Bella EXtremeASL Hurricane and Monsoon Modifications

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CLEARANCE
Response Audio / Bella EXtreme has been working on some large ventures under the radar the past year.
We now need to move a lot of equipment to make room for these new, exciting ventures.
This is your chance to save on some of our most popular products. SEE THE DETAILS

Antique Sound Lab Hurricane 200DT and Monsoon

Bella EXtreme Modifications

Consumer supplied Antique Sound Lab
Hurricane and Monsoon mono bloc amplifiers
Includes both original pre 2007 and post 2007 MKII models

The EXtreme Hurricane Modification has been our best selling high power tube amp modification for the past 18 months. We only schedule a limited number of these per year (one pair a month) due to the extensive time and labor involved.

Response Audio is very familiar with all version of the Hurricane amplifiers from the very first stainless steel chassis to the latest vertical design. We can and have performed the EXtreme modifications on any Hurricane version including the older chrome chassis design. We have worked on them all.

Aside from the sonic enhancements, our Extreme modifications also assure you have no more biasing problems (drift), tubes going dead, resistors going up in smoke or fuses blowing. These are known problems with the ASL Hurricanes, especially in older models. With dozen of the EXtreme Hurricanes currently in consumers' homes, we have had no problems with these units to date. You can rest assure that after our extensive upgrades, you will have a set of amplifiers that will give you years of trouble free opperation.

Don't already own one of these products? You can purchase brand new EXtreme MKII amplifiers. We have a trade in pair of the pre-2007 version here right now in stock form. We will modify these at time of ordering.
You can also purchase brand new EXtreme Hurricane MK II units. DETAILS

ASL Hurricane pre-2007 ASL Monsoon pre-2007

ASL Hurricane MKII ASL Monsoon MKII

Full details on what's involved in the modification.

EXtreme Hurricane Modifications

EXtreme Monsoon Modifications

** Reference Grade V-Cap Teflon capacitors installed in the signal path coupling stages. x16 pieces
The capacitors are mounted using a high quality double sided adhesive tape as well as being secured with zip-ties to eliminated vibration.

** Reference V-Cap Teflon capacitors installed in the innerstage coupling positions. x4 pieces

** Mills non-inductive resistors replace the input tube cathode resistors. x6 pieces

** Mills non-inductive resistors are used for the grid stop applications. x16 pieces
All grid stop resistors are mounted directly to the grid pin of each power tube eliminating all unnecessary wiring. It is a common practice to mount the body of grid stopper resistors as close to the tube grid as possible. Many tube amp manufacturers do not utilize this practice. All grid stop resistors are then mounted directly to the leads of the coupling capacitors and all leads are cut to minimum length.

** Mills non-inductive resistors are used for the screen grid applications. x16 pieces

** High quality 5 watt Mills non-inductive resistors used in cathode ground locations of all power tubes x16 pieces

** Dale/Vishay 1 watt 1% non-magnetic resistors used throughout the signal path. 40-60+ pieces. The signal leads of these resistors are shortened to the shortest lengths possible and all exposed leads are covered with heat shrink to help eliminate vibration and protect against shorts.

** Dale/Vishay 1 watt, 1% resistors are used in the bias stage in series with the coupling capacitors. These resistors are mounted in series with the coupling capacitors and then into the bias stage circuit boards. Again, we keep all signal wiring as short as possible.

** Dale/Vishay 3 watt 1%, non-magnetic resistors utilized throughout various power supply locations.

** All exposed resistor leads throughout these amplifiers have heatshrink applied to help reduce mechanical vibration as well as preventing circuit shorts.

** The grounding layout is reworked to provide a the best possible results with a dead quite background and lower noise floor.

** All power supply capacitors are bypassed with SoniCap Platinum Teflon units. Each power supply filter capacitor receives its own bypass unit. Total of 8 Teflon bypass capacitors depending on model

** Bybee Quantum Purifiers are installed in the B+ voltage of the power supply directly at the rectifying stage. 4 pieces total.

** Bybee Quantum Purifiers are installed in the input signal path of the signal ended input.

** Fairchild "Ultra Fast - Soft Recovery" diodes are utilized in the rectifying stage of the power supply. The diodes are mounted directly to the capacitors of the power supply.

** High quality silver plated solid core copper internal signal wire. x8 feet (Solid core 22 awg. OFC copper also available)
We also apply a full shield to this wire to also further reduce any possible noise.

** RCA input jacks are high quality gold plated "RA Jack" RCA jacks.

** WBT Silver solder used throughout (on US models only)

** Bench tested for 2 hours

** Minimum 12 hour burn in

** Labor : 17+ hours per pair

** Pricing: does not include return shipping.

Pre 2007 Hurricanes $5300
After 2007 Hurricane $5500

Quick Start Manual - We have put together a quick manual to better help you install and bias the output tubes in your EXtreme ASL Hurricane amplifiers.

This process will also help aid you in diagnosing a bad tube.

** Reference Grade V-Cap Teflon capacitors installed in the signal path coupling stages. The capacitors are mounted using a high quality double sided adhesive tape as well as being secured with zip-ties to eliminated vibration.

** Reference SoniCap Platinum Teflon capacitors installed in the single ended input stage.

** Innerstage signal coupling capacitors are replaced with SoniCap Platinum Teflon capacitors. (4 pieces total)
These capacitors are securely mounted in a way that eliminates mechanical vibration as well as radio frequency interference.

** Mills non-inductive resistors replace the input tube cathode resistors.

** Elna Cerafine electrolytic capacitors used for cathode bypass on input stage (where applicable).

** Mills non-inductive resistors are used for the grid stop applications. All grid stop resistors are mounted directly to the grid pin of each power tube eliminating all unnecessary wiring. It is a common practice to mount the body of grid stopper resistors as close to the tube grid as possible. Many tube amp manufacturers do not utilize this practice. All grid stop resistors are then mounted directly to the leads of the coupling capacitors and all leads are cut to minimum length.

** Mills non-inductive resistors are used for the screen grid applications. These resistors are removed from their circuit mounting boards and also mounted directly to the screen grid pin of each power tube eliminating all unnecessary wiring.

** High quality 5 watt Mills non-inductive resistors used in cathode ground locations.

** Dale/Vishay 1 watt 1% non-magnetic resistors used throughout the signal path. 40-60+ pieces. The signal leads of these resistors are shortened to the shortest lengths possible

** Dale/Vishay 1 watt, 1% resistors are used in the bias stage in series with the coupling capacitors. These resistors are mounted in series with the coupling capacitors and then into the bias stage circuit boards. Again, we keep all signal wiring as short as possible.

** Dale/Vishay 3 watt 1%, non-magnetic resistors utilized throughout various power supply locations.

** All exposed resistor leads throughout these amplifiers have heatshrink applied to help reduce mechanical vibration as well as preventing circuit shorts.

** The grounding layout is reworked to provide a the best possible results with a dead quite background and lower noise floor.

** All power supply capacitors are bypassed with Teflon units. Each power supply filter capacitor receives its own bypass unit. Total of 4 or 8 Teflon bypass capacitors depending on model

** Bybee Quantum Purifiers are installed in the B+ voltage of the power supply directly at the rectifying stage. 4 pieces total.

** Bybee Quantum Purifiers are installed in the input signal path of the signal ended input.

** Fairchild "Ultra Fast - Soft Recovery" diodes are utilized in the rectifying stage of the power supply. The diodes are mounted directly to the capacitors of the power supply.

** High quality silver plated solid core copper signal wire both from the input RCA jack to the first stage of the circuitry as well as for the balanced input signal. (Solid Core OFC copper also available)

** RCA input jacks are high quality gold plated "RA Jack" RCA jacks.

** High quality Neutrik XLR connectors are used for the balanced inputs where applicable.

** High quality WBT replacement speaker binding post used at the 4 ohm and 8 ohm positions as well as commons.
Total of 6 pieces. OPTIONAL on Hurricane MK II models

** WBT Silver solder used throughout (on US models only)

** Bench tested for 2 hours

** Minimum 12 hour burn in

** Labor : 12-20+ hours per pair

Pre 2007 Monsoon: $3900
After 2007 Monsoon $5400

OPTIONS: In conjunction with your EXtreme modifications, we also make available a few additional options including Bybee Purifiers, Cryogenic Fuse Holders and IEC connectors.
Click on the pictures below for available options and pricing.

Some Customer Feedback

"I unpacked them, set them up, biased them and ran them for about 40 hours (low volume music). Then I sat down for an initial listening session. HOLY CRAP !!! The difference is not at all subtle !!! Yes, I liked the pre-modified hurricanes: they were very detailed, had good liquidity and did space very well, but the modified hurricanes are in an altogether different league. The detail and space portrayed is far better, but the entire musical tapestry is still woven as one cloth. I've had these gentle giants turned on for over 80 hours now, unfortunately not much listening due to other commitments. However, this weekend I did some serious listening and they are getting better, no doubt the capacitors breaking in. Prior to the modifications I enjoyed very much listening to the hurricanes but always would find some areas where improvement would be welcome. However, to date, I cannot find any wrong doings. I dare to say that at some points in my listening sessions I would swear that I had some large solid-state units installed, especially during some bass and/or very dynamic passages. But then the continuousness and spaciousness reminded me that tubes were at work. Marvelous..."

"The stock Hurricanes sounded good, but with Bill's modifications the Hurricanes soared to a whole new level. The new nonexistent background noise helps to squeeze out every detail and produce a blacker background. The sound now has a nice liquid, non fatiguing feel to it with. This has increased both my quality and quantity of the time spent with the Hurricanes.........."
<READ FULL TEXT>

Bill,
From what I have heard, you don't need any more glowing reviews on the Hurricane extreme mods but you are welcome to use my humble expressions that do not convey the true worth of these
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While I would like to offer you more customer feedback, many of my customers for these products would prefer to stay out of the limelight and not have their comments posted even though I promised not to use their names. I can tell you that EXtreme Hurricanes have found their way into some very prestigious 2-channel audio systems costing upwards of $140k.

More words on the ASL Hurricanes
"..........This amplifier has been extensively auditioned by the same associate who owned the rare and expensive CAT JL-1 mono blocks, now in "Class A". A comparison of the two models was made on his own (very high resolution) system. The results are............."
< READ FULL TEXT >