Author Topic: Rhodes Stage MKI Hiss  (Read 804 times)

Offline guizmo

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Rhodes Stage MKI Hiss
« on: January 14, 2019, 02:55:31 PM »
Hi guys !

I've got a problem with my 2 Rhodes. The 2 are 73 stage MKI, the first is a 77/78 model, the other a 71/72.
I'm a bit lost because I don't know if it really comes from the Rhodes or my gear.
When I plug a Rhodes it can be good or bad. After some minutes a bad hiss appears.
There's a sample on attachement. The first part is the good sound and the second was recorded few minutes later with the same equipment when the hiss came.
It was recorded from the rail output to an UA 6176 and in a RME UFX.
The hiss appears on my amps too, but much less noticeable than in the UA 6176 (here, the UA 6176 setting has high gain and treble boost).

Thanks

Offline The Real MC

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Re: Rhodes Stage MKI Hiss
« Reply #1 on: January 18, 2019, 10:14:42 PM »
Since it's a stage piano, you're going to need a DI with input impedance of at least 1Mohm.  The pickups in Rhodes pianos are very sensitive to impedance loads, and if it is too low then hiss is created.  The wrong impedance greatly affect the tone too.

I had a real problem with hiss and it took a Countryman Type 10 DI to get rid of it.

Offline guizmo

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Re: Rhodes Stage MKI Hiss
« Reply #2 on: January 19, 2019, 01:46:47 AM »
Thanks for your answer !
But like I said, I use a UA6176 to record, and it has a 2.2MOhms built-in DI.
So the high Rhodes impédance is transformed into a line level signal when I record.

Offline pnoboy

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Re: Rhodes Stage MKI Hiss
« Reply #3 on: January 30, 2019, 11:37:20 AM »
If the harp of your stage piano is connected to the standard front-panel controls, it is already seeing a 10k impedance, and if you then connect it to anything with an input impedance higher than about 100k,  the load on the harp has not changed by any appreciable amount.  If you want to hear more of the "ting " of the hammers hitting the tines, then you must bypass the front-panel controls, or scale the values up to a higher impedance.

Offline guizmo

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Re: Rhodes Stage MKI Hiss
« Reply #4 on: January 30, 2019, 12:26:32 PM »
That’s why I use the High Z input of my preamp, using a DI put my high impédance signal to low.
I don’t have problem with my signal level or something like that, my problem is the hiss audible on the second part of the sample I put on attachement.

Offline pnoboy

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Re: Rhodes Stage MKI Hiss
« Reply #5 on: January 30, 2019, 03:34:01 PM »
I've found stage pianos to be pretty dead quiet.  If you are hearing hiss, look to your signal chain, some interference, or even a ground loop, though ground loops usually produce hum.

Offline guizmo

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Re: Rhodes Stage MKI Hiss
« Reply #6 on: January 30, 2019, 04:11:04 PM »
Have you heard the hiss I am talking about on my record ?

For example, when I recorded this sample, everything was OK, but at a moment the hiss appeared.
It appears on my 2 Rhodes stage, even on my Roland JC or fender Twin... So that’s why I was asking my question on the forum, thinking that it maybe was a known Rhodes issue...

I have several vintage keyboards and have no problem with... that’s weird, because a Rhodes is so simple, compared to a preamped Clav or wurli...

Offline sean

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Re: Rhodes Stage MKI Hiss
« Reply #7 on: February 05, 2019, 02:34:21 PM »


I guess I am too old to hear the hiss on the mp3 that you posted.   If the hiss is kicking in a bit after you play, could it be coming from the compressor?

When the note decays, and the compressor kicks up the gain, it could just be amplifying noise.  Does the hiss change when you lower the compression ratio?  Does it get worse if you set the ratio to 20?

Sean

Offline guizmo

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Re: Rhodes Stage MKI Hiss
« Reply #8 on: February 05, 2019, 02:48:29 PM »
Thanks Sean !

It’s not a problem of compression, because on this sample I don’t use compression.
In fact, the hiss appears sometime after 15 minutes on a session, and after, it’s constant...
There’s no variation on attack, decay or sustain of the note...

But, now I have a doubt... maybe is a hiss who appears on all my equipment, but I ear it because my Rhodes are the cleanest EPs that I have ! I’ll check that !

Offline sookwinder

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Re: Rhodes Stage MKI Hiss
« Reply #9 on: February 24, 2019, 05:25:23 AM »
I too have been "fighting" hiss/noise that comes and goes on my Mk1 stage piano.
It occurs when the tonal controls are bypassed or set at 10.

It has taken about a year of on-again and off-again experiments to determine that the 73 "guitar pickups" that is the rhodes are picking up something emanating/radiating locally... whether that is a function of the normal street lights / power transmission lines that are nearby or modern switch mode power supplies that are everywhere I have not been able to determine. [I have spent many a lunchtime discussing that latest data with my manager who is an electrical engineer]

I know it isn't self generated by the Rhodes (obviously), it isn't from any of the amplifiers or preamps that I have put in or out of the signal line, recording system, house wiring, solar panels, other electrical equipment within the home that is causing the issue.

While I have no real idea what is causing the issue, I believe I have a fix, that being lining the under side of the cover with copper foil and securing it at the two ends/sides to the earth/chassis of the piano.  Trying to create a faraday cage was impractical , so I went for the shielding approach.  My experiments have been quite successful and am now awaiting the roles of 0.3mm copper foil.

I will document this in a thread once I have completed the "upgrade".
Late 60s Pianet N - Late 70s Pianet T - Ensoniq ESQ1 - Hammond XK2 - Wurli 206A converted to a 200A - 1973 Rhodes Stage 73 - Roland RD150 - Vintage Vibe 64 EP - s**t load of guitars, basses & amps

Offline guizmo

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Re: Rhodes Stage MKI Hiss
« Reply #10 on: February 24, 2019, 11:33:53 AM »
Cool thanks !! I’m not alone in this world !!! Have you heard my sample ? Your hiss was similar ?
Ok, I’ll try the copper foil solution !!