Dumble Overdrive Special 3rd Gen Build

[desertmouth90]

I have a question about the filter caps. Does it matter I cannot find 300uf 350v Caps for the filtering?

Builds coming along nicely, learnt a lot from the first one about aesthetics. Gonna make this look tip top.

As this is the 50w version I will be ordering some Transformers either from TT or Modulus (the 100w ones where supreme!).

Let me know if you have any advice.

[martin manning]

I have a question about the filter caps. Does it matter I cannot find 300uf 350v Caps for the filtering?

220uF will be fine. You certainly don't need 300uF for a 50W.

[ijedouglas]

I have a question about the filter caps. Does it matter I cannot find 300uf 350v Caps for the filtering?

Builds coming along nicely, learnt a lot from the first one about aesthetics. Gonna make this look tip top.

As this is the 50w version I will be ordering some Transformers either from TT or Modulus (the 100w ones where supreme!).

Let me know if you have any advice.

HAD typically used 100uf 350V for the 50W amps.

[desertmouth90]

Would it make much of a difference between 220uf and 100uf?

[dbharris]

It's roughly twice the filtering. The amp will feel more stiff with the 220uf caps (approx. 110uf capacitance) versus 100uf caps (approx. 50uf capacitance) on the first B+ node.

When in doubt, build it like HAD.

-Dan

[desertmouth90]

Well Dan, thank you for your guidance, I hope I can produce a decent clone for the might HAD god!

I used 100uf for 100w, reckon that is still adequate?

Thanks

Clive

[ijedouglas]

Well Dan, thank you for your guidance, I hope I can produce a decent clone for the might HAD god!

I used 100uf for 100w, reckon that is still adequate?

Thanks

Clive

Hey Clive,

I have seen HAD use 100uf in a 100W amp although he mostly used 200uf, 220uf and 300uf. 100uf will loosen up the amp a little. Does it sound good? How is the response under the fingers?

[desertmouth90]

I havent yet tested what it sounds like, I went through somewhat of a breakup and decided to take it to my parents.

But I have the time now so will fetch the 100w later this month.

THIS NEEDS TO HAPPEN!

[desertmouth90]

Update!

I have retrieved my Dumble ODS 102 clone from my parents and I have become reather dissatisfied with the aesthetics of it. I would need to modify a faceplate for... Rookie error.

However I am deteremind to make the 3rd Gen 50w build right! The Transformers are currently being wound so I am just doing basic wiring.

Also my Variac arrived, should I bother building a Light Bulb Limiter or just use the variac?

Thank you!

[martin manning]

Also my Variac arrived, should I bother building a Light Bulb Limiter or just use the variac?

The Variac won’t limit current, so it’s best to use both.

[desertmouth90]

I wish I could build an off the shelf item, finding it hard to source stuff in the UK

[Steve AA1164]

How is the build coming along? What transformers did you order?

I'm thinking of building the same.

Regards,

Steve

[desertmouth90]

Funny you ask, I’ve been working intensely on it.

Been let down with some suppliers over the 12b 12a 11a input conundrum… but ordered loads from mouser to keep me ticking over.

I got the transformers custom wound again by Modulus amplification.

So far I have thoroughly enjoyed this build and I’m intending to improve on my first amp by making this much neater. And installing bias probes on it for ease of use.

It’s going to slay!

[desertmouth90]

So on my Output Transformer I have taps for 4ohm 8ohm and 16ohm. Im think of using just the 8ohm and 16ohm for now on the output of the amp but connecting it up to the 100w/50w switch instead of installing a rotary switch, does anyone have a diagram for this?

Thanks,

Clive

[desertmouth90]

Finished all the wiring last night, only thing missing is the bright cap.

Decided to use a 3 way switch for the impedance selection.

Thanks all