Wurlitzer 200a Amp Trouble

[nwiehl]

Hi, I'm hoping to get some advice from anyone who has knowledge on wurli amps and speakers.

I've had my 200a for about two months now, and during that time, it's been sounding great. However, it had this annoying, mechanical rattling sound going on with it, so I decided to open it up and see if any screws or anything inside need to be tightened. I tried not to mess with any of the electronics because that stuff is outside my wheelhouse. I just gave a few screws some small turns, put the hum shield and lid back on.

But I must've accidentally messed up something electrical because now, when I turn it on, it just makes this low output, distorted, pulsing sound: https://youtube.com/shorts/-CiheS2Xqw0?feature=share

Any help would be appreciated, thanks

[amorrison651]

Hey there, sorry to hear your having this issue

A key question is does this also happen when using an external speaker with the aux out?

Whilst I don't recognise that exact pulsing sound, my suggestion would be to check the two fuses on the amp to see if either has blown and replace if needs be

When you open it up again check that the wire's connected to the speakers and elsewhere haven't frayed and check that you've definitely reconnected all of the green grounding cables to the Hun shield screws - loose wires or frays can cause shorts

Have a look at the connection points, are they particularly dirty? Perhaps also buy some contact cleaner spray

Whilst replacing a blown fuse might fix the issue, you want to be sure you didn't cause a short somewhere else, which would just blow the replacement fuses too

If the fuses look fine, have a good look at the physical condition of the amp, are any of the capacitors looking bloated/leaking, is there a lot of dust/grit?

[Electrickey]

Isn't that a 200 NOT a 200A with the speakers on the chassis not in the lid?

If it's a ground issue any green wire bolted to the points on the chassis should be taken apart and some cleaner and light sand paper to burnish the connection areas, (washer, nut, chassis) to get a better ground. There are also special connectors going to the amp and preamp that might need cleaning and tightening. If you don't trust yourself to work on things you might want to get someone who is rather than risk making more issues that will be a problem to get fixed.

How to remove hum from you Wurlizter guide.

[Alan Lenhoff]

Isn't that a 200 NOT a 200A with the speakers on the chassis not in the lid?

The earliest 200As had the speakers on the chassis, like on the 200s. Instrument manufacturers of the era were quite frugal, and tended to use up stocks of old parts rather than discard them. 

Alan