Dumbleator is Complete!

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amplifiednation
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Dumbleator is Complete!

Post by amplifiednation »

Got the build all done, this was a fun project!! Aside from the sheilded runs, which are a pain. The jumpers makes things much easier than trying to ground the shield to pots.

Hammond 16x8x2 Enclosure
Fender Reverb unit PT
022707 choke
56k dropping resistor
Bridge Rectifier

220pf bright caps

I used an off/standby/play switch that I had laying around...pretty cool idea to come with (not me, the guy that designed the switch)

I'm going to power this up today and hopefully I will have a new toy to play with!

Thanks to Tonemerc for all his help sourcing parts and the pro-boards he made me. Also thanks to Structo for his great thread with the trials and errors of this design. Without these two guys this build wouldn't have happened so quickly. Ultrahooked's pictures surely helped too!! Thanks guys!

I will report back with voltages this morning once I find a .5A fuse and bring her up slowly. Maybe I should wait for the smoke test before signing praises!! Hahah!!

Structo's thread:

http://ampgarage.com/forum/viewtopic.ph ... tor+reverb

[IMG:1024:768]http://i817.photobucket.com/albums/zz97 ... ator/2.jpg[/img]
[IMG:1024:768]http://i817.photobucket.com/albums/zz97 ... ator/5.jpg[/img]
[IMG:1024:768]http://i817.photobucket.com/albums/zz97 ... CN0308.jpg[/img]
[IMG:1024:768]http://i817.photobucket.com/albums/zz97 ... ator/4.jpg[/img]
[IMG:1024:768]http://i817.photobucket.com/albums/zz97 ... CN0311.jpg[/img]
[IMG:1024:768]http://i817.photobucket.com/albums/zz97 ... CN0312.jpg[/img]
Last edited by amplifiednation on Sat Feb 11, 2012 3:50 pm, edited 1 time in total.
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martin manning
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Re: Dumbleator is Complete!

Post by martin manning »

Looks great Taylor!
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Re: Dumbleator is Complete!

Post by amplifiednation »

martin manning wrote:Looks great Taylor!
Thanks Martin! When I realized I already had the choke I went ahead and used it. I thought it might help balance the weight of the chassis, but i was wrong, the PT has all the weight.
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martin manning
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Re: Dumbleator is Complete!

Post by martin manning »

Cool, so what are the voltages? The choke should get you the highest possible B+1, and that is an advantage when using that PT. I would move the purple wire to the tip terminal on the send jack. That way you can get a line-out from the send, and you can still quickly bypass FX by pulling the return plug.
catears
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Re: Dumbleator is Complete!

Post by catears »

Looks great, Taylor!

Building a box for it next?
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Re: Dumbleator is Complete!

Post by tubedogsmith »

Taylor, that looks great!! What are the specs on the trannie you used?
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Re: Dumbleator is Complete!

Post by Cliff Schecht »

*puts on monocle*

Is that a 1/4W resistor I see next to your AX7?

:P

Looks great Taylor!
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Re: Dumbleator is Complete!

Post by amplifiednation »

Thanks guys!! I used the replacement Fender reverb unit PT, I'm not sure on the specs, but its putting 255 out of the secondaries before the rectifier.

Tubedog, the Hammond box was a great call thanks!!

I had some minor start up issues--wired that fancy switch wrong-so I haven't had an opportunity to test voltages yet. Preliminary tests have me in the ballpark...I will dig in later heading to the city for awhile, finally just got actual electricity through the unit. I couldn't figure out what was going on. I should have done more continuity checks...all is well though.
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Re: Dumbleator is Complete!

Post by amplifiednation »

Voltages...

I have a new production EH 12AX7 installed. Still haven't played through it. My voltages are spot on with Structo's build with the same PT

Mains 120.8
Heaters 6.88
Secondary 255.4

B1 345.0
B2 278.1

Pin 1 279
Pin 2 16.75
Pin 3 34.85

Pin 6 230
Pin 7 0
Pin 8 1.7
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ToneMerc
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Re: Dumbleator is Complete!

Post by ToneMerc »

I'm glad it's working out for you.

TM
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Re: Dumbleator is Complete!

Post by amplifiednation »

I have been troubleshooting this all night...it wasn't passing signal, triple checked joints and connections, one of which was in fact wrong...

But the overall cause of the silence was some of the cheap purple insulation on one coax shield jumper wire had melted right over the tip terminal of the 'out' jack!! The bare wire was shorting it to ground! It must have been touching the terminal when I soldered to it.

Once I fixed that it fired right up. I can't believe the difference! What a great addition to a spectacular build. You all were not exaggerating about the smoothing effect. Three more knobs too!! Haha. Very cool

I can't wait to crank it up!!!
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Re: Dumbleator is Complete!

Post by catears »

amplifiednation wrote:I have been troubleshooting this all night...it wasn't passing signal, triple checked joints and connections, one of which was in fact wrong...

But the overall cause of the silence was some of the cheap purple insulation on one coax shield jumper wire had melted right over the tip terminal of the 'out' jack!! The bare wire was shorting it to ground! It must have been touching the terminal when I soldered to it.

Once I fixed that it fired right up. I can't believe the difference! What a great addition to a spectacular build. You all were not exaggerating about the smoothing effect. Three more knobs too!! Haha. Very cool

I can't wait to crank it up!!!
I mentioned this in another recent dumbleator thread but it goes for all iron work, watch that coax if you have a heavy hand. If you do a search for coax there are a few older threads I believe that touch on different types. I would try some Belden RG 59 'thin net'. I don't use it on the grids, but I like it better going to the pots, a more sturdy wire, thick dielectric, and it's dead quiet. 16.5pf/ft. And sometimes the beefier wire just looks cool 8)
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angelodp
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very nice

Post by angelodp »

Great work Taylor. Great to have the extra bit of tone shaping.

Cheers Ange
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