Author Topic: Dyno eq curve  (Read 1931 times)

Offline b2112g

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Dyno eq curve
« on: August 02, 2016, 03:05:47 PM »
I used to have a printout of the Dyno eq curve and I lost it. I can't find it in the web, I think it might have come from the patent. If anyone knows where to find it, or could post it please help. Thanks.

Offline pnoboy

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Re: Dyno eq curve
« Reply #1 on: August 12, 2016, 07:24:58 AM »
I made a SPICE model of the dyno preamp, and so can print out a frequency-response curve.  Of course, the frequency response changes with pot settings.  Also, I have seen a few different dyno schematics, and some of the component values differ between them.  Does anyone have a definitive schematic that they know is correct because it was checked by comparing it to an actual original dyno preamp?

Offline DynoCzarus Rex

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Re: Dyno eq curve
« Reply #2 on: August 12, 2016, 08:58:49 AM »
I have a picture of the preamp and a schematic of of it. I think this one is an original from 1979.
Rhodes Mark I 73 key Suitcase Model (1978)
Fender Rhodes 88 key Stage Model (1973) with original 1982 Dyno-My-Piano Pro EQ
Rhodie Preamp
Yamaha CP-300 Stage Piano
Crate G40CXL Stereo Chorus Amplifier
Boss CE-2 (1982)
Roland KC-150 Keyboard Amp
Amdek CHK-100 Chorus
MXR Phase 90 1974 Script Logo Reissue
MXR Phase 100 (1978)
Dave Smith Instruments Prophet '08

Offline DynoCzarus Rex

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Re: Dyno eq curve
« Reply #3 on: August 12, 2016, 09:20:19 AM »
And pnoboy is right. The layout for these preamps did change over the time Dyno-My-Piano was in business. This is my Pro EQ and Chorus unit from 1982 that I'm having placed in my 1973 stage Fender Rhodes. Notice that it's much more compact than the '79 one.
Rhodes Mark I 73 key Suitcase Model (1978)
Fender Rhodes 88 key Stage Model (1973) with original 1982 Dyno-My-Piano Pro EQ
Rhodie Preamp
Yamaha CP-300 Stage Piano
Crate G40CXL Stereo Chorus Amplifier
Boss CE-2 (1982)
Roland KC-150 Keyboard Amp
Amdek CHK-100 Chorus
MXR Phase 90 1974 Script Logo Reissue
MXR Phase 100 (1978)
Dave Smith Instruments Prophet '08

Offline Tim Hodges

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Re: Dyno eq curve
« Reply #4 on: August 12, 2016, 11:07:59 AM »
That is amazing, I thought that these smaller chorus modules were developed by Chuck Monte (not the famous tri-chorus ones) in fact it's just a Boss CE-2 chorus PCB added on.

Thanks for posting.
Bristol Electric Piano
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Offline pnoboy

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Re: Dyno eq curve
« Reply #5 on: August 14, 2016, 10:20:04 AM »
I have a picture of the preamp and a schematic of of it. I think this one is an original from 1979.

In the schematic you posted, some of the components have 2 different values--one in black, and one in red.  Can you verify the value of each of these components with your actual unit?  If so, maybe we could say that we have a correct schematic.  I suppose it's also possible that dyno preamps from different eras had one or the other of these component values.  Some of the differences are small, while others are significant.

Offline DynoCzarus Rex

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Re: Dyno eq curve
« Reply #6 on: August 22, 2016, 09:33:20 AM »
That is amazing, I thought that these smaller chorus modules were developed by Chuck Monte (not the famous tri-chorus ones) in fact it's just a Boss CE-2 chorus PCB added on.

Thanks for posting.

Chuck Monte did develop a stereo version of the CE-2 chorus known as the Dyno-My Piano 1215 Dual Chorus. Then the dual was later developed into the tri-stereo chorus rack mount module.
Rhodes Mark I 73 key Suitcase Model (1978)
Fender Rhodes 88 key Stage Model (1973) with original 1982 Dyno-My-Piano Pro EQ
Rhodie Preamp
Yamaha CP-300 Stage Piano
Crate G40CXL Stereo Chorus Amplifier
Boss CE-2 (1982)
Roland KC-150 Keyboard Amp
Amdek CHK-100 Chorus
MXR Phase 90 1974 Script Logo Reissue
MXR Phase 100 (1978)
Dave Smith Instruments Prophet '08

Offline Groove4Hire

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Re: Dyno eq curve
« Reply #7 on: September 10, 2016, 03:06:57 AM »
The Tri stereo came about in a slightly different way... I have never seen the mod in real life, only read about how they did it, but they used two chorusunits, where they routed 1/3 of the pickups into one unit, the other 2/3 into the other unit and lft the last 1/3 unprocessed, creating a tri stereo effect. This is what supposedly led to the rack unit developed and produced by San Music Corp in Japan.
Jon
Rhodes-tech, www.vintagebua.no, Norway

Offline JanneI

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Re: Dyno eq curve
« Reply #8 on: September 11, 2016, 12:59:39 PM »
I made this based on the same schematic. Works fine, but since there is like 20x boost on highs, it's pretty noisy.

https://www.youtube.com/watch?v=Cf-HroHJsQo

You can get pretty similar results with the bbe sonic maximizer. And if you are more into chorus than the suitcase tremolo, CE-1 is the king of choruses for Rhodes, in my opinion.

Cheers,
Janne