Some feedback from a recent Lamington builder

I continue to receive very favourable feedback from builders of Lamington amps as to how happy they are with how the amp sounds. To some degree, this is a little surprising, as the Lamington amp was developed to be a low cost introduction to valve guitar amp building and not necessarily to be a tone monster. That it sounds so good is a real bonus, and makes it doubly worth building.

This email is typical of responses I receive:

Hi Grant,

Just wanted to let you know that we fired up the lamington last night, and….

 …it was amazing!

 I was truly taken with how great it sounded. We ran it through my 4×12 with celestion vintage 30’s and it was really great. The tone is excellent and I was loving how responsive to touch it was. It seemed nice and clean with gentle playing, and then you dig in a bit and it rips your head off… Seems at first play like it has great cleans (with the right amount of chime) and great bluesy overdrive. 

I think you are really onto something with the lamington, which of course you knew! (I’m not sure I did!)

 Any plans for other amps…? (Yes, the Lamington III design is now released)

Thanks again for all your help with this – it’s truly one of the best amps I think I’ve played.

Kind regards,



6 thoughts on “Some feedback from a recent Lamington builder”

  1. Grant many thanks for this design. This was my first valve build though I have been in the electronics industry since the 70s.

    Worked first go and sounds fantastic. I housed mine in a 2RU high 19″ rack chassis (available from Jaycar) with the valves and transformers on top – it will eventually be house in a sturdy case with mesh protection for the items on top.

    My interest has been piqued with the 40W version – should I modify what I have or should I build another…

    1. Hi Tony and thanks for your kind comments. The Lamington amp continues to surprise me with how great it sounds considering it was originally developed simply to be a low cost intro to valve amps.
      Re the 40W Lamington III – it is a different amp with a different sound – think an old Goldentone 60W amp. I’d recommend you build both!!

  2. Hi Grant,

    I’m writing to express my sincere thanks and gratitude in regard to your contribution and sharing of your passion for guitar valve amp designs. My passion started around 5 years ago when I stumbled across your Lamington design on the web. It was my first amp build from scratch and I have built many more since including some of my own designs which I’ve modified from other ready available circuits.

    I notice now you have a Lamington III design using 6CM5 valves which I am keen to try out. I have a query though in regard to the biasing. Your circuit uses a single Potentiometer to bias both valves. I’m assuming this is to reduce cost and keep the component count down. However, this will mean there would need to be a compromise setting for biasing both valves as I’m sure these valves will not be ready available in a matched set. So my question is “Do you think it’s important to have the biasing of both valves with similar bias currents?” I have used circuits in the past which by adding a few resistors and another potentiometer allows for separate biasing of both valves. Your comments would be most appreciated.



    1. Hi James,

      Great to hear from you and thanks for your kind words! It is a great source of satisfaction for me to be able to offer some encouragement to others as they begin to build valve amps.

      With regards to the bias arrangements in the Lamington III, you are correct in that in theory, different valves require differing bias settings. However in practice, my experience is that with the circuit configuration of the Lamington III (lowish HT of 300V, 1/2 HT for screens), a wide selection of 6CM5 valves tend to bias within about 10% of each other as bias sensitivity is not critical with these operating points. It is interesting to note that all of the Goldentone amps that used the similar 6DQ6 valves in a similar configuration to the Lamington III had no individual adjustment for bias, and in fact had fixed resistors setting the bias with no overall adjustment! Of course, individual bias adjustment can be added if desired, but I chose to use the arrangement seen in the schematic to simplify both the build and the setup of the Lamington III for prospective builders.

      Nonetheless, I appreciate your question and it is great to see how your knowledge of valve amps has increased considerably over 5 years!

      Best regards,


  3. G’day.

    I built a Lamington III from your design & played it for 5 hours on New Years Eve.

    Good stuff, thanks.

    Anybody looking for 6CM5 at a good price you can get them from a bloke in Western Australia on eBay at present. Just search 6CM5, you’ll find them. The listing says ‘pick up only’ but if you contact the seller with your postcode, he will give you a quote on postage. He is selling them in lots of 4 & he has tested them & matched them. I got 8 posted from WA to FNQ very well packed for just under $18 postage.

    1. Thanks Cliff for the update. Yes, 6CM5s appear regularly on ebay so supplies are pretty much guaranteed for the Lamington III well into the future which is cool 🙂

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