Author Topic: 1960's Sparkle top suitcase issues  (Read 1257 times)

Offline craig

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1960's Sparkle top suitcase issues
« on: July 21, 2016, 11:38:04 AM »
Hey guys -

Still getting my teardrop sparkle top up and running. I've got the modules working fine (silicon conversion via VV), but I've got a couple of issues. I'm just not too familiar with this model and my harp output seems low compared to my Mark I. I'm getting 390 ohms resistance at the RCA jack as opposed to 1430 r for my Mark I.  I've measured some of the pickups and they all measure about 33 ohms each though they're still connected. Is this right?

Also, my power amp +35 output isn't measuring (the -25 and -35 are fine.  What would be causing that?  Thanks everyone!

Offline The Real MC

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Re: 1960's Sparkle top suitcase issues
« Reply #1 on: July 21, 2016, 12:10:15 PM »
Sparkletop pickups will be different from the later ones.  All Rhodes pianos have a set of 6 pickups wired in parallel and those sets are wired in series.  Sparkletop pickups measure about 180ohms so with six wired in parallel the set will measure about 33ohms.  At the output the serial chain is the sum of the sets so your measurements are correct.  They will measure differently from later pianos.

Can't answer your voltage problems though.

Offline craig

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Re: 1960's Sparkle top suitcase issues
« Reply #2 on: July 21, 2016, 12:13:57 PM »
Real MC - thank you for your reply, much appreciated...and helpful.

Offline craig

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Re: 1960's Sparkle top suitcase issues
« Reply #3 on: July 21, 2016, 12:24:45 PM »
Actually, one more thing.  I want to recap the pre-amp, but the values are different than later Peterson models (6.4 uf instead of 4.7uf, 125uf instead of 100uf, and 50uf instead of 47uf). Should I/would I be OK to sub the new values for the old ones? They're the original caps, who knows how spec they are anyway. Thanks!

Offline K-man

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Re: 1960's Sparkle top suitcase issues
« Reply #4 on: July 22, 2016, 01:32:26 PM »
Actually, one more thing.  I want to recap the pre-amp, but the values are different than later Peterson models (6.4 uf instead of 4.7uf, 125uf instead of 100uf, and 50uf instead of 47uf). Should I/would I be OK to sub the new values for the old ones? They're the original caps, who knows how spec they are anyway. Thanks!

47u and 50u is the same. 6,4u - now its a 6,8u and 125u - now is 120u
1973 Rhodes 73 stage
Hammond x-2 + Elka leslie
2014 Kurzweil MPS 20