Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: DummyLoad on December 19, 2012, 04:52:12 pm
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picked this up off craigslist a couple of days ago - not exactly a sweet deal (150 clams) but interested me enough to throw-down the scratch.
purportedly has as sweet and deep tremelo.
previous owner mentioned he'd been hauling the "damn thing" around for over 15 years with the intention of getting it fixed but budget crunch forced sale. he also claimed it leaked smoke during a practice session and has been shelved since. i figured worst case it was either PT or OT and i have donor iron for either. surprise and good fortune so far - PT & OT are in pristine condition for the age - what leaked smoke were two 4.7K 2W resistors in parallel that fed the screens of the 6L6 and 2.2K cathode resistor under V3b (12AX7 gain stage.).
put the magic smoke back in and patched in new resistors and gave it a cap job.
some gear porn. have a look under her skirt (http://s2.beta.photobucket.com/user/pmitchel/library/Danelectro)...
i'll some cabinet photos when i get her buttoned back up - in the meantime there's one on fleabay (http://www.ebay.com/itm/1950s-Danelectro-Challenger-Series-D-Model-89-Rare-Vintage-Tube-Amp-/190761823401?pt=LH_DefaultDomain_0&hash=item2c6a4a6ca9) and they're awfully proud of it...
mine looks like it, however, mine is different tolex color and it has some odd connectors on the amp - there are two cinch-jones 4 pin male-plugs that tap off the 6SN7 feed to 6L6 grids - i presume there may have been slave cabinet(s) or some sort of effects option available. i'm tempted to graft them out carefully so as to facilitate an undo if necessary.
i reverse engineered it and i did check my work - i believe it to be near to 100% accurate - but ya never know... if something stands out, then please post up.
this amp is similar to to a wards airline model GDR-8517A
--DL
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this one is finished & updated photo album.
http://s2.beta.photobucket.com/user/pmitchel/library/Danelectro (http://s2.beta.photobucket.com/user/pmitchel/library/Danelectro)
made a couple of mods, took out the slave plugs and changed the divider resistor on the bias ckt. gave it a cap job, replaced the power switch and added 3 wire line cord. had to rebuild tremelo, 1 cap was bad and 2 resistors drifted in value >20%. gave it a near complete compliment of NOS sylvania tubes; 2x12AX7, 1x6AU6, 2x6L6GB & a rauland branded RCA 5Y3GT. the crometop sylvania 6SN7GT tested near new.
cool sounding amp, very nice tremelo and tone stack works very well. gonna flip it on CL locally and post here.
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Interesting to see where O'Connor got the Bass control idea from. I'd never seen it before his books, until this amp.
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Interesting to see where O'Connor got the Bass control idea from. I'd never seen it before his books, until this amp.
danelectro used 1MA pots and the bass control is reversed - look at some of panel pics - fully CCW is max bass.
do you think it's possible to replicate the function with a reverse audio taper pot and wire it in pin 1 to pin 3 and pin 3 to pin 1? that way when fully CW would be max bass.
--DL
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nice clean rebuild. is that a 12" spkr? maybe you know, were the Dan amps all built by one mfg. or were there numerous?
thx, jack d :think1:
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nice clean rebuild. is that a 12" spkr? maybe you know, were the Dan amps all built by one mfg. or were there numerous?
thx, jack d :think1:
jack, it's a 15" w/ an alnico magnet and aluminum voice coil dust cap. don't know much about danelectro amps other than they built amps to market themselves and also for sears and montgomery wards. there may be others they built for. what it does seem like is that danelectro built several similar models with a variation of a model built exclusively for each re-seller.
--DL