Hammond AO 43-1 Converted Into A Guitar Amp

The Hammond AO 43-1 Reverb Tube Amp is finally ready!
This amp build over a chassis of Hammond AO 43-1 power amp from L-100 organ.
I've converted it to a guitar / organ amp with spring reverb.
I've added a control panel with two inputs (same as the classic Fender input circuit), added a Princeton tone stack and a dwell control for the reverb. I've also replaced the two prong power cord with a modern 3 prong cord , added an on / off switch, a fuse and a red pilot light.
I've build a wooden cabinet out of an old pine shelves that I found on the street one day.
Here's a sound check of the finished amp.
My talented brother Ilan Vam Smilan playing few different styles, from jazz to hard rock.
I recorded the amp with an old Sennheiser MD-421 thru my Amek Angela preamp to the Motu 16A.

[@mobicus1]

Very cool!

[@DeanAnderson-hy7ow]

Hi Asaf,
You have that AO-43 sounding beautiful! I also have an AO-43 I would like to do something with. I wanted to ask you what type of speaker you were using when recording, because it sounds great. Thank your brother for great playing, by the way. Also, I would love to see how you connected the Princeton Reverb tone stack and potentiometers into the AO-43 circuit. If you have any drawings of the circuit you could share, I would love to see them! Again, wonderful job all around on the video! Thank you, Dean

[@AsafSmilan]

Hi Dean,
The speaker is an 8 Ohms 12" fender blue label speaker from a 1990's.I had to remove the large 50uF/450V cap from the top of the chassis and replace it with a modern one placed inside the chassis.At the place of this cap I installed a 9 pin miniature socket and installed another tube for the reverb recovery circuit.I had to move the reverb tank jacks to the back of the chassis to gain more space for the potentiometers.I have another amp based on the AO 43-1 and on this amp I added a front panel made from an old reverb tank chassis and with this larger panel I was able to add 3 knob tone controls and a tremolo circuit.Unfortunately I don't have pictures / drawings of the inside of those amps.

[@DeanAnderson-hy7ow]

@@AsafSmilan Thanks for the quick reply! I can't wait to see what you do with the tremolo on your other AO-43-1.

[@AsafSmilan]

@@DeanAnderson-hy7ow Send me an email and I'll send you a picture of the other amp asafsmilan (at) gmail (dot) com

[@Tom-th1oy]

Hi Asaf, that Amp sounds very good.. Just a couple questions if you don’t mind.. Did you utilize the AO-43’s original reverb, or are you using one of your other units? And How or where did you get the faceplate for the amplifier made as it looks really nice with the print for the controls and power, fuse etc.. Thanks, Tom

[@AsafSmilan]

Hi Tom, I didn't have the Hammond original reverb tank, so I used a 4FB2A1C tank that I had. I designed the front panel with "Front Panel Designer" (it's a great free software) and cut it at a local CNC workshop.