‘Super Rare’ 1966 Marshall JTM 45 MK ll Plexi Amplifier Head


Here we have a classic piece of Marshall amp history, in the shape of this lovely 1966 JTM-45 MK ll. The JTM45 was the first Marshall amplifier and essentially remains as the be-all end-all for collectors and tone-crazed guitar slingers alike. The highly sought-after Marshall JTM45 MK II amplifiers rocked the world when they were introduced in 1963 after a short run of garage-built prototypes. Electronically, these early Marshalls are basically clones of the 1959 Fender Bassman amp, but the use of different preamp (ECC83) and power amp (5881 or KT66) tubes in the JTM45 gave them a raucous, present voice all their own. Compare prices on this legendary first run of Marshall amps on Reverb and bring home a piece of history.
This old bird really sings, giving all the classic vintage Marshall tones that you would want.
She has been fully serviced by our engineer and any age-related problems have been rectified, all electrolytic caps in the amps power supply and bias circuit were changed, the first stage cathode resistor bypass cap was changed. We changed the 15K resistor in the bias circuit, added a 1K 5w resistor to the screen circuit that was missing. All chassis grounds were cleaned and made good. Valve sockets were cleaned and re-tensioned. Bulgin mains connector replaced. One output jack socket replaced,new mains switch, new output valves and a new valve rectifier, new fuses, any missing screws and board mounts replaced. Chassis cleaned and pots all cleaned.
This is a rare opportunity to get your hands on what is now a rare bird and in great condition. She is ideally for collection only, but would consider shipping, dependant on the destination!
Below is a link to a concise history of this iconic amp:


Payment can be done via PayPal, bank transfer, cheque or cash on collection!

Very important: If paying by PayPal, please note that we will only ship to confirmed Paypal addresses! Please double check your address is confirmed with Paypal!

Feel free to drop us an email for our bank details for SWIFT/BACS transfers and for any international shipping costs.

If paying by cheque, or collecting in person, please contact us on 07932 074096 to arrange.


Our shipping policy is simple: We ship Guitars, Amps and Accessories to the UK, Europe & ROW. We’ve been shipping items to the UK and abroad for many years without any issues, as we always use the best and most reliable shipping companies. All guitars and amps will be shipped insured and tracked. So you can check your shipping status anytime. We always package them to the highest possible standard.

Note: All amps are preferably UK shipping or collection only. We rarely ship amps internationally, due to potential breakage, unless this is agreed separately. If you are outside Europe and are interested in any of our guitars or amps please contact us for a special shipping quote.


We operate a 48hr approval period for on-line mail order purchases only. Customers who buy goods in the RGG showroom can fully evaluate them prior to making the payment, and as such do not have this return and refund option available to them. The 48hr mail order returns period offered is with regard to either a problem with the guitar upon receipt, IE, the goods appear to have a defect that was not outlined in the sale listing or clearly not sold as advertised. If the purchaser wishes to return the goods for any other reason, then there will be a re-stocking fee of 10% of the original sale value & return carriage must be paid by the purchaser, there are no exceptions to these rules.

If you want to return an item please make contact for a returns authorisation. You have 2 days to try the instrument. We offer a full refund minus our shipping costs (including our cost of free shipping if applicable) It is the purchaser’s responsibility to organise the return promptly to the company in the condition it was received, using the original packaging and with a copy of the sales receipt. (We recommend you insure the item in transit). The item must be shipped back via a service comparable with which it was delivered, within 24 hours (Excluding weekends) upon receipt of the return authorization. Goods that have been altered from their original condition in any way cannot be returned.

Any items returned after the 48hr agreed approval period, and not exceeding more than two weeks, are subject to a 10% re-stocking fee, based on of the original sale value of the goods. PayPal, Credit/Debit card refunds will be processed immediately upon receipt of the returned goods and normally take 3-5 working days to show on the customer’s account. Bank transfer and cash purchase payments will be refunded by Bank transfer to your nominated bank.