Fender 5e3p from Wurlitzer organ amp

[Zombie_stomp]

Pin 2 and 8, 5u4 rectifier removed, meter set to AC. 5.5 volts shown. (Yeah, the underscore part of one of the digits in the display is out sometimes, making it look like an 'n' in this photo.)

[Zombie_stomp]

I will need to find another 5u4 and test again. I am guessing that the amp could have still functioned very quietly with this bad 5U4, the only other possibility being that moving the amp around somehow knocked it into being bad suddenly. Ideally I could throw it in a tube tester and find out what's up with it. The 6L6s in place of 7027 power tubes probably couldn't make it go bad, could they?

[Phil_S]

6L6 and 7027 are pin compatible, provided that pins 1 and 6 are not used. Check pin out diagrams here: http://tubedata.itchurch.org/index.html
See if you can find a new 5U4GB, not an ordinary 5U4. Though it is easy to get taken, you can probably get a used working one on eBay if you aren't have luck elsewhere.

5.5VAC will drop to around 5V when you put the tube in. As I said, it is good to know you've got filament voltage, as that focuses the problem on the tube.

[Zombie_stomp]

I searched around all over 2 towns at music shops looking for a local 5U4GB, no luck. I'll have to wait, I guess. Are you saying with a good tube that the voltage will drop when I put that in? I wonder what the reading would be with the tube I already have would do to that reading between the two pins.
I don't know the conditions of the 6L6s are, and the guy at the music shop 30 minutes away was all hot and bothered and didn't want to test them since he was in the process of working on an amp for someone with a gig in an hour. I'll just run with them until I feel the need to replace them, I guess.

[Phil_S]

I'd assume 6L6 tubes are good for now. If you didn't have good patience before, you will benefit from learning to have that now. Repurposing an old amp is a slow process. Solve one problem after another, in a certain order, one at a time. Unfortunately, it is not the 60's or even the 70's when you might have been able to go into a TV repair shop and just buy the tubes you need and/or get them tested.

If you get jammed up on getting another 5U4GB or 6L6's PM me. I have some used 5U4BG and some Russian 6p3s (6L6 wannabes, but good enough) that I can part with for a bargain price. I don't have a tester. I'll have to plug the rectifier into an amp to see if I've got one that really works.

Anyway, the first step is to get a working rectifier into the amp to see if you can make B+ voltage. Then we can see about the power tubes.

[Zombie_stomp]

At least my knobs and tube sockets came today. I satisfied my own curiosity of the readings I'd get in AC to the rectifier. Although we think it's bad, it does drop to 4.8-9 when it put the tube back in, now it's reading more like 5.3 with it out. I am remembering the rectifier helps the transformer turn the AC into smooth DC. I'm bound to learn better in this situation where there are problems I want and need to fix than just out of casual curiosity.

[Zombie_stomp]

I ordered a Philco 5U4GB for $7.95, free shipping from Ebay. I sort of made the decision because 2 people named Phil are helping me or are very interested in the forum. The one other than on this forum did try to sign up and I know him here in town. He had trouble getting his confirmation e-mail, but I'm sure that will be resolved in good time.

I also checked with Weber's site. I seem to have no option to remove the chassis from the order, and it comes to no less than $358. I did write them an e-mail about what I wanted out of the order, so I'll see how customized ordering from them is allowed to be. It seemed like a lot of money when I wanted to recap a tiny amp out of an old wire recording machine for $30 on the Mouser electronics catalogue, but now that I'm trying to build an amp that suits the needs of something I was about to spend $1200 on, I don'y mind ordering all the separate parts if it is the difference between $450 and $200 or so and a few hours.

What I would want is specific descriptions of the types of composition of the semiconductors I'm going to want. Some of you prefer axial lead capacitors not only for practical reasons but tone as well. So key words about caps, resistors, and pots is helpful. I also heard I could be needing a choke transformer. That is the one thing I didn't mention in the email to Weber, since I don't quite yet understand what it does. I just want to see what I'm going to need to spend on this project, and how I might spend my time making it less expensive, and how it might balance out.

[matt h]

(deleted)

[jazbo8]

My advice: stop.

Yup, stop what you're doing. Ordering kits minus a chassis because you want to rebuild this into something else? Nope. That's not how to roll. That's not what people are telling you to do.

I'm going to sound like a massive jerk for a second, and I realize that, so withhold anger. Semi-conductors? That you're using this term with relation to things like resistors and capacitors tells me you need to learn a lot.

My advice is to stop. Or rather, stop what you were doing... learn, explore, research. Learn as much as you can before dropping money into a project. Your original goal of 150 bucks? yeah- that is totally doable if you know what you're doing. You keep going down the path you're on, it'll be easy to drop three, four, six hundred dollars to end up in the same place.

+1 to what matt said, before spending money willy-nilly on parts that you may or may not need, learn as much as you can - there are tons of materials online at your disposal. AND spend $10 bucks to get the manual so you know exactly what the circuit looks like, and what entails to convert this into a guitar amp.

[Zombie_stomp]

Stop and learn? I'm not going to learn anything if I stop now. I've been asking the entire thread if there is a detailed build that shows the guts of where all the basics of this type of amp are instead of a dull diagram. I've been searching for something that shows where the schematic meets the soldering iron, and have yet to find such an article.

I may have used a dumb word for electrical parts, but I haven't ordered anything I haven't absolutely needed. Tube sockets, knobs, and the rectifier tube. Now Phil has been giving me excellent step-by-step advice. He's suggested I do a certain type of amp, and ordering caps and resistors from weber instead of searching individually on Mouser electronics website. Although I know enough to do that, I thought I would check into the possibility of getting pots, resistors, caps for a certain type of circuit in one package. Phil made the case for that option, not I. And most importantly: yes, I understand I need to wait until I learn more about what I've got before I order all the other stuff.

I hope this explains what my plans are: to learn by doing and have patience.

[jazbo8]

How about this one? Wurlitzer 4200 Owner's Manual

[cbass]

IMO the best way to learn is jump in and do it. Yes you'll make some mistakes .probably spend more tahn yoiu need to.it may not even sound good if you get it running . I don't think getting a kit is the way to go.if you do that you may as well just build the kit. You aren't gonna find Step by step instructions for the project you are taking on. I think there are instructions from one of the kit suppliers you might be able to find.there are a few YouTube videos also.

[matt h]

(deleted)

[Zombie_stomp]

Ugh. Thank you to those of you who are pointing me in the right direction and being constructive. I appreciate the forward guidance. There are a few posts that do nothing for the cause and should be deleted. What I COULD do is recap the amp and use it as it was, more or less. One of the reasons I started this project is because I once had a film projector with sound, and it was a tube amp and when I plugged my guitar into it, it sounded REALLY COOL just as it was, until it blew a wax capacitor. I still have a couple parts from that thing. It was just so crammed into the projector that it was going to be very difficult to pick it apart and lay it out on a chassis. So now for the price of half a tank of gas, I've got a chance to do something like that again.

I am experienced enough to recap the entire amp and could probably find a way to eliminate all the extra junk or at least get an input to work, and I don't need much more than that.

I think 'just build a kit' is something I would learn a lot from, and I do I tend to use one of the fender reverb unit kits in one or both of the amps I build, and they're about $180.

Also, yeah, I intend to write a paint-by-numbers step-by-step out of a dull diagram and finished amp. He doesn't say a lot about steps, but there is a schematic. I have purchased a Hammond organ amp for less than $60 for this project: http://www.solorb.com/elect/musiccirc/hammonator1/

[Zombie_stomp]

IMO the best way to learn is jump in and do it. Yes you'll make some mistakes .probably spend more tahn yoiu need to.it may not even sound good if you get it running . I don't think getting a kit is the way to go.if you do that you may as well just build the kit. You aren't gonna find Step by step instructions for the project you are taking on. I think there are instructions from one of the kit suppliers you might be able to find.there are a few YouTube videos also.

Thanks, I agree. I could start by finding a schematic for this amp as it is. I don't want to tear it too much apart where there's no going back, but a lot of the inputs and maybe some outputs could be eliminated since it's. It going to interface with the organ anymore. I have thought about taking other parts of the organ out and connecting them temporarily to help figure out how they are interacting with the amp and get some of the guys on the table, as well as the schematic.