First up I thank you "drone on" and "Kreutzfeldt" for listening and supporting music of this kind, and not only mine...your comments really mean the world to me.
This is the story of "butterfly".
I was riding my pushbike one day past a thrift store, stopped in and found a box of twenty or so 7" reel to reel tapes. The price was 50 cents(what a bargain), so I had to give the guy 2 dollars...it didn't seem right. So the actual master came from that box and WAS'NT one of the ones I had to pitch/throw away because of the EXTREME!!! tape hiss. In hindsight I should have given him 50 cents.
It was recorded live onto two 1/4 track Akai tape decks at 3 and 3/4 ips. to make for the slowest loop possible. I had the longest RCA jacks that you could buy at that time which I believe were around 8' and placed the tape decks apart...the only problem was the tape dragged on the carpet and fowled the tape. So I put a bottle on top of a phone book and ran the tape over that...Unfortunately the friction of the tape would either move the bottle producing extreme wow and flutter or it would just plain stop. I filled the bottle with water and it worked so now we have "butterfly " and 2 others recorded in that week in August 1977.
The guitar effects were a Roland Space Echo RE201, the stomp boxes were Ibanez Equalizer & Flanger and Volume pedals a Roland Jet Phaser and a Foxy Lady sustain pedal. I used a double necked Aria guitar and bowed the 12 string portion with a violin bow.
The master sat around until 2004 where I committed it to mini disc. After one play the oxide came off the tape rendering it almost useless, so I was left with transferring it digitally to cd. from the mini disc. As I only use a computer to transfer analog into mp3 and wavs. for release ,I bought the cheapest and easiest software to use and still use to this day. Magix Studio 11 Deluxe...I got it for 20 dollars at Circuit City (open box).
To cut a very long story short, "butterfly" and the other two travelled across the world, went through 6 Florida hurricanes, humidity and came through it unscathed. These tapes had a charmed life. So to answer the question, I have know idea why there isn't any tape hiss on it. I certainly didn't do anything to it other than the fact it's always sounded that way.