Author Topic: Wurlitzer 200a grounding? or normal...  (Read 7503 times)

Offline garagebandking41

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Wurlitzer 200a grounding? or normal...
« on: February 12, 2011, 09:55:59 PM »
My wulri 200a's line out has a lot of hum/hiss. the volume of the hiss is constant from 0 volume, to 100%. it's even there when the amp is off. of course, when i unplug the wurli from the wall, there is no hum.

I was wondering what could be causing this type of hum/hiss. its alright in some amps, but very noticeable in a recording setting, or on PA's. I've looked for any loose grounds, but Im a bit inept when it comes to troubleshooting something like this...
Noisy Wurltizer 200a
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Offline pianotuner steveo

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Re: Wurlitzer 200a grounding? or normal...
« Reply #1 on: February 17, 2011, 06:45:48 PM »
In general, the first thing always recommended in wurlis is to replace the caps. Old dried out caps will eventually cause other problems, so I would check into that.
1960 Wurlitzer model 700 EP
1968 Gibson G101 Combo organ
1975 Rhodes Piano Bass
1979 Wurlitzer 206A EP
1980 Wurlitzer 200A EP
1980 Wurlitzer 270 Butterfly Grand
2000 Yamaha acoustic piano
2004 Hammond XK3
2009 73A Rhodes Mark 7
2009 Korg SV-1 73
....and a few guitars...

Offline garagebandking41

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Re: Wurlitzer 200a grounding? or normal...
« Reply #2 on: February 21, 2011, 11:05:35 AM »
Could old caps cause this symptom? Considering the hum is still there when the power is off, i would think it was a grounding issue. But you're right, I've been wanting to do a rebuild anyways, just didnt think the caps would cause hiss when the power was off.

I've done some minor stuff like replacing the soldering in fuses with easy access ones, and i've been meaning to get a new pre-amp for it as well. I'm trying to make the darn thing studio ready, so i can make some recordings...I should have stuck with just Rhodes...hah!
Noisy Wurltizer 200a
Buggy Moog LP Tribute
Heavy Rhodes Mark V

Offline pianotuner steveo

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Re: Wurlitzer 200a grounding? or normal...
« Reply #3 on: March 08, 2011, 07:31:30 AM »
I find it odd that you hear hum if the power is off.....is the hum through the speakers or is it coming from the transformer?
1960 Wurlitzer model 700 EP
1968 Gibson G101 Combo organ
1975 Rhodes Piano Bass
1979 Wurlitzer 206A EP
1980 Wurlitzer 200A EP
1980 Wurlitzer 270 Butterfly Grand
2000 Yamaha acoustic piano
2004 Hammond XK3
2009 73A Rhodes Mark 7
2009 Korg SV-1 73
....and a few guitars...

Offline jim

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Re: Wurlitzer 200a grounding? or normal...
« Reply #4 on: March 29, 2011, 01:20:21 AM »
I'd really like to know the outcome of this, am having exactly the same problem.

Offline jim

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Re: Wurlitzer 200a grounding? or normal...
« Reply #5 on: March 31, 2011, 02:33:55 AM »
bump bump bump?

Offline jim

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Re: Wurlitzer 200a grounding? or normal...
« Reply #6 on: April 03, 2011, 03:59:07 AM »
really? nobody has anything? :-\

Offline pianotuner steveo

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Re: Wurlitzer 200a grounding? or normal...
« Reply #7 on: April 03, 2011, 07:59:58 AM »
Jim, in your case, could it have anything to do with you being in Australia?

( The difference in your electricity,with whatever transformer you use?)

Just for the record, what is the electrical standard in Australia? Is it 220v 50 Hz?


1960 Wurlitzer model 700 EP
1968 Gibson G101 Combo organ
1975 Rhodes Piano Bass
1979 Wurlitzer 206A EP
1980 Wurlitzer 200A EP
1980 Wurlitzer 270 Butterfly Grand
2000 Yamaha acoustic piano
2004 Hammond XK3
2009 73A Rhodes Mark 7
2009 Korg SV-1 73
....and a few guitars...

Offline jim

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Re: Wurlitzer 200a grounding? or normal...
« Reply #8 on: April 03, 2011, 07:09:48 PM »
Hi Steveo, long time no chat!
we are 240V down here.
the transformers in our wurlys are different, but i've played others without this sound many times so it doesn't seem to be an australian thing.

If this where a passive rhodes i'd be putting my hands all over it trying to lower the noise by grounding it. But I'm not doing it on a wurly! i'm scared!

Offline Legato72

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Re: Wurlitzer 200a grounding? or normal...
« Reply #9 on: May 09, 2011, 01:24:19 PM »
Same issue here. (and I'm American thus 120 V.) Even when the wurli is off and it's plugged in an amp it will have horribly loud hum. I had always figured it was because mine is a 200 and needs the AC fix where you twist the wires and shield them, then replace the neon bulb. That doesn't make sense on second thought, because it hums when its off. I'm a little shocked to hear someone with a 200a having the same issue. I'm doing a lot of fixes to it right now and I am checking all the grounds, I'll let you know how it goes. won't be done for a while though, have an amp rebuild ahead of me.
« Last Edit: May 17, 2011, 08:42:53 PM by Legato72 »

Offline Legato72

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Re: Wurlitzer 200a grounding? or normal...
« Reply #10 on: May 17, 2011, 08:35:40 PM »
I have successfully installed the VV hum killer kit into my 200. In the back of my mind the whole time I was installing it I thought it probably won't fix this problem, because it still hums when the wurli is off, and is unaffected by the volume knob. I was right.

The obscenely annoying hum is still there. It's sounds like when you hold your finger on the end of the 1/4 inch guitar cable when it plugged into an amp. Also please note that this only happens on an external amp plugged into the aux (or headphone) jack. This hum doesn't exist on the on-board speakers.

I checked and double checked all my grounds. I can't figure out what it could possibly be if it seems to be grounded alright. It cant be the transformer because that's only activated when you turn the switch. As the topic author stated, when you pull the power cable it stops.

Maybe a bad input cable? the one that runs from aux to the circuit board? but the headphone jack causes hum too. A real head-scratcher.
« Last Edit: May 17, 2011, 08:39:48 PM by Legato72 »

Offline Legato72

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Re: Wurlitzer 200a grounding? or normal...
« Reply #11 on: May 18, 2011, 10:55:10 AM »
GROUND LOOP.
The issue is a massive ground loop. A circuit formed through the grounds between my vibrolux (external amp) and my wurlitzer. To solve the problem I went to Lowe's and got myself 3 to 2 prong ground lifter for 77 cents. put it on the end of my wurli power cable and problem solved. all that awful hum disappeared. I imagine you could also solve the problem with a guitar cable that is tip only on one end, not having the ground connected on one end of the sheild. I think that too would eliminate the loop, but it is a lot easier to just use a ground lifter. Its still safe because the wurli then becomes grounded through the external amp.

Again, if you are having external amp hum that is constant no matter the volume of the wurli (or if it is switched off even), you have a ground loop. I can't believe this isn't a more widely known issue in the wurlitzer community. but then again, maybe its so obvious to some people its not even worth mentioning.

EDIT: Don't quote me on the safety thing. I'm actually not sure how safe it is exactly.. a guitar cable that is only tip and no ground on one side would probably be "safer" because you eliminate the loop and both the amp and wurli would be grounded safely to the wall on their own. But then that cable becomes purposed soley to plug the wurli into an external amp.
« Last Edit: May 18, 2011, 12:41:42 PM by Legato72 »

Offline pianotuner steveo

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Re: Wurlitzer 200a grounding? or normal...
« Reply #12 on: May 18, 2011, 02:20:10 PM »
That is great news. I have been collecting Wurlis since the 70's and have never heard of this problem before this thread, and I dont think it was ever brought up on the yahoo wurli board.
1960 Wurlitzer model 700 EP
1968 Gibson G101 Combo organ
1975 Rhodes Piano Bass
1979 Wurlitzer 206A EP
1980 Wurlitzer 200A EP
1980 Wurlitzer 270 Butterfly Grand
2000 Yamaha acoustic piano
2004 Hammond XK3
2009 73A Rhodes Mark 7
2009 Korg SV-1 73
....and a few guitars...

Offline mickeyziggyk

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Re: Wurlitzer 200a grounding? or normal...
« Reply #13 on: July 02, 2016, 07:00:46 AM »
Hi

My first post.

Not wanting to start a new post, but i have this issue too.

Wurli 200a on the headphone output with power on or off hums like crazy through certain amps.

To a normal guitar amp it is fine (koch se6 or orange crush), but to a hifi,  class d yamaha amp or a hifi or an elektron octatrack it hums like a giant bee. It's also fine with headphones. I've noticed that the aux output does not have this issue at all just the headphone out.  Naturally if I disconnect from the mains, the issue goes away too. Passing the signal to a radial jdi sorts it out too but then the signal is very quiet and needs a heap of boost.

It's quite bizarre. As a workaround I'm thinking of disconnecting the internal speakers so i can use a quiet line out.

Would anyone care to comment on the quality of the signal via headphone or aux as the aux out seems more 'open' in its quality and the headphone out seems 'narrower'.

Offline pianotuner steveo

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Re: Wurlitzer 200a grounding? or normal...
« Reply #14 on: July 02, 2016, 08:43:44 AM »
The headphone out should not be used in lieu of a line out. The signal is hotter, and can distort easier.
That's my 2 cents worth.

It sounds like you may need to ground your power cord also?
1960 Wurlitzer model 700 EP
1968 Gibson G101 Combo organ
1975 Rhodes Piano Bass
1979 Wurlitzer 206A EP
1980 Wurlitzer 200A EP
1980 Wurlitzer 270 Butterfly Grand
2000 Yamaha acoustic piano
2004 Hammond XK3
2009 73A Rhodes Mark 7
2009 Korg SV-1 73
....and a few guitars...

Offline mickeyziggyk

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Re: Wurlitzer 200a grounding? or normal...
« Reply #15 on: July 02, 2016, 09:06:07 AM »
Thank you for your input Pianotuner Steveo

I decided to mod my wurli and add a switch to kill the speakers so i can have dedicated line out via the aux.

I'm not good at these sorts of things but I've got it working and for my 200a and I'm very happy with the sound via the aux than the headphone. Just in time for a wee jam, as the fellas should be round soon.

The reason i want a dedicated line out is that i love fx and processing the wurli via delay, vibrato, phase, chorus, filters, volume pedal, and synths.

And the reason i posted is that maybe someone else whi is struggling to get a good line out signal might come across this post, as the previous posters helped me.

Offline cinnanon

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Re: Wurlitzer 200a grounding? or normal...
« Reply #16 on: July 04, 2016, 08:29:58 PM »
You didn't need to add that switch. All you needed was to plug in a 1/4" to 1/8" stereo adapter
« Last Edit: July 04, 2016, 08:34:00 PM by cinnanon »

Offline Max Brink

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Re: Wurlitzer 200a grounding? or normal...
« Reply #17 on: July 11, 2016, 10:44:03 PM »
Quote
I have successfully installed the VV hum killer kit into my 200. In the back of my mind the whole time I was installing it I thought it probably won't fix this problem, [because it still hums when the wurli is off, and is unaffected by the volume knob. I was right.]

Quote
Wurli 200a on the headphone output with power on or off hums like crazy through certain amps.

...If the Wurlitzer is off and you still have noise it is definitely because of a ground loop between the Wurlitzer and the amplification circuitry. Wurli's are incredibly prone to electromagnetic interference and ground loops just due to their design. Where to address this symptom within the instrument is going to be hard to diagnose over the internet and if you're uncertain I would take it to a Wurli expert or EE.


Quote
I imagine you could also solve the problem with a guitar cable that is tip only on one end, not having the ground connected on one end of the sheild.

^^^I would be very surprised if this ever works. Respectfully, to the person who wrote this years ago, I wouldn't try this ever.
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Offline pianotuner steveo

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Re: Wurlitzer 200a grounding? or normal...
« Reply #18 on: July 14, 2016, 07:21:15 AM »
I agree with Max on that last point, I don't see how that would solve anything.
1960 Wurlitzer model 700 EP
1968 Gibson G101 Combo organ
1975 Rhodes Piano Bass
1979 Wurlitzer 206A EP
1980 Wurlitzer 200A EP
1980 Wurlitzer 270 Butterfly Grand
2000 Yamaha acoustic piano
2004 Hammond XK3
2009 73A Rhodes Mark 7
2009 Korg SV-1 73
....and a few guitars...