McPherson

Builder: Gil McPherson

From Mk 1 to at least Mk 4, around 1964.

New: 5/1/10
Source: Ray Carlton

New: 28/12/09
Source: TimR

Power supply circuit (368k)
Amplifier circuit trem, 2x KT88's (602k)

E-mails between Tim and Ray Carlton of Carlton Guitars.

Tim to Ray
I'm about to start restoring a McPherson 50W amp and am quite interested in what you recall about the amp you had. I only have scant info about Gil McPherson from what is written in the 30 years of live production article. The amp dates from mid 1960 s but I haven t spent much time on it as yet. I would be most grateful for any background info you may have come across regarding Gil and his activities.

Ray to Tim
as far as i know there were very few of these made
i have seen only one - thats the one i used in the late 80's to mid 90's it was a 50 watt head with a plastic front which had buckled a little over the years from the heat of the output valves
i sold it through paul gale at soundworks in ringwood in the mid 90's great amp and i often rue the day i sold it to buy a pcb based fender deville - which of course didnt last
a mate of mine found it in a machinery shed on a farm out the back of frankston and i got it off him
gil mcpherson is still around apparently

Tim to Ray
The following is a brief summary of the amp I have.

The amp I have appears to be similar to your amp Ray - it has a sloping plastic front (cracked and part missing) - and the front panel says McPherson Twin-channel 60W Instrument Amplifier. Amp has normal and a tremelo channels, each channel with vol, bass and treble. Tremelo has speed and depth. Also has a Presence.

Attached are the power and signal schematics of what is presently wired in the amp. The amp has been modified a bit - the tremelo channel bass and treble are removed and the 12AX7 is only partly wired (and wasn't fitted).

The amp is likely to be mid-late 1960's - it has GEC KT88's with TG date stamp (July 1963), and 1961 dated Rola chokes. I am unsure when the A&R 4008 OPT started production. No other identifying chassis number or markings.

The amp is interesting due to: using a 6AN8 pre/PI; using KT88 in UL (similar to playmaster PA amp); tremolo spelt as 'tremelo' on front plate - and uses an LDR and neon bulb housed in an 8-pin connector plug that plugs into a valve base on the chassis - the LDR has Holland written on it and may be something like an OPR61; the inputs have 470k series resistors going direct to vol pot.

The magnetics are pretty top notch - the OPT is the premium A&R range with 40Hz 50W 1% spec.

The wiring and valve base fitting is pretty agricultural.

Ray to Tim
i didnt really look inside that amp at all - i just noticed it had lots of valves and was pretty dirty inside

it was a heavy little mother - it had 2 chromed handles that looked like they would be more at home on a kitchen drawer either side of the top vent - the vent had bronze mesh i think under it as a bit of protection for the valves - the control knobs were aluminium with skirts - they were quite large

i cranked it up 1st and loved the smooth mildly overdriven tone - i used it for round 3 years i guess as #2 to my old fender twin - the trem never worked and had no reverb - i kept it at the rehearsal studio for quite a while so i didnt have to lug the twin and there i came to appreciated the warm woody tone of this lovely old amp - when my twin had a major league melt down it became #1 - i ran it into a grey cabinet with a 12" and 8" yammy with a xover - the cab had steel mesh on the front

i always thought it lacked punch but never thought to have it overhauled and bought up to spec - i sold it in the end to buy a fender deville 4x12 which was crazy loud and suited me at the time - it brought a paltry $250.00 - today would be worth way more than that

the more i think about it the more i wished i never sold it :-(

Tim to Ray

Yes the handles are very kitchenesque - a sign of the “cobbled together” nature of earlier amps. I can replace the poor condition plastic cover with Perspex - no big issue. The front panel graphic is a commercial printing on stiff paper (thin cardboard) - I will either try to resurrect/patch or get another one printed. The case is a ~15mm plywood with a blue textured thin vinyl covering and aluminium mesh top section. Appears like four round rubber feet were originally fitted. The entire front panel is sloping and comprised the plastic/graphic. The rear opening had some form of cover at one stage - do you recall if your amp had a complete open back - or some mesh - or a partial cover of some sort?

I don't have any front panel knobs - so your recollection will be most helpful in choosing something similar.

And Doh! I just noticed some small printing on the inside of the case “July 1964”, and what appears to be a name in much lighter text “KEITH N???RIN?” -but the surname letters could be wrong. The date indicates the amp pre-dates the likes of Lenard, Wasp, Vase, but a year or two after Strauss started, and probably about the time of the first Goldentones.

New: 11/1/11

“The Spartans”/“The Cruisers”/“Two by 2” - 1965
Note also Moody GA35 and rare Moody tape echo

Source: John Fox

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