Modifications on ASL Hurricane 200 DT ?

Yes I did. I am very happy with them.

However, there were growing pains - the previous owner was compulsive/obssessive and he apparently tweedled the bias all the time, often blowing up the tubes. A couple of sacrifice tube resistors in these amps needed to be replaced. One tube was not connected to the meter, which due to a design flaw simply "holds" the previous tube's current - very dangerous, as you are fooled into thinking the tube is biased just the same. Finally, the fuze holder on one was not screwed down all the way, causing the amp to switch off randomly.

Now all is fixed and they are fabulous and very stable. Love them. My particular pair has silver wiring and Relcap Multicap for coupling. I plan, sometime in the future, to send them to the "extreme" shop for $5k's worth of TLC. I think, for me, these are the final amps.

Bill Baker at Response Audio will do a FINE job of making them better, but YOU or someone who knows how to solder can make them sound a good bit better by further upgrading the 10 0.22µF couplers per amp with SoniCap Platinums. The Platinum uses a film that's an alloy of teflon; they sound VERY quick, clean, smooth, detailed, and tonally neutral while being significantly less expensive than the V-H teflons that Bill uses. My ASL dealer loves the sound of Jensen paper-in-oil-copper-foil caps, but others tell me they sound artificially warm.

I just received a new pair of 'Canes and have chosen the Platinums for the 1st position and Cardas Golden Ratio solids (which are close to the SC-Ps sonically) for the 2nd position.

What are you using for 'N7s and '88s? I'm collecting new and used 'N7s, but, not being a GEA, it takes me a long time to determine the character of the input tubes. I'm still using the stock Chinese '88s, but probably I'll buy a set of the Penta '88SCs with closed plates; they're getting rave reviews on the Tube Asylym.
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Thanks for good tips! I am currently using Electro-Harmonix tubes in all positions, but have been thinking about NOS for the input, as well as tube dampers from Herbie's Audio Lab. I will definitely investigate the caps you recommend!

Hurricanes Forever!

Dimitry, I summarized my thoughts on couplers for the 'Canes here http://www.audioasylum.com/forums/tubediy/messages/94704.html . If you were ready to spend upwards of $5K at Bill's, you definitely can afford the SoniCap Platinums. And...they're $23 each less expensive than the V-Cap TFTFs, = $460 for the 2 amps.

Do you have detailed notes on modifications already performed? If so, if you share them, probably I can give you more to consider. Pls e-mail me at jeffreybehr(at)cox(dot)net. I've ordered the couplers and other parts and am currently co-designing a serious upgrade of the main PS. I'll let you know how that goes with my advisor who has LOTS more experience at this than I.

Where are you? Maybe I can physically help you improve your amps.

I've bought about 4-dozen* 'N7s, NOS and used, and I know they work in the amps, but I've yet to characterize them.

* Just another example of why my wonderful wife calls me Mr. Excess.
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Wow, you seem very involved in improving your amps. Keep me posted on you endeavors. I am a sometimes tweaker, but some of the things you are contemplating are a bit above my level. However, there is always something to learn from knowledgeable people ! I am in Massachussetts, by the way. If you decide to go commercial, let me know. I am especially interested in you 6SN7 experiments.