Dumble 102 ODS

[The Quadratus]

I’m guessing the MV ground was sketchy from the start, and that was the root cause.

I thought that might be the case, but, that doesn't explain why I could control when it came on and off after I had reconnected the ground on the MV pot. Whatever it was, it's gone now

Now to try and sort out that transformer hum/vibration.

[The Quadratus]

Sorry, brother, I should have clarified. No noise, as in, no squeal or feedback. It is working absolutely perfectly.

I hate it when that happens! Makes me nervous when I think I forgot something, but it ain't broke.

Yeah, my comment could be taken either way. A good lesson on being succinct

[desertmouth90]

My amp died the other night, my friend was using it haha... I think I set it up with the wrong impedance

[The Quadratus]

I just had a worrying thought. Am I mismarching what my amp wants to see in terms of speakers by running my 4ohm fender twin reverb speakers on the dumble? I built the 3rd gen 50w model and since it uses both the OT and PT from a fender twin, I just assumed that I could run the fender twin speakers.

Using a hammond 290fex for PT and a 1750w for OT with only 2 6l6gc tubes... I need a higher impedance load?

[The Quadratus]

My amp died the other night, my friend was using it haha... I think I set it up with the wrong impedance

Oh dear, sorry to hear. What symptoms were reported?

[martin manning]

I just had a worrying thought. Am I mismarching what my amp wants to see in terms of speakers by running my 4ohm fender twin reverb speakers on the dumble? I built the 3rd gen 50w model and since it uses both the OT and PT from a fender twin, I just assumed that I could run the fender twin speakers.

Using a hammond 290fex for PT and a 1750w for OT with only 2 6l6gc tubes... I need a higher impedance load?

1750W is listed at 2k primary with 4 ohm secondary. 2x 6L6 need a nominal 4k primary, so you should be running an 8 ohm speaker load.

[The Quadratus]

I just had a worrying thought. Am I mismarching what my amp wants to see in terms of speakers by running my 4ohm fender twin reverb speakers on the dumble? I built the 3rd gen 50w model and since it uses both the OT and PT from a fender twin, I just assumed that I could run the fender twin speakers.

Using a hammond 290fex for PT and a 1750w for OT with only 2 6l6gc tubes... I need a higher impedance load?

1750W is listed at 2k primary with 4 ohm secondary. 2x 6L6 need a nominal 4k primary, so you should be running an 8 ohm speaker load.

How on God's green earth do you know so much?

[martin manning]

It just comes with experience. Lots of folks here could have answered the question.

[desertmouth90]

My amp died the other night, my friend was using it haha... I think I set it up with the wrong impedance

Oh dear, sorry to hear. What symptoms were reported?

accidentally set the Impedance to 4ohm through a 16ohm cab

I reckon the valves have gone, but I hope its just a resistor or Fuse

[The Quadratus]

My amp died the other night, my friend was using it haha... I think I set it up with the wrong impedance

Oh dear, sorry to hear. What symptoms were reported?

accidentally set the Impedance to 4ohm through a 16ohm cab

I reckon the valves have gone, but I hope its just a resistor or Fuse

Let's hope the iron is all good too.
It almost seems criminal that a set of 4 tubes costs as much as an OT these days. Was watching some vids on when tubes were in production back in the day, they were practically giving them away.

[nuke]

How on God's green earth do you know so much?

Make a lot of mistakes, break some things, bang head on wall, rinse lather repeat.

[desertmouth90]

I just had a worrying thought. Am I mismarching what my amp wants to see in terms of speakers by running my 4ohm fender twin reverb speakers on the dumble? I built the 3rd gen 50w model and since it uses both the OT and PT from a fender twin, I just assumed that I could run the fender twin speakers.

Using a hammond 290fex for PT and a 1750w for OT with only 2 6l6gc tubes... I need a higher impedance load?

1750W is listed at 2k primary with 4 ohm secondary. 2x 6L6 need a nominal 4k primary, so you should be running an 8 ohm speaker load.

How on God's green earth do you know so much?

I imagine your man Matrin Manning could have taught Dumble a thing or two haha

[desertmouth90]

Oh dear, sorry to hear. What symptoms were reported?

accidentally set the Impedance to 4ohm through a 16ohm cab

I reckon the valves have gone, but I hope its just a resistor or Fuse

Let's hope the iron is all good too.
It almost seems criminal that a set of 4 tubes costs as much as an OT these days. Was watching some vids on when tubes were in production back in the day, they were practically giving them away.

I believe it is the valves, upon visual inspection everything looks good, no fuses gone

always invest in a spare quad or duo of valves

[desertmouth90]

So, I have to finally admit I drilled a cabinet wrong, The chassis is too far back. despite me measuring 4 times and drilling once!

Do I just make the holes elongated? I think the ferrule washers will cover the gap.

Clive

[Guy77]

So, I have to finally admit I drilled a cabinet wrong, The chassis is too far back. despite me measuring 4 times and drilling once!

Do I just make the holes elongated? I think the ferrule washers will cover the gap.

Clive

If the washer doesnt cover it put a nice finishing machine screw in that hole and lock it from underneath with a nylon insert nut and washer, Then drill the correct hole.

Cheers
Guy