Maestro - MP-1 Stage Phaser

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
User avatar
seziertisch
Information
Posts: 9
Joined: 21 Mar 2008, 14:43

Post by seziertisch »

Hey, I have a service manual for one of these babies. It includes a full list of components as well as a pcb layout, schematic and advice on how to troubleshoot the thing. This was bought as photo copy from a company on Ebay a few years ago, and I'm guessing their selling of it was not too legal as a few months later Ebay contacted me saying that their was a breach of the law involved in their selling of the manual to me.

Anyway, this is an awesome sounding phaser, and the manual pretty much contains all the info necessary for building one, so if anyone is interested I will try and get it out to the pedal building public. That said I don't know if there are any legal issues surrounding me making the original pages available online? If the schematic needed to be redrawn or something I would just send it to one of the more knowledgeable amongst you as a pdf document.

Let me know what y'all think.

User avatar
aanz
Information
Posts: 2
Joined: 14 Apr 2008, 16:26
Has thanked: 1 time

Post by aanz »

Are you talking about the big aluminum foot pedal with the wheels on the sides? If so, I have one that's not working and I've been looking for repair info/schematic. Please shoot me an email.
Thanks!

aanz (at) mindspring (dot) com

User avatar
MoreCowbell
Transistor Tuner
Information
Posts: 1101
Joined: 06 Aug 2007, 14:39
Been thanked: 15 times
Contact:

Post by MoreCowbell »

The best thing is to redraw the schematic. Then it becomes "your" artwork, and is yours to do with as you wish.

User avatar
seziertisch
Information
Posts: 9
Joined: 21 Mar 2008, 14:43

Post by seziertisch »

Ok, I am good to go with the schematic and maintenance manual. I will leave the redrawing to someone else, but considering that I paid 10 dollars or something to some guy on Ebay selling a photocopy and that it is such an excellent phaser I think someone should do a redraw. Drop me a line and I can send it to you.

User avatar
analogguru
Old Solderhand
Information
Posts: 3238
Joined: 26 Jun 2007, 13:58
Been thanked: 124 times
Contact:

Post by analogguru »

....that I paid 10 dollars or something to some guy on Ebay....
:shock: :shock: :shock:

on June 28, 2001 it was available free on the web.... File size: 1.109.448

analogguru
There´s a sucker born every minute - and too many of them end up in the bootweak pedal biz.

User avatar
HNY
Information
Posts: 11
Joined: 31 Dec 2007, 20:27

Post by HNY »

aanz wrote:Are you talking about the big aluminum foot pedal with the wheels on the sides? If so, I have one that's not working and I've been looking for repair info/schematic. Please shoot me an email.
Thanks!

aanz (at) mindspring (dot) com
There was a schematic to be found at the more advanced forum:
https://www.diystompboxes.com/smfforum/ ... ?board=2.0
dated 4-21-2001 where I did a search for you, the result of which
you shall find in your personal message box.

User avatar
FearlessFlyingFrog
Information
Posts: 14
Joined: 05 Oct 2008, 16:39

Post by FearlessFlyingFrog »

Is there anybody here who happens to own one and is willing to post some detailed gut shots?
There are plenty of pics of these pedals online, but none of the insides.

Pretty Please???

User avatar
rocklander
Old Solderhand
Information
Posts: 2726
Joined: 18 Apr 2008, 11:33
my favorite amplifier: my jansen bassman 50
Completed builds: rebote 2.5; supreaux; odie; heartthrob tremolo; ross phaser; dr. boogey; thor; baja black toast; slow gear attack, rebote, tri-vibe, small clone, little angel, magnus modulus, echo base, hex fuzz, big muff, 22/7.
Location: Rotorua, New Zealand
Has thanked: 1406 times
Been thanked: 231 times
Contact:

Post by rocklander »

FearlessFlyingFrog wrote:Is there anybody here who happens to own one and is willing to post some detailed gut shots?
There are plenty of pics of these pedals online, but none of the insides.

Pretty Please???
I managed to have a play on one of thee on the weekend.. LOVED it.. so cool to be able to simply adjust the pots with the feet.

I've asked the owner if he could take some up close and personal gut shots for me, he's got that pencilled in for the weekend after easter so will post when I get them :D

I'd be dead keen on making one.. might have to mess out a new PCB though as I'm told sh'es quite a rats nest inside?
world's greatest tautologist ...in the world
Ronsonic wrote:...the lower the stakes the more vicious the combat.

User avatar
marshmellow
Cap Cooler
Information
Posts: 469
Joined: 16 Aug 2007, 07:31
Location: Germany
Has thanked: 20 times
Been thanked: 127 times

Post by marshmellow »

Here is the service manual including schematic and layout.

User avatar
rocklander
Old Solderhand
Information
Posts: 2726
Joined: 18 Apr 2008, 11:33
my favorite amplifier: my jansen bassman 50
Completed builds: rebote 2.5; supreaux; odie; heartthrob tremolo; ross phaser; dr. boogey; thor; baja black toast; slow gear attack, rebote, tri-vibe, small clone, little angel, magnus modulus, echo base, hex fuzz, big muff, 22/7.
Location: Rotorua, New Zealand
Has thanked: 1406 times
Been thanked: 231 times
Contact:

Post by rocklander »

marshmellow wrote:Here is the service manual including schematic and layout.
datasheetarchive.com used to offer an 'equivalent' option in searching and it's not there now..
any idea what an equivalent for the ca3094 is, and is there an alternative site for searching for equivalent components?
world's greatest tautologist ...in the world
Ronsonic wrote:...the lower the stakes the more vicious the combat.

User avatar
Dirk_Hendrik
Old Solderhand
Information
Posts: 4193
Joined: 03 Jul 2007, 08:44
Location: Old Amsterdam
Has thanked: 232 times
Been thanked: 887 times
Contact:

Post by Dirk_Hendrik »

There's no direct replacement. Easiest and cheapest is to re-layout to LM13700. Another, already more expensive option is to combine CA3080 OTA's with a discrete darlington trannie.

Or pay your guts out on a pile of 3094's........

It's worth it for sure.. Great phaser.
Sorry. Plain out of planes.

http://www.dirk-hendrik.com

User avatar
rocklander
Old Solderhand
Information
Posts: 2726
Joined: 18 Apr 2008, 11:33
my favorite amplifier: my jansen bassman 50
Completed builds: rebote 2.5; supreaux; odie; heartthrob tremolo; ross phaser; dr. boogey; thor; baja black toast; slow gear attack, rebote, tri-vibe, small clone, little angel, magnus modulus, echo base, hex fuzz, big muff, 22/7.
Location: Rotorua, New Zealand
Has thanked: 1406 times
Been thanked: 231 times
Contact:

Post by rocklander »

Dirk_Hendrik wrote:There's no direct replacement. Easiest and cheapest is to re-layout to LM13700. Another, already more expensive option is to combine CA3080 OTA's with a discrete darlington trannie.
bugger.. that'd be well out of my abilities league...
Dirk_Hendrik wrote: Or pay your guts out on a pile of 3094's........
bugger.. that'd be well out of my wallet league...
Dirk_Hendrik wrote: It's worth it for sure.. Great phaser.
no argument from me.. it was almost like the 'talent' stompbox when I was playing on it.. I could trip over the guitar with that thing on and it would have sounded cool..., then they switched it off and boom.. I was my usual crap player self :lol:
world's greatest tautologist ...in the world
Ronsonic wrote:...the lower the stakes the more vicious the combat.

User avatar
marshmellow
Cap Cooler
Information
Posts: 469
Joined: 16 Aug 2007, 07:31
Location: Germany
Has thanked: 20 times
Been thanked: 127 times

Post by marshmellow »

Dirk_Hendrik wrote:There's no direct replacement. Easiest and cheapest is to re-layout to LM13700.
Hi Dirk,

would you say the LM13700 works as a direct replacement function wise? What would be the relevant parameters in the datasheet to look for? I don't know that much about OTAs yet.
If it would work, then I might do a new layout at some point in the future. I find an OTA design way more attractive than the circuits using optocouplers or matched FETs.


Volker

User avatar
rocklander
Old Solderhand
Information
Posts: 2726
Joined: 18 Apr 2008, 11:33
my favorite amplifier: my jansen bassman 50
Completed builds: rebote 2.5; supreaux; odie; heartthrob tremolo; ross phaser; dr. boogey; thor; baja black toast; slow gear attack, rebote, tri-vibe, small clone, little angel, magnus modulus, echo base, hex fuzz, big muff, 22/7.
Location: Rotorua, New Zealand
Has thanked: 1406 times
Been thanked: 231 times
Contact:

Post by rocklander »

marshmellow wrote:
Dirk_Hendrik wrote:There's no direct replacement. Easiest and cheapest is to re-layout to LM13700.
Hi Dirk,

would you say the LM13700 works as a direct replacement function wise? What would be the relevant parameters in the datasheet to look for? I don't know that much about OTAs yet.
If it would work, then I might do a new layout at some point in the future. I find an OTA design way more attractive than the circuits using optocouplers or matched FETs.


Volker
mate, I'd be all over that if you were up to doing it 8)
world's greatest tautologist ...in the world
Ronsonic wrote:...the lower the stakes the more vicious the combat.

User avatar
Dirk_Hendrik
Old Solderhand
Information
Posts: 4193
Joined: 03 Jul 2007, 08:44
Location: Old Amsterdam
Has thanked: 232 times
Been thanked: 887 times
Contact:

Post by Dirk_Hendrik »

marshmellow wrote:
Dirk_Hendrik wrote:There's no direct replacement. Easiest and cheapest is to re-layout to LM13700.
Hi Dirk,
would you say the LM13700 works as a direct replacement function wise? What would be the relevant parameters in the datasheet to look for? I don't know that much about OTAs yet.
If it would work, then I might do a new layout at some point in the future. I find an OTA design way more attractive than the circuits using optocouplers or matched FETs.
Volker

Jep. Just replace the CA3094's in the schematic with LM13600 or LM13700. You might want to add a 6th stage since you'll have one 13700 stage left.

Other than that, I do happen to like optocoupler based phasers a lot :mrgreen:
Sorry. Plain out of planes.

http://www.dirk-hendrik.com

User avatar
FearlessFlyingFrog
Information
Posts: 14
Joined: 05 Oct 2008, 16:39

Post by FearlessFlyingFrog »

marshmellow wrote:Here is the service manual including schematic and layout.

Thanks, mate.

I already had that and I'm currently struggling to draw a PCB from that.
But since this is the first time I'm trying it with a circuit as complex as that, I reckoned it might be good to have some pics of the real thing to double check that I'm not screwing it up.

User avatar
marshmellow
Cap Cooler
Information
Posts: 469
Joined: 16 Aug 2007, 07:31
Location: Germany
Has thanked: 20 times
Been thanked: 127 times

Post by marshmellow »

Here is a first schematic how I would do it. Now there are seven phase stages instead of six. Would it make sense to have one stage switchable to preserve the "original" sound? I can't really predict how much of a difference it will make.

Comments, suggestions, spotted mistakes are always welcome. Layout is on it's way, but don't expect it too soon, it's exam time :?.


@Dirk: I like them too of course. But optos are just so big, expensive and still have questionable tolerances :wink:.
Attachments
der_meister-phaser.png

User avatar
Dirk_Hendrik
Old Solderhand
Information
Posts: 4193
Joined: 03 Jul 2007, 08:44
Location: Old Amsterdam
Has thanked: 232 times
Been thanked: 887 times
Contact:

Post by Dirk_Hendrik »

Looks cool!
Your schematic drawing style is pretty similar to mine (euro-style?) , making it a very easy read. Nice. :horsey:

Maybe give that last stage some testpoints so you can jumper it in and out of the circuit.
Sorry. Plain out of planes.

http://www.dirk-hendrik.com

User avatar
marshmellow
Cap Cooler
Information
Posts: 469
Joined: 16 Aug 2007, 07:31
Location: Germany
Has thanked: 20 times
Been thanked: 127 times

Post by marshmellow »

Thanks! :) But I'm not really long enough around in the electronics business to estimate whether this is european style :wink:. I just draw the way it's easy to read for myself...


Some pads to jumper the stage out seem like a good idea. Or finally use a switch if the change of sound is worth it.

User avatar
Dirk_Hendrik
Old Solderhand
Information
Posts: 4193
Joined: 03 Jul 2007, 08:44
Location: Old Amsterdam
Has thanked: 232 times
Been thanked: 887 times
Contact:

Post by Dirk_Hendrik »

bump because there's more interesting stuff than fuzzes :mrgreen:
Sorry. Plain out of planes.

http://www.dirk-hendrik.com

Post Reply