I am looking for info on the Maestro (6 stage) Phase Shifter - the one with the three speed rocker-switches on it. I have a schematic, but I think some of the parts could be subbed for ones I already have. Has anyone tried to clone one of these? If so, what parts did you use?
I do have a collection of JFETS that I matched and sorted back when I was building Phase 90's. Could these types also work with the Maestro circuit?
Also, I was thinking that I wouldn't need to reproduce the three-speed switching circuit, unless it contributes something to the sweep of the phaser. I'm not sure what the LFO waveform would look like from this circuit as opposed to the Phase-90 style LFO, but having infinite range of sweep speeds I think would be a nice touch instead of only three speeds. Any thoughts?
Dave
It may be my favorite phaser of all time. I think it gets looked over because most have not heard it before. I also think these might have been expensive pieces back in the day, and may account for their lack of popularity amongst the average musician. Just put on the beginning of "No Quarter" by Zeppelin and you'll hear what a cool piece it would be to have in your collection.
The three speeds are really two and a on/off switch. It's a 6 stage phaser that had a really full phase sound by comparison to the Phase 90's and other's out at the time. If you like P90 phase over the others, the Maestro is your phaser. You could do a number of mods to it including switching in and out stages (P45, P90), cap changes for Uni-Vibe etc.. The speeds were setup to emulate a Leslie and it does a convincing job. I don't remember if they ramped up or down or not (me thinks not), but that would be an excellent mod to this piece as well.
Sounds like a good one to clone for sure. Hopefully someone will take you up getting this cloned. I don't have the time!
John
I was actually turned onto the Maestro PS-1 while trying to find out which phaser Alex Lifeson used on the early Rush albums, and specifically on parts of "Lakeside Park". Somewhere on the net it referred to his use of Maestro phasers, so I began to look into them. Then I came across the John Paul Jones reference and I knew this was an effect I would like to re-create. After looking at the schematic, I thought some of the parts could be simplified or done away with, but then again, it really isn't all that complicated, so perhaps for authenticity's sake, I should make one as-is. I don't have the proper JFET's but as I mentioned I do have matched sets for Phase 90's (2N5952 I think), so I will probably start with them and see how it goes. By the way - if anyone needs matched JFETS, I will have some of these left over ( I bought 200 and used the op-amp jfet matcher to sort them into clusters matched within 4mV).
Dave
i'm pretty sure it is a ramp up/down style. check out some of the soundclips from mode zero...
http://www.modezero.com/maestro-ps1a.htm
Quote from: caress on June 27, 2007, 01:34:08 AM
i'm pretty sure it is a ramp up/down style.
Yeah I think it was. And I think that was another one of the reasons I really liked it. On guitar it really was a beautiful effect. It was very much the "Leslie" in a box for the day.
Quote from: polaris26 on June 27, 2007, 01:22:11 AM
After looking at the schematic, I thought some of the parts could be simplified or done away with, but then again, it really isn't all that complicated, so perhaps for authenticity's sake, I should make one as-is.
I'm sure a charge pump could help this one out. I doubt it has a big current draw. I'll have to look at the schematic again. It would be really cool with 3 stomp switches. The unit I had (and most of them for that matter) was missing the stomp adaptor. You had to be very careful to push the rocker switches back and forth with the tip of your toe because you could accidentally turn on one of the other switches (I think the faster speeds override the slower when that happens). I think I would much rather have the 3 switches over a single dial. I have phasers with speed controls. This would react more like a Leslie. Then true bypass the off/slow switch (on/off).
What would be really cool would be to add a Uni-Vibe mode to this one. I think with 6 stages it would be very "Vibe" like. I've done Uni-Vibe mods to 4 stage and 2 stage phasers and the effect it rather weak (better on a 4 stage but not there) by comparison to the real thing. I think a 6 or an 8 stage (it would be easy to tack on an additional stage to this one) phaser with the "Vibe" cap mods would be the ticket. Anyone agree?
i dont hear any ramping on those mode zero clips.
the mode zero guitar clips dont give a very good example of what the maestro sounds like.
the univibe was a 4 stage phaser.
cheers
ulysses
In looking at the schematic, I guess the 220uF cap across the base of the emitter-follower transistor that establishes the source voltage for the LFO JFET is what allows for the Lesliesque ramping. The parts breakdown doesn't specify the type of JFET used for the six phase-shift stages, it just says "FET, N-channel, Matched Set of six" There are other JFETs used in the circuit - one for the LFO and one for the mixing of phase-shifted & dry signals (the gate of which is used to control whether you have "off" or "slow" phase - tied through a resistor network to the first rocker switch I suppose. It seems like a funky way to blend the two - why wouldn't you just put a switch on the phased output to open up that path when you wanted dry out only? In any case the unit is of course not true bypass, as the signal always goes through an emitter-follower buffer at the input. This is where cloning old effects gets funky - do you re-do the sections that you think could be done better, or do you try to be as true to the original sound as possible (since it worked back then, it must be good now)? If you keep that output-mixing JFET in there, what type do you use? It calls for 2N4303 which seems expensive today - I guess you could just use the 2N5952's throughout?
Dave
rg would be the man to ask about the ramping.
when it comes to cloning old effects its fairly common practice to update the parts of the circuit that dont effect the tone by using more effecient methods - bypass switching - buffers - switching modes that my not be desirable to create a simpler circuit.
rg recently modded the phase 90 and the ea trem (two completly different circuits) to contain the "same essence of the tone" as the brownface vibrato.
another example is son of screamer which is the "core tone creation" of the tube screamer without unneccesary buffered switching.
cheers
ulysses
Is part of what people mean by "Univibing" using staggered cap values for the phase shift stages? The Univibe had staggered cap values which I have found in simulations decreases the slope of the "linear portion" of the phase vs. frequency plot of the all-pass filter as a whole, and thus spreads the notches further apart. I would imagine trying this with a two-stage phaser would simply result in a changed notch center frequency, which would of course sound different, but since there is only one notch, then there is no spacing between notched as you would have with 4 or more stage phasers. I think you have to be careful with 6 or more stages to space the notches in soncically interesting areas for whatever instrument you have running through the effect. I liked using staggered values in the Phase 90 - it seemed to give it a "chewier" sound to my ear - much like the Univibe itself. I am wondering if as a 6-stager were swept across it's range, the highest notch would pass right out of audibility - you might need to play with notch spacing and sweep range to get it all worked out - I usually do things on a solderless breadboard just so I can play with all the values and test by ear.
Dave
Quote
What would be really cool would be to add a Uni-Vibe mode to this one. I think with 6 stages it would be very "Vibe" like. I've done Uni-Vibe mods to 4 stage and 2 stage phasers and the effect it rather weak (better on a 4 stage but not there) by comparison to the real thing. I think a 6 or an 8 stage (it would be easy to tack on an additional stage to this one) phaser with the "Vibe" cap mods would be the ticket. Anyone agree?
Check out this sample for the ramp sample, It sounds pretty convincing on a guitar (not so much on a synth).
http://www.modezero.com/sounds0000/rs09a-maestro-ps1-3.mp3 (http://www.modezero.com/sounds0000/rs09a-maestro-ps1-3.mp3)
I think the Uni-Vibe mod would work good. You would have to figure out the staggered cap values for a 6 stage phaser (or better make this an 8 stage? Very easy to do). If not you could have it where you could switch in/out stages and switch in the vibe mode for the 4 stage only. I really think staggered caps on a 6 stage phaser would be the ticket.
A pulse LED would be cool, as would a feedback loop (for spacey phase stuff).
J201's for all the JFET's. They seem to be the magic JFET's for these types of phasers.
;)
hmmm.. i dont hear ramping in that sample.. ???
except momentarily when the speed is switched slow and fast.
cheers
ulysses
I definitely can hear it, all be it subtle it's in there. It's not like it goes slow right to fast. A value change here or there might make it more pronounced. To me it's close to a real Leslie ramp. When I got my first Leslie I had expected it to ramp up like a helicopter. I was supprised to find the transition to be rather quick.
Hi,
I have just finished a Maestro clone. I used a Traco Power TEM2-0521 (DC / DC converter) to power the system.Circuit consumption is 140mA.
The power supply is a 9V adapter, a 5V regulator and Traco Power(+/_12V +/_80mA---2W).
Regards,
box
Pictures please :icon_smile:
I would dearly like to build one of these, I really would. There are a couple of people making clones of it, but no one selling a PCB. I tried a vero, but couldn't get it to work properly after much time and effort.
Madbean has a few boards available for what I assume is this model, here's a link to the build doc:
https://www.madbeanpedals.com/projects/_folders/FilterMod/pdf/StageFright2015.pdf
The Madbean schematic is a clone of the later-issue MP-1, not the original Oberheim/Maestro unit. It is also a 6-stager, but uses OTAs instead of FETs, and has a continuous speed control, rather than the 3-speed arrangement with ramping. None of that is a "bad" thing, but may not be what you're aiming for.
Quote from: kaycee on May 11, 2021, 11:31:49 AM
Pictures please :icon_smile:
I would dearly like to build one of these, I really would. There are a couple of people making clones of it, but no one selling a PCB. I tried a vero, but couldn't get it to work properly after much time and effort.
Hi,
I am sending materials that may be helpful.
(https://i.postimg.cc/5QQMB0SZ/Maestro-clone.jpg) (https://postimg.cc/5QQMB0SZ)
(https://i.postimg.cc/bZ9fH41N/Maestro-clone1.jpg) (https://postimg.cc/bZ9fH41N)
(https://i.postimg.cc/7ChtGRVR/Maestro-schematic.jpg) (https://postimg.cc/7ChtGRVR)
(https://i.postimg.cc/fSNvKqcD/Maestro-PS-1-Alayout.webp) (https://postimg.cc/fSNvKqcD)
(https://i.postimg.cc/5YwB65ZG/Maestro-PS-1-Atransfer.webp) (https://postimg.cc/5YwB65ZG)
(https://i.postimg.cc/BX3hcbpH/Power-supply-maestro.jpg) (https://postimg.cc/BX3hcbpH)
Quote from: Mark Hammer on May 11, 2021, 12:21:50 PM
The Madbean schematic is a clone of the later-issue MP-1, not the original Oberheim/Maestro unit. It is also a 6-stager, but uses OTAs instead of FETs, and has a continuous speed control, rather than the 3-speed arrangement with ramping. None of that is a "bad" thing, but may not be what you're aiming for.
Thanks, Mark! I didn't realize that there was more than one Maestro phaser.
The phaser your hear here is the Oberheim/Maestro unit that box provided drawings for. I know because I went to see them when the album first came out, and saw it when I walked up to the stage before the show.
Quote from: box on May 11, 2021, 12:24:37 PM
Quote from: kaycee on May 11, 2021, 11:31:49 AM
Pictures please :icon_smile:
I would dearly like to build one of these, I really would. There are a couple of people making clones of it, but no one selling a PCB. I tried a vero, but couldn't get it to work properly after much time and effort.
Hi,
I am sending materials that may be helpful.
(https://i.postimg.cc/5QQMB0SZ/Maestro-clone.jpg) (https://postimg.cc/5QQMB0SZ)
(https://i.postimg.cc/bZ9fH41N/Maestro-clone1.jpg) (https://postimg.cc/bZ9fH41N)
(https://i.postimg.cc/7ChtGRVR/Maestro-schematic.jpg) (https://postimg.cc/7ChtGRVR)
Box, excellent work there, a proper reproduction of the board too, very well done, Sir. Thanks very much for the pictures, particularly the power supply, I think thats where I went wrong before. I don't etch, but someone did me a board many years ago that I might have kept after I couldn't get it going (although, I don't recall having seen it for a long time...). If I can't find it, anyone fancy etching one for me? I'm in the UK.
Question for you folks on this one. Would a TC1044 or Maxx1044 chip be fine to provide +/-12 from a 9V supply? I have a friend that is interested in this pedal, but that power supply is not cheap.
Quote from: orangetones on June 13, 2021, 09:59:35 AM
Question for you folks on this one. Would a TC1044 or Maxx1044 chip be fine to provide +/-12 from a 9V supply? I have a friend that is interested in this pedal, but that power supply is not cheap.
Hi,
their output current is insufficient to supply power this circuit.My recommendation:
https://canada.newark.com/tracopower/tmr-1222/isolated-board-mount-dc-dc-converter/dp/13M3240?ost=tmr1222
Regards,
box
Thanks for the link. Looks good. I'm assuming the 2n5485 need to be matched for this?
Also, looking at that Traco you just looked, it seems to accept 9v input. Is there the need for the 7805 in this case?
Last question for now... I have 8x 2n5485. Abs 10x 2n5484. Would the 5484 work in this circuit? I also have some 2n5457 as well.
Quote from: orangetones on June 13, 2021, 01:51:23 PM
Last question for now... I have 8x 2n5485. Abs 10x 2n5484. Would the 5484 work in this circuit? I also have some 2n5457 as well.
so these transistors are suitable(2N5485 ).For DC/DC power supply regulator 5V (7805) not required , this model is input voltage 9-18V.
Found a source at Digi key for that power converter. 20 bucks.
The 2n5485. An I correct that they need to be matched? How closely?
Quote from: orangetones on June 13, 2021, 09:40:35 PM
Found a source at Digi key for that power converter. 20 bucks.
The 2n5485. An I correct that they need to be matched? How closely?
Matching to 5% or 10% of the reading is probably good enough.
http://www.geofex.com/
4/16/02 and 10/24/01
Fetmatch for matching .
Box,
Looking at the schematic, it seem like the 4.7uF cap should have the positive leg towards ground. I notice yours is the other way. The picture of the layout you posted seems to also have the FETs and one transistor reversed. This one seems to be the correct layout/orientation.
https://www.aronnelson.com/gallery/main.php/v/jdub/MaestroPS-1Alayout_zpsaeda6660.png.html?g2_imageViewsIndex=1
Wondering if you ever had ticking or noise issues with yours?
Did you do any modifications? I know some talk about a different input buffer in other threads.
Quote from: orangetones on June 26, 2021, 10:36:44 AM
Box,
Looking at the schematic, it seem like the 4.7uF cap should have the positive leg towards ground. I notice yours is the other way. The picture of the layout you posted seems to also have the FETs and one transistor reversed. This one seems to be the correct layout/orientation.
https://www.aronnelson.com/gallery/main.php/v/jdub/MaestroPS-1Alayout_zpsaeda6660.png.html?g2_imageViewsIndex=1
Wondering if you ever had ticking or noise issues with yours?
Did you do any modifications? I know some talk about a different input buffer in other threads.
Yes you are correct regarding polarity of 4u7 but I left as it is on the components side board.All my FET transistor are J113 and PNP is BC560.
No ticking and noise issue. I did not make any modifications.
Quote from: box on June 26, 2021, 11:43:06 AM
Yes you are correct regarding polarity of 4u7 but I left as it is on the components side board.
So you left it facing the wrong way?
Quote from: box on June 26, 2021, 11:43:06 AM
All my FET transistor are J113 and PNP is BC560.
No ticking and noise issue. I did not make any modifications.
How closely did you match those J113? I have some 2n5485 that are pretty close for this, and will try those first. I am guessing you used the J113 for the MPF102 as well? I'll socket things so I can mess around if need be. Likely try the 2n5087 first.
I did manage to get that TRACO TMR1222.
https://www.tracopower.com/sites/default/files/products/datasheets/tmr2_datasheet.pdf
Guessing I don't need to mess around much with this, basically, 9V+ and GND into it on pins 2 and 1 and then pins 6, 7 and 8 out for +12V, GND, -12V.
Should I implement some kind of power filtering there? What would you do with that power supply?
Quote from: orangetones on June 26, 2021, 05:05:00 PM
Quote from: box on June 26, 2021, 11:43:06 AM
Yes you are correct regarding polarity of 4u7 but I left as it is on the components side board.
So you left it facing the wrong way?
4u7 I'll check later
Quote from: box on June 26, 2021, 11:43:06 AM
All my FET transistor are J113 and PNP is BC560.
No ticking and noise issue. I did not make any modifications.
How closely did you match those J113? I have some 2n5485 that are pretty close for this, and will try those first. I am guessing you used the J113 for the MPF102 as well? I'll socket things so I can mess around if need be. Likely try the 2n5087 first.
https://www.youtube.com/watch?v=7Br3L1B80ow
Nice tool recommended for matching and for testing components.
I did manage to get that TRACO TMR1222.
https://www.tracopower.com/sites/default/files/products/datasheets/tmr2_datasheet.pdf
Guessing I don't need to mess around much with this, basically, 9V+ and GND into it on pins 2 and 1 and then pins 6, 7 and 8 out for +12V, GND, -12V.
Should I implement some kind of power filtering there? What would you do with that power supply?
Schematic attached.
(https://i.postimg.cc/YjMqFRkr/TMR1222-Power-supply.jpg) (https://postimg.cc/YjMqFRkr)
Thanks very much for the clarity. One more question. I get that the ground connection should not be connected to the 0V. The main board only has one connection for ground. That would be the 0v connection, right. So for the 9v power in, world that ground be connected to anything other than the Jack and the filter cap? Would my input and output jacks be grounded there then? What about wiring for the indicator LEDs?
Thanks again for the help.
Actually, looking at your posted pics, it seems the jacks are grounded to the board. It seems you added a pass to ground then with that grey wire.
Wondering about LED indicators.
Quote from: orangetones on June 29, 2021, 09:04:09 AM
Actually, looking at your posted pics, it seems the jacks are grounded to the board. It seems you added a pass to ground then with that grey wire.
Wondering about LED indicators.
If you are looking on the left side of the board-3 wires my power supply( is on the separated board) is connected only from isolated ( Orange+12V,Green 0V , Brown-12V). Do not connect GND from power supply from the socket power ---only +9V and GND).
For LED indicators use DPDT switch and one section connect to +9V input power and GND , not from isolated power!!!!
On the my board input signal and output is grounded from 0V Grey( isolated ground).
About the LEDs. Is each speed engaged when the switch is closed or open? Something I saw from another person leads me to believe that when the spst is open for each speed, it is engaged.
Quote from: orangetones on July 02, 2021, 05:52:48 PM
About the LEDs. Is each speed engaged when the switch is closed or open? Something I saw from another person leads me to believe that when the spst is open for each speed, it is engaged.
All switches are active in the closed position. OFF/slow phase---open ---signal bypass, close---active.
Medium phase---close-----active.
Fast phase ----close----active.
Dpdt switch , one section for changing phases, second one for LEDs.
Sorry for the late response here. Thanks for that clarification. I will check with the other person as to why they had things wired that way. Maybe something else going on that I didn't notice.
(https://i.postimg.cc/5jsWKJy5/LED-Wiring.png) (https://postimg.cc/5jsWKJy5)
Here is how another member suggested wiring the LEDs. Can you make sense of this? It would seem to me that the LEDs would be on when the phase switches would be open?
Also, this member had an input and output buffer.
In my project I used all DPDT as mentioned earlier.Switch OFF/Slow phase is working when is off the signal is sent to the output( 3k and next to 4k7).
When is on position jfet(Q8)transistor carries the signal from IC3 pin no1 to the output.
Other switches are also DPDT and the diodes are connected as in the previous description
Hi- nice work on this, looks like you are using the layout I posted on here back in-whoa!-2013. Haven't been around for a while, life gets in the way, etc.
So, this has always been my favorite phaser, but I've never been completely satisfied with the power supply for it- I have the GGG bipolar power board powered by an 18v AC supply. I've recently been working on a reduced-size version of my earlier layout to fit in a BB-size box with built in power supply and buffer. Got the board etched and populated, and used the Traco TMR3-1223 DC-DC converter to get +/-15V from a 9V DC supply. That unit can do 100mA per rail, which I figured should be sufficient, and I put some basic filtering similar to Box's on the input and output. It powered the board, but I got some nasty clipping on the output, similar to a mis-biased transistor. Swapped some parts around plus other tweaking, thinking it was something in the board, but could not get the harshness to go away. My original never had that problem, but it uses +15 and -15 LM regulators that put out like 1A each, so I thought maybe it was due to the Traco supply.
As a test, I tried using the Traco with my original board, and sure enough the clipping was present. Box, did you have any problems like this with your build? At this point, I'm not sure if it's noise on the output of the power supply or if it's clipping because that unit does not have quite enough juice for the Maestro (the 12V version puts out 125mA per rail, a little greater than the 15V version). I should mention that I have bypassed the isolation and connected the input ground to the isolated ground, because my build didn't work without it. I haven't tried grounding the input and output jacks to the 0V- I'll give it a try. I'm also looking into some L-C filters on the input and output.
Box, any suggestions you might have about using the Traco supply would be appreciated- I'd love to get it working. I'll be glad to post my modified layout if I can get the thing working properly. Many thanks!
Box, did you have any problems like this with your build?
Quote
Please follow this reply:
« Reply #32 on: June 27, 2021, 07:28:34 AM »
my effect working without any issue.
Thanks Box- I also see that your Traco converter only puts out 80mA per rail, so it wouldn't seem that low current is my issue. Hmmm, I guess I'll try grounding to the isolated ground and see what happens. The only other difference I can see between yours and mine is that I am also powering a Klon-type buffer from the supply, but that shouldn't draw more than 15mA tops- and I've also tried bypassing the buffer with no improvement.
From the datasheets of the 2 Traco products we are using, it seems the unit you used has internal filtering, but the noise specs are the same in both- 50mV p-p @ 20MHz, so I'm not sure if output noise is the issue with mine. Last night I tried it with an added L-C filter on the input (as recommended in the application notes for the TMR3), and there was no difference. I also have external filtering on the output.
Frustrating! :o
Success! ;D Finally got the new layout working with the Traco supply. After some audio-probing and numerous hours peering over the board, turns out it wasn't the power supply after all, it was the op amps in the phase section- seems one or more wasn't making good contact in the (new) sockets on the board, or they were just faulty, I'm not totally sure which yet. Gonna do some more testing to make sure everything is solid then I'll post. I have some concerns about the heat generated by the converter- not a lot, but may move some caps a bit to get them further away. Basically the same layout from back when, but slightly rearranged to make it smaller, with on-board power converter and buffer, running off standard 9-18V DC center negative supply. Cheers!
Quote from: jdub on August 01, 2021, 09:36:11 PM
Success! ;D Finally got the new layout working with the Traco supply. After some audio-probing and numerous hours peering over the board, turns out it wasn't the power supply after all, it was the op amps in the phase section- seems one or more wasn't making good contact in the (new) sockets on the board, or they were just faulty, I'm not totally sure which yet. Gonna do some more testing to make sure everything is solid then I'll post. I have some concerns about the heat generated by the converter- not a lot, but may move some caps a bit to get them further away. Basically the same layout from back when, but slightly rearranged to make it smaller, with on-board power converter and buffer, running off standard 9-18V DC center negative supply. Cheers!
Good news! I had forgotten this project as I got busy with many others.
Remind me again why you needed the buffer on this?
Also, using the Traco TMR1222, I have decided to do up a board like this. Pretty simple, but could someone put eyes on it and make sure I haven't messed something up with the power supply?
(https://i.postimg.cc/7C2w9Pgz/Maestro-Powersupply.png) (https://postimg.cc/7C2w9Pgz)
Anyone want to comment on this?
Quote from: orangetones on November 13, 2021, 11:30:49 AM
Remind me again why you needed the buffer on this?
The original design has a relatively low input impedance, adding a decent input buffer will compensate for that.
Quote from: box on June 29, 2021, 11:31:48 AM
Quote from: orangetones on June 29, 2021, 09:04:09 AM
Actually, looking at your posted pics, it seems the jacks are grounded to the board. It seems you added a pass to ground then with that grey wire.
Wondering about LED indicators.
If you are looking on the left side of the board-3 wires my power supply( is on the separated board) is connected only from isolated ( Orange+12V,Green 0V , Brown-12V). Do not connect GND from power supply from the socket power ---only +9V and GND).
For LED indicators use DPDT switch and one section connect to +9V input power and GND , not from isolated power!!!!
On the my board input signal and output is grounded from 0V Grey( isolated ground).
Question. If the input and output jacks are connected to 0v on the board, but are not supposed to connect to the 9v /ground of the power supply, do I not need to use a dedicated power supply? If I was using a daisy chain power supply, wouldn't the ring on the input and output jacks connecting to the other pedals essentially connect the 0v on this board to that ground? Am I confusing myself or making sense?
Quote from: orangetones on January 12, 2022, 06:48:20 PM
Quote from: box on June 29, 2021, 11:31:48 AM
Quote from: orangetones on June 29, 2021, 09:04:09 AM
Actually, looking at your posted pics, it seems the jacks are grounded to the board. It seems you added a pass to ground then with that grey wire.
Wondering about LED indicators.
If you are looking on the left side of the board-3 wires my power supply( is on the separated board) is connected only from isolated ( Orange+12V,Green 0V , Brown-12V). Do not connect GND from power supply from the socket power ---only +9V and GND).
For LED indicators use DPDT switch and one section connect to +9V input power and GND , not from isolated power!!!!
On the my board input signal and output is grounded from 0V Grey( isolated ground).
Question. If the input and output jacks are connected to 0v on the board, but are not supposed to connect to the 9v /ground of the power supply, do I not need to use a dedicated power supply? If I was using a daisy chain power supply, wouldn't the ring on the input and output jacks connecting to the other pedals essentially connect the 0v on this board to that ground? Am I confusing myself or making sense?
Hi,
if you read with the note, note that I did not connect the ground from the 9V power supply to the insulated ground. The isolated ground is the ground on the board, so the input and output of the ground is unchanged.
Regarding the LED power supply, because you use the + 9V and Negative (GND) power supply, you can connect to one section of the 3PDT diode.
Rgds,
box
Quote from: polaris26 on June 27, 2007, 01:22:11 AM
I was actually turned onto the Maestro PS-1 while trying to find out which phaser Alex Lifeson used on the early Rush albums, and specifically on parts of "Lakeside Park". Somewhere on the net it referred to his use of Maestro phasers, so I began to look into them.
There has been a few times recently while playing my newly completed Ampeg Phazzer clone with a mix/depth control that I thought to myself that it sounded very much some of things I've heard on Rush's Caress Of Steel Album. Interesting things going on in the Maestro circuit. I don't recall seeing caps in the opamp feedback loops on any other of the popular phase shifting circuits. I wonder what affect that has on the sound.