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Fwd: Bias adjustment W551 amp
by Shankar Singh 09 Apr '25

09 Apr '25

Has anyone done the modification below? Was any tweaking of the 6.8 Ω resistor required? What are some of the tested transistor replacements for these Wurlitzer part numbers? 130537-5 130537-4 131262 131777 Would like to try on a 550 amp. Thank you Shankar Singh Begin forwarded message: From: Jay Hennigan via Jukebox-list <jukebox-list(a)lists.netlojix.com> Date: June 1, 2020 at 14:00:27 GMT-4 To: jukebox-list(a)lists.netlojix.com Subject: Re: [Jukebox-list] Bias adjustment W551 amp Reply-To: jukebox-list(a)lists.netlojix.com, Jay Hennigan <jay(a)west.net> On 6/1/20 08:40, SFC(r) Rich Myers via Jukebox-list wrote: > Need to replace the output transistors on a W551 amp. Have sourced > replacements NTE121(?).I think are the model. The current transistors are > color coded green..not sure that is.as important today as it was back in the > 60/70s. As others have said, not adjustable. Check the values of the emitter resistors at 0.5 ohm (they're probably OK and difficult to check with most ohmmeters), also the voltage divider resistors on the base circuit. Whenever I repair or rebuild amplifiers of this vintage with blown or previously replaced and mismatched germanium output transistors I will typically replace with silicon and change the values of the bias resistors to match. Looking through my notes I haven't done this swap on a Wurlitzer 551 so can't give you the specifics with 100% certainty but if you go that route, use MJ15016 transistors and replace the 2.7 ohm 2-watt resistors with 6.8 ohm in the base circuit. This should do the trick. Silicon transistors are more reliable and far less expensive than the generic NTE germanium parts available today. -- Jay Hennigan - jay(a)west.net Network Engineering - CCIE #7880 503 897-8550 - WB6RDV _______________________________________________ Jukebox-list mailing list Jukebox-list(a)lists.netlojix.com http://lists.netlojix.com/mailman/listinfo/jukebox-list Searchable Archives: http://jukebox.markmail.org/

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Wurlitzer 2900 Amplifier Issue
by M De Simone 07 Apr '25

07 Apr '25

I remember many questions about model 2900 on this forum and now I have a head scratcher, well for me anyway. I’m trying to figure out why relay RY5 located in the amplifier burns up. I have -29.5vdc across it (calls for -28v) and all the voltages around it seem to be very close as well. When I take an AC measurement across RY5 I get 15vac, not sure if that’s significant? It’s been recapped but C35 (3000@50v) is original and tests good with an esr meter. Any thoughts on what might be causing this relay to overheat? I’ve never worked in a model 2900. Thanks, Mauro Sent from my iPhone

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Wurlitzer key?
by Tony Miklos 07 Apr '25

07 Apr '25

Is there a TF-50 I have one that almost opens a Wurlitzer 850 and the number isn't stamped on, it's scratched on (looks like I did it) (I now have a punch set). I suppose I need an LF-50, but what is a TF-50? -- Tony Miklos Tony's Jukebox Repair

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Wurlitzer 2304s
by Stephen Andrews 02 Apr '25

02 Apr '25

Hi everyone, I have a set of carousel top ring letter /number water slide decals for picking a record. For Free if anyone is interested. Sent from my iPhone

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Wurlitzer 2900 side glass wanted
by Tony Miklos 30 Mar '25

30 Mar '25

For a Wurlitzer 2900 Does anyone have the side glasses, or know someone who might have them? Thought I'd ask again before having some cut. -- Tony Miklos Tony's Jukebox Repair

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Rowe R85 Lock Out
by Jukebox Repairman 23 Mar '25

23 Mar '25

Customer brought me his R85 that he drilled the cabinet door lock on. Problem is the cam and pull rods fell down inside the cabinet so I cant access it to open. This is a first for me so I am looking for advice from anyone who has experienced this problem and what was the trick to get it open? Thanks Rick

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DS160 and Stepper issue
by Jukebox Repairman 19 Mar '25

19 Mar '25

Had a call today from a gentleman who said he added a stepper and wall box to his DS160. The wall box selects perfectly but now when making a selection directly from the juke both alpha and numeric buttons stay latched down and nothing happens. He disconnected the wall box but the juke buttons still stay latched down. I have to say this is a new one on me so I’m throwing it out to the group for consideration. Regards, Rick

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Rock-Ola CD Bubbler 58440-A part
by NotarySojac 18 Mar '25

18 Mar '25

I'm in need of a good power amp for a Rock-Ola Red Cybersonic amp. Part # PCB 58440-A. That or any info on someone who can repair a few of these for me. Checking everywhere at this point. Tried contacting Rock-Ola but getting any response has been problematic. Thanks for any help. Robert P. Cachur Georgetown Texas

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Wurlitzer 3700 Americana
by Tony Miklos 12 Mar '25

12 Mar '25

Hoping someone can help me with this Americana. The gripper arm was over the carousel, but not in line with the slot. I touched the safety switch and the motor cycled and acted normal except the gripper didn't go straight enough to get the record in the slot and would jamb. I was trying to degrease it and get it free when it pops apart and he says he took that clip out of the other end of that. I was able to get it working almost as free as it should be, but when it popped apart the nylon gears got all out of sync. I'll be darned if I could figure out how it all goes together. I should have taken a picture before I left. I've never needed to take one of these apart in that way and I'm a bit lost. -- Tony Miklos Tony's Jukebox Repair

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continental 2
by Russell Lilley 04 Mar '25

04 Mar '25

hi. i have a couple of ongoing problems with my conti. that seems to happen when not used for a while. selects track no worries but after carousel has turned and stopped at track number ,quite often the lever that decides which side of the record it puts down,dosent pull across enough. i dont know its name but it is directly behind the grabber arm, and has 2 coils that pull left or right . i presume its the switch that these coils are triggered from.? results in the record grabber ,slightly twisting but record falls out .any help or idea greatly appreciated

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