Dear hywelg and Nick,

I was chopsticking around the indicated shielded cable and although I could not reproduce the noise (the amp had its quiet moments), it was obvious that the solder joints are not optimal. I have redone them and now chopsticking around  this area has not effect whatsoever.  Let's see if my amp behaves now 

Thanks for the help!!

fm4

Hywelg,

Good point and well taken.

Following your suggestion, I tried to change the guitar while hearing the "voodoo" noise and saw that the noise stays even when I entirely unplugged the guitar cable from the amp.

I'll have to go on hunting for the culprit within the amp. The first time my band colleagues heard it, one was asking who had the guts to far** in the practice room...I guess they have to stick with it a bit longer 

Thx,
fm4

Hi,

My Overtone Special 100W is up and running for a couple of month now. Voltages are OK, 1/2 power mod is installed and working. I build the Kleinulator and it is working smoothly. Overall, great amp and great tone....but...

only thing that I find quite annoying with my amp is a strange noise, which shifts between cracking and something that you would get when you rub two balloons. I checked again voltages and cold soldering joints, but strange enough everything is working well. The noise is not influenced by any poti or switch, nor the master/preamp volume. It's just there. The funny thing is that this strage noise seems to come and go. One week nothing at all, then again for 10min.

I switched power and preamp tubes, no change.

If anybody has ever experienced something like that let me know. It would help me to track down the culprit faster. Or maybe it is just Voodoo....

Thx,
fm4

Thanks, ic-racer!

I have built it in and it works well. I am switching to 4 Ohm (Ohm in the 100W mode) when activating the 1/2 power mod.

fm4

Following ic-racers suggestion, I tried to adapt the Overtone100 layout with the #124 schematics for the 1/2 power switch (see attached file).

As I am new to the tweaking business and still in the learning stage, I am of course glad about any hints and tips.

Thanks,
fm4

Thanks ic-racer......I guess it means rather on "crappy" side  ....sorry, folks, my strenghts might be in other subjects I took the wiring from the general Ceriatone mod site and adapted it to the Overtone100. At least it makes sense to me and I works as I tried it out. However, I left out the initial connection from the 3k3 resistor to the power tube. The amp with the 1/2 switch on has less headroom (obviously).


I will try this mod if the gurus believe this is a better solution.

Thanks for some feedback....

Cheers,
fm4

Dear All,

That's my first thread to the Forum! I just finished my Overtone100 and it eventually runs after some minor problems with the wiring.

I start getting on the nerves of my neighbors. Awesome tone!!!   I have some hum though, so I intend to have a closer look at the heater cables (in my previous amp glueing the cables to the chassis did the trick). Nik already mentioned that shielding of the head shell would help as well.

But now for topic of this thread: I prepared a layout for the 1/2 power mod for the Overtone100 and I thought before tweaking the amp maybe one of the gurus here in the Forum could have a quick look on the attached pdf file.

Looking forward to getting some feedback.

Thanks and cheers,
fm4