Dumble Overdrive Special 3rd Gen Build

[desertmouth90]

on second thoughts, I think im just gonna drill a hole on the back of the amp and put in a B250k Pot as id hate to have to open the amp up every time to adjust this.

[martin manning]

on second thoughts, I think im just gonna drill a hole on the back of the amp and put in a B250k Pot as id hate to have to open the amp up every time to adjust this.

I think I would rather build in the 3rd gen entrance, and then add a ratio control on the back like this: https://ampgarage.com/forum/viewtopic.p ... 08#p466508

[dbharris]

on second thoughts, I think im just gonna drill a hole on the back of the amp and put in a B250k Pot as id hate to have to open the amp up every time to adjust this.

I think I would rather build in the 3rd gen entrance, and then add a ratio control on the back like this: https://ampgarage.com/forum/viewtopic.p ... 08#p466508

I agree with Martin, and not just because that is my amp he helped me with. The OD trigger is really a set and forget. Leave the chassis out and tweak it small amounts for a few days. You will find your sweet spot and never want to adjust it again.

[desertmouth90]

on second thoughts, I think im just gonna drill a hole on the back of the amp and put in a B250k Pot as id hate to have to open the amp up every time to adjust this.

I think I would rather build in the 3rd gen entrance, and then add a ratio control on the back like this: https://ampgarage.com/forum/viewtopic.p ... 08#p466508

I agree with Martin, and not just because that is my amp he helped me with. The OD trigger is really a set and forget. Leave the chassis out and tweak it small amounts for a few days. You will find your sweet spot and never want to adjust it again.

My only issue is I dont want to be opening the amp every time to tweak it, it sounds like crap at the minute for example

[dbharris]

I think I would rather build in the 3rd gen entrance, and then add a ratio control on the back like this: https://ampgarage.com/forum/viewtopic.p ... 08#p466508

I agree with Martin, and not just because that is my amp he helped me with. The OD trigger is really a set and forget. Leave the chassis out and tweak it small amounts for a few days. You will find your sweet spot and never want to adjust it again.

My only issue is I dont want to be opening the amp every time to tweak it, it sounds like crap at the minute for example

Hi, feel free to make the OD trigger external. I think it's more likely you will end up feeling annoyed when it gets accidentally bumped, than find it something you often adjust. But you never know until you try.

What does sounds like crap mean? Can you post voltages? What have you done to dial in the bias, OD trigger, and PI balance? Is the problem on clean, overdrive, or both, etc.

-Dan

[desertmouth90]

I agree with Martin, and not just because that is my amp he helped me with. The OD trigger is really a set and forget. Leave the chassis out and tweak it small amounts for a few days. You will find your sweet spot and never want to adjust it again.

My only issue is I dont want to be opening the amp every time to tweak it, it sounds like crap at the minute for example

Hi, feel free to make the OD trigger external. I think it's more likely you will end up feeling annoyed when it gets accidentally bumped, than find it something you often adjust. But you never know until you try.

What does sounds like crap mean? Can you post voltages? What have you done to dial in the bias, OD trigger, and PI balance? Is the problem on clean, overdrive, or both, etc.

-Dan

The main problem is the OD channel sounds fuzzy when you push it, I think due to excessive gain. Not 100% sure. The plate voltages are 430v.

I used the 1ohm resistor to the cathode and biased it to 38mV.

I dialed the OD trigger to 350k above ground. Not touched the PI balance or the FET input but this weekend I will give it an overhaul.

[dbharris]

My only issue is I dont want to be opening the amp every time to tweak it, it sounds like crap at the minute for example

Hi, feel free to make the OD trigger external. I think it's more likely you will end up feeling annoyed when it gets accidentally bumped, than find it something you often adjust. But you never know until you try.

What does sounds like crap mean? Can you post voltages? What have you done to dial in the bias, OD trigger, and PI balance? Is the problem on clean, overdrive, or both, etc.

-Dan

The main problem is the OD channel sounds fuzzy when you push it, I think due to excessive gain. Not 100% sure. The plate voltages are 430v.

I used the 1ohm resistor to the cathode and biased it to 38mV.

I dialed the OD trigger to 350k above ground. Not touched the PI balance or the FET input but this weekend I will give it an overhaul.

I would start with the OD trigger all the way down. Slowly increase it while playing guitar and you will find the sweet spot. It is going to be much lower than you have it set now. Good luck!

-Dan

[desertmouth90]

I have changed the filter two main caps from 220uf to 100uf. Before I proceed, and for future reference, do you suggest I use a Current limiter test the amp voltages and then rebais?

Thanks