Rickresource Rickenbacker Forum

I've got an old Selmer Treble 'n Bass head that I picked up for next to nothing a while back. I purchased it from a man in England and had it shipped over to North America. I love the sound of the amp, but at home, I've noticed a distinct hum during operation. I know that any valve amp is likely to generate some noise just by virtue of its age and the electrical environment that it's in, but I've noticed that the hum is almost non-existant when I plug it in at our rehearsal space. At home, it's ever-present and renders any attempt to play at low volume impossible. Recording would be just out of the question. The only difference I can see in my home/rehearsal space set up is the speaker cabinet that I use. At home, I have a small cabinet with a single Celestion greenback (non-vintage). I have no idea what ****** speakers are in the cabinet at the (rented) rehearsal space, but there are certainly more of them (four) and they seem to have a much higher impedence. I would like to buy a cabinet for the Selmer, but I don't want to shell out good money for speakers that contribute to my hum problem. As for the amp itself, I've already had it serviced and buffered as much as the schematic will allow. I know next to nothing about amps and speaker set-ups, so I'd appreciate any suggestions any of you may have. Thanks.

John; Welcome to the Selmer club!! I've got one of these myself and at one time owned 4 of this model. sold two after I fixed them and American Airlines lost/stole one and have one left. Great value for an U.K. made amp that uses Partridge & early Drake tranny's, point to point wired componets.
Your problem sounds to me like you need new filter cans and caps. Those cans/caps will only effectively last 7-10 years. I would bet that if you had them replaced your amp would be really quiet and sound much tighter. This model will give an original JTM-45 Marshall a run for it's money!

BTW, the original speakers Selmer used were the Celestion G-12 AlNiCo's.!
Persoanlly, I think these are the best sounding guitar speakers made and the new one's are made on a special line that uses all of the original types of cones, voice coil's, gaskets & glues.

John, Fane makes one of the best alnico guitar speakers going. It is a great lesser known speaker for a great lesser known British amp. From what I can gather, Fane was always been a better built speaker than Celestion. The better quality oriented companies like Hiwatt, Matamp, and Orange used Fane speakers in their cabs. I only have upgrade Celestion speakers in my Marshall and Traynor amps because I got a killer closeout below-dealer-cost deal on Celestion G12H80 speakers, which are about as good a speaker as Celestion ever made, save for the alnico Celestion Blue. Marshall doesn't use Fane because they never could get them as cheaply as Fane. I'm not saying that Celestion sounds bad, but only that Fane will probably outlive them and sound as good all the while. Otherwise, Avatar Speakers has Celestion G12H80 speakers on sale right now for $42, and at that price you simply can't go wrong. The cheap pressed steel basket frames have a thick dull black powder coat that seems to suppress resonances similar to a cast frame when I thumped them. It probably costs more to make them, and that's probably one reason they got discontinued.

Phillip; I can say this from the horse's mouth: Marshall is the biggest buyer of Celestion Speakers in the world. They have been for at least the last 35 years. When the original Vox/JMI company tanked & was sold in`68, Marshall was on the rise and basically took over this spot from Vox. There would not be a reissue AlNiCo blue speaker in the new Vox AC-30's without Marshall's involvement. All Vox AC-30's are made in the Marshall Factory under license & contract from Korg.
The reissue AlNiCo's are made in the Celestion factory in Ipswich on a special assembly line that builds only this model. The line is setup to build them exactly as they were done in 1960 and use's exactly the same coil, cone and glues and production methods as the original's.
Although Fane makes excellent speakers, When you go changing the voice coil former to Kapton, Nomex or aluminium from paper it changes the tone. Sure you get a speaker that handles alot more power but doesn't sound like the Celestion's they were originally intending to copy.

Granted, a synthetic coil former doesn't sound like a paper one, but does that mean it is worse? I'll just say they sound different and let people form their own opinion. My old Fisher speakers used paper coil formers in the drivers, and no way do they compare to the more modern Peerless and Vifa drivers in my Vandersteens. The Fane alnico speaker was the tone runner up to the Celestion Blue in the alnico speaker shootout, but it can handle 100 watts which makes it feasible in modern combo amps like my Traynor and Marshall. Since the Celestion Blue can't survive in either of my amps, the Fane alnico is the Tone King by default for most modern amp owners. But at the price they sell for, a G12H80 at $50 delivered still beats the pants off of either one in value. Man, is that speaker ever loud and does it ever pound out the bass! It can even turn an open-backed YCV40 into a decent bass practice amp. Can any alnico speakers do this? Totally blew away the stock Seventy 80 in this regard. It could also be a great bass cab driver for somebody wanting a vintage Jack Bruce tone with their Marshall tube bass head. I wonder where Celestion would be today without Marshall?

For those wanting a different sound, a 10" Eminence BP102 makes a fine guitar speaker and is clean enough for acoustic guitar amps. It simply can't be overdriven in any 10" combo guitar amp, so it is great for those who derive tone from pedals and effects. It should turn a YCV40 twin 10 into a real metalhead amp for detuned guitars. It turned my Marshall AVT20 into a really versatile little beast.

I've got the original 30 watt 10" speakers in my SVT cabs Phil and I wouldn't trade them for the new 100 watt speakers they use now for anything. I think something about the delicateness of these old speakers makes them much more responsive to your touch.

I think you are thinking about the Eminence B102 speakers, Bob. They are the modern version of your SVT speakers. The BP102 has a whizzer cone for extended high end and looks a lot like a Lowther full range loudspeaker. They are vastly different speakers, even though they have only a single letter difference in their name. The BP102 has an extremely heavy duty cast frame and a much bigger magnet than the B102. The B102 is designed for about one octave lower operation. The BP102 is for Funk and Slap bass. The B102 is definitely NOT extended enough on the high end for guitar operation, unless it was in a separate cab for handling the lows. The Rolling Stones once used Ampeg bass amps in the early 70's for the guitars for a fatter bottom end.

Gee.. I don't know anywhere where I'd need more than a 30 watt amp.
Most venues we play are from 500 to 5,000 seaters and it all gets mic'd up and run back thru the various monitor mixes. My AC-30HW does the job just perfect.
I remember one gig we did about two years ago at the House of Blues in Hollywood and I used my early sixties AC-15. Needless to say the sound guy loved me..

Bob, I reversed the model numbers. The BP102 is like your SVT drivers and the B102 has the whizzer cone and extended top end. The 100 watt SVT drivers are NOT the B102 that I have. You basically have to order B102 drivers yourself at $100 or more each and install them yourself if you want to try them. They are a very different animal. You can put some of each in your cabs to extend the range both ways, the same way that a guitarist pairs a G12H30 with a Vintage 30. Then you can toss that cheap horn tweeter, or at least turn it down.

Don, bass takes gobs more power to play clean, and the speakers are less efficient because they are designed to go low. High efficiency and bass extension are conflicting design parameters. The B102 has 95dB efficiency, and that's very high for a bass driver, but the Celestion Century has 101dB efficiency which only requires 1/4 the power for the same sound level. That's before you add in the fact that the human ear loses sensitivity in deep bass tones and that a bass amp generally needs to stay much cleaner than a guitar amp. A general rule of thumb is 4-10 times the power the guitar player has on tap, with most modern bassists preferring to stay closer to the higher figure. But you are right about YOU (as a guitarist) not needing more than 30 watts. My 40 watt YCV40 with a single G12H80 can get painfully loud with no problem. A 300 watt SVT would be running flat out to keep up with it.

Philip; When I worked at SWR the rule of thumb for wattaged needed was always that it takes 4x the amount of wattage to reproduce the same volume level for bass as it does for guitar. So, if you have a 30 watt guitar amp, you need a 120 watt bass amp just to keep up. Since all amps are rated at the point of clipping(distortion for those of you that don't know..)my little 33 watt AC-30 cranks out 55 watts flat out. So you'd really need a 220 watt bass amp to compete and also, that's per amp. If you had Two guitar players with the same wattage amps, you would need a bass amp that's a good 400 watts roughly. But, I never use my amp full up. I like to get a great clean tone and use my pedals for distortion. with my gig, I have to go from squeaky clean shimering Vox tones on some songs to distortion on others. I've never heard a good channel switching amp so rely on my Fulltone & HotCake pedals for the distortion.

Don , its funny then how my Trace Elliot combo (150w with single 15") can keep up with 100watt guitar amps. Admittedly its not totally clean (actually it never is , its a very "violent" amp) but its not clipping and is only set to 4 out of 10

Eminence makes a 15" bass guitar speaker that has 99dB efficiency, so something like that can keep up with a guitar speaker on the same amount of power, or maybe say twice more. You actually get rolloff in the bottom octave with these high efficiency bass speakers, but room boost of the bottom octave and full output of the 2nd and 3rd harmonics keeps it sounding loud. More modern bass guitar speakers can be flat to 40Hz or lower, but their efficiency is around 95dB at best, so they need at least double the power of a guitar speaker to be as loud, plus you have to account for the lessened sensitivity of the human ear at very low frequencies, so the power requirement is at least doubled again.

Put a 2.83V sine wave signal into an 8 ohm speaker (2.0V if 4 ohm speaker, 4.0V if 16 ohm) and measure the sound level at 1 meter with a Radio Shack sound level meter. That is the efficiency of your speaker at 1 watt of power. There are alternate ways to measure. Run a 100 watt amp until it begins distorting, take a reading, then subtract 20 dB from the reading, and that is your 1 watt efficiency rating. Some amps put out more power than their rating when significant distortion is heard. Get the speaker away from reflecting surfaces that distort the reading. Out in an open yard or field is best, unless you have an anechoic chamber or want to measure the speaker in combination with a particular room. Here are the numbers for different power levels: 1W -0dB, 2W -3dB, 5W -7dB, 10W -10db, 20W -13dB, 40W -16dB, 80W -19dB, 100W -20dB, 160W -22dB, 200W -23dB, 400W -26dB, 800W -29dB, 1000W -30dB. Make sure C weighting is selected on the meter, as A weighting ignores low frequency signals to a great extent as the ear is less sensitive there. This meter has lots of uses, like measuring your sound level when practicing so that neighbors don't get disturbed. Watching a concert on home theater late at night to keep yourself in check. Setting levels on your stereo and helping position speakers for greatest linearity in a room. Checking noise levels around loud machinery. Checking your playing venue for room boost at certain frequencies when used with a CD player and a frequency sweep generator CD through a flat response PA speaker. You can draw a room curve on graph paper and save it for setting up your gear in a hurry next time in that room, or save the amp settings it takes to get a flat response in that room. I checked my meter at work on a sound level meter calibrator, and it was within 1/2 dB of perfect. It's $40 or so well spent. Even on low efficiency home stereo speakers, playing at a 1 watt level per speaker is quite loud.