albatros_1994
Kungen
Hi guys,
here is my next build, a Sunn O))) Model T Replica, not the Fender 90s reissue, not the 2nd Gen, i want the first one from the mid 70s, but 30w using 2x KT66.
(i have anothe thread where i built a Hot-Rodded 20w Mesa-Boogie Rectifier in case you wanna check it out)
The kit i ordered this time was supposed to be a JTM45, but as the preamp is very similar to the Model T, it fits this build perfectly. I have the feeling this is gonna be fun.
I wanted to copy the really mean look of the original amp so i painted the chassis black and built a cabinet myself. Too bad i could not find a grill for the front so i went all-wood instead. Decent job i must say
Other than the usual and original controls i'm planning to add some more stuff,
a "NFB" pot to control the negative feeback going to the phase inverter, a "resonance" pot, another one to control the bias of the phase inverter and a spare one that i might use to tweak the tonestack, we'll see what i want to do with that. I'm gonna wire one of the outputs to 2x25w resistors that are gonna lower to output power to around 10%, so 3w, this is to get that cranked power stage overdrive and distorsion that the Model T is so famous for. I also want a switch to go from "pentode" mode to "triode" for the two KT66s, just to get a different distorsion caracteristic and lower the max output power to around 50%, might be useful combined with the 10% output jack.
I planned 3 switches on the front, the first might become a parallel-cascade selector for the "brite" and "normal" channels to get some more gain in the preamp section, the other two...well, i'll find something to do with those, maybe different "bright" selectors for the 2 channels. And, i'm also going to use diodes instead of the GZ34 rectifier tube, more voltage, less sag and more like the original Sunn.
The cabinet is 77x23x20cm, pretty compact
Here some photos of the build, i'm gonna wire the entire thing in the next days, i wanted to get the look right before starting soldering and running cables
![](https://i.ibb.co/PQDFDMz/photo-2022-02-12-12-57-53.jpg)
![](https://i.ibb.co/Gcm0XXd/photo-2022-02-12-12-58-09.jpg)
![](https://i.ibb.co/x5f6ryQ/photo-2022-02-12-12-57-57.jpg)
![](https://i.ibb.co/pf4K33x/photo-2022-02-12-12-57-43.jpg)
![](https://i.ibb.co/52H7T9x/photo-2022-02-12-12-57-18.jpg)
![](https://i.ibb.co/yfm9V20/photo-2022-02-12-12-58-06.jpg)
![](https://i.ibb.co/jT52jfG/photo-2022-02-12-12-57-50.jpg)
![](https://i.ibb.co/GWXc5Hh/photo-2022-02-12-12-58-15.jpg)
![](https://i.ibb.co/3ThT0KZ/photo-2022-02-12-12-58-00.jpg)
![](https://i.ibb.co/10vQprj/photo-2022-02-12-12-58-03.jpg)
![](https://i.ibb.co/jbkMVyr/photo-2022-02-12-12-57-47.jpg)
here is my next build, a Sunn O))) Model T Replica, not the Fender 90s reissue, not the 2nd Gen, i want the first one from the mid 70s, but 30w using 2x KT66.
(i have anothe thread where i built a Hot-Rodded 20w Mesa-Boogie Rectifier in case you wanna check it out)
The kit i ordered this time was supposed to be a JTM45, but as the preamp is very similar to the Model T, it fits this build perfectly. I have the feeling this is gonna be fun.
I wanted to copy the really mean look of the original amp so i painted the chassis black and built a cabinet myself. Too bad i could not find a grill for the front so i went all-wood instead. Decent job i must say
Other than the usual and original controls i'm planning to add some more stuff,
a "NFB" pot to control the negative feeback going to the phase inverter, a "resonance" pot, another one to control the bias of the phase inverter and a spare one that i might use to tweak the tonestack, we'll see what i want to do with that. I'm gonna wire one of the outputs to 2x25w resistors that are gonna lower to output power to around 10%, so 3w, this is to get that cranked power stage overdrive and distorsion that the Model T is so famous for. I also want a switch to go from "pentode" mode to "triode" for the two KT66s, just to get a different distorsion caracteristic and lower the max output power to around 50%, might be useful combined with the 10% output jack.
I planned 3 switches on the front, the first might become a parallel-cascade selector for the "brite" and "normal" channels to get some more gain in the preamp section, the other two...well, i'll find something to do with those, maybe different "bright" selectors for the 2 channels. And, i'm also going to use diodes instead of the GZ34 rectifier tube, more voltage, less sag and more like the original Sunn.
The cabinet is 77x23x20cm, pretty compact
Here some photos of the build, i'm gonna wire the entire thing in the next days, i wanted to get the look right before starting soldering and running cables
![](https://i.ibb.co/PQDFDMz/photo-2022-02-12-12-57-53.jpg)
![](https://i.ibb.co/Gcm0XXd/photo-2022-02-12-12-58-09.jpg)
![](https://i.ibb.co/x5f6ryQ/photo-2022-02-12-12-57-57.jpg)
![](https://i.ibb.co/pf4K33x/photo-2022-02-12-12-57-43.jpg)
![](https://i.ibb.co/52H7T9x/photo-2022-02-12-12-57-18.jpg)
![](https://i.ibb.co/yfm9V20/photo-2022-02-12-12-58-06.jpg)
![](https://i.ibb.co/jT52jfG/photo-2022-02-12-12-57-50.jpg)
![](https://i.ibb.co/GWXc5Hh/photo-2022-02-12-12-58-15.jpg)
![](https://i.ibb.co/3ThT0KZ/photo-2022-02-12-12-58-00.jpg)
![](https://i.ibb.co/10vQprj/photo-2022-02-12-12-58-03.jpg)
![](https://i.ibb.co/jbkMVyr/photo-2022-02-12-12-57-47.jpg)