Castle Flanger Schematic

[gordonraphael]

hello gentlemen: I have both the dual phaser rack mount and dual chorus flanger by castle, and yes they are both some of the finest sounding instruments of their kind. I lucked out and found them in a pawn shop in New Mexico while on tour with a band. My Phaser has been "dead" for almost 4 years.. won't turn on, will not light up-- and what has prevented me from getting it repaired is that no one seems to have any schematics and so (I guess, as I am not a repair person) they can have no clue as to how to proceed. Do you have any advice for me?? cuz I want that thing back in action. I bought a Mutron BiPhase, to help me ease my sorrow, and for as amazing as that one is, its not as unique and musical as the Castle! thank you..

[52 Bill]

I would suggest taking it to any repair shop that has a history of repairing older equipment. There are a number of guys here that have service shops that would be able to help you.

When something will not power up, there are a few specific things to look for that any qualified repair person should be able to find, even without a schematic. The power supply on these units are basic analog designs with linear voltage regulators. Any tech should be able to fix this with no problem.

Once the power supply is working, if there are any issues with obsolete chips or other parts you may have to do some creative thinking to get around this, but there is always hope.

[gordonraphael]

Thank you for that very clear view, Bill. I thought that a decent repairman would be able to sleuth it out. I think the places here (Berlin) that I've taken it to have been just swamped with work, and they didnt want to do any kind of creative thinking, without the schematics to hand! Im inspired to try again!

[Zalmo]

hello gentlemen: I have both the dual phaser rack mount and dual chorus flanger by castle, and yes they are both some of the finest sounding instruments of their kind. I lucked out and found them in a pawn shop in New Mexico while on tour with a band. My Phaser has been "dead" for almost 4 years.. won't turn on, will not light up-- and what has prevented me from getting it repaired is that no one seems to have any schematics and so (I guess, as I am not a repair person) they can have no clue as to how to proceed. Do you have any advice for me?? cuz I want that thing back in action. I bought a Mutron BiPhase, to help me ease my sorrow, and for as amazing as that one is, its not as unique and musical as the Castle! thank you..

Hi. It IS possible that I have schematics for the unit I have and less possible that I have the Phaser schematics.
Please, every so often, remind me to look...as these may be stashed away somewhere a bit difficult to get to...and, on occasion, will get up the courage to hunt and search them out!
All the best,
zalmo

[Mark Hammer]

This picture of the floor unit board provides some insights into the circuit. First, it uses OTAs (the CA3080 chips) for the eight phase shift stages, similarly to what the much simpler EHX Small Stone phaser does. Second, where the CA3094 chip in the Small Stone includes both an OTA and a buffer, the Castle design uses one half of a TL072 dual op-amp as buffer, to compensate for what the CA3080 lacks. Finally, you can see an NE570 chip, which is used for companding, to both manage the limited headroom of the 3080s, and to keep the signal output quiet.

The site where I got this notes that later issues used the long-since out-of-production SSM2040 instead of the 3080s. I have no idea if the dual-rack version was concurrent with, or subsequent to, the version shown here.

The 2040 was four OTAs on a chip, and was regularly used for 4-pole synth filters in many popular synths of the early 80's (e.g., the Prophet 5 used five of them). I will note that Roland came up with its own comparable proprietary chip in the early 80's - the IR3109 - which they also regularly used for both synth filters as well as phasers. Both the Boss PH-2 and RPH-10 used a pair of them. Though I imagine you might find some in the Akihibara in Tokyo, they are otherwise unobtainable, and in any event are not pin-for-pin compatible with the SSM2040. The late, and deeply missed, Jurgen Haible came up with an all discrete replacement for the 2040.

But I digress. This thread is about the flanger, and not all things Castle.

[52 Bill]

gordonraphael, just like the flanger that I repaired, my guess would be that your problem is repairable. I enjoy the challenge of figuring out why things stop working.

I for one hope that the schematics for Castle products do eventually turn up. Even though many of the chips have gone into oblivion, I'd still like to see what the designers did to make them tick.

And Mark, I doubt that any one minds the fact that you have added your insight here. Unless you start one there will probably never be another Castle thread on this forum.

[buck1107]

It's great to have more info on the Castle stuff here! I had no idea they made anything other than phasers (the Phaser III).
Does anyone know how long they were in business?

[52 Bill]

It's great to have more info on the Castle stuff here! I had no idea they made anything other than phasers (the Phaser III).
Does anyone know how long they were in business?

Welcome to the place. I don't know, but I guess I remember seeing the ads for the phasers for at least 2-3 years. Maybe Mark Hammer has some better information in his files.

Do you own any of their products?

[buck1107]

Welcome to the place. I don't know, but I guess I remember seeing the ads for the phasers for at least 2-3 years. Maybe Mark Hammer has some better information in his files.

Do you own any of their products?

Thanks for your post.
No, I don't currently own any, but it's been a nearly life-long quest, beginning with receiving their then-new catalog back in June 1981.

Any information would be welcomed.

[buck1107]

hello gentlemen: I have both the dual phaser rack mount and dual chorus flanger by castle, and yes they are both some of the finest sounding instruments of their kind. I lucked out and found them in a pawn shop in New Mexico while on tour with a band. My Phaser has been "dead" for almost 4 years.. won't turn on, will not light up-- and what has prevented me from getting it repaired is that no one seems to have any schematics and so (I guess, as I am not a repair person) they can have no clue as to how to proceed. Do you have any advice for me?? cuz I want that thing back in action. I bought a Mutron BiPhase, to help me ease my sorrow, and for as amazing as that one is, its not as unique and musical as the Castle! thank you..

Hi! It's great to hear from a Castle fan. I might be able to help you with this, if you're still looking to get your Dual Phaser III repaired.

[Zalmo]

There was also a Chorus Echo unit which about a dozen were made....which I happen to have one, owned by Mickey Lee Lane, Top 40 Rocker.
I plugged it in and it still works.
Who knows the last time this unit got to eat some electricity?