OWNERS MANUAL

Response Audio

Bella Extreme 3205

Response Audio would like to thank you for your interest in the Bella Extreme 3205 tube amplifier series. Response Audio is a company that stands behind your amplifier with over 10 years of design and modification experience. In addition to our experience, Response Audio is committed to providing it’s customers with the highest level of quality sound at an affordable price. Response Audio has achieved this goal through many years of listening to its customers and using only the most highly regarded parts to assemble these units. You will also not find another company that is committed so much to providing top notch customer service before, during and after your purchase.

 

Before using your new amplifier, please take a moment to thoroughly read and understand the safety instructions and operating procedures before you attempt to operate you new Bella Extreme 3205 amplifier. Becoming familiar with important facts about your amplifier and its correct operation will help assure safe usage, maximum musical satisfaction and reliable, long term operation.

 

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SAFETY PRECAUTIONS
          IMPORTANT SAFEGUARDS

 

PLEASE READ CAREFULLY ALL THE FOLLOWING IMPPORTANT SAFEGUARDS THAT ARE APPLICABLE TO YOUR EQUIPMENT

 

CAUTION – RISK OF ELECTRICAL SHOCK – DO NOT OPEN
To reduce the risk of electrical shock, do not remove screws or open your unit. No user-serviceable parts inside. REFER SERVICING TO A QUALIFIED SERVICE PROFESSIONAL.

 

1)                    Read the safety instructions in this owners manual. – All safety and operating instructions should be read before attempting to operate this product.

2)                    Retain the owner’s manual – Please print and retain a copy of this manual as information contain should be retained for future reference.

3)                    Heed Warnings – All warning on the product should be adhered to at all times.

4)                    Follow Instructions – All operating and use instructions should be followed at all times.

5)                    Power Sources – This product should be operated using only the type of power source indicated on the marking label, If you are not sure of the type of power supply to your home, consult your product dealer or local power company.

6)                    Grounding – This product is equipped with a three prong plug. Always use an electrical outlet that is grounded. If you do not know if your outlet is grounded, consult your electrician or power company.

7)                    Power Cord Protection – Power supply cords should be routed so that they are not likely to be walked on or pinched by items placed on, against or near them.

8)                    Fuses – For continued protection against fire hazard, replace fuses with ONLY the same type and rating of fuse supplied with the amplifier and mentioned in this manual.

9)                    Vacuum Tubes During Operation – Please do not attempt to touch the vacuum tubes while your amp is in operation or within one half hour after turning the unit on. This could result in severe burns.

10)                 Overloading – Do not overload the wall outlets that your amplifier is plugged in to.

11)                 Lightning – For added protection, unplug your amplifier during an electrical storm or when the unit will not be used for an extended amount of time.

Installation:

Water and moisture – Do not place or use this product near water – i.e. near a bath tube, sink, laundry tub or in a damp basement or swimming pool. Do not place this product under or near a house plant that requires watering.

Heat: This product should be situated away from heat sources such as heating vents, radiators, fireplaces, stoves or other appliances that produce heat. Also, avoid placing this unit in direct sunlight.

Ventilation: This product should not be placed in a built-in or closed-in installation or rack unless proper ventilation is provided. It is recommended that at least 6 inches of clearance is provided above power tubes with ventilation in front of and behind the unit. Never place anything on the shelf above this unit that can be affected by heat as the rising heat from the tubes could damage the piece.

Foreign Material – Care should be taken to prevent objects and/or liquids from falling onto or into this unit. Do not subject this unit to excessive smoke, dust, mechanical vibration or shock.

Surface – Care should be taken to assure this unit is placed on a flat level surface. Do not place this unit on an unstable surface. The product may fall causing serious injury to a child or adult as well as damage to the unit. Use only with carts, stands, racks, tables or wall mounts that are recommended by the manufacturer or sold by an authorized audio dealer design for such purpose.

Maintenance:

Never push anything through any opening of this product. Any foreign object could touch dangerous voltage or other hazards causing serious bodily harm or death.

Damage Requiring Service: Unplug the unit from the electrical wall outlet and refer any and all servicing to a qualified service professional under the following conditions;

1)       When the power cord or plug is damaged.

2)       If liquid or any foreign object has fallen into the unit.

3)       If the unit has been exposed to rain or water.

4)       If the unit does not operate properly when following the operating instructions.

5)       If the unit has been dropped or mishandled in any way.

6)       When the unit exhibits a distinct change in performance- this indicates a potential need for servicing.

7)       When the unit needs tube replacement.

Replacement Parts: When replacement parts are required, be sure the service technician uses replacement parts that specified by the manufacturer or parts which maintain at least the same values and voltages as those in need of replacement. Unauthorized substitutions may result in fire, electrical shock or other serious hazards.

Tube replacement: Should it become necessary to replace any tubes in the unit, carefully follow the instructions contained within this manual. When replacing your tubes, be sure to unplug the power cord from the wall and wait at least 1 hour for high voltage capacitors to discharge

Getting Started:

Construction and Testing: Like every Bella Extreme product, your Bella Extreme 3205 amplifier has been carefully hand assembled using only the best precision mechanical and passive components. To assure consistent performance, each Bella Extreme 3205 is individually inspected, electronically tested and system tested for several hours before sending to you for your listening enjoyment. Yes this is a very time consuming process but we feel it necessary to provide the best in musical satisfaction and long lasting value.

Handling Vacuum Tubes: With the increase and popularity of vacuum tubes over the years, many may not have had experience in the handling of tubes. As with a light bulb, you should not touch a vacuum tube while it is in operation of within an hour after being shut off as serious burns can result. Similarly, if you drop a vacuum tube, there is a good chance that it could break. Even if the outer glass remains intact, there is the chance that the internal construction has been damaged.  When replacing a vacuum tube, you should make sure the power cord has been disconnected from the wall outlet and the tube has cooled down.

Packaging: Save all packing material in a cool dry place. Your Bella Extreme amplifier is a delicate electronic instrument and should be properly packaged any time shipment is needed. Because of its weight (45 pounds), it is highly probable that the unit will be damaged in transit if the proper packaging material designed for the unit is not used.

You may have occasion to ship your unit for one reason or another. Should shipment prove necessary, the original packaging may save your investment from unnecessary damage, delay or additional expense.

Preparation for Use.

Place your amplifier on a flat, level surface.

Your Bella Extreme 3205 has been shipped with the vacuum tubes in separate boxes or parts of the original material to protect them during their journey. You can now install your vacuum tubes in their proper location as indicated in the diagram below. It is very important that you pay close attention to the proper location of the different tubes as damage could result by placing one of the tubes in a position they were not intended to be used.

On the larger output tubes, you will notice there is a “key” on the plastic located in the center of the tube. You will notice the tube socket for these power tubes also shows this “key” and care should be taken to assure the tube key lines up with the key in the socket.

NOTE: Contact enhancers are not recommended for use on vacuum tube pins and all warranties will be void is any such substance is used.

 

Biasing your 3205 amplifier:

Biasing is simply adjusting the amplifier bias trim pots to make certain the tubes are electrically operating in a similar manner and 
within the parameters the circuit is design for. Biasing is a simple procedure requiring only an inexpensive mult-imeter and 
small slotted screwdriver.

When you first receive your Bella Extreme 3205 amplifier, all bias pots will be in their lowest settings. Biasing of the amplifier is required. 
Four bias holes marked BIAS ADJ are on the top of your unit. Below the chassis surface are trim pots that are adjustable via a 
small slotted screwdriver. Each pot is adjusted by turning the pot clockwise to increase bias and counterclockwise to decrease the bias. 
Also on the amplifier chassis, located in front of the main transformer is a five slot socket with each slot corresponding with one 
of the numbers 2-3-0-6-5. The probes of the multimeter are inserted into these slots.

Procedure:

1.       Before plugging in the amplifier, install all the vacuum tubes as indicated in the layout diagram above.

2.       After the tubes are installed, connect your loudspeakers to the appropriate binding post on the back of the unit.

3.       Making sure the AC power switch is in the OFF position; plug your amplifier’s AC power cord into the wall AC outlet.

4.       Connect your preamp to the RCA inputs on the back of the unit.

5.       Turn the amplifier power switch to the “ON” position and allow the tubes to worm up for about 5 minutes.

6.       Take out your digital multimeter and make sure it is set to the lowest DCV setting.

7.       To bias the tube in the V3 position, take the black/negative probe of your multimeter and insert it into the “0” or middle slot of the five 
slot socket on the top of the chassis. Take the RED/Positive probe of your multimeter and insert it into the “3” position of the five slot 
socket. Make certain that the two probes do not touch each other.

8.       While the probes are in the five slot socket, take the small flathead screwdriver and adjust the bias pot marked V3 clockwise until the 
reading on the multimeter corresponds with the recommended bias voltage as indicated on the paper titled “Important Biasing Details”. 
Remember it takes only minute movements of the screwdriver to increase or decrease the voltage readings.

9.       To bias the tube in the V4 position, take the black/negative probe of your multimeter and insert it into the “0” or middle slot of the five 
slot socket on the top of the chassis. Take the RED/Positive probe of your multimeter and insert it into the “4” position of the five slot 
socket.

10.   While the probes are in the five slot socket, take the small flathead screwdriver and adjust the bias pot marked V4 clockwise until the 
reading on the multimeter corresponds with the recommended bias voltage as indicated on the paper titled “Important Biasing Details”.

11.   Continue this procedure to properly bias the V7 and V8 tubes.

If you are not comfortable with this bias procedure, please do not hesitate to call for assistance at (607) 785-3440. We can normally walk you 
through the entire biasing procedure within a 10 minute phone conversation.

NOTE: The two most common errors in biasing the Bella Extreme 3205 amplifiers are:

1)       Turning the bias adjustment pots the wrong way.

2)       Incorrectly using or not using a multimeter at all can result in the wrong bias levels for the output tubes. The bias adjustment screws are 
extremely sensitive and a minor turn of only 20 degrees can change the bias setting more than 10mV which is approximately equal to 
10mA plate current of the vacuum tube being biased. This will not only result in inadequate sonic perform, it could also cause damage
 to your vacuum tubes and/or amplifier.

    a) Attempting to “tweak” the bias levels by ear and without using a multimeter can easily result in an out of balance bias level.

     b) Incorrect usage of the multimeter can also result in an out of balance bias. The most common mistake is placing the meter’s probes in 
the wrong test slots. You can easily tell if you have connected correctly as the bias reading on your meter should change as you turn the
 bias pot. If it does not change, make sure your multimeter us properly hooked up and in the proper slots.

 

 

Important Biasing Details

 

 

Recommend Bias Setting:

 

EL34: output tubes       Setting: 35mV - 45mV      Optimal: 35mV - 40mV

 

6550: output tubes        Setting: 45mV - 55mV     Optimal: 45mV - 50mV

 

KT88: output tubes        Setting: 45mV - 55mV     Optimal: 45mV - 50mV

 

 

It is not necessary to re-bias your "3205" amplifier when replacing the 12AX7 input tubes or 12AT7 driver tubes.

 

If you have any questions in regard to setting up or biasing your new Response Audio "3205" amplifier, please contact Bill Baker at Response Audio

SPECIFICATIONS

Maximum Power Output:  75 W per channel at 8 ohms, 1KHz (EL34 tubes)
                                            85 W per channel at 8 ohms, 1KHz (6550/KT88 output tubes)

Rated Output Power:        50 W per channel at 8 ohms, 25Hz to 70KHz (EL34 tubes)

                                            60 W per channel at 8 ohms, 25Hz to 60KHz (6550/KT88 tubes)

Frequency Response:      (at 1 watt into 8 ohms) 8Hz to 130KHz +/- 1dB

Bandwidth:                        13Hz to 80kHz + 3dB; 0dB 50 or 60 W 1KHz

Distortion THD:                 Less than 1% at 50/60 W output, 28Hz to 15KHz

Circuit Type:                      Ultra Linear, Class AB

Input Impedance:              100Kohms

Input Sensitivity:               500mV at 1KHz and 8 ohms for 50 watt output

                                            600mV at 1KHz and 8 ohms for 60 watt output

Output Impedance:           4 ohms and 8 ohms

Negative Feedback:          Less than 5 dB

Noise and Hum:                85dB below rated output

Tube Complement:           4 pieces 6CA7/EL34 or 6550/KT88 power output; 2 pcs. 12AX7 input tubes; 2 pcs.12AT7 driver tubes    

Power Requirements:       110V-120 VAC 60Hz 180 watts-standby, 450 watts maximum

Dimensions:                       17 inches wide by 15 inches deep by 7.5 inches high.

Weight:                               40 pounds net, approximately 48 pounds packaged.

Warranty:                            one year parts and labor. 90 days on supplied tubes

Recommended Bias:         35-40mV / 45 mV maximum (EL 34 power tubes)

                                            45-50mV / 55mV maximum (6550/KT88 power tubes)

 

LIMITED WARRANTY
Bella Extreme 3205 MKII
This product is warranted for the period stated from the date of original purchase.

1. Chassis and Transformers 1 year
2. Electron Power Tubes 90 days

Who is protected by this warranty.
Your new tube product warranty protects only the original owner, so long as original bill of sale is presented when warranty service is required. In addition, a warranty card is not included with your product. Your original invoice will serve as proof of purchase. A copy of this invoice MUST be submitted prior to any warranty or service work.

What is covered by the warranty

Your new product warranty covers all defects in material and workmanship with the following specified exceptions. These are:(1) Supplied electron tubes are warranted for only 90 days (2) damage caused by accident, unreasonable use or neglect (including the lack of reasonable and necessary maintenance); (3) modification or internal tampering to the product; (4) damage accruing during shipping (all damage claims must be submitted to the carrier within the specified time, (5) damage to or deterioration to any accessory or decorative wooden or aluminum surface; (6) damage resulting from failure to follow instructions contained within the manual for this product if so provided; (7) damage resulting from the performance of repairs by someone other than the authorized repair facility as listed above; (8) any product on which the serial number has been effected, tampered with or removed; (9) products used as demonstration or display models prior to purchase by owner (10) products used for purpose other than home entertainment use (any product used for commercial use will be void of any warranty coverage).(11) Any consumer installed vacuum tubes including current production and/or NOS pieces. Only those vacuum tubes supplied with this product are covered under this warranty.

How to obtain warranty services

If your new tube product ever needs service within it’s warranty period, please write to or call Response Audio NY (Attn: Customer Service dept.). We will direct you to the proper location to send your unit for repair in which case we will provide a Service Return Authorization and complete shipping instructions. Either way, you will be required to provide a copy of the original bill of sale to establish the date of purchase. Please do not ship your product without first obtaining the proper instructions.

Who pays for what

We will be happy to pay all labor and/or material expenses for all repairs covered by this warranty. If necessary repairs are not covered by this warranty, or if this unit is examined which is not in need of repair, you will be charged for the repairs and/or examination.

You will be responsible for any shipping charges in getting your product to our authorized repair facility. We will pay for return shipping back to the consumer only if repairs were covered by the warranty. Please be sure to save all original packaging material and boxes because a nominal charge will be made for additional replacement cartons.

For all warranty service in Canada , Alaska and Hawaii , the consumer is responsible for shipping charges BOTH ways.

Limitation on implied warranties

Implied warranties of merchantability and fitness for particular purpose are limited in duration to the length of this warranty unless otherwise provided by state law.

Exclusion of certain damages

Product liability is limited to the repair or replacement at our option, of any defective product and shall in no event include incidental or consequential damages, so the above limitations may not apply to you.

We sincerely thank you for your expression of confidence in theses products. These products have been painstakingly assembled and/or modified by highly trained personnel.