Monkeymatic Rocket 64

Express, Liverpool, Rocket, Dirty Little Monster, etc.

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xtian
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Monkeymatic Rocket 64

Post by xtian »

I pulled a nice pile of components from a pristine 1964 Baldwin 54A chassis. I can't fathom how everything stayed so clean and perfect. Ad said was pulled from a working organ, but I can't see how it ran more than a couple hours in its life before being boxed and shelved.

RJ is sending a chassis, and I'm going to make some vintage-vibe Rocket thing, maybe with digital reverb.

IMG_8522.jpg
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norburybrook
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Re: Monkeymatic Rocket 64

Post by norburybrook »

oooh nice...I like re using things , that stuff looks in great shape. Keep us posted with the build.



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ChopSauce
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Re: Monkeymatic Rocket 64

Post by ChopSauce »

Nice! These parts could hardly "felt down" in better hands than yours. I'm looking forward to see what you'll build with these 8)

If you don't mind one question: why not mosfet driven tank, rather than digital reverb?

I am surprised because I read several negative comments about digital reverb. I suppose it's not that bad if you envision it, though :wink:
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xtian
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Re: Monkeymatic Rocket 64

Post by xtian »

I really like the sound of the Accutronics BTDR reverb "brick", and the 15v PSU that Lou designed for it. Allows 30v p-p swing, so you can add verb just prior to PI.
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xtian
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Re: Monkeymatic Rocket 64

Post by xtian »

Big thanks to RJ for sending a chassis and Rocket PCB (and extras!).

Here's the populated board:
IMG_8562.jpg

and the +15/-15v PSU and BTDR reverb boards (PCBs by Lou!). There are two PSU boards (top) and two reverb boards (bottom, one flipped so you can see both sides):
reverb.jpg
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joeboo88
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Re: Monkeymatic Rocket 64

Post by joeboo88 »

Nice!
I am just populating the same board from RJ for my Rocket.
I too like the brick reverb. Mines a pedal I built
Keep us posted
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M Fowler
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Re: Monkeymatic Rocket 64

Post by M Fowler »

Very nice boards indeed.
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xtian
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Re: Monkeymatic Rocket 64

Post by xtian »

I had hidden an old MosValve cabinet in the closet...and guess what. It was designed around a 17" x 8 x 2 chassis! So now we've got a combo.

Because of the way the chassis fits the cabinet, I had to rotate both transformers and squeeze them toward the rear of the chassis, but the hum cancels, everything fits, and I didn't bleed.

I expect higher than comfortable voltages before the 5U4GB knocks it down, so I'm going to use 4x 47uF radial caps in parallel/series to get a 47uF/900v reservoir.

RJ's removable chassis top made working the metal MUCH easier on the drill press. Should do this will all my one-offs!

IMG_8563.jpg
IMG_8565.jpg
IMG_8564.jpg
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joeboo88
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Re: Monkeymatic Rocket 64

Post by joeboo88 »

Nice cabinet, you can call it “Monkey valve”.... ok maybe not :mrgreen:

I have the same chassis, RJ does have some cool stuff.

Your build is looking great.
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xtian
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Re: Monkeymatic Rocket 64

Post by xtian »

More progress.

IMG_8575.JPG
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romberg
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Re: Monkeymatic Rocket 64

Post by romberg »

The reverb and PS boards are pretty cool. I'm interested how it turns out!

Mike

P.S. It may just be the photo and/or my eyes but it looks like there are no grommets in a couple of those holes?
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xtian
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Re: Monkeymatic Rocket 64

Post by xtian »

Correct. Still early going.
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Re: Monkeymatic Rocket 64

Post by RJ Guitars »

I'm along for the ride... looks like a great project and I know the Rocket builds tend to be a pretty friendly platform for adding your own flavor to them. I used a 5U4 rectifier in one of my earlier Rocket builds and I thought it sounded really good. Looking forward to the rest of this build.
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xtian
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Re: Monkeymatic Rocket 64

Post by xtian »

Up and running. I'm leaving the reverb out until I get the bugs worked.

First thing was getting the dissipation under control--with the original value 47R cathode resistor, plate voltage was 300 and dissipation was up around 170%! Using 90R cathode resistor gave me 320 plates and 95%, and 25 watts clean output into 8 ohms load.

I'm chasing some ground loop hum, though it may just be the proximity of my PT and OT--I had to squeeze them together in order to fit the combo cabinet.

I think I'll add a MOSFET B+ reducer to drop the plate voltage closer to 280, and this will lower the hum a little also.

IMG_8578.JPG
IMG_8580.JPG
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xtian
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Re: Monkeymatic Rocket 64

Post by xtian »

Updated schematic for this build.

Screen Shot 2017-10-09 at 10.23.30 AM.png
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