Behringer PH9 - a cheap Phase 90 made for modding

[Mark Hammer]

Picked up a Behringer PH9 phaser today; new, for $30.  Yanked it apart, and it is a Phase 90 in SMT form. The only thru-hole parts are the 2N5952 transistors, the status LED and the pot/switches.

I thought the case would be plastic, but surprise surprise, it is a regular cast-aluminum chassis.  The switch is a bypass-on-board DPDT type, with a spring-loaded plunger/actuator that makes it look like a stompswitch.  I gather one set of contacts does the old-fashioned SPDT output switching, while the other set turns the blue status LED on.  If a person was dead set on installing a 3PDT to do full bypass, simply removing the small DPDT switch would provide plenty of space for a retrofit, and the mounting hole will easily accommodate it with juuuuuust a tiny bit of filing or reaming (the existing mounting hole is nearly round, with two slightly flat sides for securing the plunger in place while screwing on the retaining nut

A "swirl" slide switch enables/disables regeneration, and the familiar 250k bias trimpot is there on the board.  The unit is as well-built as anything SMT these days.  Unfortunately, Behringer has a penchant for using TL064 op-amps, which adds a little more hiss than is necessary.  I'll see if one of these days I can swap it out for a TL074.  If they wanted to save on current, they could have stuck a slightly larger current-limiting resistor ahead of the LED which is pretty darn bright.

So much for the description.  The real purpose of this post is to note that there is all kinds of room inside for adding mods.  I'm going to stick in a few and post some pix.  I've been trying to find the old familiar landmarks and a few have made themselves visible.  For example, the 1M resistor between the bias trimpot and FET gates is just beside the trimpot.  This can be easily modded into continuous variable sweep width, as RG shows at the GEOFEX website, or a person could easily insert a 3-position toggle for 3 different width presets by replacing 1M with 1M2 and a toggle to switch in one of two other fixed resistors in parallel to select two wider ranges.

I also look forward to installing a small (9 x 5 perfboard holes) daughterboard I have with two additional fixed phase shift stages to increase the overall amount of phase shift.  Again, loads of room in there for such mods.

I'll keep you posted as things progress.  Bottom line, though, is that if you can contain your disdain for all things Behringer, this is a real bargain that saves one all the work in getting a P90 up and running in a machined case, and has wads of space for your creative aftermarket add-ons, and at a price that doesn't make you queasy to experiment.

I can only begin to imagine how much room there is for creativity inside the Visual Sound Oil Can phaser, which comes in an even bigger chassis.

[Mark Hammer]

Don't know why I didn't notice earlier, but one of the reasons why there IS so much room for modes is because the chassis Behringer is using is bigger than a 1590B.

It is the same width as a 125-B, and closer in depth (top surface to floor) to a 125-B, but only about 1mm longer than a 1590B.  So, in general, about 95% of the same internal volume as a 125-B.

[zombiwoof]

There is also a Behringer comp that is in that same box, probably a Dynacomp clone.  I thought those were supposed to be true bypass already?.  Is that not so?.
I was thinking of picking one of those phasers up for a while, as they are really cheap.  How does it sound stock, aside from the hiss?.

Al

[Mark Hammer]

Sounds decent and not unlike the P90 I made using the Tonepad layout.

People may think its TB because of the outward appearance of the switch, but its just a plunger.  Sort of like this one, but with a bigger spring.

[igerup]

Interesting. What's the sound like if compared to the Small Stone? I have the Nano version so I'm a bit curious.

[zombiwoof]

Sounds decent and not unlike the P90 I made using the Tonepad layout.

People may think its TB because of the outward appearance of the switch, but its just a plunger.  Sort of like this one, but with a bigger spring.

What I really mean is that they advertise is as being true bypass, are you sure it isn't one of those newer true bypass methods using electronic switching?.  It's not that big of a deal, I just wondered, as I had seen it advertised that way.

They call it "true hardwire bypass":
http://www.behringer.com/EN/Products/PH9.aspx

Al

[Mark Hammer]

What I really mean is that they advertise is as being true bypass, are you sure it isn't one of those newer true bypass methods using electronic switching?.  It's not that big of a deal, I just wondered, as I had seen it advertised that way.

They call it "true hardwire bypass":

I have an MXR "stereo" flanger that has one input jack and one output jack.

I wouldn't believe everything a pedal manufacturer claims in their ad copy.  The PH9 does a decent Phase 90, and sounds pretty much like my DIY unit, but I'm still looking for the "mind-blowing hypnotic swirls".

I've combed every inch of the PCB, and there is absolutely nothing to suggest that the switching arrangement does anything more than switch the output and turn on an LED.  There are exactly as many transistors and op-amp stages on that board as you see on any P90 schematics, and no additional FETs or CMOS.  Admittedly, SMT boards can be a little hard to decipher, so it may well be the case that the bypass output is fed from the input buffer stage and not the input jack directly, but I'm not seeing any additional semiconductors that might suggest electronic switching actuated by the mini-DPDT.  As near as I can tell, the switching is pretty much identical to that used in the Commande series noted above: a foot-operated actuator that presses a DPDT mini-switch on the PCB, which either disables the effect and status LED, or enables the LED and connects the output.

So far, I swapped the existing 2k2 current limiting resistor for the bright blue LED for a 10k 1/8w.  That brought the brightness down to something that wouldn't suggest a landing strip to any jumbo jets overhead, and should help to conserve current.  To the right of the Rate control, I installed a width/range control.  RG's schematic over at GEOFEX shows a 1M pot replacing the 1M fixed resistor, but quite frankly not very much of the total range is usable.  I replaced the 1M with a 680k fixed resistor, to establish minimum sweep width, and a 500k linear pot.  Increasing that resistance widens the sweep so that it sweeps "higher", and reducing it keeps the sweep down in the gurgly range, more suitable for a nice little throb with open strum rhythm work.  A total resistance of around 1M2 extends the sweep range a bit, which is nice with a slow sweep and the regen turned up.  If a person wanted, you could simply use a 3-position toggle to select between 1M2, 910k and 680k, or thereabouts, for 3 different sweep widths.

I've been looking to install either a vibrato switch and/or an insertion point for an additional 2 fixed stages.  There's plenty of room for it inside, once you bend the 5952s over, but as I say, deciphering the board has been tricky.  There are few differences in the overall topography of the circuit (the input op-amp stage seems to have a gain of just over 4x, rather than unity gain), but some component values are different, and that has made recognizing familiar landmarks difficult.  For instance, it does NOT use 150k mixing resistors.  Identifying the 24k regen resistor was tough because it uses 24k resistors to ground (in parallel with the JFETs) instead of the 22k units.  The .01 and .05uf input and output resistors are replaced with larger values.  And, of course, use of plate-through holes makes following a trace from one side of the board to the other a little tricky.

I'll work on it, though.

[zombiwoof]

In fairness, it is supposed to be nothing more than a Phase 90 with a switch to go between vintage script sound (no regen) and modern sound with the regeneration.  If it achieves that it is doing what it is supposed to.  The switch cuts out the 22/24k regen resistor and maybe the other stuff that is in the later block version (just like the Dunlop MXR Custom Shop "Script Phase 90"), so unless you want to disable that completely there is no reason to look for it, they already have it bypassed by the switch.  Also, the Dunlop Phase 90's also use 24k resistors instead of the 22k in the originals, maybe 24k's are easier to get now than 22k's (I have an early Dunlop which has the same board as the last version block logo Phase 90's by the original company, with case mounted jacks and switch, and it has the 24k's).

I have read about a newer true bypass scheme that uses a momentary switch like that one that some companies are now using, so I thought that Behringer was probably using that.  I can't find the info online right now, though.  Do you see any buffers in there?.  The Boss system, which isn't true bypass of course, uses two buffers, one input and one output, in their switching.

I'm glad to hear that it sounds like a Phase 90 at least, for the price that's pretty cool.

Al

[zombiwoof]

I found this on one of Stinkfoot's articles on true bypass:

"Some of the Behringers use a mechanical stomp switch, and are described as having "true hardwire bypass", which seems reasonable. Not true bypass, of course, but they didn't say that either, did they? By the way, according to one owner of the PH9 (MXR-style phaser also advertised with "true hardwire bypass"), the switch is actually just an actuator pushing down on a micro switch on the circuit board - to me, that sounds like electronic bypass. Again, nothing wrong with that. But why call it something else?"

So it doesn't sound good for it being true bypass.
I did see that the new Digitech Hardwired pedals actually use relay switching to disconnect the circuit input and output in bypass, which is a new method that actually achieves true bypass, but I doubt that the Behringer pedals would use something like that.

It's very confusing, due to the many terms these manufacturers use for their bypass methods.  In the Dunlop pedals, the ones that say "true hardwire bypass" really are true bypass, while the ones that are described as "hardwire bypass" are just the same old lousy tone sucking bypass the MXR pedals always had, where the circuit input is still connected in bypass.

Stinkfook has some great articles on bypass methods in pedals, what manufacturers claim about their pedals and the real truth about what the bypass is.

Al

[Mark Hammer]

In this instance (and many others), "true hardwire bypass" simply means that the audio signal passes through the switch itself.  In e-switching approaches, the signal passes through an FET or similar (e.g., the e-switch of a 4016/4066/4053/4027), plus a buffer, to get where it's going, and the foot mechanism simply actuates the switching circuit.  Unfortunately, for many of us, "true hardwire bypass" is easily confused with "true bypass"; the one being the bypassing of output only, and the other being complete bypass of the circuit at input and output, to provide a "straight wire" connection between input and output jack.

At least "ice cream" and "frozen dairy dessert", or "cheese" and "processed cheese food", are not so easily confused.

One should be realistic about such matters, though.  There are output-switched-only circuits where the input stage really does load down the signal in bypass mode (easily identified when conversion to "straight wire" bypass results in unanticipated level differences between effect and bypass), and there are circuits where the design of the input stage has little impact on level or tone.  Keep in mind, as well, that a lot of folks are going to have another pedal before their phase shifter which will likely have all the buffering needed to make the input stage of the PH9 (or comparable) suck very little tone or level, if any, in bypass mode.

As always, one should consider any single design not in isolation but in the context of the "normal" signal-path/pedalboard, etc.

[Toney]

This would appear to be an outright, conscious attempt at deception on Behringer's part.
Given the popularity of (actual) true bypass in the effects world over past decade, any reasonable consumer would immediately identify the terms "true" and "bypass" from the phrase "true hardwire bypass" and assume that term "hardwire" augments or further reinforces the concept of actual full signal-switching, bypass. How else can a reasonable consumer interpret it?
Behringer really would be completely aware of this.
A terminology con-job and a quite an unnecessary one, given the value in the product.

[Mark Hammer]

I find myself surprisingly, ironically, and awkwardly in the position of defending Behringer's ad copy, but here goes:  What phrase/term would YOU suggest to refer to a mechanical switching system that only selects between outputs?  Remember, it needs to be short, distinctive, intuitive (i.e., you don't have to be a founding member of this forum to know what it means) and memorable.

I ask, not to be a smartass, but rather because when people try to come up with something short and sweet. the risk of confusion goes up.  In my work, I am constantly being urged to trim back on word-count, often in the most needlessly disruptive ways.  And inevitably, whenever I do, somebody misunderstands what was intended.  Adding a couple of words would have eliminated 99.9% of possible confusion, but someone got antsy about using 7 words instead of 4, or 5 instead of 3.  

I honestly do not expect any music equipment manufacturer to spend the time and money to focus-group test possible technical terms and seek maximum clarity.  They play a hunch, and call it what they call it, and that's what we, the consumers, see.  Maybe, someone in the company or marketing, says "Well, that might be confused with X", but my guess is that is a very rare event.  Remember that the same people coming up with trade names for things are the same folks that bring you factory schematics with errors in them, spec sheets that are technically meaningless or impossible, ads with descriptions that are nothing but confusing hyperbole, and instruction manuals that impede comprehension, rather than enhance/facilitate it.  I'm not expecting their brief shining moment of success to be the invention of technical terms that make folks like us go "Ohhhhhhh, NOW I get it.".

[joegagan]

thanks for the detective work, mark. nice job.

all this marketing hype from mfgrs only means that the aftermarket still has good cause to offer real, wired bypass switching arrangements for users of pedalboards.

[Mark Hammer]

...and once my wife gves me back the family camera and I can take some shots, I can show you good folks how to convert the pedal from output-only switching to full straight-wire bypass on this pedal.  I certainly don't plan to do it myself, but understand that it may be desirable for some.  Thankfully, unlike the Dano pedals, this one accommodates conversion quite easily, as I suspect many of the other Behringer pedals that use SMT construction and "true hardwire bypass" do.

[CynicalMan]

There are gut shots here: www.muzicki-forum.com/forum/viewtopic.php?f=43&t=3022

Except for the cheap jacks and pot, it doesn't look too bad.

[zombiwoof]

In this instance (and many others), "true hardwire bypass" simply means that the audio signal passes through the switch itself.  In e-switching approaches, the signal passes through an FET or similar (e.g., the e-switch of a 4016/4066/4053/4027), plus a buffer, to get where it's going, and the foot mechanism simply actuates the switching circuit.  Unfortunately, for many of us, "true hardwire bypass" is easily confused with "true bypass"; the one being the bypassing of output only, and the other being complete bypass of the circuit at input and output, to provide a "straight wire" connection between input and output jack.

At least "ice cream" and "frozen dairy dessert", or "cheese" and "processed cheese food", are not so easily confused.

One should be realistic about such matters, though.  There are output-switched-only circuits where the input stage really does load down the signal in bypass mode (easily identified when conversion to "straight wire" bypass results in unanticipated level differences between effect and bypass), and there are circuits where the design of the input stage has little impact on level or tone.  Keep in mind, as well, that a lot of folks are going to have another pedal before their phase shifter which will likely have all the buffering needed to make the input stage of the PH9 (or comparable) suck very little tone or level, if any, in bypass mode.

As always, one should consider any single design not in isolation but in the context of the "normal" signal-path/pedalboard, etc.

Actually, in the case of Dunlop pedals, "true hardwire bypass" is their term for actual true bypass, and "hardwire bypass" is their confusing term for the old MXR type bypass in which the circuit is still connected to the input when in bypass.  So, I had assumed that since Behringer is in the case of the PH9 (and the related clone of the DynaComp they are making) copying the MXR pedal that they were adopting this same terminology for true bypass, but obviously I can't assume that.  Don't get me wrong, I have buffered bypass pedals and true bypass pedals as well as the MXR-type "half-assed bypass"  pedals,  I just wish these pedal manufacturers would standardize their terminology so we could know what we are getting.

There is one good thing to report in the case of Dunlop's pedals, it seems as the new revisions of the old MXR pedals come out, they are now making them true bypass (or in their terminology "true hardwire bypass").  This is the case with the production versions of the DynaComp and SuperComp, in which revision E and earlier are the older MXR bypass, and the newer revision F and later are now actually true bypass.  So they are finally coming to the realization that the older MXR bypass scheme is not acceptable to many players, and doing something about it, even though they have always defended the older bypass.  Most of the newer signature Dunlop wahs are now true bypass, as well as many of the custom shop pedals and newer releases.  If anyone is interested in finding out exactly what the bypass used is in their Dunlop pedal, they now have a blog article that explains the bypass methods they use, which includes a chart of all of their products detailing which bypass method is used:

http://www.jimdunlop.com/blog/?p=384

By the way, here is the other MXR clone Behringer makes in the same box, which I'm guessing is a DynaComp clone:

http://www.behringer.com/EN/Products/DC9.aspx

Al

[Mark Hammer]

Frankly, I'm surprised that no one has, as yet, started producing a 3PDT version of those little PC-mount push-switches.  Their advantages are many:

1) Tiny footprint leaves lots of room on the board for other stuff, or space in the chassis for jacks, batteries, toggle switches, etc.

2) Cheap in comparison to stompswitches.

3) They can be wave soldered to a board, which means you don't have to pay people to solder wires from the board to the switch (which can increase production costs noticeably).

4) They don't require support circuitry to work the way that SPST momentaries on Boss/DOD/Ibanez-type pedals do.

Hell, using a mini boardmount 3PDT is such a no-brainer that I'm baffled by why it isn't currently in use by more companies.

Or is there some technical reason I am unaware of why such an obvious solution is not being used? (e.g., the form-factor of such switches is 6-pin DIP, which might preclude other configurations)

[richon]

Hell, using a mini boardmount 3PDT is such a no-brainer that I'm baffled by why it isn't currently in use by more companies.

Or is there some technical reason I am unaware of why such an obvious solution is not being used? (e.g., the form-factor of such switches is 6-pin DIP, which might preclude other configurations)

maybe they just bought, or make a business agreement, a few years back and bought/payed too much SPDT switches, so they have to use them all before the 3PDT.

[zombiwoof]

Maxon is now using a mini pc-mount 4PDT switch in some of their pedals for true bypass, not exactly what you're asking for but close (it's the pic on the right down at the bottom of the page under "updates"):

http://www.stinkfoot.se/andreas/diy/articles/maxon.htm

It might be a proprietary part, though.

Al

[Toney]

I find myself surprisingly, ironically, and awkwardly in the position of defending Behringer's ad copy, but here goes:  What phrase/term would YOU suggest to refer to a mechanical switching system that only selects between outputs?  Remember, it needs to be short, distinctive, intuitive (i.e., you don't have to be a founding member of this forum to know what it means) and memorable.

I ask, not to be a smartass, but rather because when people try to come up with something short and sweet. the risk of confusion goes up.  In my work, I am constantly being urged to trim back on word-count, often in the most needlessly disruptive ways.  And inevitably, whenever I do, somebody misunderstands what was intended.  Adding a couple of words would have eliminated 99.9% of possible confusion, but someone got antsy about using 7 words instead of 4, or 5 instead of 3.  

I honestly do not expect any music equipment manufacturer to spend the time and money to focus-group test possible technical terms and seek maximum clarity.  They play a hunch, and call it what they call it, and that's what we, the consumers, see.  Maybe, someone in the company or marketing, says "Well, that might be confused with X", but my guess is that is a very rare event.  Remember that the same people coming up with trade names for things are the same folks that bring you factory schematics with errors in them, spec sheets that are technically meaningless or impossible, ads with descriptions that are nothing but confusing hyperbole, and instruction manuals that impede comprehension, rather than enhance/facilitate it.  I'm not expecting their brief shining moment of success to be the invention of technical terms that make folks like us go "Ohhhhhhh, NOW I get it.".

I think the terms "mechanical bypass" or "hard wire switching", "hard wire bypass" would all serve to distinguish the  arrangement from Behringers usual buffered "soft" bypass. The inclusion of the magical term "true" in the phrase "true hardwire bypass" when applied to bypass as it has become understood to be known in the effects world,  would lead (or mislead) any reasonable person to expect the term to be no other than actual "true" bypass.
Of course, flip side, language and the expectation-sets that accompany it are fluid entities, so given few more Behringers and Behringer band wagon joiners, the boutique world may eventually have to extend the idiom and perhaps adopt the term ACTUAL true bypass to establish a point of difference any other smear-ers of the concept. By which point Behringer may well dip their toes I again and thus the cycles repeats.
Several decades on, tone-chasing guitarists of discretion will only buy "true, actual, real, deception-free bypass (with a blue LED).