the neck pickup (with 13 flatwounds,) but I should play around with those settings for the hollowbody.

    BTW - I played through a Roland Cube 30 last night and the sound was much cleaner, so I could turn it up with no problems and still keep the lows and the reverb. It is pretty powerful for such a small amp.

    Thanks,
    Nick
  • Those cube amps are great- and the newest ones are REALLY good.... probably the best solid-state amps made to date. I'd like to check out a Stage Cube or Artist Cube. (but I'm never giving up my tube amps!)
  • The Cubes are really good for the money the cost and how easy they are to move around. Something like that would do you fine. If you're not looking for break up and not planning to gig then a small solid state amp would be a good choice. In an ideal world we'd all be playing vintage tube but if you have something in mind that you know you like the sound of; that's where you want to be :)
  • Actually, the breakup on the new cubes is excellent- check out some of the new videos.

    I'll never give up tubes, but I have to admit... getting one of the new cubes, like the Stage or the Artist, is really tempting, if for no other reason than to have a reliable back-up that you don't have to worry about finding good tubes for... or if you lose a power tube at a gig, you can't really re-bias at the gig, lol, so you could just plug in the solid state for the rest of the night.
  • If you like the sound of the cube artist then thats what it's all about. I hadn't seen it and just had a look online at the blues cube artist. In the uk it's going at almost £900. For me I'd never dream of paying that for an amp that's designed to emulate tube tone. The only drawback of tubes is that sometimes you need to crank the volume to get the tone. I read they've designed the artist to be that way too. Why not just get a tube amp?

    In the uk for that kind of money and under I'd be looking at tube amps such as: Princeton Reverb reissues 65 or 68; Deluxe Reverb reissue - Jim's not a fan of the 65 I gather so the 68 ... it's Jim's forum after all and I've never played one ;) Peavey Delta Blues, Peavey Classic 30. I'd also give a shout out to the Blues Deluxe and the Blues Jnr. And of course there's what you can pick up on the used market too.

    Now I'm not saying any of those are dream amps, but they're all capable of giving really good sounds and genuine tube tone for around the same or less money than the Roland that's trying to emulate a tube tone. Of course that's just me and I've heard all sorts of amps and guitars be made to sound good :)
  • Hello again :)

    To jump back to discussing the FSR Princeton... I took three 12AX7s out of my twin and stuck them in the the Princeton. They are messa boogie tubes. The amp is starting to break up more! I think the tubes are gonna be the first change I try. I've been thinking of changing out the Celestion G10 Greenback but think I'll change the tubes first up and give the Celestion a try.

    What does anyone recommend for tubes for a Princeton?
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