Light-weight Fender Twin Reverb

[StephaninMelb]

I've been thinking that a light-weight enclosure can be developed that can hold a Fender Blackface or Silverface Twin Reverb Chassis. For an open-back combo I don't believe that it is technically necessary to have a large heavy wood (or plywood or MDF or particleboard) cabinet to contain the speakers. These materials just add unnecessary weight and do little acoustically in an open-back configuration.

One design I have envisioned replaces the entire cabinet with a hollow rectangular frame made out of polished aluminum tubes. The technology uses the same alloy tube materials used to build light-weight bicycle frames and the same construction methodology.

With this design the whole speaker cabinet structure disappears. The chassis is housed in a piggy-back enclosure mounted on top of the frame. The frame would be designed to quickly snap apart into sections for portability and the head would lift off.

The speakers would work well mounted on the front of a fibreglass or aluminum nacelle (tube) shaped structure. Just envision a shape similar to a nacelle holding a jet engine underneath a wing. These speaker nacelles would snap mount onto the aluminum tube frame. Wiring would be contained inside the tubes. All electrical connections to the speakers would be an automatic click fit.

The rear of the speaker nacelles would have a fibreglass sealed reflector and the sound would be bounced forward through two tubes running parallel to the nacelle housing. The exit ports would be angled 10-15 degrees off centre to increase dispersion.

Two of these speaker units could be suspended between tubular frame uprights. With Neo speakers and a light-weight frame it should be possible to get a Twin Reverb weight down to around 40-50 lbs.

Tolex covers with snaps (like covers used on boat cockpits and pick-up truck beds) could be used to cover the frame sides if someone wants a "closed" cabinet look.

An alternative to the speaker nacelle folded horn approach would be to use a more traditional compact 212 speaker cab mounted in a vertical configuration inside the aluminum combo frame. This would actually have superior sonic dispersion compared to standard combo side-to-side speaker arrangement inside a combo cabinet. Speakers in a vertical configuration have more ideal dispersion than in a horizontal configuration (which is why PA columns are often setup this way).

An example that illustrates how a compact speaker container can work is that companies such as TC Electronic build a 2 x 12 speaker cab in a very compact shape (e.g. RS212 Bass cab), much smaller and lighter than the typical combo box enclosure. Essentially in an open-back design you can get rid of most of the box and associated weight. I think it is possible to go further and build a folded compact semi-closed speaker system.

To complete the light-weight Twin, a reverb tank would be mounted on two aluminum tubes that running horizontally between the upright frame tube supports. The reverb lead wiring would be routed inside the aluminum tubes.

Do you think there is a market for light-weight Twin amps, Twin clones or light-weight combos? If yes what technical features would you like to see?

[Jakedog]

For some reason, I'm not really able to envision what you're talking about, but I LOVE what you're saying.

There is not reason for a good amp to weigh a million pounds in this day and age.

I replaced my whole PA close to two years ago. Old mains handled 400 watts RMS, and weighed 53 pounds each. JBL cabs with 15's and horns.

The monitors handled 250 watts RMS, and weighed about 40 pounds each. Yamaha wedges with 12" and horns.

The powered mixer was a yamaha, 8 channels, 600 watts (300 main and 300 monitors) and weighed in at over 50 pounds.


New PA- Mains handle 1000 watts RMS, 15's and horns, and weigh 27 pounds each. They sound, in a word, AMAZING.

Monitors are twelves and horns, handle the same power, and weigh 24 pounds each.

POwered mixer runs 400 watts right, 400 watts left, and 400 to monitors, has 10 channels, better FX (and you can use two at once) and is all around a much more full featured mixer. It weighs 13 pounds.

I went from nearly 240 pounds for cabs and mixer, to under 120, with twice the power and way more flexibility and useability. I also spent less on the new system, than I did when I bought the old one twelve years ago.

If this kind of tech can be put into great sounding PA and Bass gear, I don't see why it can't be applied to good tube amps.

The one drawback, is that guitar players are stupid when it come to "new" ideas. It doesn't matter if you build them the coolest, best sounding amp in the world, or guitar either for that matter. if it doesn't look like something that was made 50 years ago, 90% of them don't want anything to do with it. Sad, but true. Even worse, they'll make up any excuse to diss it. They'll sit there and look you in the eye and tell you it doesn't sound as good, because it isn't made out of real wood, and then in a blind test, pick the new design every time. The majority of guitar players are a goofy lot.

[Ringo]

A local builder made a lightweight Twin some time back, just one channel, solid pine cabinet, neo magnet speakers, it was still fairly heavy.
Most of the weight is in the chassis, short of using some torroidal transformers I don't see much way to reduce the weight of the chassis.

Not sure how to visualize the cabinet the way you are describing it.
Since a lot of guitar players are "purists" they won't even think about something that doesn't look like a traditional amp, but there could be some market for a super lightweight Twin.

The other thing is how many folks are using high wattage amps these days?
Seems like the trend is to use smaller amps , PR, DR etc...

[jh45gun]

It is not a problem get a cart or a hand truck.!!!! The guys are right label that thing a Fender Twin Reverb and folks would RUN away from it.

[JohnS]

Light-weight Fender Twin Reverb = oxymoron

[jhundt]

my bass-player friend is on tour here in Europe, and stopped by my place for a while. He had his bass and his 675-Watt amp... which is as big and heavy as a car radio. Genz Benz... and he says it sounds better than all the SVTs that the promoters set up for back-line. If you want a light-weight amp, you better think beyond tubes, I guess.

[WireLine]

Baffle boards are meant to vibrate some, hence the chosen wood is pretty important to the sound of the amp. Using a lightweight compound would eliminate that factor. There is also the seals inside the other seams which all play a critical role in the sound of an open back cab. Dove tailed joints have it, others don't. I don't see how your design could compensate for these factors.

As you know, the meat of the matter is the transformers, and until you can design away interleaved iron...you may be stuck somewhat? I don't know. Perhaps some sort of DSP switching system to command what a small transformer does, instead of a dedicated trannie for each function.

I can honestly tell you that there is no chance I would spend money on an amp that asked me to put snaps on anything. Ever. Those are for shirts and pickup bed covers.

Based only on your description (which I do applaud your forward thinking, if that matters) it sure seems like this thing would be awful top heavy, likely to tip over at the drop of a hat.

[Jakedog]

Originally Posted by WireLine

Baffle boards are meant to vibrate some, hence the chosen wood is pretty important to the sound of the amp. Using a lightweight compound would eliminate that factor. There is also the seals inside the other seams which all play a critical role in the sound of an open back cab. Dove tailed joints have it, others don't. I don't see how your design could compensate for these factors.

As you know, the meat of the matter is the transformers, and until you can design away interleaved iron...you may be stuck somewhat? I don't know. Perhaps some sort of DSP switching system to command what a small transformer does, instead of a dedicated trannie for each function.

I can honestly tell you that there is no chance I would spend money on an amp that asked me to put snaps on anything. Ever. Those are for shirts and pickup bed covers.

Based only on your description (which I do applaud your forward thinking, if that matters) it sure seems like this thing would be awful top heavy, likely to tip over at the drop of a hat.

Everything adressed in your first paragraph, could be addressed successfully. To say there's no way it could, is like saying "You can't build a plane with a jet engine. That's just silly, because planes have propellers!". It can most certainly all be done, it's just a matter of figuring out how.

You're dead right about trannies, and being top heavy. One solution of course is to think outside the box. No pun intended... Why not put the chassis in the bottom, like an old Gibson amp, and still put the controls on top? That would weight distribute all the topple possibilities right out of the design.

As far as looks, I just don't give a crap. But I am a VERY rare guitarist. I don't have any attachment to what a Twin looks like. I only care that it sounds right. If it can do that with torroidal trannies, neo speakers, an alternative materials cab, and even (gasp!!) a class D output section, I'd be all over it. I know I'm one in a million, but I have no loyalty to anything but sound. If the sound can be achieved another way, I'll take it.

[StephaninMelb]

Originally posted by WireLine
Based only on your description (which I do applaud your forward thinking, if that matters) it sure seems like this thing would be awful top heavy, likely to tip over at the drop of a hat.

Originally posted by Jakedog
You're dead right about trannies, and being top heavy. One solution of course is to think outside the box. No pun intended... Why not put the chassis in the bottom, like an old Gibson amp, and still put the controls on top? That would weight distribute all the topple possibilities right out of the design.

Thanks... I hadn't considered to mount the electronics in the bottom section, but the advantages now seem obvious. The design issue is now working out remote controls. Also your comments make me think that a Twin Reverb conversion is a dead end and to just design a brand new amplifier from the ground up.

As far as looks, I just don't give a crap. But I am a VERY rare guitarist. I don't have any attachment to what a Twin looks like. I only care that it sounds right. If it can do that with torroidal trannies, neo speakers, an alternative materials cab, and even (gasp!!) a class D output section, I'd be all over it. I know I'm one in a million, but I have no loyalty to anything but sound. If the sound can be achieved another way, I'll take it.

I should change the request to what features would a working musician like to see in a 2012 designed guitar amplifier?

[WireLine]

controls would likely be best served with digital control of analog circuitry. This would also facilitate a certain number of presets, speaker dependent or course. It 'could' also make biasing. ground checking, operating temperature, and some other things accessible at the touch of a few buttons...

But please, for the love of God - NO effects other than reverb (spring only or I leave the room) and standard issue Fender tremolo...cramming too much into DSP is what is srong with electronics today anyway...there is a very thin line between clever implementation and severe suck.

[Jakedog]

Originally Posted by StephaninMelb

Thanks... I hadn't considered to mount the electronics in the bottom section, but the advantages now seem obvious. The design issue is now working out remote controls. Also your comments make me think that a Twin Reverb conversion is a dead end and to just design a brand new amplifier from the ground up.



I should change the request to what features would a working musician like to see in a 2012 designed guitar amplifier?

I like the direction bass amps and PA gear are moving in. I'd like to se emore of that in guitar amps. A steel player I work with sometimes has an Evans amp. 200 watts and a 15" speaker, sounds amazing, and weighs next to nothing at all. Of course, it isn't a tube amp, and I think that's what you're aiming for.

With tubes, comes weight. The transformers, as noted before, are gonna be heavy in a high wattage, high headroom tube amp. They just are. I'm not an engineer, so maybe there is a way around it. Torroidals were mentioned, but not being an engineer, I don't know how well those would play with tube design.

My criteria would be- Lightweight. 40 pounds max, would prefer less.

High wattage. 80-100 preferably.

Nothing smaller than 12" speaker(s).

Master volume, and a cirecuit design to get cranked amp tone, at restaurant gig volume, without having to use a small amp. Small amps get farty and splatty when cranked, they don't sound good. Especially little ones with 10, 8, or 6 inch speakers. They just don't get the big, full spectrum tone one associates with a big amp. Or the tight, punchy, and focused bottom end.

In my ideal amp, the amp would have an interactive gain and master, that would keep that big amp tone regardless of volume, whether you dialed it in clean or dirty. Maybe a combination of big iron, 12's, and power scaling that actually works?

I'm totally with Ken on effects. Nothing but reverb and trem. No presets, no banks of crap, no nothing like that. I'm open to other possibilities than spring reverb thought. My two main tube amps right now have spring, and frankly, the 'verb in my digi amp sounds better. I don't mean I prefer it, I mean it's a better sounding 'verb. I love a GREAT sounding spring 'verb sircuit as much as the next guy, but I'm not married to it. If something else does the job, and saves weight, I'm all for it.

Mostly, it has to be reliable. I'm all for using technology to better our lives, as long as it actualy does better out lives. Convenience, light weight, advanced design, all of that means nothing if the thing won't run without a hiccup for twenty years like a good old Twin will.

Make it look like anything but a vintage amp. I don't want to look like everybody else in the world. I don't want people to look up at the stage, and go "wow, he's got a black face Super Reverb!". The people who would notice or care, are only other guitar players, and I'm not there to impress them. I think it would be really cool to have an amp on stage that made everybody in the audience, musician or not, say "Wow, what in the world is THAT thing?". That would be cool.

That said, if it sounds right, works right, and meets all the criteria for those two factors, I don't care if it has to look like a Twin or an AC30. Sound and funcionality are paramount, looks are a dead last concern.

[aunchaki]

A CRATE PowerBlock sounds like an ideal starting point. I had one a few years ago and loved it. It had good--but not great--stereo capabilities. If it would have had L & R inputs, you could make a modern, lightweight JC-120 that fits in a shoulder bag (you'd need a stereo 2x12 cab).

The PowerBlock was with us a short time. The talk was that they stopped making them because they were prepping a PB II (with built-in effects). It hasn't materialized yet.

[printer2]

A switching power supply comparable to your computer supply can take care of the power transformer. The output transformer, we are just stuck with it. Toroidal transformers do not like dc offset which means tubes have to be matched well. Maybe a microprocessor controlled tube amp could help, but the added complexity will only save a percentage of the transformer weight. What we need to do is go back to field coil speakers, electrical power is light, ceramic magnets are heavy.

[vjf1968]

I say forget tubes entirely. There is really no reason that a transistor amp can not sound good. Stewart Ward did it with the Sessionette and the ZT line of amps are amazing.

[Dave_O]

Originally Posted by jhundt

my bass-player friend is on tour here in Europe, and stopped by my place for a while. He had his bass and his 675-Watt amp... which is as big and heavy as a car radio. Genz Benz... and he says it sounds better than all the SVTs that the promoters set up for back-line. If you want a light-weight amp, you better think beyond tubes, I guess.

+1 on that. The bass player in the band I'm in uses a Markbass amp: 500watts RMS in a box that looks like a big DI unit.



Check the weight...

[WireLine]

Something else to consider (since all of this is theoretical at this point) ... laws of physics.

A 15" will move x amount of air when it moves forward, and when it moves back. A 12, a pair of 12s, a quad of 10s, etc, all exhibit different movement of air. That movement is affected by the baffle kind, thickness, pliability, depth of enclosure, cabinet porting/openings, seals, Q factors of the speakers, humidity and ambient air pressure surroundings, and dozens of other factors. These are all real world situations. Anything other than these are just simulations or re-creations. How are these going to worked? These all matter a great deal, hence a speaker cannot just be suspended from an open framework. (try it sometime, you'll see what I mean.)

[jh45gun]

Originally Posted by WireLine

Something else to consider (since all of this is theoretical at this point) ... laws of physics.

A 15" will move x amount of air when it moves forward, and when it moves back. A 12, a pair of 12s, a quad of 10s, etc, all exhibit different movement of air. That movement is affected by the baffle kind, thickness, pliability, depth of enclosure, cabinet porting/openings, seals, Q factors of the speakers, humidity and ambient air pressure surroundings, and dozens of other factors. These are all real world situations. Anything other than these are just simulations or re-creations. How are these going to worked

. (try it sometime, you'll see what I mean.)

Exactly kids used to put raw speakers in the back window deck of their cars sounded like crap but put them same speakers mounted in the deck so the trunk area acted like a cabinet and they sounded great.

[Toppscore]

Originally Posted by Jakedog

For some reason, I'm not really able to envision what you're talking about, but I LOVE what you're saying. There is not reason for a good amp to weigh a million pounds in this day and age. I replaced my whole PA close to two years ago. Old mains handled 400 watts RMS, and weighed 53 pounds each. JBL cabs with 15's and horns. The monitors handled 250 watts RMS, and weighed about 40 pounds each. Yamaha wedges with 12" and horns. The powered mixer was a yamaha, 8 channels, 600 watts (300 main and 300 monitors) and weighed in at over 50 pounds.

New PA- Mains handle 1000 watts RMS, 15's and horns, and weigh 27 pounds each. They sound, in a word, AMAZING. Monitors are twelves and horns, handle the same power, and weigh 24 pounds each. POwered mixer runs 400 watts right, 400 watts left, and 400 to monitors, has 10 channels, better FX (and you can use two at once) and is all around a much more full featured mixer. It weighs 13 pounds.

I went from nearly 240 pounds for cabs and mixer, to under 120, with twice the power and way more flexibility and useability. I also spent less on the new system, than I did when I bought the old one twelve years ago.
If this kind of tech can be put into great sounding PA and Bass gear, I don't see why it can't be applied to good tube amps.

Hi, Jake Dog! Thanks for your share.
I have six Mackie SRM450 450w self-powered PA speakers
Which brands did you get?
Question: Do you feel the 1000w speakers are louder than lower wattage speakers?
Or, does not the amperage, wattage, voltage, etc. play an important role producing overall speaker volume.
Or, would a 1000w PA speaker be more than twice as loud as a 450w speaker?
Thanks for and & all comments. Toppscore

[jebbo]

Even with a lighter cab, a twin will still be heavy. The transformers in a twin are HUGE. I get your idea though. Not only that, but having the big wooden cab gives a twin some of its tone. I guess there could be a market for a light-weight twin. I wouldn't buy one, but it's a good idea.

[Toppscore]

Originally Posted by Jakedog

The one drawback, is that guitar players are stupid when it come to "new" ideas. It doesn't matter if you build them the coolest, best sounding amp in the world, or guitar either for that matter. if it doesn't look like something that was made 50 years ago, 90% of them don't want anything to do with it. Sad, but true. Even worse, they'll make up any excuse to diss it. They'll sit there and look you in the eye and tell you it doesn't sound as good, because it isn't made out of real wood, and then in a blind test, pick the new design every time. The majority of guitar players are a goofy lot.

JakeDog.
More modern players love gadgets and new toys & sounds than do "Old-Skool" playa's. Not all,
but many of the "over 50 year old" guitar players tend to, as a group, not be open to modern.

For them, old-school is best:
33.3 RPM albums are better than CDs.
Cassettes are better than CDs.
Analog is better than Digital.
Tube amps are better than solid state amps.
Current amp modeling never sounds good.
It goes on and on and on that "some older guitar players" are narrow minded.

The newer generation of guitar players who grew up on video games,
Silicon Valley technology, IPad, Sony Walkmans, IPhone, Guitar Hero, IPod,
1980s Hair Bands, Reggae, Punk, Ska, Thrash Metal, etc.
of course tend to be more open minded.

Just generalizations, but there is a definite beautiful sound generated from
a Telecaster through a 1950s/1960s Fender amp and out Jensen Speakers.

Yet, there are fantastic tones and sounds coming from Fender Supersonics amps,
modern boutique amps, Peavey Vypyr series of amps, Fuchs, Dr Z, Matchless,
Orange, Soldano, Peavey 6505, Blackstar, Laney, Mesa, Hughes & Kettner, etc.
Plus, Vox, Fender & Marshall currently make amps that are not directly related
to the 1950s/1960s vintage models.

What do you old school players think?
What do you "under forty" guitar players think?

Are my generalizations anywhere towards being accurate?
Toppscore