Upcoming ODS Project

[ryanf]

It may be awhile before I start this, but I am planning on doing an ODS-101 with a few tweaks.

1. Dual EQ- Basically, I will have another relay to switch tone stacks, which includes the bright, deep, and mid switches. I will probably have a common PAB. Also, I want seperate input volume controls, rather than a shared one. When I played a Fuchs ODS 50 awhile ago, it seemed that the Input Volume had a greater effect on gain than the Drive Input control. I'm just wondering if its going to be annoying with three volume controls on the front panel, plus a trim pot.


2. Everything mounted on the eyelet board- I know that most swear by putting the cathode caps and resistors on the tube, but I want to experiment with trim pots, and possibly have some LDR switching of these along with the channels. Will this have a dramatic impact on the tone? I'm not exactly going for a pure Dumble sound as much as I want a proven amp that I can tweak and make better.

I'm wondering if I should go HRM or not. It was initially appealing, as I wanted to be able to tweak the OD channel seperately. However, if I have seperate EQ, I'm wondering if its just going to be a hassle. I'm going for a more aggressive, Marshally tone, if that helps any.

I appreciate any insight or suggestions!

Thanks, Ryan

[Bob-I]

It may be awhile before I start this, but I am planning on doing an ODS-101 with a few tweaks.

1. Dual EQ- Basically, I will have another relay to switch tone stacks, which includes the bright, deep, and mid switches. I will probably have a common PAB. Also, I want seperate input volume controls, rather than a shared one. When I played a Fuchs ODS 50 awhile ago, it seemed that the Input Volume had a greater effect on gain than the Drive Input control. I'm just wondering if its going to be annoying with three volume controls on the front panel, plus a trim pot.

I've thought about that more than once, but in actual practice I don't see the need. I'm getting a wide variety of tones just by using the guitar controls.


]quote]2. Everything mounted on the eyelet board- I know that most swear by putting the cathode caps and resistors on the tube, but I want to experiment with trim pots, and possibly have some LDR switching of these along with the channels. Will this have a dramatic impact on the tone? I'm not exactly going for a pure Dumble sound as much as I want a proven amp that I can tweak and make better.[/quote]

No, not the cathode resistors and caps, these are always on the board. It's the gride stopper resistors that NEED to be on the tube socket. Moving them onto the board will make an unstable amp.

[ic-racer]

Others may not share this same experience but mine has been that the Dumble circuit has a certain sound intrinsic to the circuit you build . The tone and presence controls let you tweak this basic tone to suit your guitar/speaker and playing conditions, but the underlying tone is dictated by the circuit. If your OD and Clean circuits are sonically 'balanced' then the tone control settings will carry over fine and you may find there is little need for separate controls.

[Luthierwnc]

What they said.

Maybe leave yourself a little room on the board/chassis for adjustments later but stick to the program on #1. That way, you can follow the bread crumbs back home. Make sure to get extra resistors and caps in the neighborhood of the ones you plan to use (i.e. get both 100k and 220k/150k with corresponding cathode resistors and caps, nearby feedback resistors, etc.) so you aren't waiting on a seven dollar Mouser order.

I take some liberties with the boards but there are a lot of hots and grid wires flying around. They don't like each other. Also consider that a lot of people have heaved a lot of amps out of windows so you could benefit from their wisdom.

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