Thoughts on Dyno'ing a suitcase Rhodes?

[DynoCzarus Rex]

So I've recently acquired an original 1979 Blue label Pro Piano Dyno preamp from a gentleman named Linwood Bell out of Las Vegas (link: http://linwoodbell.com). I'm planning to place it on the far right side of my '78 73 key suitcase Rhodes namerail and use it as the main EQ. I'm wanting to find a way to inactivate the original janus EQ but still use the suitcase vibrato along with the Dyno EQ. Is it possible to power the Dyno preamp with the five pin cable or will it need to be replaced with another type of multi-pin? Looks like it's been done before as evidenced by this screenshot of Rob Mounsey's suitcase Dyno but I don't know for sure how it would be done. Any thoughts would be greatly appreciated!

[pnoboy]

It's truly simple to disable the Janus tone controls--simply set them to their midpoints.  They provide no equalization at that setting.

[DynoCzarus Rex]

It's truly simple to disable the Janus tone controls--simply set them to their midpoints.  They provide no equalization at that setting.

I'm not so sure if that would sound too good, as Ben Bove pointed out in an earlier post that EQ on top of EQ is not a good idea--i.e. poor signal to noise ratio. Looks like the light next to the Janus volume pot is not on, which tells me that the power to that part of the preamp along with the EQ is getting bypassed to power the Dyno.

[Ben Bove]

pno's right about the EQ settings being set to zero, however I do believe daisy-chaining a Dyno and a Janus together would be unpleasantly noisy.  With a naturally hissing Dyno on top of a high-end hissy Janus preamp, you might be able to scare away alley cats with that setup.

An easy way to test it would be to use the accessory jack - power up and loop that mono Dyno preamp in like an effects pedal, using a 1/4" adapter on the rear Dyno RCA cable, and see how it sounds.  The accessory jack comes before the Rhodes preamp, right off the harp, so it would be Harp > Dyno > Janus.

It is possible to wire up and run the Dyno preamp off the Janus suitcase, instead of the factory preamp, because that vintage of Rhodes preamp and the Dyno preamp both handle 15 volts.  However, in your case you'd need to power both separately because both are needed to perform a function - EQ and vibrato.  You'd have to dig into the janus preamp schematic and figure out (or have a tech figure out) how to jumper over the EQ section.

[DynoCzarus Rex]

pno's right about the EQ settings being set to zero, however I do believe daisy-chaining a Dyno and a Janus together would be unpleasantly noisy.  With a naturally hissing Dyno on top of a high-end hissy Janus preamp, you might be able to scare away alley cats with that setup.

An easy way to test it would be to use the accessory jack - power up and loop that mono Dyno preamp in like an effects pedal, using a 1/4" adapter on the rear Dyno RCA cable, and see how it sounds.  The accessory jack comes before the Rhodes preamp, right off the harp, so it would be Harp > Dyno > Janus.

It is possible to wire up and run the Dyno preamp off the Janus suitcase, instead of the factory preamp, because that vintage of Rhodes preamp and the Dyno preamp both handle 15 volts.  However, in your case you'd need to power both separately because both are needed to perform a function - EQ and vibrato.  You'd have to dig into the janus preamp schematic and figure out (or have a tech figure out) how to jumper over the EQ section.

Thanks Ben, I'll have to try that out when I get it! As far as 12" speakers go are there any appropriate brands that come to mind as far as bringing out the most of the high frequency EQ characteristics of the Dyno preamp (i.e. JBL, Celestion, etc...)? I'm just not real sure if my stock speakers will be able to handle these higher frequencies.

[Ben Bove]

The 12" alone have never been able to match what I hear in the headphones or direct line-outs.  I'd probably recommend getting the amp situation figured out via headphones or line-out, and move onto speaker shotgun tests

[DynoCzarus Rex]

The 12" alone have never been able to match what I hear in the headphones or direct line-outs.  I'd probably recommend getting the amp situation figured out via headphones or line-out, and move onto speaker shotgun tests

Did some digging around and I think these may be the best solution for those trying to get a little more brightness out of the Janus suitcase cabinet. Here are some full-range/PA drivers I found with a much greater frequency response for Janus era cabinets:
1. https://www.parts-express.com/eminence-beta-12lta-12-full-range-pa-driver--290-409?utm_source=google&utm_medium=cpc&utm_campaign=pla
2. http://www.mcmelectronics.com/product/55-5305

[pnoboy]

The 12" alone have never been able to match what I hear in the headphones or direct line-outs.  I'd probably recommend getting the amp situation figured out via headphones or line-out, and move onto speaker shotgun tests

Did some digging around and I think these may be the best solution for those trying to get a little more brightness out of the Janus suitcase cabinet. Here are some full-range/PA drivers I found with a much greater frequency response for Janus era cabinets:
1. https://www.parts-express.com/eminence-beta-12lta-12-full-range-pa-driver--290-409?utm_source=google&utm_medium=cpc&utm_campaign=pla
2. http://www.mcmelectronics.com/product/55-5305

Those seem like good speakers, but they have fairly large values of Vas, which means that you need a pretty large enclosure to put them in or you end up with a boomy bass, which no Rhodes needs.  The suitcase speaker cabinet is large, but it also has 4 12" speakers in it, so volume/speaker isn't as big as one might imagine.  Does anyone know  the interior dimensions of the suitcase?

[DynoCzarus Rex]

The 12" alone have never been able to match what I hear in the headphones or direct line-outs.  I'd probably recommend getting the amp situation figured out via headphones or line-out, and move onto speaker shotgun tests

Did some digging around and I think these may be the best solution for those trying to get a little more brightness out of the Janus suitcase cabinet. Here are some full-range/PA drivers I found with a much greater frequency response for Janus era cabinets:
1. https://www.parts-express.com/eminence-beta-12lta-12-full-range-pa-driver--290-409?
utm_source=google&utm_medium=cpc&utm_campaign=pla
2. http://www.mcmelectronics.com/product/55-5305

Those seem like good speakers, but they have fairly large values of Vas, which means that you need a pretty large enclosure to put them in or you end up with a boomy bass, which no Rhodes needs.  The suitcase speaker cabinet is large, but it also has 4 12" speakers in it, so volume/speaker isn't as big as one might imagine.  Does anyone know  the interior dimensions of the suitcase?

Found an older post on the forum here about the outside dimensions of the suitcase cabinet. The width & length, and depth are 45" x 23" x 12" respectively (or 3.75' x 1.917' x 1'). All that together would be about 7.1875 ft^3, so I guess the inside dimensions would be somewhat less than these. Don't know what the relationship would be with <7.1875 ft^3 to the Vas value.