Description
From Phil Jones:

The DOUBLE FOUR is the pinnacle of micro bass amps. With new driver design, acoustic loading and the latest digital amplifier technology, this tiny bass combo may be designed as a practice amp but continues to amaze everyone with the great PJB signature bass tone. From a cabinet with size of a jewel box, this seems to defy the laws of physics.

Driver and Amplifier Technologies:
Pushing our expertise of using smaller drivers to get the ultimate bass sound, we applied our vast experience to an even smaller, “Neo Power”4 inch driver built with precision of a Swiss watch. This 4” baby is able to cope with the extreme signals coming in from an amplified bass guitar. By using our extensive R&D facility which includes the largest anechoic chamber in the bass guitar amplifier industry, and the KLIPPEL transducer measurement system, we were able to develop the perfect 4 inch transducer for our purpose. We analyzed the neodymium magnetic system, the cone behaviors at all frequencies in 3D representation, cone suspension and frame, until we achieved our goal. We then looked at the acoustic loading using the acoustic simulation software and calculated exactly the full power cone displacement at every frequency.

Each one of these 4” speaker is fed with its own Pulse Width Modulation PWM amplifier. PWM amplifiers are extremely efficient compared to the traditional analog solid state amplifiers, converting electrical energy to power using on the speakers instead of wasting it on hot. Since the amp is running at lower working temperature, the DOUBLE FOUR will give years of service long after other amps have faded away. By using dual amplifiers one for each speaker, the bass control is greatly improved since the damping factor ( the amplifier’s ability to put on the “brakes” to stop the speaker cone from overshoot ) is doubled. The end result? A bass tone that is well controlled, punchy, tight and never muddy or bloomy.


Enclosure Technology:
To maximize its tiny cabinet enclosure, we designed a custom Rectangular Auxiliary Low Frequency Radiator (RALFR®). RALFR® is a pneumatically coupled radiator loaded to the rear of the two 4 inch speakers that operates at the lowest bass frequencies only. It augments the output of the loudspeakers at frequencies from 30 to 150 Hz. It also reduces the cone excursion of the speakers, so power handling is greatly improved. The cabinet is also heavily braced internally and lined with acoustic damping materials. This damping prevents cabinet coloration that can interfere with the true sound of your instrument. Now, what you hear from the DOUBLE FOUR is the most realistic amplification of your instrument.

Power Output: 70 Watt (RMS)
Speaker: 2 x PJB NeoPower, 4 inch speakers. Rectangular Auxiliary Low Frequency Radiator (RALFR®) Switch able high gain input OR low gain stage with mute function
EQ: 3-Band EQ (Treble, Mid, Bass)
Input: AUX-Input Jack, DC-Power Input Socket
Output: Line-Out, Headphone-Out
Other: Power Switch
Power: 100/240V AC
Dimension (W x D x H): 11 x 8 x 6.8 inch / 280 x 203 x 172 mm
Weight: 8.8 lbs / 4 Kg
Chicago Music Exchange

Chicago Music Exchange

Call
Phil Jones
Brand New
Red
15 Years
$479.99
Chicago Music Exchange
Chicago Music Exchange
773-525-7773
Chicago, IL
12:55 AM
Monday-Saturday 11 A.M. to 7 P.M. Sunday 11 A.M to 5 P.M.

Payment Terms - Orders Internet orders may be paid for using the following methods: VISA, MasterCard, American Express, Discover, and PayPal. For phone or mail orders you may pay money orders and cashier's checks by mail. Just call us at 773-525-7773 to place your order. All non-credit-card orders are subject to a 10-business-day hold. We do not accept international credit card or PayPal payments from international accounts. For international security reasons, please call the store to arrange a Bank Wire: +01-773-525-7773.

Shipping Charges - Taxes and Title Separate charges for shipping and handling will be shown on your order form. As a security precaution, initial orders and orders shipping to alternate addresses may be held for extended verification. We reserve the right to make partial shipments, which will not relieve you of your obligation to pay for the remaining deliveries. All items purchased from Chicago Music Exchange are made pursuant to a shipment contract. This means that the risk of loss and title for such items passes to you upon our delivery to the carrier. The published rates are for US domestic shipping only. Contact us directly if you wish to place an international order. For more information on our shipping policies, including rates, delivery times, and delays, please visit our website at chicagomusicexchange or call us at: 773-525-7773. If applicable, a separate charge for taxes will be shown on the invoice. We are required to collect sales tax on all orders shipped to Illinois.

3-Day / 15-day Return Policy If you are not completely satisfied with any product, return it for a full refund of the product purchase price, full credit, or exchange of your choice. We give you 3 days from the shipping date on Vintage instruments, and 15 days on New instruments. Credit card returns are issued a credit for purchase price. Refunds are made for product value only, excluding shipping and handling charges. New, Unopened items: You may return most NEW, untouched, unopened items within 15 days of delivery for a full refund. if the return is a result of our error (you received an incorrect or defective item, etc.) we'll also pay the return shipping costs. AmEx credit cards: Note that if your order was paid using an AmEx card we may pass on a 3.5% fee of the purchase price to process your refund. Vintage, Used items: We have to evaluate vintage and used guitars, amps, and other items on a case by case basis. We spend a lot of time with you and the item before your purchase to try to avoid any surprises after your purchase. AmEx credit cards: Note that if your order was paid using an AmEx card we may pass on a 3.5% fee of the purchase price to process your refund. You should expect to receive your refund within four weeks of giving your package to the return shipper, however, we strive to issue your refund sooner. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days). Send your return to: Chicago Music Exchange 3316 N Lincoln Ave Chicago, IL 60657 The following items are returnable only if defective OR unopened or unused: strings, harmonicas, microphones, cleaners, polishes, and polishing cloths. Software/soundware, cassettes, CDs, DVDs, and videos may be returned for credit only if they are in their original, sealed packaging. If defective, these items will only be exchanged for the same product. For complete details on our guarantees, shipping, and return policies, please contact our Customer Service Department at 773-525-7773; fax us at 773-525-2775; visit our website at www.chicagomusicexchange.com, or write us at Chicago Music Exchange, 3316 N. Lincoln Ave, Chicago, IL 60657.