S4 E2: How to upgrade the stock Leslie driver

Leslie Cabs

Hi folks, this week I finally took delivery of a package that would enable me to upgrade the stock Leslie driver on my 145.

My ‘stock’ Leslie 145

My 145 is my go to gigging Leslie and subsequently gets a lot of use. The amp is from 1974/5 and is only 40watts and sometimes when performing live you end up relying on the monitors to hear yourself fully; I’ve felt for a while that this is a crying shame. The thing is, and I have mentioned this is previous blogs, of the things that you can do to make your Leslie louder many of these will result in actively changing the tonal quality of the amplifier all together and I didn’t fancy this as I am very happy with the sound that I get – its just too quiet.

Always in the mix as an option is the Atlas PD60a driver. Its championed by http://www.tonewheelgeneral.com/ as the ideal replacement/upgrade to the Leslie at its characteristics are broadly similar.  I think we have discussed in the past that the stock Jenson V21 is an inefficient speaker and it is this inefficiency that actually proves its charm. Treble-wise the driver actually hits a ceiling around 7500hz and the suggested Atlas has a similar range making it an ideal replacement.

The Atlas PD60-a from Tonewheel General Hospital

After talking to Rick and Jesica at Tonewheel General I finally summoned up courage and bank balance to place the order for a replacement. The driver itself I think is pretty reasonably priced from those guys its just that as an international customer (to them) prices tend to stack up. Do remember that if like me you are buying from the UK you need to consider the exchange rate, any credit card transaction fees, delivery charges and then finally any customs duties that are due. All in then its probably cost me just over £200 to get to my door and for the money you not only get Rick’s quality advice but the driver and a Tonewheel General mounting plate, with all screws, that allows you to mount the Atlas to the Leslie with ease.


As usual I recorded a video of me performing this task (and making the odd mistake too!) so that you could do the same if you wanted to. A pretty simple upgrade all in. I also recorded the Leslie before and after the upgrade to show the difference and benefits of doing it.

What you will not be able to hear I think is the volume difference. It is much much louder with the Atlas and that for me is job done and done. The tone is a little more harsh but that comes down to the balance of Bass and Treble being thrown out. With my Hammond XK5 I was able to push the bass a little harder and find the upper mid honk that I didn’t like and just slightly EQ it back resulting in the tone being the same as stock but just much much louder.

My advice? Watch the video and see 😉