London Power's Historic Product Archive:

SPECTRUM
0-50W
power scaling bass amp


                  

Detailed description

Wider and deeper.

The amazing 700W SPECTRUM bass amp is legendary! It's heart is a highly dynamic preamp that accommodates active, passive, acoustic and electric instruments with equal ease. The massive power stage offers twice as much power than an SVT but can go quieter than a Champ because of Power Scaling technology. But even a legend must sometimes end. Or change...

We kept the preamp the same. The front-end is still the variable gain block bass players have come to expect in the SPECTRUM line. You can plug in an acoustic instrument with a raw piezo pick-up and capture the full frequency response. You can plug in any electric with high or low output pick-ups, or one loaded with active circuitry, and get a loud clean signal. The DRIVE control varies the gain of the front-end so you can set it up for pristine clean, mild compression, or heavy over-drive. Passive three-way EQ with HIGH, MID and LOW controls provide a familiar feel and easy tuning of your sound. The LOUD control taps as much of this signal as you need, passing it to the reverb loop and another gain stage.

Our proprietary all-tube push-pull reverb driver and full-length Accutronics delay line produces very clean, smooth reverb sounds. A bit like old tube reverbs. A bit like digital reverbs. Modern yet nostalgic without boinging. Cool. The reverb loop is a complete "side-chain", which means none of its gain stages are in the dry signal path. This keeps noise to an absolute minimum.

The gain stage after the reverb loop is free-running, so it lends a traditional tube warmth to the sound. Depending on how the LOUD control is set, this stage will be running totally clean or as distorted as some modern bass styles demand. Regardless, you can tap into all of this tube's touch response without overdriving the output stage - unless you want to! The LIMIT control keeps the power amp in check.

Recent advances in our guitar amp line have spilled over into the bass products. The special output stage configuration has now been adopted for use in the 50W SPECTRUM. Rock-solid tone with unique tube dynamics.

In the 50W model, your choice of output tube is nearly unlimited. For a British sound, throw in some EL34s. For a North American sound, try some 6L6s. For a bigger sound, try 6550s or KT88s. For a sweet Tweed sound, try mixing in 6V6s. While you're at it, try mixing any of these tubes in any combination to create unique sounds. This is possible because the SPECTRUM has individual bias adjusts for each output tube, and a wide enough bias range for any of the tube types listed, just like every other LONDON POWER guitar amp.

Amazing power tube versatility. That alone gets you more sounds than most amps out there. With LONDON POWER's Power Scaling technology, you can dial the output power down to milliwatts for maxed-out crunch at whisper levels. Power Scaling delivers, where speaker attenuators and load boxes fail. Recording and gigging has never been so easy. Modelling amps simply cannot match the tonal range and feel of a real tube amp.

Power Scaling lets you get all those cranked stack sounds without complaints from the neighbours! And, you can choose to dial up power tube distortion all on its own for a cranked non-master-volume amp sound, or combine that with the huge range of preamp textures for the most singing sounds around. The LIMIT control keeps the amount of power tube distortion in check- you never get more than you need regardless of how low the Power Scale dial is set. You can access both the "fast" sound of fixed-bias and the "round" tones of cathode-bias at the flick of a switch. And maybe you wish you could just "dial in warmth". You can with the BODY control, which lets you sweep from loud, clean push-pull power to warm and cozy single-ended tones. The SPECTRUM offers the modern bass player previously unimagined ranges of tone and power! Retro-mania to Futurama at the flip of a dial.

Our custom wide-band Hammond output transformer surrounds you with incredibly deep lows and scintillating highs. The special output configuration tolerates a wide range of load impedances, so you can connect any speaker cabinet to any of the direct-impedance jacks that sounds best. Go ahead: hook up any cabinet or combination of speakers and just play.

Early preamp over-drive. Late preamp over-drive. Output stage over-drive. Or any combination. And any compression level from any point, too. Plus - this is ALL-TUBE. No hybrid trickery.

Where did the active EQ go? They are no longer needed. The new SPECTRUM amps have so much feel and dynamic response that actual players can use, they don't need things that appeal to side-line spec readers. How about an effects loop? Again, real players rarely use them. Another fad from the eighties. Besides, it would interfere with the internal gain architecture and some depth of tone would be sacrificed. That was not a compromise we wanted to make.

With all the "latest greatest" 400W amps out these days, where will a 50W be of any use? Our 50W SPECTRUM driving a pair of our SESSION 112 or SUPER NOVA 212 cabinets produces far more on-stage bass sound than most sound men will tolerate. Our cabinets are more efficient and much more toneful. And our SPECTRUM has way more feel. Power Scaling makes the SPECTRUM the Ultimate recording amp!

If you really need more power, check out our SUPER SCALER models. The SUPER SCALER v700 uses the same 4CX250 power tubes the legendary SPECTRUM 700 used. Half the size of a 6L6 but capable of outputting over 800W per pair. Utter reliability, as witnessed by their aviation and military uses in radars and transmitters in tanks, ships, planes, and anywhere microphonics or failure could not be tolerated.

The SPECTRUM integrated amps are built like our other head-style amps, in a steel Hammond chassis, with venilated cover and wooden ends with flip-uphandles. A custom ToroidTech toroidal power transformer with dual primaries assures world-wide mains compatibility. Our custom Hammond output transformer, PEC sealed military pots and Switchcraft open-frame jacks are all chassis mounted. Solen polypropylene filter caps, Wima and Philips signal caps, metal-film and flame-proof metal-oxide resistors mounted on Teflon circuit cards are hand-wired for a lifetime of service. The usual Twenty Year Warranty applies to everything except the tubes and reverb tank.




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