ASL Hurricane 200 DT
Signature Plus Modifications
for the pre 2007 MK I only
200 watt KT88 tube mono bloc amplifiers
 Exclusively by Response Audio

 

With the popularity of the EXtreme Hurricane amplifiers steadily on the rise over the past several years, Response Audio have decided to continue with the more affordable version of this fine, highly regarded product. The work and attention to detail put into these units is every bit as thorough as the EXtreme units. 

Our mission with the "SP" upgrades is quite similar to the EXtremes, sonic purity. Like the EXtremes, the "SP" upgrades also include going through the entire circuitry of these amps to assure long term reliability and durability. Our Hurricane upgrades provide more quality control than most manufacturers can only dream of. Response Audio is not a production line and your amplifiers are custom modified with only one pair of hands from start to finish.

 As you look through what we offer and the additional work incorporated into these products, you will see that no one even comes close to our level of work, attention to detail or thoroughness. Also keep in mind that Response Audio was the first and possibly still the only company offering this level of dedication to the Antique Sound Labs Hurricane amplifiers as well as the other models from the line. 

The EXtreme Hurricanes are now being considered among the absolute finest high power tube mono bloc amplifiers currently on the market for under $20K. Maybe even more. The have become known as our hallmark in tube amp modification with very few equals in the industry. We wanted to offer a version that would still be considered a highly desirable product at a more attractive price.

The modifications used throughout these amplifiers utilize some of the most highly regarded, high performance internal components to find their way into the audio industry over the years. The Audience AuriCap capacitors are still considered by many as being among the finest audio capacitors available. These components were chosen for their long term integrity and sonic virtues they have always been known to deliver. 

Just as in our Reference and EXtreme products, the use of premium components is also standard practice in the Signature Plus models. To guarantee unsurpassed performance, we use high quality input connectors, coupling and bypass capacitors, Mills non-inductive resistors in the cathode applications, and much more.  Please remember each amplifier is point-to-point wired with all modifications done only by myself and they take time to complete, but they are well worth the wait.  Due to increased sales of both the EXtreme and Signature Plus Hurricanes all orders are now on a 45-60 day turnaround time..

For those who have experienced quality and/or inconsistency issues with these units, you can be assured we have found the source of these problems and address them before and during the modification process. No more tubes going dead, biasing issues, open or shorted resistors, noise issues, grounding issues or circuit shorts. We have thoroughly gone through these units to find the source of any associated problems BEFORE proceeding with the upgrades and we stand behind our work with a full 1 year warranty.

The Super Components List   HARRY PEARSON
"..........one of the biggest bargains in uncompromised high-end sonic performance."
Written about the latest generation of the stock ASL Hurricanes
June/July 2005 www.theabsolutesound.com 

 

Modification Upgrades Performed on the Signature Plus Hurricanes

• Audience AuriCap installed in the signal path coupling stages. Original capacitors are removed from their mounting plate and the new coupling capacitors are mounted using a high quality double sided adhesive tape as well as being secured with zip-ties to eliminated vibration. Total of 20 pieces

• Bybee Quantum Purifiers in B+ Voltage between mains transformer and rectifying bridge - 4 pieces per pair. These pieces are mounted direct to the rectifying bridges eliminating all wiring between the Bybee Purifiers and circuit boards. The wiring from the mains transformer to the Bybee Purifiers is then shortened to a maximum of 3 inches. Optional - See pricing below

• AuriCap high voltage capacitors used as bypass units in the power supply being used  before and after the power supply filter choke. Each power supply filter bank receives its own bypass capacitor. 

• Mills non-inductive resistors, 16 pieces, are used for the grid stop applications. All grid stopper resistors are mounted directly to the grid pin of each power tube eliminating all unnecessary wiring. All grid stop resistors are then mounted directly to the leads of the coupling capacitors and all leads are cut to minimum length with any exposed lengths covered with a heavy heat shrink to isolate and protect the circuit and provide adequate damping of the lead material to prevent mechanical vibration. In this process, almost 3 feet of unnecessary wiring (between grid stop resistor and tube socket) is eliminated.

• Mills non-inductive resistors, 16 pieces, are used at the screen grids for triode mode operation. These units are direct wired eliminating as much circuit wiring as possible. We also apply the same protection and damping techniques as with the grid stopper resistors.

• High quality 5 watt, 1% Mills non-inductive resistors used in cathode location on 6SN7 and power tubes. These resistors are mounted directly to the cathode pin of each tube.
  x24 pieces

• Dale/Vishay 1 watt 1% non-magnetic resistors used throughout the signal path. 60+ pieces. The signal leads of these resistors are shortened to the shortest lengths possible. We have chosen 1 watt units in place of the 1/2 watt pieces that come stock in these pieces for several reasons.
   1) Utilizing higher wattage units with a larger physical size provides a quieter presentation.
   2) The use of the high quality Dale/Vishay Metal Film pieces also aid in a quieter presentation as well as providing better matching within the circuitry. Dale/Vishay resistors offer a 1% tolerance. We still measure all resistors for accuracy before installation into any of our modifications.
   3) We have found the quality of the stock resistors is inferior to those use in our modifications and in many instances, we have found broken leads going into the bodies of the resistors which have caused many of the symptoms mentioned above.

• Dale/Vishay 1 watt, 1% resistors are used in the bias stage between the tube grid and bias stage. These resistors are mounted in series with the coupling capacitors and then into the bias stage circuit boards. Again, we shorten all signal wiring to the shortest possible lengths and utilize the Dale/Vishay units for the many reasons as mentioned above. In this process, approximately 3.5 feet of unnecessary wiring is eliminated.

• During the modification, we also go through and check all internal solder connections looking for and resoldering any "cold" or "dry" looking joints to prevent any future problems. All tube socket and ground plane connections are resoldered by removing all solder and applying new WBT 4% silver solder.

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

• As mentioned above, all exposed resistor leads throughout these amplifiers have heatshrink applied to help reduce mechanical vibration as well as preventing circuit shorts and RFI interference. We have found that an excessive number of long, exposed leads can actually act in a similar manner as a radio antenna pulling in "Radio Frequency Interference" 

• Fairchild "Ultra Fast - Soft Recovery" 8A/1000v diodes are utilized in the main rectifying stage of the power supply. These diodes replace the very inexpensive silicon units that come standard in the stock amplifiers.

• Internal wiring is replaced with our custom 22 awg shielded copper wiring. We do not use the shield as the ground. Total length of wire used within a pair of Hurricanes is over 7 feet.

• RA Jacks are replaced with high quality gold-plated RCA sockets with Teflon insulation lining. 

• Each unit is "scoped" and bench tested for 2 hours

• Minimum 12 hour burn in (standard 24 hours) in a full system.

• Labor - 15+ hours per pair depending on options

• Recommended break-in period - 100 hrs (60%) / 200 hrs. (80%) / 300+ hrs. (95%)
   

   

PRICE: $2,600 pr. + return shipping
(modification to consumer supplied units only - does not include amplifiers)

OPTIONS:

• Bybee Quantum Purifiers installed in the B+ voltage between the mains transformer and rectifying bridge. total of 4 pieces - $400 installed.

• Bybee Quantum Purifiers installed in the input signal path - Total of 2 pieces - $200 / Gold Bybee Purifiers $480

The Pictures Below: Just to give you an idea of just how complex the internals of the ASL Hurricanes are, here is a picture of the innards of a STOCK 2006 MK I unit before tearing apart for modifications. Even this picture cannot give a true sense of the labor involved in this project. There are over 100 resistors alone that have to be removed and replaced, 20 coupling capacitors, several feet of wiring is removed, etc. 

The early versions. In the pictures below, you will find the innards of one of the very first versions of the ASL Hurricanes (before modification). The amp in this picture was sent in for EXtreme Elite modification. So, for those who are wondering if we work on the original version, the answer is YES!! Believe is or not, due to the layout this version is actually more difficult to work on in comparison to the most current. But the results are still phenomenal. 

Signature Plus Policies: 

1) All modifications are built by special order only. 

2) There is a 50% down payment required  Balance is due prior to shipping the amplifiers back.

3) No returns or cancelled orders will be accepted

4) Turnaround time is approximately 30 days from date of order depending on current work load.

5) All modifications are performed at our New York facility only.

6) Response Audio is NOT a reseller for the Audience AuriCap  or Sonic Craft SoniCap or any of the components we use within our modifications. If you would like to obtain any of these products for personal DIY use, please contact the manufacturer or one of the many resellers.

There are NO EXCEPTIONS to these policies.