Response Audio EXtreme Antique Sound Lab Hurricane Modifications

Response Audio
EXtreme Antique Sound Lab Modifications

Consumer supplied Antique Sound Lab
Hurricane and Monsoon mono bloc amplifiers

The EXtreme Hurricane Modification has been our best selling high power tube amp modification for the past 3 years. 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 operation.

Extreme ASL Hurricane Modification List

** 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

** 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 28 awg. OCC silver with cotton also available)
We also apply a full shield to this wire to also further reduce any possible noise.

** RCA input jacks are high quality silver RCA jacks.

** RoHS complient silver solder used throughout

** Bench tested for 2 hours

** Minimum 12 hour burn in

** Labor : 17+ hours per pair

** Pricing: does not include return shipping.
Pre 2007 Hurricanes $4,999
After 2007 Hurricane MKII NA
We are not providing modification services for the vertical Hurricane MK II Hurricanes at this time.

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.

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
<READ FULL TEXT>

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 >

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