Monday, June 20, 2011

Jensen Ultraflex Cabinet for 8" Speaker

Today is the end of a long weekend commemorating the 150th birthday of our national hero Dr. Jose Rizal. I can't help but wonder whether he as well as our other national heroes died in vain... I am quite confident our current president is a sincere man who wants to get rid of corruption and lead us towards progress but there are elements in government as well as sectors in our society who don't cooperate. ;o( 

But mulling over matters beyond my control is a waste of time and energy. It's best to turn time and effort towards productivity. ;o) When I lived in the USA holidays were spent building projects to avoid heavy traffic and crowded places, so...

Years ago I wrote fondly about the Jensen Duettes as SE amp friendly budget speakers. I am not abreast with current pricing on these drivers and wonder if they still qualify as budget specials?



 Influenced by the article my buddy Rofiel collected a few Jensen and vintage Japanese drivers and wanted to try a bigger cabinet so I sent him the plans below. A few months later a pair of Ultraflex cabinets built from 1/2" phenolic plywood arrived at my doorstep.


Meanwhile these Ultraflex cabinets sat in a storage bin in the attic for over a year so a week ago I dropped by Joey's shop to cut holes on the front baffle with his router.


High quality plywood is expensive and hard to find in Manila. The closest affordable option we have available is phenolic faced plywood for industrial construction.



Simple crossover using a 2uf paper in oil cap + generic 16 ohm L-pad to the RP103 tweeter. 


Damping material for top and bottom panels as recommended on page 2 of the plan. Initially I was listening without any damping material and it was fine in free space standing on glass blocks. The moment I placed it in a corner, the bass tended to boom. Since there's no Walmart (my old source for Dacron) in Manila, I cut up an old foam pillow. That controlled the bass boom but I may have to experiment further with material and amount of damping...


Bogen B62 (Lenco L70) - stock arm fitted with a Pickering 380 or Shure M7D (coils connected in series) for Stereo LPs played in mono + Velvet Touch viscous damped tonearm with GE RPX---> JE Labs/PAS preamp - Telefunken 12AX7 phono + 12SN7 linestage (only one channel used)---> JE Labs SE71A amp.


Evolution of a mono hi-fi system in the study room...

Saturday, June 11, 2011

Crooked frames in a Barnack?


I've had this problem for years and have read modern film cassettes are 2-3mm shorter causing the image to slant and/or intrude into the sprocket holes in early Barnacks and clones. With a packet of
 stick-on green felt pads sitting in my drawer, I stuck one in the base plate lock and it worked! I did it to all my Barnacks which had this issue.


Not my original idea, credit should go to this post.



Wednesday, June 8, 2011

SU HS4

There have been quite a few procedures done to my '82 Mini which I forgot to document on digital camera. Let's back track a bit...

Safety first!

 Brake lines were bled and refilled with fresh fluid. Brake shoes were thick, master and wheel cylinders were working fine so I just cleaned all the drums, adjusted  the shoes (one full wheel turn) and made sure no air got stuck in the hydraulic line.

Pedal pressure was good for a non-servo brake system and the car maintained a straight line on hard braking.


 My dad's initial enthusiasm to test drive the car was curbed upon hearing rattles. All the swivel joints were on their last shims and duly replaced following this preparation procedure from Mini Addicts. The shot steering rack was another major rattle contributor. Haynes manual at hand, this site and the assistance of a mechanic, Gilbert, who never handled a Mini in his life; we managed to get a brand new steering rack in place in less than four hours in my drive way.

The car is already fitted with Hi-Lo adjustable suspension, coil springs + Koni Classic shock absorbers which lowered the ride height below practical road use in Manila. Standard length KYBs replaced the Konis and Hi-Los adjusted to original ride height.

Brakes, steering and suspension sorted, engine is next....

Radiator removed, cleaned, cooling system drained until there were no signs of rust colored liquid circulating from the water jackets.

I thought the engine was always running too rich and I could not adjust the carburettor for consistent mixture.


 To my dismay the throttle body had a crack, probably caused by an ill-fitting/home made cardboard gasket and over tightening the two intake manifold mounting bolts.


Epoxy steel + DIY gaskets from true gasket material tied me over for a few months....


...meanwhile I scouted eBay and snagged this older SU HS4 for $30. It probably came from a junked Austin America (Austin/Morris/MG 1100/1300). I also ordered an SU repair kit, needle, float, gaskets and etc.


I stripped/cleaned the eBay acquired HS4 and combined the best parts available from both units.

Overhauled SU HS4 to the left ready for installation

I reverted to a non-Waxstat type jet upon confirming with Seven Enterprises that it offers slightly more efficient performance. Since my 998cc engine came with an LCB exhaust, I fitted a new AAU needle. Easily done since it has the self-centering/spring loaded type piston.

The engine started on the first crank but it started to rain ;(
Fine tuning of mixture and other minor adjustments saved for another day....

Icing on the cake - K&N filter for the stock air-box ;)

Tuesday, June 7, 2011

Mini MK IV Wiper Stalk

While working on other issues in the steering column, I inadvertently disassembled the wiper stalk...
...as far as I know this is the proper way to reassemble and it works!

Key points:
brass cylinder at end of stalk = switch contact
brass spring installed in X fashion = single wipe action

Wednesday, June 1, 2011

Steinheil-Munchen Culminar VL 85mm, f2.8 LTM

DIY CLA

Typical user sample with front element cleaning marks, mild haze and some dust specs. I shot a few frames and this was the best I got. I suspected the susceptibility to flare and muted colors (like the shot below) was due to the haze.

Before cleaning @ f4

Dismantling is pretty straight forward - remove the lens head from the focusing mount.

Rear element taken off

Cleaning the haze from the middle element

Front element off

Reverse the procedure for re-assembly

After cleaning @ f4


Steinheil LTM lenses were offered by Sears Roebuck in the 50s as cheaper alternatives to Nikkor for their Tower (Nicca) RF cameras. 

Monday, May 30, 2011

Hybrid Darkroom

B&W film  processing kit 


Changing bag, Paterson tanks, chemicals, timer, thermometer, graduated cylinders and running water from a kitchen or bathroom sink. If you decide to develop your own B&W film, this is a good place to start.

Leica M6 + Canon  Serenar 50/1.8
TX400/Diafine
Diafine is an ideal developer for the tropics since it isn't very critical of temperature but also have Rodinal at hand when I want the look. I've also used Kodak D76 and Ilford DDX.




Negatives hang to dry before scanning...


This Canoscan 8400F flatbed scanner has given reliable service for more than 5 years. I use the Scangear software with all enhancement functions turned off...


...and do minimal post processing in Photoshop 7 - limited to procedures I learned in a traditional darkroom.


This was the darkroom I set up in my apartment in the USA.


Negatives and prints are inserted into Print File sleeves and stashed in binders.

Canon P + W-Nikkor 35/2.5
Kodak TX400 in Rodinal 1+50

Years ago a photographer friend advised that I will learn a lot more about photography if I process my negatives and print them. He was right, I realized I was not born with a gifted eye...he he he! Nonetheless I still enjoy the whole process ;)

Saturday, May 14, 2011

open baffle ---> how not to...


tall and thin baffle = no bass and sexy slim mids

Leica II + Summitar 50/2
APX100/Rodinal

If memory serves me right this was a production line speaker from the 70s, don't remember the manufacturer but seemingly an attempt to mimic the cosmetics of a Magneplanar using conventional drivers...

Kutztown Radio Show, Spring 2006

Update: According to Terry O this is Bob Carver's Andromeda from the early 80s.