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The Danelectro DM-25

 
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Structo



Joined: 21 Nov 2004
Posts: 26415
Location: Salem, OR

PostPosted: Fri Jul 02, 2010 1:20 pm    Post subject: The Danelectro DM-25 Reply with quote

I recently worked on this amp.
It's a Danelectro DM-25.
A guy from New York state emailed me asking me what all should be done to this amp he had just acquired.

In the end he shipped the amp head to me and I installed a three prong cord, replaced the filter and bypass caps, removed death cap and bypassed the ground switch, replaced a couple resistors that were out of spec on the power supply, cleaned all the pots, cleaned and retensioned the tube sockets and replaced the standby switch.

This is what is called a piggyback amp. The amp head stows in the bottom of the speaker cab so you can carry both in one hand.




12" Jensen C12Q speaker, one of the good ones!


UPS delivered it and the box looked like this.
I really don't understand how they can do this unless they throw it off of a four story building, several times....
It could have been packed a little tighter inside but the amp survived.



This amp called for two 7189 power tubes. They are very similar to the EL84 tube but can handle higher plate voltage.

One of the 7189 tubes was bad when I got the amp. Looked like the tube had a small crack at the base so the vacuum was lost.
Not hard to imagine when you look at the cardboard box.

The standby switch was also bad, it did not switch into standby.

This amp is a point to point amp meaning there are no circuit boards, just the components soldered to tubes, terminal strips or other components.
And since the amp is on the small side, it is very cramped in there so you have to kind of weave your soldering iron through there to solder.




Modern capacitors are much smaller than the old ones.
Here is an example, these are both 25uF 25v caps.
That is a dime for comparison.




The amp has both reverb and tremolo. The reverb tank is interesting in that it uses two piezo transducers, one at each end of the "tank" to send signals to the amp.
It has a very springy/ sprongy sound to it and really captures the surf vibe if turned up. Dick Dale would be proud!
The tremolo effect is fairly subtle but sounds good.

This amp is one of those that has a glorious overdrive when pushed.
Sounds a lot like the old Supro or Valco amps so highly prized by some guitarists.
All in all, this is a cool little amp and I'm glad I was able to help restore it back to operating properly.
Another cool vintage amp saved from the landfill! Very Happy

This is after the work was done on it.


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shattered



Joined: 28 Jun 2007
Posts: 3785
Location: Buffalo NY

PostPosted: Fri Jul 02, 2010 1:39 pm    Post subject: Re: The Danelectro DM-25 Reply with quote

[quote="Structo"]UPS delivered it and the box looked like this.
I really don't understand how they can do this unless they throw it off of a four story building, several times....
It could have been packed a little tighter inside but the amp survived.



I've seen that kind of damage before. That's what happens when some doucheflap loads a heavier package on top. I'm glad the amp wasn't damaged.... Evil or Very Mad

Excellent work, BTW! I hope to someday get up the nerve to take on a non-solid-state-mini-amp type of project like that.
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vulture



Joined: 01 Mar 2008
Posts: 4503
Location: Chicago

PostPosted: Fri Jul 02, 2010 2:30 pm    Post subject: Reply with quote

Nice Structo. I really dig the piggy back stlye. Have to remember that for future amp projects. I'm surprised it didn't get damaged more from UPS or as I call them OOPS.
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power chord hack



Joined: 31 Dec 2005
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PostPosted: Fri Jul 02, 2010 4:00 pm    Post subject: Reply with quote

nice!
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vulture



Joined: 01 Mar 2008
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PostPosted: Fri Jul 02, 2010 5:56 pm    Post subject: Reply with quote

Whoa, that has 4 channels???? and what are all the knobs for, separate channels?
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rhardman



Joined: 11 Sep 2008
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PostPosted: Fri Jul 02, 2010 7:58 pm    Post subject: Reply with quote

Cool amp Tom--

The cab construction and general layout remind me of my Valco made Silvertone. Kinda wonder if Valco wasn't making them for Danelectro, like the Supros and Silvertones. Same tolex as the Silvertone too.

Glad to see you back!!! Just listen to the docs and you'll be fine.

Rawl
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missionguitars



Joined: 06 Dec 2004
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PostPosted: Fri Jul 02, 2010 9:00 pm    Post subject: Reply with quote

Nice work!

And more importantly, glad you are feeling well enough to be working again!
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Structo



Joined: 21 Nov 2004
Posts: 26415
Location: Salem, OR

PostPosted: Sun Jul 04, 2010 12:04 pm    Post subject: Reply with quote

Thanks, it's a two channel amp.
The second channel has the reverb and tremolo on it.

It is a cool design and the owner says he loves it now. Very Happy
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Travst



Joined: 15 Jul 2008
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Location: Birmingham, AL

PostPosted: Sun Jul 04, 2010 2:30 pm    Post subject: Reply with quote

Very cool amp!
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Rock-On!!



Joined: 10 Sep 2007
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PostPosted: Sun Jul 04, 2010 3:01 pm    Post subject: Reply with quote

Cool,
Nice save.. Wink
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aquietcabin



Joined: 20 Mar 2010
Posts: 4200
Location: Crystal Lake, IL.

PostPosted: Mon Jul 05, 2010 10:01 am    Post subject: Reply with quote

thats awesome, i have the bigger 610 or 1485 piggy back silvertone version of that amp.


sweet dan-o
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