Vintage Bose 800 802 901 Equalizer Repair & Upgrade Service

Vintage Bose 800 802 901 Equalizer Repair & Upgrade Service

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Vintage Bose 800 802 901 Equalizer Repair & Upgrade Service:

Please read through the entire listing. I take pride in the quality of my work, and the carefully selected components I use. Unlike some others, I want YOU, the customer to know up front what you'll be getting for your hard earned dollar, how long it's going to take, and what to expect when you receive your re-conditioned Equalizer. This listing is for my Basic Capacitor Replacement and Maintenance Service. I urge youreveiw andconsider all ofmy Exclusive Upgrade Options, which will take your Equalizer to the next level. If you decide that the additional options are beyond your budget, no worries, my Basic Service will correct the most common problems, and your Equalizer will sound as good, if not better than when it was new, due to the premium components I use and the cleaning and other services provided. I invite you to review my response, and visit my website facebook more details, photos, and customer reviews. Please see my other listings for custom rebuilt Bose and othe Vintageitems.

Please don't be intimidated by all the upgrade options. I know they can be a bitconfusing. If you have any questions please feel free to contact me here, or via my website.

Restore your Bose® 901 Series I through VI Equalizer, Bose® 800, 802-E Controllers to like new condition. Most problems associated with these Equalizers can be traced directly to aging capacitors, dirty switch contacts, dirty or worn rear connectors, and contaminated sliders (potentiometers). Symptoms may be subtle or dramatic, and can manifest themselves as a loss of signal in one or both channels, intermittent or erratic switch operation, various forms of distortion in the music signal, flat or lifeless sound, and little or no change in sound quality when adjusting the bass and treble controls. All Electrolytic Capacitors used in these Equalizers are subject to age. Some are over 40 years old now. Over time, the electrolyte dries out or leaks, the casing may begin to bulge, and in some cases may rupture. This causes capacitance values to drift, or complete failure of the components. All electronic components that contain Electrolytics when left sitting idle, unused, packed away, in an un-powered state can accelerate this condition. Although Bose® used quality General Purpose Capacitors typical for the day, no two equalizers were fitted with the same Capacitors. Each production run used whatever they had on hand. Capacitors from several different manufacturers are commonly found in the same equalizer. As with most other things, Capacitor technology has advanced dramatically in the past 30-40+ years. Electrolytic Capacitors are not like fine wine, they don't get better with age. If your equalizer is more than 12-15 years old, your Capacitors have already begun to deteriorate.

Basic Capacitor ReplacementAnd Maintenance Service: $82.95

My Basic service replaces all the aging, and defectiveElectrolytic Capacitors with Premium, Fresh Stock, Aluminum Electrolytics (I do not use "New Old Stock").The Capacitors I use havetemperature and voltage ratings equal to orhigher than the originals, and are vastly superior to the General PurposeCapacitors Bose® used originally.The power section willreceive higher value, Premium Panasonic FM Series,Aluminum Electrolytic Capacitors. I've decided to make these costlier,higher value FM SeriesCapsstandard for the Power Supply Section on all rebuilds. They offer longer life, lower impedance, higher ripple current, and better filtering than the originals. This is critical for the earlier Series I through III Equalizers which haverelatively simple Power Supply Sections.The Audio Sectionwill befitted with Premium Panasonic® FC/FM Series, Aluminum Electrolytic Capacitors, which are highly regarded by audio enthusiasts.

In addition, some early Series Equalizer'srear RCA connectors were not properly grounded. This can cause intermittent signal lossand distortion. If your Equalizer does not have the improved ground connections, I'll install a dedicated copper ground lead tocorrect the problem at no additional cost. Some Series IVEqualizers also suffer frompoorly soldered RCA connectors. These will bere-soldered as necessary,again atno additional cost to you. Some early Series IV Equalizers and 802-E Controllers were shipped with marginal, or defective dual operating amps (please read the notes section below).

All switches, sliders (potentiometers), and rear jacks will be cleaned and lubricated with Caig Laboratories DeoxIT® brand cleaners, lubricants and contact enhancers. Where possible, the rear connections (RCA and 1/4"), will be straightened and re-tensioned to provide better contact. The Series I & II Equalizers in particular, are known to have very dirty switch contacts, and worn RCA jacks. The rocker switches that Bose® used were open type, and subject to lubricant dry-out and contamination, and the RCA jacks were mediocre quality, typical for the day, and are easily damaged. I use only the finest Soldering/De-Soldering Materials and Techniques,including Ultra Premium CardasQuad-Eutectic. After completion, all Equalizers are tested. This service is limited to fully and or partially functioning equalizers only (partially functioning means the unit at least powers up). Why choose me over some others, or Bose® Factory Service? I'm a Bose® owner, and have been for over 35 years. I've owned every Series 901 from the originals through Series VI, as well as the 800 and 802 Pro Series. I know what they're supposed to sound like, and what improvements can be made. I've personally seen very shoddy workmanship and poor quality parts from Bose® Factory Service, and Factory Authorized Service. Several customers have sent me Equalizers previously serviced by Bose®, which failed, or were deemed un-repairable. I invite you to read my response to see what others have said about my restoration work. Applicable Equalizers and Controllers are: 901 Series I through VI, All Series 800, 802-E. Simply pack up your Equalizer, and ship it to me. I'll perform all the work mentioned above, re-pack it, and ship it back to you free, via FedEx Home Delivery, or USPS Priority Flat Rate, Insured for a replacement value of $200.00. Turn-around time is usually 3-5 days, depending on my workload, it's "first in, first out" and does not include shipping time both ways. Note: buyer is responsible for all shipping and insurance cost associated with shipping the unit to me.For international shipments: if your country applies a Duty Fee or VATTax, those fees will be basedon the$200.00 Declared Value on the return shipping Customs Forms, not the amount you paid for the service. 's shipping calculator seems to have a mind of it's own. Please contact me directly for allInternational shipping.

All Upgrades And Their RespectivePrices Listed Below, AreIn ADDITIONto the $82.95 Base Recap And Maintenance Service

My Exclusive Upgrades:

Neon Lamp/LED Replacement: For ALL 901 Series I throughIV Equalizers, and 800 Series Equalizer/Controllers, I offer a replacement for dim, flickering or burned out neon indicator lamps. The replacement is a low output LED, available in OEM Style Amber/Orange for Series I, or Red for Series II through IV and 800 Series. If the original neon lamp holder and lens are serviceable, they will be re-used. If the lamp holder and lens are broken or missing, a new LED with an integral lens and trim will be installed. This newer, integral type is not an exact match for the original, but is close in appearance and does blend well with the equalizer's front plate. Note: aging/flickering neon lamps are a knowncauseof addednoise in the audio signal, since they are not isolated from the rest of the power circuitry. Bose's own Factory Service frequently replaces these with LEDs when this problem occurs. The additional cost for this is $12.00 if the original lamp holder and lens are salvageable, and $16.00 if a new LED with integral lens and trim are required.

PowerOn/Off Switch:For 901 Series II through VI, and2nd generation 800 Series Equalizers, I offerinstallation of a newOn/Off Switch. The switch is a single hole mount, rocker type, which would be installed on the rear of the equalizer. Bose® eliminated the power switch on these later models. They advisedplugging the equalizer into a switched accessory outlet on the back of your receiver, or leaving it powered 24/7. Due to liability issues,manylate model Receivers do not have switched outlets anymore. Since we're all going Green, whether we want to or not, leaving the Equalizer powered on, when not in use, is a waste of energy. The additional cost for the switch is $18.50.

Copper EMI Shielding:For ALL 901 Series I through VI Equalizers,800, 802-E Controllers, I offer the installation of copper shielding on the power transformer. The transformers Bose® used wereaveragequality, and had minimal electro-magnetic interference shielding at best. The copper foil I use wraps around the entire transformer, and reduces unwanted EMI interference that can leak into the audio signal. The additional cost for this is $10.00.

RF Shielding: For 901 Series III and IV Equalizers. I offer heavy duty, Aluminum Foil, RFShielding, covering the entire underside of the wood cap. The original shielding provided by Bose was minimal at best, and only covered a portion of the underside of the cap. The Series III are especially vulnerable to this. The additional cost for this is $10.00.

New Rubber Feet:For all Series 901 Equalizers, 800, and802-E Equalizer Controllers with missing or damaged feet. I offer Quality,Through-Hole, Mushroom Base/Grommet Style, Heavy Duty Rubber Feet.These are direct replacements for 901 Series I & II, and 800 Series Equalizer Controllers (the originals are 1/4" high, half-round. The new feet are 1/4" high, flat, disk type). For 901 Series III through VI, 802-E, the cheap, stick on feet will be removed, and new holes drilled in the bottom of the chassis for a secure fit. Youcan purchase replacement, stick-on feet at any hardware store, but they'll eventually fall off just like the originals did. If you wantthe best for you Restored Equalizer, consider these. These are highly recommended for the 802-E, since the stick-on feet are totally inappropriate for Pro use.The additional cost is $6.00 for 800,901 Series I & II, and $12.00 for 802-E and 901 Series III through VI.

Replacement Treble Control Knob: For 901 Series I & II, I offer a replacement for your damaged or missing Treble knob. These are quality, solid, brushed aluminum. They are not an exact replacement, but do blend well with the front face plate. They also feature a knurled edge for easier turning. The additional cost is $7.50

Replacement Transformer, Voltage Conversion & Dual Voltage Operation: For 901 Series I through VI, 800, and 802-E. I offer quality replacement Transformers that are robust andbetter than the originals. Since Bose® no longer sells parts for their equalizers, or anything else for that matter, It took me a while to find suitable, low height, quality parts, thatare compatible with the entire line of Bose® Equalizers. These new Transformers areamodern design, with full EMI shielding. Theyhavedual voltage primaries, whichallowsthemto be configured for120V, 240V, or both via a Selector Switch. There are two versions.The smaller version fits Bose® 901 Series I through IV, 800, and802-E Series,whilethe larger version fits the 901Series V, VI. Pricing: 901 Series I through IV, 800 &802-E Series, $30.00, 901 Series V, VI$35.00, Three Position VoltageSelector Switch with Center off $20.00. Note: Some modifications to the circuit board and tracesmay be required. For Voltage Conversion, use in other Countries, or if your cord is defective,I stock replacement US 120volt, and EU compatable 240 volt power cords.

Special note for Series I, II, III and 800 Series, 220-240 volt models:Most units that were shipped from the factory did not contain a true 220-240 volt transformer. Bose® used a rather unique, some would say dubiousmethod to "convert" a 120 volt model to 240 volt. A five watt resistor was installed in the powercircuitry to lower the input voltage to the transformer. You can verify this for yourself, by removing the wood cap. On Series I, II and 800 Series, the resistor is located on the front terminalstrip, or the attached to the power switch. On Series III, the resistor is located at the left rear of the cicuit board, behind the transformer.This scenario causes twopotentialproblems: 1st is excessive heat, and 2nd is voltage drift. When the Equalizer is under full load conditions, the resistor gets very hot. Thiscauses the internal cabinet temperature to rise, and may contribute to premature failure of certain components including the resistor itself.The 2nd problem is voltage drift. The active components in theEqualizer require certain minimum voltages to operate properly at all signal levels. The 5 watt resisitor's value can drift due to heat. When combined with the mediocre quality of the original transformers Bose® used, these minimum required voltages can and do drop well below that which is required for proper operation.The bottom line is: Your 220-240 volt equalizer may not be operating at peak performance, and quite possible never has.

Gold Plated RCA Jack Upgrade:For 901 Series I through IV. Replace all the worn, misshapened, poor quality, and poorly spacedoriginal RCA Jacks with Premium, Gold Plated Jacks. For Series I & II, plug spacing is increased, so most premium RCA interconnect cables can be used.The original Jacks furnished on all early Bose® Equalizers were mediocre at best, and are a constant source of problems. Whether it's corrosion, elongated/misshapened internal sleeves and contacts,deteriorated solder points,poor spacing, or grounding issues, the original Jacks will fail unless treated with kid gloves. My new Jacks are made of heavy brass, with gold plating, and will last a lifetime with normal use, and proper care. Due to the amount of labor involved, the price is set at $60.00.

Tape Monitor Switch Bypass:For 901 Series I & II. Bose used poor quality, open type rocker switches for all the front Equalizer Controls. The Tape Monitor Switch is notorious for causing numerous problems, such aschannel dropout, distortion, one channel weaker than the other, etc. Since very few of us actually use Tape Decks anymoreI can jumper the switch internally with OFC copper wire, and install covers over the Rear RCA Tape Monitor Connectors. This will eliminate all problems associated withthe Tape Monitor Switch. The modifications are completely reversible, and the outward appearance of the Equalizerwill remain the same. The cost for this modification is $12.50.

Series IV Overload Modification: Under certain conditions, the Series IV Equalizer can overload the Tape Monitor Circuit in your receiver or integrated amplifier. Thisonly occurs with high output sources such as CD/DVD Players. When it does occur, distortion will be heardregardless of theVolume or Gain setting. It is not universal, and only certainCD/DVD/Receiver combinationsare affected. The Modification consists ofPrecision,1% tolerance,Audio Grade Resistors inserted in the output circuit of the Equalizer. The cost for this modification is $20.00. Notes:This overload condition will not occur when using thePre-amp out/Main-amp in connection method. Bose addressed this with theSeries IV-B Equalizer, which is a heavily modified Series V Equalizer. Unfortunately, very few were ever produced.

Amplifier Upgrade # 1:For all 901 Series I & II Equalizers. I can replace the old, tired Amplifiers (Transistors) with With New, Premium Fairchild Low Noise Amplifiers. These Amplifiers do all the "heavy lifting" when creating the Boost Curve for the Equalizer. I'll also include replacing the Six Ceramic Capacitors which are in series with several of the Amplifiers with Premium Vishay Capacitors. The additional cost for replacing all 10 amplifiers and 6 Ceramic Capcitors is $24.00.

Amplifier Upgrade # 2:For 901 Series III Equalizers. I can replace all 14 old, tired Amplifiers (Transistors) with New, Premium Fairchild Low Noise Amplifiers. As with the other Equalizers, these Amps do all the "Heavy Lifting" when creating the Boost Curve for the Equalizer. The additional cost to replace all 14 Amplifiers is $26.00

Amplifier Upgrade # 3:For 901 Series IV Equalizers & 802-E controllers. As described in the notes below, The early production units were furnished with dodgy LF353 Dual Operating Amplifiers, and Bose issued a Service Bulletin addressing this. Like the Amplifiers for Series I & II, these Dual Operating Amplifiers do all the "heavy lifting" when creating the Boost Curve. I always recommend replacing these pre-emptively when rebuilding the Equalizer. These can be replaced with New, Matched, Audio Grade Amplifiers. The additional cost for replacing all four Dual Op/Amps is $12.00 if Socketed, and $25.00 if soldered in place.

Voltage Regulator Replacement: For 901 Series V & VI. I'm seeing an increasing number of Series V & VI Equalizers with defective or marginal Voltage Regulators. The Voltage Regulators supply the required +15 & -15 Volts to the Quad Operating Amps. Their operation is critical since the Quad Op/Amps are the heart of the Equalizer. The Voltage Regulators are acomplementarypair, and must be replaced as a pair, from the same manufacturer. A common symptom is a low frequency hum, with no music signal from either channel. The additional cost for replacing the pair is $7.50. If yours are defective or marginal, you will be notified after I inspect the unit. They can also be replacedpreemptively, to prevent problems down the road.

NEW! Voltage Regulators for Series I, II & III: The early 901 Equalizers have rather simple Power Supplies, with fixed resistors, and sometimes marginal Transformers. The Amplifiers which produce the Boost Curve require specific voltages for proper, consistent operation.These fixed voltages can vary due to incoming line voltage fluctuations, and a varying load on the Equalizer depending on the incoming music signal. The new voltage regulator is a heavy duty model, rated for 1.5 amps DC. Thisexceeds the power requirement for the EQ, but I choose it for longevity, and cool running. It will maintain the required DC voltages within 3%, under nearly all conditions, providing the existing Transformer is not weak or compromised. The cost for this modification is $15.00. If your Transformer is weak, or not supplying the required output voltage, you will be notified. I can also offer a package price to completely upgrade the Power Supply, with a New Heavy Duty Transformer, New Ultra Fast Rectifier Diodes, and the New Voltage Regulator. Contact me for details.

Audio Upgrade # 1: For ALL 901 Series I Through VI Equalizers, 800, 802-EControllers: Upgrade to Ultra-Premium, Audiophile Grade,Elna® Silmic II, High-End, Silk Fiber Aluminum Electrolytics. Regarded by many Audiophiles as the Ultimate Electrolytic Capacitor for Audio applications(with the exception of uber expensive, specialty, hand made, and oil filled capacitors). These Elna® Capacitors are equal to or better than the prized Rubycon® Black Gate® Capacitors, which are no longer in production. In addition to the exclusive Silk Fiber Electrolyte, these Elna capacitor feature Oxygen Free Copper Leads. Additional pricing varies depending onwhich Series Equalizer Controlleryou have. For 901SeriesI & II, 800, 802-E, the additional cost is$10.00. For 901 Series III Through VI, the additional cost is $6.00. Note: Panasonic® FM/FC Series will still be used in the Power Section.

Audio Upgrade # 2:For 901 Series I & II Equalizers, and 800 Series Equalizer Controllers: The input coupling and signal path capacitors can be replaced with PremiumMetalized Polypropylene Capacitors. Unlike the bypass/filter Electrolytic capacitorsincluded in the basic service listed above, these capacitors are used directly in the audiosignal path. In other words, the actual music signal from your pre-amp, or the pre-amp section of your receiver passes through them.The original capacitors Bose® usedweregood quality Mylar or Polyester, but weregeneral purpose, dipped film (usually "Orange Drop" or encapsulated, epoxy sealed), 10% tolerance. This means that the total capacitance values between channels my differ up to 20%, and may be audible to discerning listeners.Although these film capacitorsdon't age like electrolytics, they do have a direct impact on the quality of the audio signal. (Note: Premium Electrolytic Output Coupling Capacitor replacement is already included in the basic re-capping price, however these twooutput capacitors can also be upgraded, see below.). I recapped my own Series II Equalizer with theseCapacitors. Ican tell you the Bass, which was rather loose andmuddyfrom my Series II and more controlled, the Mid-range and Treblebecame crystal clear and smooth as silk. I've received similar reports from my customers who opted for this upgrade.Theadditional costdepends on which SeriesEqualizeryou have and which revision it is (different Series and Revisions have different quantities which vary from4 to8 capacitors). The price for this upgradeis $22.00 for Series I, $16.00 for Series II, and $20.00 for 800SeriesEqualizer Controllers.

Audio Upgrade # 3:For 901 Series I & II Equalizers, and 800 Series Equalizer Controllers, in addition to the Audio Upgrade # 2 listed above, theOutput can also be replaced withPremiumMetalized Polypropylene Capacitors. The Original Output Electrolytics have a 20% tolerance, which means the capacitance value differencebetweenchannels could be as high as 40%. TheseCapacitorsare large, and expensive, and require specialprocedures duringinstallation. The cost for these would be $28.00 in addition to theabove upgrades.Once again, I modified my own Series II Equalizer with these PremiumMetalized Polypropylene Capacitors, and can tell you these were the icing on the cake as far as sonic clarity is concerned. Your Series I& II Equalizer and 800 Series Equalizer Controller willperform better than when Bose firstbuilt them.

Audio Upgrade # 4: For 901 Series I & II Equalizers, and 800 Series Equalizer Controllers: There are 6 additional film capacitors in theHigh Frequency Audio Section, that can be replaced with PremiumMetalized Polypropylene Capacitors.The original capacitors Bose® usedweregood quality Mylar or Polyester, but weregeneral purpose, dipped film (usually "Orange Drop" or encapsulated, epoxy sealed), 10% tolerance. This means that the total capacitance values between channels my differ up to 20%, and may be audible to discerning listeners.Although these film capacitorsdon't age like electrolytics, they do have a direct impact on the quality of the audio signal. Once again,Iinstalled thesein my own Equalizer and tested them with my Series II Continentals. The Upper Midrange and Treble have never sounded better.The additional cost for this final upgrade is $14.00.

Upgrade Combination Packages: For 901 Series I & II Equalizers, and 800 Series Equalizer Controllers: I offer special combined pricing which includes all four Audio Upgrades. The performance and sonic clarity of your Equalizer and Speakers will far exceed anything Bose® ever imagined or produced. Bass response, vocals, detail, clarity and imaging are brought to a whole new level. Additional pricing depends on which Equalizer & Series you have. Please contact me before or after purchasing the Basic Recapping Service for Special Combination pricing.

AudiophileUpgrade #5: THE ULTIMATE UPGRADE PACKAGEFor 901 Series I & II Equalizers and 800 Series Equalizer Controllers. For those that want only the finest replacement components installed regardless of price. This Ultimate Audiophile Upgradereplaces the Upgrade Combination Package (upgrades 1-4)listed above,and includes Ultra Premium Elna Silmic II Silk Fiber Electrolytic Capacitors in the Audio Section,a rebuilt and Improved Power Supply Sectionwhich includesbeefier Elna and Panasonic Capacitors,and newUltrafast, Soft Recovery Diodes, Decoupled with Ceramic Capacitors. All existing Metal Film Capacitors in the signal path will nowbe replaced with Ultra Premium, AudiophileGrade,Sonicap Gen I & Gen II Metalized Polypropylene Capacitors. Sonicaps are one of thefinest, affordable, high-endcapacitors money can buy. Capacitors replaced with Sonicapsin this upgrade include: Input Coupling, Signal Path,High Frequency, and Output Coupling Electrolytics. There is no comparison to this upgrade sonically, it's simply the best.Your treasured 901s will sound as never before. The detail, imaging, and clarity are jaw dropping. Bass response is gut punching, but never flabby. I rebuilt my own Series II Equalizer once again with these new Capacitors and Power Supply Modifications, and my Continentals have a completely different character. I guarantee you'll hear details and subtlety in the music whichyou've never heard before. Please contact me for special pricing on this Ultimate Upgrade Packagefor your Series I, II or 800Equalizer. Note: I do not stock these capacitors. They will be ordered after your purchase. Please allow extra time for your Equalizer to becompleted.Additional Note: To truely appreciate your Series I or II 901s with these improvements, your amp should be a high current design, with a high damping factor, and at least 150 to 200 watts per channel. Most modern receivers do not have sufficient power supply capacity, and will run out of steam very quickly. Do yourself and your 901s a favor, and use a quality, high power amplifier.

Audio Upgrade # 6: For 901 Series I & II Equalizers, and 800 Series Equalizer Controllers: There are numerous NPO Ceramic Capacitors in the signal path. Ceramic Capacitors are inexpensive, however their use in Audio Coupling Circuitscan beless than stellar. The best replacement for them is Silver Mica. Silver Mica Caps have been around for decades, but due to their high cost, manufacturers rarely use them in place of Ceramics. They are only available in the smaller values, generally under 1uf. The Series I Equalizer has eight Ceramics that can be can be changed, the Series II has six, and the 800 Series, may have six or eight depending on when it was produced. I've refitted my own Series II with the Mica Caps, and the difference, especially inthe upper midrange and treble was immediately apparent. It's as if a veil was lifted, and fine grained detail improved dramatically over the Ceramics. Silver Mica's are relatively expensive compared to some other premium Capacitors. I don't normally use New Old Stock (NOS), but due to cost, and the fact that Silver Micas don't age,you may receive a combination of New and NOS parts. Each Series would bequoted individually. When combined with the Ultimate Audio Upgrade # 5, the results are astounding. Please contact me for special pricing on these options.

Please Note:901 Series III through VI Equalizers, 802-E Controllersdo not qualify for AudiophileUpgrades # 2, #3, # 4, Ultimate Upgrade Package # 5, and # 6. The circuit design and components usedare vastly differentfromthe original901 Series I & II, and 800 SeriesEqualizer Controllers. For these SeriesI can offer combined discounts on other upgrades along with Audiophile Upgrade # 1.

Pleasecontact me directly before or after your purchase, if you're interested in any of these additional upgrades. You will be invoiced separately via PayPal for all upgrades and additional items


For 901 Series I and II Equalizers: One of the most frequent questions/complaints I receive for these early models is the spacing between the rear RCA jacks. When using modern premium interconnects, the diameter of the RCA plug's coveris, in many cases, much larger than the RCA interconnects that were available when these models were produced 35-40 years ago. When these fat or large diameter plugs hit each other, the pins go in at an angle instead of perpendicular/straight. There are two ways to addressthis, you can file, grind, or block sand a flat spot on the part of the plug's coverthat you grasp on to when inserting or removing it, or select my RCA Jack Upgrade option listed above.By creating a flat spot on both plugs, and aligning the flats to one another, it gives you just enough clearance for the plugs to slide in correctly.Failure to do either of these, will result in the RCA jack's internal sleeves becoming misshappened, andelongated again,causing intermittent, orcomplete loss of signal.

For 901 Series III:Having serviced dozens of these models, I've observed the following: All Series III Equalizers have a relatively high noise floor, and are susceptible to RF and EMIinterference. Although nearly identical in appearance to the Series IV, theSeries III circuitry and component layout is very different.You can observe this phenomenon for yourself, by turning the gain (volume control) of your receiver or amp all the way up, with theEqualizer in the circuit, and the source connected but paused.My re-capping and maintenance service, as well as the additionalRF/EMI shielding upgradeswill mitigate some of this noise, and improve the overall sound,butI cannotfix a less than optimal design.

For 901 Series IV and 802-E Equalizers: Some early production Series IV Equalizers and 802-E Controllers were furnished with lead contaminated ICs (Dual Operating Amplifier, Integrated Circuit). Bose® issued a service bulletin addressing this. These defective ICs can produce symptoms similar to the problems mentioned in the first paragraph, such as loss of signal and distortion. If it is determined that this is a contributing factor, you will be quoted separately for replacement of these four matched ICs, as an addition to the basic re-capping service. The replacement parts would be high performance, low noise operating amps, which are superior to the originals. It's also a good Idea to replace these "proactively", since these op/amps doall the "heavy lifting" with respect to the Equalizer's Boost Curve.The replacement cost is $12.00 for socketed ICs, and $25.00 if they're soldered in place. Please inspect your equalizer to determine which factory installationmethod was used. Contact me for details.

For All 901 Series III Through VI& 802Original SeriesSpeakers: If your 901s & 802s don't sound the way they used to, or are producing odd noises, there may be another problem in addition to the Equalizer: Foam Rot. Like most speaker manufactures in the 70s and 80s, Bose® began using Polyurethane Foam for their driver's surrounds. The lifespan for this type of surround was as short as 5 years, or as long as 15 years. Bose® switched to an improved foam during the Series V production, but this newer foam still only lasts about 15 to 20 years, depending on Environmental conditions. I would advise anyone contemplating purchasing my Equalizer Service to inspect the drivers in your 901s or 802s. The easiest way to inspect them is to remove one of the rear V shaped grills on the 901s or the front grill on the 802s. If you find that your foam surrounds have deteriorated, I offer re-edging services for both the 901s and 802s which includes Lifetime Treated Cloth surrounds. Please note, 901 Series I, II, late production Series VI, and 802 Series II & III use treated cloth drivers, and should never need re-edging services.


Q: Why don't you use less expensive generic capacitors?

A: There are numerous Capacitor Manufacturersaround the world. Some inthe US andEurope,but mostlyfrom Asia and the Pacific Rim. The markets are flooded now with capacitors made in China, and are dirt cheap.

Iuse onlyquality Capacitors, from well respected companies whose names are known to everyone in the industry. Panasonic®, and Elna® are two fine examples of Japanese made Capacitors. Their quality is consistent, production impeccable, and their products are sold through reputable dealers that I purchase from. Irefuse tosave a few bucks using generic or grey market capacitors,and risk early component failure, poor quality sound,and anunsatisfied customer. Not going to happen.

Q: I notice you use Radial (upright) Capacitors on the early Bose® Equalizers, instead of the original Axial (lay flat) type, why is that, and does it affect the operation of the equalizer?

There are several reasons for using Radial Capacitors.First, and foremostis availability.Nearly allof the Premium Capacitors I use are not available in an Axial version.On those rare occasions when theyare, they'remanufactured in limited quantities, and are thus more expensive than the Radial version. Second, many of the values I keep on hand, are used in several different Series, and Generations. I'm a "one manshop", "alittle guy", I simply can't affordto keep on hand, different versions of the same value capacitors even if they'reavailable. There is no difference what-so-ever in the performance of the Equalizer using Radial Capacitorsinstead ofAxials. In fact,modifying the leads on the Radials actually takes more time to install vs Axials. Others may use no-name, generic, general purpose, grey market capacitors, or new old stock NOS,because they're easier to installand fit the old style Axial mounts, I do not. The Capacitors I use are carefully chosen for quality, longevity, andmoreimportantly, they way they sound,not for ease of installation.

Q: Why don't you include the cost to ship the Equalizer to you in your price?

A: I receive Equalizers form all over the world. There's no way I could possibly calculate the shipping, insurance, customs, and VAT fees for every Country.

Q: Why should I choose you over other repair companies, or Bose® Factory Service?

A: I'm a Bose® owner, and have been for over 35 years. I've recapped hundreds of Equalizers for my customers, through my local business, and for my own use. All the parts I use are carefully selected specifically for their intended purpose, depending on whether they're used in the Power Supply,or Audio Sections. I've seen all manner of capacitors and components used by other Service Companies, and Bose® themselves. My Audiophile Upgrades and other improvements are based on my own electronics knowledge, information gleaned from numerous audio hardwareenthusiasts, and direct contact with other Bose® 901 owners around the world, who've modified their own equipment. My Upgrades and Modifications are exclusive. No one I know of is doing anything even close.

Q: How long does theRecapping Servicetake, what's the turnaround time?

A: Normally, the entire process takes3-5 days, depending on my workload, it's "first in, first out". This does not include shipping/transit times both ways, nor any acts of god and nature. I always have sufficient stock on hand for the Basic Recapping Service, and most of the Audiophile Upgrades. If I don't have the parts on hand for some reason, my suppliers can get whatever I need within a few days.

Important! There are others on and elsewhere advertising a similar service, as well as Bose® themselves. I invite you to review my response, and compare them to others. I give a full, detailed description of the work I'll be performing, plus the premium components I'll be using, others do not. If you're still not convinced, drop a note to any of my previous customers. Ask THEM about the quality of my work, communication before, during and after, and most importantly the sound and performance of their 901s, 800s, and802safter the re-capping service.

Other services for Bose® owners:

Re-edging/Re-foaming for 301s, 601s, 901s, 4.2s, 6.2s, 10.2s, and 802 Professional models.

Re-Coning Services for most Bose® models dating back to the early 70s, as well as most other makes and models. This serviceincludes a new voice coil, spider, cone and polyether surround. Your Bose® woofers will be essentially new when completed. Please contact me for additional information and pricing.

Connector and internal component upgrades for 800 and 802 Professional Systems using industry standard Neutrik® Speakon® connectors, and premium quality capacitors.

Please see my other listings, my store: my website:, or contact me directly for further infomation on any of these additional products or services..

Local drop-off and pick-up available at reduced pricing.

This listing includes priority return shipping and insurance for USA, all 50 states, plus certain possessions/protectorates (It does NOT include the cost forshipping your Equalizer to me). For my Canadian, Mexican, Australian, and UKfriends, additional fees apply. Please selectyour countryfrom the drop down list under Shipping and Payments. Buyers from other countries are welcome. Please contact me before purchase for a shipping quote,or simplyuse a US based, mail/parcel forwarding service such as MyUS, Bongo etc.

Note for International Shipping: I insure your Equalizer for $200.00 US, should something go wrong during the return shipping proccess. In order to do this, on the customs form,Declared ValueAND Insured Value must match. If your Countryapplies a Duty Fee orVAT Tax, those fees will be based in the Declared Value, not the amount you paid to purchase my services. Unfortunately there's no way around this.

Important! I am NOT selling an Equalizer! This listing is for servicing YOUR equalizer, not furnishing an equalizer. Please READ the description before you buy! I've had to cancel numerous sales because buyers didn't READ the description!

Vintage Bose 800 802 901 Equalizer Repair & Upgrade Service:

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Rare Jbl L36 3-way Speaker Pair picture
Rare Jbl L36 3-way Speaker Pair

Original Large Advent Speakers From Original Owner  picture
Original Large Advent Speakers From Original Owner

Vintage Speaker Stands picture
Vintage Speaker Stands

2 Vintage Boston Acoustics 860lf Woofer Speakers - 3.4 Ohms 120w Peak picture
2 Vintage Boston Acoustics 860lf Woofer Speakers - 3.4 Ohms 120w Peak

Pioneer Cs-500g 10
Pioneer Cs-500g 10" Alnico Speaker Woofer Driver Pair

Utah  8
Utah 8" Full Range Speaker Driver Pair