Vox AC30 website updates
June 2020
30th June (2)
Some updates to the pages on serial numbers in the 9000s and 10000s - early 1964.
30th June
Below, serial number 9434, from early 1964. Its Celestion blues are dated "07LH" = 7th December 1963. Other date codes in the amp are also of December '63. Further pictures can be found here.
29th June (3)
Old pictures of two more amps in a light blue. Painted or original vinyl? Difficult to say for sure, but in the case of the first picture the latter seems most likely.
Could the second be paint over beige vinyl? The brown showing through in places may of course be the vinyl backing. The highest serial number for a beige AC30 at present is 7109.
A single image of this amp at the moment.
Serial number 7568N. It may be possible to provide further images shortly.
29th June (2)
A note on Woden transformers in 1964. If indications are correct, Woden produced a large batch for JMI in early 1964. Mains and output transformers had the date code "AV" (January '64), the choke "BV" (February '64).
These were mostly used by Burndept through to the middle of the year. Woden then drops out of the picture. The two chassis subcontractors used Albion and Parmeko, more or less exclusively.
But Woden had not been phased out. In the autumn of '64, the company produced a new set of transformers for JMI, constructed differently, and given new part numbers accordingly. The earliest units have date codes of August 1964, apparently being used for the first time in amplifiers with serial numbers in the 15000s.
Serial number 12004 - output transformer date code is "AV" = January 1964; the choke has "BV" = February 1964.
Serial number 15881 ( not 15531 as previously stated. The date code of both output transformer and choke is "HV" = August 1964. Part numbers are 76853 and 76854. The mains transformer that should accompany this set has the number 76852. But in the case of the amp above we have a Parmeko.
29th June
Thanks to Chris, pictures of the plate of AC30/4 serial number 4606N, and the speakers that travelled with the plate, presumably from the amp's cabinet. The date codes of the blues are "16FF" and "29FF" = 16th and 29th June, 1961.
AC30/4 number 4606N will therefore have been ready for sale at some point in early July '61.
"AC30 4W" "4606 N" The "N" for "Normal voicing" was stamped over a "B" for "Bass". The cab is later - from 1964, with rounded corners to the backboards, basketweave vinyl, and black vents.
The cone code is "RIC 1YG"
Date codes "16FF" and "29FF" = 16th and 29th June, 1961.
28th June (2)
The page on AC30s with serial numbers in the 14000s has now been started.
28th June
A page coming soon on AC30 stands. Below, the famous Dezo Hoffman pic of the Shadows, and a detail of one of their early "tray" stands.
Photo by Dezo Hoffman, late March / early April 1962.
Detail, showing the applied/embossed "VOX" logo.
27th June
Serial number 6364 now registered here. Thanks to Nick for the pictures. The Celestion blues have date codes "04MG" and "18MG" = 4th and 18th December, 1962.
Serial number 6364B
25th June
A page dedicated to AC30 transformers has now been set up here. It may be necessary to divide it up in due course, as it will certainly grow.
22nd June (2)
Some pics showing: (a) values of the cathode resistor in 1961 and early 1963, i.e. before the revision of the circuit in late 1963; and (b) the arrangement of the grid resistors in 1961, early 1963, and later 1964.
1961
AC30/4. Value of cathode resistor: 80ohms (as indicated on the schematic). Note that the 1/4watt (Type 9) Erie 100ohm grid resistors are arranged parallel to the tag-strip.
Early 1963
AC30/6. Chassis assembled by Burndept. Value of cathode resistor: 82ohms.
AC30/6. Erie grid resistors curl from the tag-strip.
Last third of 1964
AC30/6. Chassis assembled by Westrex (grey panel, link voltage selector, integral top boost). Value of cathode resistor: 50ohms. Brown Dubilier grid resistors.
22nd June
At first, the picture immediately below seemed to be of a third Super Twin in red. But if one looks closely at the marks on the grille cloth (speaker cabinet and amplifier section), one can see that it is actually serial number 7086N, the alteration in condition of the vinyl pronounced in the later published photograph.
Serial number 7086N. Note the new-style plastic handle = early 1963.
21st June
Pictures of the TV Front AC30/4 that emerged in 2010 (entry below, 18th June) are now here.
20th June (3)
More on AC30 mains transformers, in particular pass-through holes in chassis for the primary voltage taps.
In Haddons and Albions the wires that feed to the voltage selector issue from the upper section of the transformer and pass through the upper chassis.
In Woden transformers, the wires feed from the underchassis, passing through the preamp chassis much lower down.
The interesting thing is that the adoption of Wodens by JMI required the provision of an extra hole in the preamp upright. One would have thought that Woden would have been asked to produce a transformer to suit the existing chassis - with primary wires feeding from the top (as in the case of Haddon and Albion) - but obviously not.
Presumably it was easier (and perhaps cheaper) to have chassis made with an extra hole than to ask Woden to produce a transformer with a different type of primary.
Serial number 4763. Haddon mains transformer, wires passing through the upper chassis to the voltage selector.
Serial number 5329. Albion mains transformer, as above, wires pass through the upper chassis to the voltage selector.
Serial number 6097. Woden mains transformer, wires passing from the underchassis up to the selector. Note the presence of an unused hole higher up (so an Albion could also be fitted).
AC30 from early 1963. Picture showing the wires feeding from the lower chassis.
20th June (2)
The mains transformer below is probably from an AC30 - a Woden? Its secondary has two pairs of wires for the preamp and power amp valve heaters (6.3v), and a twisted pair of red for the rectifier (5v).
20th June
Some pictures coming later of a knocked-down 1960s guitar amplifier mains transformer, not from an AC30, but similar in physical characteristics. NOTE (added) - the transformer is probably a Woden, see above
It turns out that the Super Twin recovered in Korg white vinyl, amplifier section with black panel chassis, is a later assemblage - the chassis does not belong with the cabinets and speakers. A picture from a folder in deep storage shows that the amplifier is in fact a pre-LOC AC30/6, i.e. from before May 1961. JMI did not introduce Super Twins until much later in the year.
Note the separate tagboard at left (with green capacitors) for the vibrato/tremelo footswitch circuit.
The entry for the amp on the page on black panel AC30/6s has now been updated.
19th June (2)
A supplementary note on the Geloso three-pin speaker connectors found on early AC30 Super Twins, late 1961 and early 1962.
In many respects, Geloso, based in Milan, was well ahead of the European field in its development of connectors. American-made Cannons were not taken up by Vox until later in 1962.
The shortlist of other instances of three-pin Gelosos at present is: early Vox and Hohner guitars (as has already been mentioned); Vox Domino piggy-back amps; and Binson Echorec echo units.
AC30 Super Twin II serial number 5002.
A Vox Domino piggy-back bass amp with its original Geloso connector and cable. In the fourth picture, the end of a NOS plug - a Geloso 396CR.
19th June
Perspex AC30s: leaving aside the question of whether perspex amps really were produced for display purposes in 1963 (it has been suggested, but there is good reason for thinking not), some examples below from 1964 and 1965:
1964
Picture taken at the Vox stand, "British Musical Instrument Industries" Trade Fair, Russell Hotel, London, 24th-28th August, 1964. This is NOT 1963. For more on the '64 Fair, see this page on the Vox AC100 website. Underneath the perspex AC30 one can see a copy of the 1964 JMI catalogue.
Detail from the picture above. Images of a 1964 dealer catalogue, a copy of which can be seen clearly on the AC30's podium, are on this page.
For the time being, a single picture of one of the amps from 1964 - note the blue speakers. Further images of this amp will be added when I have retrieved them.
"Beat Instrumental" magazine, October 1973, signalling that Dallas Arbiter had taken over Vox ("Vox Sound Limited" as it was from early 1970 to its collapse in late 1972). The perspex AC30 is certainly an old one, probably from 1964 - note the cursive "VOX" logo. The small piece of text that is visible on the gaskets of the speakers looks like "T5" = T530 - but perhaps too indistict to be wholly certain.
1965
One of the later amps, sold on ebay in 2007. Grey control panel, new-style "dome" voltage selector. The speakers, presumably T1088s, have been chromed.
18th June
Pictures from 2010 of a TV Front AC30/4, recovered in brown and blue, no serial number plate. A fifth jack socket was fitted at some point on the control panel, presumably for a plug-in footswitch.
The chassis and perhaps also the cabinet were sold later (c. 2013) - pictures halfway down this page - as a TV Front AC30/4 in blue vinyl, with a "wrong" serial number plate, repro control panel, and Celestion greenback speakers. Note, however, the blue and white capacitors and the inspection tag in the chassis.
In 2010 the amp had one straight backboard, and one with a cutaway. In 2013 it had two cutaway boards.
In the preamp, a number of black WIMA Tropydur capacitors survive. One of the potentiometers, just in picture in the fourth image, has the date code "HH" = August 1960.
In the power section (pictures to be posted shortly on the main TV front page), are Haddon transformers and Radiospares choke. The output transformer is of the same construction as the one from 1960 illustrated in yesterday's entry.
The speakers in the cab are Goodmans Audiom 61, of the right era, but perhaps not original.
17th June
Further pictures and notes in preparation for the new page on transformers. Below, three Haddon output transformers from 1960, 1961, and 1962/1963, respectively.
From 1960-1961 a pair of red wires was provided for the HT. The pair later became single.
Just to mention that transformers made by Haddon had been used by Jennings in the AC/30 of 1958-1959, and in AC1/15s produced in the same period.
1960
As Glen Lambert has pointed out, the laminations are built up in layers, in this case layers of three and four - one set of three plain end forward, the next of four at 180 degrees, with cut-outs forward.
The underside of the transformer pictured above.
1961
Still double red wires for the HT.
1962/1963
Still double red wires for the HT. Thanks to Marc for the picture, and the one above.
16th June (2)
Insofar as one can tell from outward appearances, the output transformers that Albion made for JMI retained the same internal structure from 1962-1965. This does not mean to say however that construction was always the same from year to year, or that exactly the same materials were used.
In terms of wires, a single red for HT; single green, blue and black for the speaker terminal block.
Serial number 5329. For further pictures, see this page.
Below, an Albion output transformer from c. 1964, same arrangement as above: single red wire for HT and single wires for the output taps.
Above, an Albion output transformer from c. 1964.
Albion output transformer of AC30 Super Twin serial number 3349, early 1965.
16th June
Below, a Woden output transformer made in January 1963 (date code "AU"). Note the twin red wires for the HT, and the doubled-up green (8ohm), blue (15ohm), and black (common) for the speaker terminal block.
Output transformer of an AC30 assembled in early 1963 - see this page.
Speaker terminal block.
Woden produced output transformers of the type represented above - fairly complex internally - from autumn 1962. They are likely to have been expensive and, more to the point, time-consuming to produce. The JMI part no. is: 66310 & J/83.
In the late summer of 1964, a new type of output transformer with a simplified internal structure was arrived at: a single red wire for the HT supply; and single windings for the impedance taps. The JMI part no. for this new type is: 76853.
Woden output transformer produced in November 1964 = "KV" - No! "KV" = October 1964. The plain metal shroud (instead of the enamelled green of the previous type) was doubtless a further means of cutting down on cost and time needed for production.
13th June (2)
AC30 Super Twin Reverb, serial number 7785, first version amplifier section (rectangular rather than slope-sided box), first half of 1963. Thanks to Phil for the pic.
13th June
Pictures of the interior face of a back board from a beige (fawn) AC30. On the back, in pencil:
"JENNINGS AC. 30. BACKS. 26 3/16" x 8" x 3/8" PLY. 10[0]" - the final zero of "100" probably lost when the cut-out for the top-boost controls were made.
It is very likely that this board was the top-most one in a stack of 100 from the cabinet maker. Thanks to Glen Lambert for the pictures and info.
11th June (2)
It may take a little while while to reach AC30s made in the 1970s. Leaping ahead a little though, it seems worthwhile to post a detail from an advert placed by Vox in a catalogue (of 90 pages) issued by Frank Hessy's in 1971. Vox - "Vox Sound Limited" at this point - had already released a larger version of the advert as a whole in "Melody Maker", 5th December, 1970.
Frank Hessy's is well known of course in connection with The Beatles and other groups from Liverpool. 1971 will have been its tenth year of selling AC30s.
11th June
A superb Super Twin with original maroon/burgundy covers went by on ebay.uk recently, serial number 2739.
10th June (3)
Also straddling the change from black panel to early copper panel AC30s was the use of Rendar jack sockets with fixing screws as well as solder terminals. Below, a detail of serial number 5002N showing five of its six original Rendars still in place.
"Rendar Instruments Ltd" was based in Burgess Hill, Sussex.
10th June (2)
A brief trawl through available pictures of the underchassis of early copper panel AC30s shows that the use of white EL84 sockets, carried over from production of black panel AC30/6s, continued no further than serial number 5225, and had perhaps come to an end well before that. See the entry below, 7th June (3), for the underchassis of serial number 5002N.
10th June
The page on Celestion blues has been started. Still in its infancy, it can be found bere.
8th June
Some quick shots of the speaker cabinet of Super Twin serial number 5002. Both Celestions have cones RIC 1 DJ, and date codes "22FM", one of those instances where the letters for month and year are given in reverse. The date envisaged is 22nd December 1961. "M" as the year makes no sense at all where Celestion blues are concerned.
Super Twin number 5002 is therefore from early 1962 and one of the earliest surviving with a copper panel and charcoal vinyl. Most early Super Twins seem to have gone out in beige.
7th June (3)
A few preliminary pictures of the amplifier section of Super Twin serial number 5002N - probably originally a Super Twin II. Vinyl is dark grey, very fine and tight on the cabinet. It is worn at all corners and most edges. There are no visible date codes in the preamp. One of the pots seems to present an "I" which may be 1961, but not certain.
In the power section: the main Hunts filter cap. has the date code "HSW" = 25th week of 1961. The blue Hunts 32uf cap. underchassis has "WYW" = 10th week of 1961. AC30/6 schematics indicate a 8uf underchassis; but most amps have 32uf. The Welwyn 22K resistor has the date code "SE" = May 1961.
The original leather handle is gone, the present one a later replacement.
It looks as though the serial number plate was positioned initially in such a way as to leave no room for the cup washer of the screw underneath it.
Further pics to come.
7th June (2)
Thanks to Glen Lambert, pictures of an Albion output transformer (of 1964) taken after its laminations had been removed. Glen kindly outlined the salient aspects:
- the plain rectangular tube section paxolin former - not really a bobbin at all. The wire was simply wrapped around and built up in neat layers with very fine waxy paper in between each layer.
- the grey loops of wire are the links between the interleaves. These are a way of distributing the layers more evenly throughout the "bobbin", for both mechanical and electrical benefit.
- the '64 label used by Albion.
- the single red wire used for the centre of the Primary, as opposed to using two red wires (as per Woden).
- everything is papery in its construction, and plenty of wax.
The underside of the transformer: at left the wires that feed to the output block - black (common), green (8ohm), and blue (16ohm). The Albion label across the outer cloth wrapper. On the far side of the underside, the yellow wires (to the plates of the EL84s); and red (voltage supply).
7th June
Just to add that the maker of the metal XLR sockets illustrated below was Geloso, an Italian company based in Milan. Geloso also made cable plugs to match. Thanks to Martin Kelly for the info.
6th June (2)
A short note on the XLR connectors on early Super Twins. Serial numbers 5002 and 5329 both preserve their originals - very basic metal affairs.
Such sockets are also to be found on guitars produced in 1961 and 1962 by Stuart Darkins for Vox and Hohner.
I have no idea at present who made these connectors. It looks as though their fascias were originally circular and parallel segments were cut away - presumably so they would fit on the edge of a guitar body.
Serial number 5002N, amplifier section. The jack socket is a later addition. The presence of the two sockets suggest that this may originally have been a Super Twin II.
Serial number 5329, speaker cabinet.
Hohner Holborn produced by Stuart Darkins, closely related to the Vox Ace.
6th June
This is what Dick Denney dreamt of for years of course before he came up with the AC30 twin, Martin Lukins whispering softly "Dick, Dick, put two and two together".
"Accordion Times", September 1958. The advert was repeated in slightly different formats well into 1960.
5th June (2)
Just to signal that a note has now been added (in russet) to the entry below.
5th June
Below, pictures of a black panel AC30/6, photographed in Italy a few years ago and possibly still there. There is no way of telling at present whether the circuit is pre- or post- "List of Changes" - i.e. the changes introduced in May 1961.
It is interesting to see its complement of speakers: a Celestion T3757 / T530 and a Celestion BO24. The same pairing is also found in the cabinet of a "post List of Changes" AC30/6 from the last third of 1961.
Black panel AC30/6 in Italy, box recovered, jack plug sockets replaced. In the cabinet, one CT3757 / T530 with "Vox" label, and one BO24. BO24 tend not to have "Vox" labels - or to put it another way round, Vox only had labels at the time when CT3757s came into use.
The question, which has to be left hanging for the time being, really concerns the introduction and supply of the Celestion "blue" during the course of 1961.
In overview, the chronology in terms of Celestions in AC30s was: - BO24 (and sometimes BO25) first; Celestion T3757 hammertone/oyster finish; Celestion T530 hammertone/oyster finish; Celestion T530 blue finish; Celestion T1088 silver/polygrey finish.
But there were evidently, at times, overlaps between old and new; and probably deliberate "reversions" when stocks of "new" speakers ran out.
The lack of reliable data on early Celestion blues is intriguing. Has anyone actually *seen* (rather than just heard speak of) a blue with a date code of January 1961, the month in which they were apparently introduced? The form would be two numbers then the letters "AF" - 30AF, for instance, for the 30th January 1961.
By and large most of the blues that crop up for sale on the open market are from 1963 and 1964; and quite understandably owners of early AC30s are reluctant to loosen original nuts on speaker baffles just to investigate "some code".
Note added: - One exception is an example from late 1961 that came up a few years ago:
Sold as a "1965" blue. The date code is "18KF" = 18th October 1961.
The earliest Celestion blue T530 that has surfaced recently is the one posted by Steve Walsh on the JMI Facebook group - a couple of pics below. The date code is "14EG" = 14th May 1962.
Further below are pics of a hammertone/oyster T530 from an AC15, date code "21FE" = 21st June 1960. Presumably in the second half of 1960 there was little distinction between a CT3757 and T530. For a pair of CT3757s (with "Vox" labels) from August and September 1960, see this page.
The page on speakers - link immediately above - will be expanded again shortly. Celestion T530 blues should have a new page of their own.
A beige Super Twin cabinet from the second half of 1962, exterior painted black. The date code of the Celestion blue in picture is "14EG" = 14th May 1962.
The speaker from a single-speaker TV front AC15, beige diamond-pattern vinyl. The date code of the T530 is "21FE" = 21st June, 1960.
4th June (2)
A picture from 2013 of a further AC30 in light blue. There may be something in the files to indicate where the shop was - if so, to be supplied. An overview of AC30s in coloured vinyl can be found here.
4th June
A couple of Super Twins from late 1963 still with blue JMI inspection tags. The first is distinct enough to read: "AC/36, Bass Amplifier".
3rd June
Some details of the small footswitch tagboard in five AC30/4s. The boards have 6 ways, and contain components C29, C30, C31 and R58 and R59 on the schematic (OA/032).
Note that the fifth example below is upside down in relation to the first four. The resistors are the same way up as others in the amp, however - silver tolerance band at top - and one, showing no signs of having been removed and replaced, lies squarely over one of the screws holding the board in place.
More on AC30/4s can be found on this page.
Detail from an AC30/4 now with a later Lemark output transformer as a replacement for the original. All resistors are the same way up, silver tolerance band at top. Silver indicates that the actual value of the resistor lies within +/- 10% of its marked value.
2nd June (2)
On page 5 of the Plexi Palace thread mentioned towards the end of the entry below:
Good to have eye-witness testimony. So some (or perhaps all) of the labels were evidently not applied by JMI
2nd June
Notes on JMI and AC30 transformers, some dim-witted and obvious but there anyway in the train of thought:
2. JMI
Transformers are the most expensive and largest item on most valve amp chassis. One has to know how big they are going to be before a chassis can be designed and put into production. Thereafter any transformer sourced from a new supplier needs to be of the same size - so the chassis and its cut-outs do not have to be redesigned.
To judge from the picture of the prototype AC30 chassis published by Jim Elyea, Dick Denney and Derek Underdown worked initially with bits and pieces. The question is who supplied the transformers that enabled Dick and Derek to finalise the new chassis - i.e. establish the position and size of the cut-outs, the thickness of the metal to avoid bending and buckling under the weight of the iron, and so on. Was there an existing Haddon or Radiospares unit that could be used? Probably not.
From a basic "design" standpoint certain criteria would have to be met for the transformers. For the mains: the ability to supply 5v to the rectifier and 6.3v to a given number of valves (preamp and power); the provision of a specified main voltage before rectification; centre tapping; the ability to choose from a selection of input voltages (115v-245v); and a certain amount of resilience to stand up to the heat generated in a cathode biased circuit.
Whether the transformer maker would have been given any information about "local conditions" - the box the units were to go into - is an open question. AC30s can get extremely hot, even early ones that run the valves less hard than in later amps. The chassis is extremely tight in the wooden cabinet. Heat for a mains transformer is the enemy, breaking down the insulation between windings.
For the output transformer, the criteria would be: the required power handling, in other words the output from 4 x EL84; 8ohm and 16ohm output taps; and an anode to anode impedance of around 4K ohms, though in practice this might vary between 3.3K and well over 4K.
Presumably (surmise) the general design specifications would be arrived at in consultation with the transformer manufacturer. The rest would be up to the manufacturer to define and create - the winding ratios; the grade of grain-oriented steel to use for the laminations; the type of insulation. Many of these aspects would coalesce as a matter of cost versus profit, and time versus available labour.
It is probable that Dick Denney and Derek Underdown tried several manufacturers as part of the initial setting up process - i.e. to see if there were any anomalies in terms of frequency response and so on "in the real world".
Numbers of AC30 twins produced in 1960 and the greater part of 1961 were quite small - around 700 in total. Haddon presumably could cope.
From mid 1961, JMI began to increase production of AC30s exponentially. Assembly of chassis was farmed out first to Westrex, based in north London. Burndept, based in Erith, was brought in as a second contractor around mid 1962.
Westrex used transformers made by Haddon and Albion; Burndept used transformers made by Woden.
One line of argument goes that Haddons were too expensive and so Tom Jennings, ever eager to save money, settled on the idea of using "inferior" units made by Albion and Woden.
But one also has to take into account the possibility that Haddon was unable to meet or had no interest in meeting a greater demand from JMI. Transformer manufacturers had plenty to do in the 1960s, especially those with military contracts. A certain amount of effort spent in the time-consuming process of making small high-quality transformers for JMI might have been acceptable; making huge numbers might not.
Breaking down specimen transformers from new batches and recording details on sheets, as JMI did, was a means both of documenting the make-up of the units and checking that value for money was being got - i.e. that insulation was not quietly being skimped on by the manufacturer.
In the early 2010s, a thread was started on the Plexi Palace forum - "How to recognise Parmeko, Albion and Haddon transformers". Wodens are easy enough. The thread is preserved by the wayback machine.
At the top of page 3 of the thread is this comment:
It was always wonderful reading these things - and still is - as if the magician is giving one a glimpse of what goes on back-stage. If this is based on direct report from someone at JMI, then all to the good. But no "source" is given.
Having all one's eggs in one basket would clearly not be a particularly desirable thing, especially in time of high production. If all one had was Woden and Woden faltered.... But there is also the question of supply. It's all very well having "demand", but if a single supplier cannot meet it then one has to readjust.
1st June
It seems easiest to assemble comments/notes on AC30 transformers under three main "headings" - (1) "quality" of construction; (2) what JMI did; and (3) "electronics" and so on.
1. CONSTRUCTION
The article by Sergio Hammernik of Mercury Magnetics in "Vintage Guitar" magazine, May 2011, sets the scene in a way. One can google the piece, or download the PDF here.
In his view, the pecking order in terms of quality of construction is: Radiospares, Haddon, Albion, followed by Parmeko and Woden (or perhaps Woden and Parmeko). Expert assessment is always good to have.
A few statements need flagging though: "Based on our forensic investigations, Parmeko was a low bidder - which was clear from their rather feeble attempt to copy the Radiospares". A couple of sentences later: "Their transformers were in no way even close to the Radiospares quality, as their lack of tonality proved".
There is really more to this than meets the eye. JMI's need to increase production of AC30s is key here - the employment of Burndept and Westrex to assemble the chassis, and the commissioning of new companies to produce transformers. It will not simply have been a matter of saying to Haddon "please make five times as many units in the same time-frame and at the same cost per unit". Was Haddon in a position to do this? How long did it take Haddon to make AC30 transformers?
A good number of the transformers sold by Radiospares were manufactured, by the way, under contract by R.F. Gilson of Wimbledon. Radiospares was often merely a commissioner and brander of products made by others. Quite whether Gilson made all the high-end transformers that Radiospares offered is not known however.
For a non-specialist - i.e. for someone who has not dismantled Haddons, Albions, Parmekos and Wodens to rewind or examine "forensically" - a fair number of things are wrapped up as one in the article.
Leaving aside the misnomer that the AC30 is a Class A amplifier, we are led to make certain equations: - that a poorly-constructed 1960s transformer makes for "bad tone"; that some sounds are best achieved with certain sort of transformer; and that money (cost-saving) was the principal driving force in the adoption by JMI of different types.
Comments on JMI can be left for the next section, otherwise I suppose the questions, as always, concern the extent to which one can tie anything to any one component. Do I have to have a certain type of valve to sound like X, and Woden transformers to sound like Y? What about the circuitry in the amps? AC30s age in different ways. Has anyone swapped ten different Wodens in and out of a single AC30 to see whether all Wodens "sound" the same? In terms of the "Beatles sound", what did the valve mixing desk and microphones contribute?
It was great fun in the 2000s to see all the mantras of the boutique amp makers repeated on forums - the "secret sauce" of components, the reports of "a man" or "someone who knows" stating categorically that that AC30s with Haddons "sounded best". Really? All of them? Right, good to know.
But this is not to doubt that Haddons have superior construction internally, and that there really is a pecking order in terms of the care taken and quality of the materials used by various makers. The hope is to gather together at some point sets of illustrative pictures.
The rest is flying a kite though.