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 Post subject: Wurlitzer 510 amp
PostPosted: Sep Fri 05, 2003 7:34 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 1284
Location: twin falls idaho
This is from a Wurlitzer 1250 jukebox . Can someone find this schematic for reference ( i already have one )<P>Is this an odd amp ? hooking a CD player to its input gives very low volume results . Hooked to its original phono cartridge it plays low volume .<BR>I have checked & swapped tubes and recapped the amp .. still low volume <BR> <P>------------------<BR><BR>


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 Post subject: Wurlitzer 510 amp
PostPosted: Sep Sat 06, 2003 8:56 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 1284
Location: twin falls idaho
Holy smokes it would take longer to draw that than it would to restore the whole jukebox ..thanks .. :-)<P>I figured it out , the junction box was needed to bring the tube filaments up to full power .<P>------------------<BR><BR>


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 Post subject: Wurlitzer 510 amp
PostPosted: Sep Mon 08, 2003 6:12 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 605
Location: Clovis, CA, USA
Wouldn't that amp be set up for a zenith cobra cartriage? If so, I don't believe it would operate properly with the feed off of a cd player. I have the 1400 and tried to test mine out that way and learned that it doesn't work right. Something about how the zenith cartriage works. I'm sure someone here can get technical and explain it.<P>Bill<P>------------------<BR>


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 Post subject: Wurlitzer 510 amp
PostPosted: Sep Mon 08, 2003 4:50 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 7583
Location: Beaver Falls, PA. USA
The Zenith "Cobra" pickup has a small coil and a stainless-steel vane, which is welded to the stylus. The pickup coil is part of an oscillator which operates at 2.5 Mhz. Modulation of the record grooves causes corresponding variations of the Q of the pickup coil, which varies the output of the oscillator. "Plate bend detection" occurs in the oscillator tube, providing an AF output. This information comes from an old Zenith service manual, for the S-11680 record changer. If another audio source is to be connected to a phonograph using the Cobra pickup, it would need to be connected to the output of this oscillator stage.<P>Tim <P>------------------<BR>


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 Post subject: Wurlitzer 510 amp
PostPosted: Sep Mon 08, 2003 10:11 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 11178
Location: North of Mpls, Minnesota
If this amp is set up for a Cobra tone arm with the circuit Tim describes you may have to use a preamp to bring the signal up to the level the oscillator would have put out. You would have to bypass the oscillator circuit, and feed the output of the preamp to the first amp tube. The preamp would also supply the RIAA equalization needed. <P>Dave<P>------------------<BR>


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 Post subject: Wurlitzer 510 amp
PostPosted: Sep Mon 08, 2003 10:24 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 11178
Location: North of Mpls, Minnesota
PK<BR>I would think a PA amp would be a poor choice for a guitar amp because of the very low passband and the non linear frequency response. The response on a PA amp usually drops off after 5khz. The complete circuit would have to be redesigned to widen the passband but then you would still be restricted by the small output transformer which is not designed for the higher frequencies.If you have worked out a system for doing this I would be interested as I have a couple of PA amps sitting here collecting dust.<P>Dave<P>------------------<BR>


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 Post subject: Re: Wurlitzer 510 amp
PostPosted: Jan Mon 15, 2018 8:10 pm 
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Joined: Jun Sat 25, 2016 6:36 pm
Posts: 92
If I am reading this correctly, are you saying you DO have a schematic for a Wurlitzer 1250? Would you be willing to scan or share it? Or sell it to me cheaper than I can find it in cyberspace?? Thank you!
Diane


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 Post subject: Re: Wurlitzer 510 amp
PostPosted: Jan Thu 25, 2018 3:03 pm 
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Joined: Jun Fri 15, 2012 2:22 pm
Posts: 102
Location: Wausau, WI
http://www.verntisdale.com/schem/510.jpg


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