Mosky Amp Turbo / Deluxe Amp11

mojah63 · Post by **mojah63** » 15 Feb 2019, 20:16

I just took apart my Amp Turbo. The board seems to be the same as the deluxe as it has the solder pads for the 3 switches and all the components. The components are surface mounted except the coupling capacitors witch are an orange film type, and the 2N5888 boost Transistor. All the clipping diodes are standard silicon diodes no shotkky diodes (bat46) in the boost section as a real amp 11. The boost section has 2 pairs of diodes that are selectable via the switch. One pair (D9,D10 )is a standard silicon clipping pair with cathodes opposed. The second pair (D7, D8) are wired in true parallel so the cathodes are on the same side. Quite odd, as now only one half the wave gets clipped and at a reduced voltage too. The switched diodes go to the normal clipping stage as Amp11. Now the NON deluxe version (Amp Turbo) has no clipping on the boost stage as it doesn't have a switch and Mosky didn't wire in a jumper either. An Amp11 has a shotkky Bat46 clipping stage on the boost. So I clipped out the strange pair D7,D9 and soldered Bat46's in the proper orientation, cathodes opposed. Then wired a jumper across the switch pads to enable it. The other 2 switches seem ( I did a quick trace ) to bypass each double diode stage of the "Timmy" side with a single diode. So you could have asymmetrical clipping. All the capacitor values are the same as an Amp 11 the opamp is a JRC4559 as in a "Timmy". No sure what opamp Sean uses. The boost section has a through the hole 2N5888 transistor as in the Amp 11. The Boost works independent of the overdrive. For $35 and an hour of my time it's great..

dmc777 · Post by **dmc777** » 18 Mar 2023, 15:52

Did you ever end up installing the switch and installing different diodes on this? I have the blue deluxe version as well as an amp 11.

I thought the amp 11 boost was a cot50 while the amp turbo was a sho… just determine by the sound. The amp 11 boost when engaged is above unity gain adds a grittiness to the sound. The amp turbo is also above unity when engaged and sounds exactly like a sho to me. Just add huge clean boost.