TT Artisan Light Meter

 Eleven days after I uploaded my shoe mount light meter article, I took delivery of this light meter from TT Artisan. It came in a nice Japanese-style package!

The light meter requires a 3V CR2032 battery, which is not included due to shipping restrictions. A small screwdriver is supplied for installing the battery + a user manual. The official set up instruction is available on You Tube, so I'll skip those details.

I guesstimate it to be about 15% larger than the Voigtlander VCII.

Unlike the VCII, there are no alternative locations for the feet. As is, the light meter didn't clear the rewind knob of my Contax II and clones made in Kiev. A cheap and quick solution is some sort of an accessory shoe that can elevate the meter. 

Does it overwhelm a Barnack type body?

Despite the larger dimensions, the dials and markings are smaller than the VCII. Perhaps this only matters to a certain demographic that requires reading glasses, that's why I noticed it. 😉 

The TT Artisan has a 45 degree measuring angle vs. the VCII's narrower 30 degrees. This probably accounts for the 1/2 stop difference. Since it’s equipped with a Silicone photodiode, low light sensitivity seems to be as good as the VCII or at least at par with the Vivitar 24.

The Doomo Meter D shares similar technical specs with the Voigtlander VCII, including the svelte proportions of the latter at $125. I snagged my TT Artisan at the introductory price of $56/shipped. The price is now hovering at the $70 mark, but it still is the only shoe-mounted light meter with analog dials available new for under $100.

 

The Canon P is loaded with ISO 100 film. Watch out for the results in my Flickr!😊

Tube Rolling Fun (and Peril) + Adapters

Tube rolling is a fun aspect of the audio hobby. It only gets tedious when audiophiles start splitting hairs about a VT231, 5692, etc. I draw the line when an audiophool claims, "...my line stage preamp resolves the R train rumble under Carnegie Hall better when I use a 6AS7 in place of the original 6SN7..." 🙄  

Those two tubes may be pin compatible BUT a power transformer 🔥melt-down🔥is imminent since the 6AS7/6080 draws 2.5 amps @ 6.3V. That's over 4 times more filament current drawn by a 6SN7, which only draws 0.6 amps @ 6.3V.

 💣 💣 💣 Rolling tubes is dangerous unless you have a working knowledge of electronics to comprehend tube data/specs. 💣  💣  💣 

It's been a while since I listened through Telefunken 12AX7 smooth plates on an RCA phono. Since I used to graft this circuit on a Dyna PAS preamp, I ordered a pair of 12AU7/12AX7 > 6SN7/6SL7 adapters to relive the experience on my RCA octal preamp.  

Back in the 90s, Steve @ Angela Instruments had a boatload of Raytheon 5755s and shared a sleeve with me. Since I never found a project requiring these tubes, I got a pair of 5755/WE420 > 12AX7 adapters to listen to them in the Shure M65 clone. Piggy-backed to 12AX7>6SL7 adapters, they also worked nicely with the octal phono preamp. 

Despite slight differences in transconductance and plate impedance between the 6SL7/7F7 and their younger 9-pin siblings (ECC83, 12AD7, 5751 and 5755), there was no visible variation in square waves nor frequency response aberration when I bench tested those tubes in both circuits.

Admittedly, loctals don't look as glamorous as their octal cousins with bakelite bases. But I'm very fond of them to the extent that I built and use a full function loctal preamp. I've been adopting unloved loctals at radio shows and hamfests. Essentially the industrial looking 7F7 and 7N7 are rebased 6SL7 and 6SN7, respectively! My only issue with loctals is, the tube pins are prone to corrosion. This is easily remedied by a wire brush + DeoxIT before use.

I purchased these tube adapters from the seller xulingmrs. They are very well made and fairly priced. Shipping cost and transit time from China was also reasonable. Highly recommended!