Dumble Lite? - Update, Finished!!!

[Icetech]

Very nice looking build norm:) can't wait to hear it...

[Bob-I]

All I'm really looking for is your opinion on the iron. What's the verdict?

[Normster]

I'd say the iron is decent, but not excellent. The PT is actually pretty good for a $40 tranny. The OPT tranny is a bit thin for the OD. It does a nice job with the cleans but seems to lack something with the OD engaged. When I get the new caps installed I'll tweak the voltages and give you a better idea. For now, I'm thinking it's worth it to go the next size up for the OPT.

[Ed de Jager]

Looks great!


Ed

[Bob-I]

I'd say the iron is decent, but not excellent. The PT is actually pretty good for a $40 tranny. The OPT tranny is a bit thin for the OD. It does a nice job with the cleans but seems to lack something with the OD engaged. When I get the new caps installed I'll tweak the voltages and give you a better idea. For now, I'm thinking it's worth it to go the next size up for the OPT.

That was my experience with a Deluxe xformer too. When I upped it to a Bassman the difference was dramatic. I'd bet it's not the chinese xformer as much as it is the size.

[fp2000]

Who's the maker of the Bassman transformer? Has anyone tried the ones from Mojo?
Also, where do you guys find those 2K pots for the presence control?

[Bob-I]

Who's the maker of the Bassman transformer? Has anyone tried the ones from Mojo?
Also, where do you guys find those 2K pots for the presence control?

Yes, I've tried the Mojo xfomers and found them excellent. The 2K pot is available through mouser.com

[Normster]

OK, got the new filter caps installed and corrected a wiring mistake that caused the failure. (The layout is correct, I just wasn't paying attention.) I'll do some tweaking tomorrow with snubbers and local feedback. I'm also going to order a 40 watt Vibrolux OPT. It's only slightly bigger than the Deluxe OPT but should provide a meatier bottom end. And for the cost conscious, it's only $8 more.

[Tdale]

Looking great!

One question: Where is the ground bus connected to the chassis? I can't see it from the picture..

I'm trying to decide if I should go for a bus or a start ground system, with one wire from each stage.

Tommy

[Normster]

Looking great!

One question: Where is the ground bus connected to the chassis? I can't see it from the picture..

I'm trying to decide if I should go for a bus or a start ground system, with one wire from each stage.

Tommy

Thanks, Tommy. The ground buss is connected by a ground wire at the input end of the chassis. I think you'll be fine using either a star or buss ground scheme. I use the buss because that's the way Dumble did it.

[Ed de Jager]

Normster,can you please tell me the measurements of the boards?
Thanks in advance,
Ed

[Normster]

Normster,can you please tell me the measurements of the boards?
Thanks in advance,
Ed

The preamp board is 2.65" x 7.75", power board is 3.75" x 4.0", and the rectifier board is 1.75" x 2.75". BTW, the posted layout (http://bad-domain/DumbleLite/DumbleLite16x8Layout.JPG) is drawn to scale.

[Ed de Jager]

O.k.Thanks very much!

Ed

[fp2000]

Has anyone tried the little 500 Ohm 10W power resistors with aluminum casing? they are so tiny compared to the cement ones that is hard to believe they can withstand 10 watts. I just bought one but haven't tried it yet since I want to hear any comments on it. The size does make it atractive though, it will fit anywhere.

[BobW]

Has anyone tried the little 500 Ohm 10W power resistors with aluminum casing? they are so tiny compared to the cement ones that is hard to believe they can withstand 10 watts. I just bought one but haven't tried it yet since I want to hear any comments on it. The size does make it atractive though, it will fit anywhere.

Be careful! The Al casing (DALE types, etc) dissipation ratings are based on a suitable heatsink, check the datasheet. A 12" x 12" x 1/4" heatsink plate is the usual standard heatsink reference. Try to mount it directly to the chassis and it should work fine.