12 Apr 2003

           Cactus Tube Dudes of Arizona

Boyd's House.
We went to Boyd's house to see his upgraded Main (big) and family room (little) system. Boyd put on quite a food spread. If you didn't show to this meeting, start kicking yourself and keep doing it until is starts snowing in Phoenix.

This is the big system. This is pair of MTM Altecs with a shared subwoofer. Each speaker has it's own tube power amp. According to Boyd, "Good amps used with a quality electronic crossover outperform great amps with a passive crossover."

The thing that looks like a wooden box on the floor behind the marble top table (with the chess set) is a sennsurround subwoofer driving a bass horn. This subwoofer section drives a horn with a mouth in each corner of the room. With the mouth in the corner, it should appear 4 times larger than the actual opening. I think Boyd said that the sub can go to 14 Hz.

Three guesses on what musical instrument Boyd used to play. . .

OK, your time is up. Boyd used to play BASS!

This is a shot of one tower of the big system with the grill cloth removed. The black area on the bottom is 1/2 of the mouth of the horn subwoofer.

A close-up of the Sierra-Brooks "T" in the "MTM" big system. I like the cool lighted speaker spacers.

The old midranges from the big system are shown below. These old midranges had lots of automotive window putty on them to damp them.

This is his new tweeter amps with Big Farad Capacitors from Apache. I've seen subwoofers with smaller power supply capacitors. This uses the RM-20 output transformer from Japan.

This is the "little" system. (Sorry about the picture distortion.) Edgar Horn mid-tweeters with Altecs 815As behind them.

The power amp is sitting inside the "port."

This is the most recent bass mod to the "little" system. The rear chamber was enlarged and ported out the bottom.

This is Spanky, our Music Critic. He sang along when ever Holly Cole sang. (Holly sings a little better.) Spanky is a Pembroke Welsh Corgi. Spanky also doesn't allow birds to land in HIS yard.

This is Alan's first DIY amplifier. Boy was he a proud Pappa. He Cryo'd it and said the improvement was only subtle.

Volt brought his headphone amp (made from his Foreplay) along for a quick listen. He still claims the amp sounds better with his Grados. The CD player is a vintage RS 3400. The Headphones are Sennheiser HD535s.  Foreplay Headphone Conversion Notes.



Food:
Dr. Pepper, Coke, Mountain Dew, Orange Soda, Guinness, plain beer and more
Ham Sandwiches on tortillas, Salmon, Veggies and dip, Gardettos, Shrimp and more.
 

Big System (Living Room)

CD Player:

CDP-  Phillips modded w/tube driven line stage, (14AF7)
Preamp:
Preamp-  Custom Don Allen tube design with separate power supply.  Line stage 12AU7, phono section 14F7 x 3.


Speakers:

* Electronic Crossover- modded 2-way Marchand XM9 with Welborne Labs power supply.  Linear Technology OP Amps.  Crossover freq.- 900 HZ 24 dB/ Oct slope.
* Tweeters/Midrange- Radian 16 ohm PB235 1" compression drivers mounted on Sierra-Brooks mahogany Tractrix horns.
* Woofers- Custom Altec 816A horn cabinets loaded with reconed EV SRO15 woofers (1960's vintage)
     More info on the custom Altecs
* Subwoofer- MCA Studios Sennsurround model "M" with extended exponential horns, totaling 14 foot horn length x 2.  Loaded with an Eminence Kappa 18 woofer.


Amps:

* Tweeter/Mid amps- custom monoblocks with Softone RW-20 output iron, 5814 driver, 6BQ5 power tube.  3.5 Watts
* Woofer amps- custom monoblocks with Softone RW-20 output iron, 5963 driver, 6BQ5 output tube. 5 Watts
* Sub amp- German Hypex HS200 plate amp with toroidal transformer. Crossover freq- 60 Hz 24 dB/ Oct slope.

RW-20 Transformer Used in Boyd's amp


Small System (Family Room)

CD Player:

CDP-  Phillips modded w/tube driven line stage, (14AF7)
Speakers:
* Electronic Crossover- modded 2-way Marchand XM9 with Welborne Labs power supply.  Linear Technology snob OP Amps.  Crossover freq.- 1320 HZ 24 dB/ Oct slope.
* Tweeters/Midrange- Radian 16 ohm PB235 1" compression drivers mounted on Edgar  horns.
* Woofers- Wall-mounted Altec 815A horn cabinets concrete reinforced with rear chamber scoop porting each loaded with dual Eminence Omega Pro 15's.
Amps:
* Tweeter/Mid amps- Gutted and rebuilt Decware- 5963 driver, 6BQ5 output tube. 3.5 Watts
* Woofer amps- custom monoblocks Push-pull 2A3's, dual rectifiers.  12 Watts
* Alan's S5 electronics 11BM8 8W push-pull tube amp kit ran the tweeter for a while.
 Arizona Hi-Fi, where Alan got his kit.
 Tubes and more carries it too
Low level Interconnects:
Silver plated Teflon microwave coax with toroidal common mode chokes/ Radio Shack polystyrene connectors.
Speaker Interconnects:
2 AWG cables from Apache.
Turntable:   Not used today.

Some of the Vinyl  Played: Not used today.

Some of the CDs  Played:

 
Artist Title
Tuck & Patti Chocolate Moment
Keb Mo  Just Like You
Chris Rea  Road to Hell
Patricia Barber Night Club
Holly Cole Temptation
Khani Cole 

 Tuck and Patti's web site
 Keb Mo's web site
 One of many Chris Rea pages.
 Patricia Barber
 Holly Cole's web site
 Khani Cole

Attendees:
Volt      S.
Dan       A.
Howard    F.
Dave      R.
Dale      S.
Alan      K.
Bill      E.
Sam
Keto
Boyd      B.