I ordered a Weber "Blue Pup" AlNiCo 15-watt eight-inch driver for my '15R to replace the stock ceramic-magnet speaker. The replacement went nominally well except the original driver must have been installed while the paint on the cab inside was still tacky; it was a fussy job to get the original speaker off without messing up the ring gasket. This is the first time I've had this amp apart. The electronics design and workmanship are excellent; very, very clean. There is even a ferrite toroid at the point the speaker wire exits the chassis. This is excellent protection against common-mode interference from things like radio transmitters, dirty old florescent light ballasts, leaky neon signs, et-cetera. Even an Ampeg SVT does not incorporate this excellent feature.

After I put it all back together I played the new speaker at moderate volume for about twenty minutes. Compared to the stock speaker, the Weber is noticeably livelier; somewhat louder, and much more touch sensitive which is to be expected with the very lightweight moving parts and the AlNiCo magnet. It will be interesting to hear how this speaker settles in over the next few weeks. Thus far I am highly pleased, and glad I went to the tiny trouble involved.

Oh, I will keep y'all up to speed, you bet. I have an old Supro 16T, a single-ended 6V6-based amp made in Chicago c.1965. It uses a 5Y3 rectifier tube and probably puts out four watts RMS going downhill with the wind at its back. I bring this old amp up here for two reasons. It also uses an eight-inch speaker, so it's convenient to do side-by-side comparisons with the '15R. For the 16T I installed a Weber AlNiCo Jensen Clone after I bought the amp in '02. The original Jensen is fine and in a good box. I wonder sometimes why I changed it! The old Supro also has tremolo, but it is totally different from the '15R. The Pathfinder trem resets with each signal input. The Supro trem operates more like a clock, and just chugs along regardless of the input picking or strumming, so the effect is completely different.

Anyhow, I've had the Weber in the 16T for around ten years and it is fabulous. I expect the Blue Pup Weber I just stuck in my '15R will wear just as well. Weber puts these speakers together when they are ordered; the workmanship is excellent and the price is very reasonable. This latest one was a little over $40.00 (9% discount expires tomorrow - otherwise $45.00).

I'm glad I got to take a good look at the innards of my '15R. As stated above, the build quality is very good. Also, the components are rather conservatively sized for such a low-cost amp. As long as I don't drop it into a swimming pool or operate it wrapped in blankets, it should perform for a good long while. The chassis is the heat sink, and it is huge in comparison to the heat needing to be dissipated. Good solid design. Heat dissipation may be the principal reason we don't see this basic design in a higher-powered version. I've tried my '15R using the line out into an external power amp as suggested elsewhere in this forum. It sounded pretty hard, but was much better, in my case, using an A.R.T. TubePac as an active direct box in that application.

Right off the bat the Weber speaker gives much better texture when a little gain is kicked in as compared to the stock speaker. The proof will come after the speaker is settled in using max clean sound. I have high hopes for that. We'll see. Ric

Hey Ric:

Don't mean to hijack the thread...

I had a Chicago-made Supro (don't remember which one, but it wasn't soft by any means; had 2 8"s or 10"s in it, I think I remember) in the late 60's when playing in an R&B/Soul group (the one in my photo)...good times! Unfortunately it got stolen after a gig )-:

hey gndboy, replaced my questionable speaker with the same weber blue pup and it' all vam-blam again! sounds great!.... can't wait to fire it up again... has even helped the original humbuckers in my jagmaster sound bearable!.... though, that ultimately still won't save 'em.
Peace!

Heat dissipation is solved by larger dissipation area with regard to the available cooling air. Who wants a fan?

Anyhow, it's been a few weeks now with the Weber in the '15R, and I must say it sings. The low mids have loosened up a bit, and this seems to be a good marriage of driver to amp. The highs are great without being zippy. One concern is the 15-watt rating of the speaker itself; I believe the amp is capable of frying this little voice coil if driven hard for long. For recording, it is perfect, and I can recommend the sound without reservation. Maybe I'll ask Weber if they can do one of these with a 30-watt voice coil. It certainly wouldn't sound the same. As it is now, all broken in, the 8" AlNiCo Weber is a couple notches above the stock '15R speaker (which was pretty good to begin with) in tone with particular regard to the high end and overall articulation. With things all in tune, it can sound very big at low volume. I regard this new speaker trial as a success. Your mileage may vary.

Edited for spelling

randman - I have tried the '15R through a good cabinet containing 1X12 Celestion 30 (ceramic magnet type). It is noticeably louder, yet the overall effect is not nearly as cool as the 8" AlNiCo Weber. The above cabinet sounds great with an Orange Tiny Terror with all different tubes than stock. A 12" Blue would probably be pretty nice. If so inclined, I'd be tempted to try a Weber 12" AlNiCo speaker. One is one.

The Weber Blue Pup 8" continues to amaze. I now think it is MUCH better than the stock whoever-made-it speaker. I still have a concern with regard to potentially burning the voice coil; the Weber 'eights are really intended for the five-watt single-ended tube combos, so I am using mine under the assumption of zero speaker headroom. Full-tilt with the boost switched in is off limits. The medium-low midrange is particularly good in the tiny cabinet with the bass just below noon and the treble just above 9 o'clock with the gain boosted a tiny bit. With more traditional settings of the EQ knobs everything is about as one would expect, except the Weber offers a little higher SPL and much nicer touch sensitivity.

I bring this up again because the speaker surprisingly (to me) continues to improve.

rjbee - Once you have the amp totally removed from the cabinet, you may encounter the original speaker gasket being stuck to the inside of the baffle. What I did for this was to use a big-blade flat screwdriver tapped LIGHTLY with a hammer at many points around the outside frame rim. The stock speaker then lifted right out. I hope you enjoy the new speaker as much as I have! Ric

The Weber Blue Pup continues to deliver great sound in the studio.

Hello all! A number of folks (in various threads) have talked about putting larger speakers in their Pathfinder 15R's. I've been playing around with an old Hudson Mill City Blues 12" Alnico speaker in a generic cabinet. I bought this in the early 90"s, and used it in a Fender Princeton and Deluxe Reverb, and it always sounded great. It also sounds good with my PF 15R. It is so much fuller than the 8" stock speaker.Do the math- a 12" has more than twice the surface area of an 8". I didn't want to cut up the stock baffle board, so I removed it. I cut a new baffle from 3/8" plywood, and just before I was going to cut out the hole for the speaker, plus altering the cabinet bracing to allow for the larger speaker, I thought to check if the amp unit itself would interfere with the speaker. Sure enough, the speaker frame was too large (depth-wise) to fit. So I am temporarily stymied in my attempt. If I can find a good quality speaker with a slimmer profile, I'll be back on it. In the meantime, I installed a beamblocker in front of the little 8", and it helps with the shrillness a lot. I'm also considering modding the ext. speaker jack to allow using an external speaker and the internal speaker together. While the load recommended is 8 ohms, if it stays above 4ohms, it should be o.k. Has anyone ever gotten confirmation from Vox regarding the PF15R being discontinued? HUGE mistake, Vox. Best wishes to all.