BJFE / BearFoot fx Guitar Effects Community

Yes I see I missed the 1m resistor to ground Between SW and C1.

I have recently became a big fan of the NE5534, I am using that in the bypass buffer of my EQ. I like OPA2134 a lot as well. Either way we end up with 3 IC's and either 5 or 6 op-amps. What about using an op-amp at the output where the mix control is, should be able to keep the gain at unity that way. Or should I say fake unity becuase what sounds to be unity would actually be about a +3db I think.

Hrm 4 stages?!?!?!? really would make the ramp intense. I am curious to hear your thoughts after listening to the phase 45 tomorrow. You may want to swap out the all pass caps with a 1:10 ratio to hear what I am talking about with the Vibe style setting.

Just had a thought about doing a 4 stage but putting each pair of stages in parallel instead of series like the phase 90. Has that ever been done? Could set a high pass for one and a low pass for the other...... This is one to talk about some more I think. Parallel 45 degree phasers offset to vibe. Now we are getting into true Leslie Sim territory as the LFO for the High could have a 1.5:1 or 2:1 ratio against the low, would have to see the ratio on an actual Leslie.

I am pretty confident this can fit in an MXR style box (1590B) but only if you wanted to have pretty limited controls, a 1590BB would be much easier, the middle of the road would be the 125C box, has the same footprint as a Boss Pedal and is a little taller than an MXR. Since this will have two footswitches, perhaps I don't try and cram the design into a 1590B, I have more ideas on this but PCB design is still a bit down the road.

Hey Guys,

This one sounds like great fun! My vote would be to not have a buffer.

Buffers are very personal and subjective and really affect the placement possibilities for the pedal.

When will the sign up be?!

Regarding the buffer.... I just built a new EQ pedal that has switchable true-bypass or buffered bypass so it's there if you want, for a DIY project you could have it switched or just leave it out of the circuit. The more I mess with buffered bypass the more I like them if they are done correctly. They have a bad rap from incorrect implementation or bad design but buffers can be a very good thing.

Sign up will be similar to the other project, we will need to get 100 boards to make it worth while.

The switchable buffer is definitely a good idea although the placement of a vibe/phaser effect (often before fuzzes) might make a buffer less usable for many people. If we have to use that last half of an opamp the buffer is a good option though. A preamp like those found in many vibe clones could be useful for adding some glassiness to the tone and I think people might be more likely to use a switchable preamp than a switchable buffer.

I would like to see the phaser switchable between two and four stages as the added intensity could really liven things up but if it dramatically increases the size of the board or makes the build trickier for new builders it might not be a good idea. Chances are if they stuck it out with the folk fuzz people should be able to handle this build.

jfromel wrote:Yes I see I missed the 1m resistor to ground Between SW and C1.

I have recently became a big fan of the NE5534, I am using that in the bypass buffer of my EQ. I like OPA2134 a lot as well. Either way we end up with 3 IC's and either 5 or 6 op-amps. What about using an op-amp at the output where the mix control is, should be able to keep the gain at unity that way. Or should I say fake unity becuase what sounds to be unity would actually be about a +3db I think.

Hrm 4 stages?!?!?!? really would make the ramp intense. I am curious to hear your thoughts after listening to the phase 45 tomorrow. You may want to swap out the all pass caps with a 1:10 ratio to hear what I am talking about with the Vibe style setting.

Just had a thought about doing a 4 stage but putting each pair of stages in parallel instead of series like the phase 90. Has that ever been done? Could set a high pass for one and a low pass for the other...... This is one to talk about some more I think. Parallel 45 degree phasers offset to vibe. Now we are getting into true Leslie Sim territory as the LFO for the High could have a 1.5:1 or 2:1 ratio against the low, would have to see the ratio on an actual Leslie.

I am pretty confident this can fit in an MXR style box (1590B) but only if you wanted to have pretty limited controls, a 1590BB would be much easier, the middle of the road would be the 125C box, has the same footprint as a Boss Pedal and is a little taller than an MXR. Since this will have two footswitches, perhaps I don't try and cram the design into a 1590B, I have more ideas on this but PCB design is still a bit down the road.

Hi,
Yes I thought maybe that resistor just slipped off the schematic.

Ah, yes the NE5534 ( preferably the NE5534A) became an industrial standard almost right away when it came and it's one that has held its position since then. Indeed the OPA134 and OPA 2134 are spinoffs, while at twice the noisefigure- nice OP's indeed.

Right an OP could be used at the output to maintain unity gain.

I played an MXR Phase 45, an old one with crumbing isolation. I found that to have an effect albeit a little weak.

I realize it would be easier to build a one notch phase shifter than a two notch one but a two notch one could make more of a vibe sound aswell as more phasing.
Adressing the depth of the effect, this could be done elegantly as discussed before with locking the range of the biascontrol, which would also then shift the range on a dial.

To make this the J-FET's used would have to be matched well or trimmers could be used to set the range of this biascontrol. Just food for thought.

I would agree that most phaser if not nearly all I have played have had a too deep effect to be useful on guitar.

I have also learnt through many experiments that the range is what can make the effect irratic and this especially at high speed and at high speed the one notch Phase 45 works just fine while being almost lost at slow speeds.....this is partly the amplitude of the oscillator output diminishing at slow speeds.

Hehe phasers do really like to be parallell and this could be parallell also to show the point of that.
That's a great suggestion. Hm that could be made in a non conforming way;)

It is possible to make the range so that it shifts through speed range and that's what I suggested with the value of C18 which also then would integrate the output of the oscillator to form a smoother sway .........

Personally I have this thing about tall boxes..........that has to do with if heal can rest on ground while switching..

I would also think that a wider box like Hammond 1590BB could allow desired controls for ramping and speed and depth and switching from ramping to normal operation by footswitch, allowing half a foot between the footswitches aswell as being easier to assemble.

This also just food for thoughts.

On the subject of buffers, I like to have at least one in a pedalboard but not necessarily in each effect.

On the fun side examining buffers and the subjective sides in a project of building your own adjustable buffer.
Things to ponder would include loading of the source-both resistive and capacitive, desired matching to effects downstream and possible cables losses aswell as unity gain as in a gain of one times.
This could be another project at an easy level of assembly but that could reveal many things about loading desired or not?

Ofcourse only if there's interest.

Have fun
BJ

BJF wrote:
This also just food for thoughts.

On the subject of buffers, I like to have at least one in a pedalboard but not necessarily in each effect.

On the fun side examining buffers and the subjective sides in a project of building your own adjustable buffer.
Things to ponder would include loading of the source-both resistive and capacitive, desired matching to effects downstream and possible cables losses aswell as unity gain as in a gain of one times.
This could be another project at an easy level of assembly but that could reveal many things about loading desired or not?

Ofcourse only if there's interest.

Have fun
BJ

Yes, I am sure several would be interested in this.

I don't know if you're looking for who's interested but you can count me in for two kits when they're ready.

So, after reading this and thinking about it more, I like using the last op amp to keep things at unity gain. I sold the last phaser I had because the volume drop (or percieved drop?) bothered me. I think there's already lots of potential for controls without adding more, and think that the simpler answer is probably good in this case.

I really like the parallel arrangement idea. I think there's lots of potential there. And, since the two switches means a bigger box, I think that it should be possible to squeeze it in whether series or parallel? I dunno, I think that separating speeds and frequencies could get interesting, even if its subtle.

(also, I'm glad I'm not the only one that doesn't like a tall stompbox. I always felt a little rediculous not wanting to put things into 125B sized box )

Bjorn I would be interested in a buffer build as well. it would be nice to have a dedicated pedal for buffering with some control, to allow adjusting for different guitars.

im starting to realize that using a pedal for both the sound and the buffer can make it a pain when i want to rearrange the effect chain. you arrange the order of the pedals based on what sounds youd like to get, but the byproduct is that the buffered pedal or 2 end up in a less than ideal place sometimes.

so id vote for gain or tone control

count me in!!

oh yea!!