Later cathode bias amps

Grey panels - mid 1965

Continued from

Serial number 391 - currently in the USA

A complete AC100 SDL, as serial number 392 below, in great condition. In common with all grey panel AC80/100s, the choke has the date code "AW" = January 1965, and the two main transformers "BW" = February 1965. The original amplifier section cover survives, as in the case of 392 (click on "further pictures" below) with an off-centre VOX logo.

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Serial number 392 - formerly in the USA, now in the UK

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Chassis no. 1020. A single owner amp, purchased new in Oklahoma City along with a second AC100 for use in the band "The Concepts". Aside from one minor addition in the preamp, all original. Only the valves and casters have been replaced (the original valves still exist). Note that "92" is chalked on the inside of the box and the back board. The speakers are dated May 1965. The second AC100 was sold in 1967. Thanks to Dave for the details and pictures.

Serial number unknown - probably high 300s - currently in the USA (collection: Robert Furgiuele)

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Chassis no. 1083, but no serial plate. A fine looking amp: in the left-hand picture in its original thick-edged box atop a North Coast Music trolley and cabinet; in the right, in a thin-edged North Coast Music cabinet. Grey panel, domed voltage selector. Evidently does not have a separate tab board for the rectifier diodes, as has been reported for serial nos 406 and 420. Thanks to Robert for the pictures.

Serial number unknown - probably high 300s - whereabouts unknown

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Chassis no. 1091 (see the last picture). Cathode biased. Sold on ebay in August 2007. Note the presence in the fourth picture of the Woden output transformer with an unpainted shroud (the mains tranny is evidently a replacement), and in the other pictures, the white Erie resistors. Serial plate number unknown. Another fine-looking amp. In these pictures, the Woden transformer codes are unfortunately too small to read.

Serial number 406 - currently in Florida

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Chassis no. 1094. No pictures of the amp available at present, but above, the original Cannon power socket, which came from the amp's original owner, Chuck Kirkpatrick, guitarist with the "Proctor Amusement Company", a highly successful Florida band. For pictures and info, see the and the interview .

In an email, Chuck related: "I actually had 2 AC-100s. The first was stolen out of a warehouse. I found another and paid $150 for it (this one)! I drove 2x12 Altec 417s in a Bandmaster cab. Played a Rick 360-12 and a Tele through it...no effects at all. Talk about "jangle" and "chime". Years later I drove a Marshall 4x12 slant-bottom with it, fed from the preamp output of a blackface Super Reverb. Imagine a Les Paul wide open through a Super with 2x12s and then 4 more Celestions driven by the AC-100. Popped the output transformer in '81 and couldn't afford the $200 to fix. Left it at the shop and the guy finally sold it off."

The grille cloth and logo were changed early on to match the Bandmaster cab. No. 406 (certainly an AC80/100) was later acquired by "Florida Sam" on VoxTalks. Verified by Ted Breaux as having the small "stand-up" Woden choke, old-style Woden mains and output transformers, and a separate tagboard for the rectifier diodes [not sure what that signifies]. Although sections of the VoxTalks archive are now inaccessible, a pdf of the text, which relates to this amp and no. 420 below, is available here.

Serial number 408 - formerly in Oregon, currently in Russia

Below, older pics

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Chassis no. 1002. An AC80/100 in good condition, and still in excellent working order. A few replaced capacitors here and there, otherwise all original. The choke has the code AW and the mains transformer BW, as is the case with amps further up this page, and no. 416 below.

Serial number 416 - currently in the US

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The serial number plate is a repro, but is likely to preserve the original number. This is certainly a cathode biased amp. Chassis no. 1019, as reported by Jim Elyea. for the Plexi Palace thread. Some of the vinyl has been refurbed (and the corner protectors, now with double pins) - but note the central fixing on the upper back panel of the amp, and the rectangular Cannon XLR sockets. A great inventive repair to the trolley (back view). Thanks to Paul for the pics.

Serial number 420 - currently in Louisiana (collection: Ted Breaux)

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Chassis number variously reported as 1070 and 1073, but actually 1074, as one can see from the pictures. A nice cathode biased amp in excellent condition. The Woden transformers (with unpainted shrouds) have codes BW = February 1965; and the choke has AW = January 1965. Note that these are the same as serial no. 337 above. At some point in the amp's history, a fan was fitted to the box - a useful precaution in a warm climate.

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Caught in the devastation of Hurricane Isaac in 2012, the amp restored in a new livery - a fantastic thing.

Serial number 424 - currently in the US

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Chassis no. 1130. Note that there is a wrong second number (as in the amp below) - in this case 1027. Original transformers in place. Elements in the power section have been renewed - note the 500ohm cathode resistors. The preamp is in original order.

Serial number 430 - currently in the US

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Chassis no. 1135. "1135" was added, however, after something went wrong with the original stamping. "108", which is in the correct position for the chassis number, is stamped out. Perhaps it was meant to be a number in the 1080s. The choke has the code "AW" = Jan. 1965, and the transformers "BW" = Feb. 1965, as all the amps higher up on this page. The dust cover of the amp has the name of the 1960s Milwaukee band "The Skunks" on it. The current owner acquired the amp from Zeb Billings' Piano and Organ store in Milwaukee probably at some point in 1965. The last image above is from Billboard magazine 1969, available Thanks to Gary for the pictures.

Serial number in the 400s - currently in the UK

Chassis number 1140 (1004 crossed through). The Woden mains transformer has the standard date code "BW" = February 1965. The cathode bypass caps and resistors underchassis have "WA" = January '65. The amp was owned by Robert Valentine, who worked at JMI from 1959 to 1964, and repaired for him by Alan Pyne, also formerly of JMI, in 1979. Thanks to Martin for the pictures.

Serial number 444 - currently in the US

A later AC100 Mark 2 produced by Triumph Electronics in later 1965 and given the plate 444. Plates on Triumph-made AC100s are fairly random. See .

Serial number 448 - currently in the US

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Chassis number 1010, changed to 1145. Preamp and power amp very little changed. The Woden transformers have the standard date code "BW" = February 1965. In the power section, the Welwyn cement resistors and Dubilier cathode bypass capacitors have "WA" = January 1965. On the back board, the mains socket has been replaced with another XLR. At least one of the Sylvania-branded Mullard XF2s has the date "B6I2" = 2nd week September 1966. Thanks to Tony for the pictures and info.

An early Woden output transformer in a later AC100

2098

A late AC100 - serial no. 2098, registered on - has an early Woden output transformer with unpainted shrouds - part no. 79806 (as in serial number 337, and other amps above) The date code is JW = September 1965, however. Perhaps from an AC100, or more likely, an AC50.

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