St-35 build pic.

[Brik]

Hi all,

Thank you, Ed, for the information regarding magnetic orientation of the PA774.
I did not realize this even though I took the bell housing off for painting. Yellow_Light_Colorz_PDT_02

I made this amplifier for my 16-year old daughter to go with her brand new iPod. The size and color scheme were her choices.
She thinks vacuum tubes are “cool”! I hope she is old enough to know not to touch the 6BQ5s when they are on…Yellow_Light_Colorz_PDT_08

It’s difficult to estimate the cost of this project since I buy common parts such as capacitors, resistors, sockets, etc
in bulk packages or in large quantities when there is a sale. The estimate below assumes regular, non-sale,
non-bulk prices.

Summary of parts:

Power Transformer: Triode PA774 : $60
Output Transformers: Triode TF110-48-UL : 2 * $23 = $46
Vacuum Tube Set: Antique Electronic Supply T-DKST35-2 : $48
Chassis/Bottom: Hammond 1444-15/1434-16(10”x6”x1”): $16
Power Filter Caps: 3 * 450WV/120uF : 3 * $3 ~ $10
Assorted Orange Drops/WIMAs: $15
Other Caps/Assorted Resistors: $15
Switch/VR/Terminal Strips/Power Cords/Fuses/Sockets/etc.: $20
Paint: Krylon Appliance White Epoxy Spray Paint: $7
Krylon Satin Gold: $6
Shipping & Handling: ???

All told, I spent less than $250 on this project.

/b

[EWBrown]

Those 6BQ5s do get hot... but then, so do 100 watt lightbulbs.

If you're near Boston, (and Cambridge) check out the MIT swapfest / flea market which is held on the third Sunday of each month from April through October. I haven't been there lately, but there are always good bargains and lots of "vintage electronics" available. I've precently osted particulars about this flea elsewhere on this site.

My best "hit" there was a big zip-lock bag full of dual triode "pulls" that were found in a dim dark corner of some storage room of the MIT Computer Lab. All were 12AX7s, 12AT7s and 12AU7s, the price was a dirt cheap five bucks , and the yield was about 95% testing as perfectly good. These tubes were swapped out on a timed regular basis on the 1950s vintage computers, and other than a couple with their top nipples broken off, none were really "bad", just a few slightly less than "like new" test results.

A later find, that a friend brought to me, was even more dual triodes, this time including LOTS of GE 6350s, price was even dirtier and cheaper (a whole buck). Not that these nice bargains crop up every time, but who knows...

Lots of the NNETG (Northern New England Tube Group) NNUTs show up almost religiously, selling and seeking.

ALso, don't overlook yard sales and local flea markets, I've found ocasional tubular bargains and even a few freebies (they just want to get rid of that "old tube junk") .

/ed B in NH

[Brik]

Hi Ed,

Thank you for the tips regarding the swapfest. I live 20 miles West of Boston, so getting to Cambridge is no problem. Was it at Albany and Main?

I love the idea of building a large stash of "interesting parts" and "potentially useful parts some day" in addition to current "likely to be needed parts" and "needed parts."

I am hoping to find a magic eye tube for a bias adjustment indicator for the next fixed-bias build.

/b

[Shannon Parks]

I love the idea of building a large stash of "interesting parts" and "potentially useful parts some day" in addition to current "likely to be needed parts" and "needed parts."

It doesn't take long to get to this point! Just ask my wife. :)

[EWBrown]

I believeit is Albany and Main, or in the parking garage? I haven't been there in a long time, I don't remember all the details, and Kendall Square and area has changed a LOT since I have last ben there...

(lifted from an earlier posting)

If you're in the Boston area, check out the MIT hamfest / swapmeet that is held everh third Sunday all spring and summer long. I believe it starts this coming Sunday, and every month through October.

15 April Cambridge MA, FLEA at MIT, Nick 617 253 3776
Third Sunday April thru October

It's big enough you can't miss it...


/ed B in NH