The Amp Garage

Who makes a real one?

No one. But there are plenty of NOS models around at very decent prices.

Hilarious... "This TS was converted around 1984 from a stock TS-9 into a TS-808 by THE MASTER of Boutique Amplifiers himself. Yes, the founder and one-man-show extraordinaire of TRAINWRECK TW Amps. Ken was a friend of the gentleman that I acquired this pedal from. He knew Mr. Fischer personally and ...

Primary:

BLK, WHT 117V
ORN shield (should be connected to the chassis)

Secondary:

RED, RED 420V
RED/YEL CT
RED/BLU 60V bias tap
GRN, GRN 6V3

Doug Hoffman sells high quality turrets for $0.11 ea. in x1,000 quantities.

Reverb tanks love current, they behave just like speakers. A 12AT7 works fine there.

An old "nobody wants it" EL83 and/or russian 6P1P in EL84 pin configuration. What's to be excited about?

More like the SV83 of yore if i understand correctly.

Or the Songwriter 30 which seems to me is a Constellation.

Constellation: two differently voiced preamps, one using a 6SN7GT, the other a 12AX7, hi-cut crossline + bright switch, std 12AX7 PI

Songwriter 30: one single 12AX7-based preamp, 6SL7GT probably used in the PI

How you test and verify a cap?

Handheld Tecpel LCR-612 meter for basic measurements (capacitance, ESR...), bench Heath IT-28 for leakage tests and reforming and Sencore LC53 for qualification - both go up to 600 V.

The PT is a F22798. Hammond part number P-T290DX The sight will not allow me to paste a link. But looking at the secondary it shows a 5 volt tap and 3A. So I guess it is safe to assume I can run a 3 amp rectifier tube? No problemo at 3 A. Primary: 120 VAC / 60 Hz. Secondaries: 325-0-325 V @ 200 mA ...

Try connecting a 35V electrolytic to 450V. Molten metal, smoke and lots of powder. Whats the difference? Well, subject a 25 V-rated generic tant to 30 V, then to 35 V, and see what happens... Some of the guys on this board regularly use ancient NOS electrolytics. NOS 'lytics can be fine if properly...

My tip of the week to folks is don't write off good quality Tantalum caps as a replacement for low uF value electrolytics in cathode bypass applications. Tants explode when subjected to over-voltage. Not the kind of caps I use in MI applications... Some elcos are really good for bypass or even coup...

So is this the circuit?

Here it is, straight from Kendrick. The 14K slope resistor seems quite strange, 56K or 100K would be better IMO. Also note that the 100p bright cap is hard-wired.

What about a parallel triode cathodyne arrangement with a 12AU7. It seems that that tube has the "gusto" to drive these tubes properly.

You may consider using a 12AY7 or similar in the cathodyne, with a 12AU7 driver or paraphase follower.

You guys ever use the triodes in the 6bm8?

They are similar to half a 12AT7. Purrfect for a PI or a reverb driver or...

sometimes I just use a particular value cuz I like the way certain band colors go together.

Zen and the art of amp building. That's why masters of the craft don't like the new Mallory 150s in their white guise. No soul, man, no tone.