What is a BBE Sonic Maximiser

[CodeMonk]

Off and On.
Although my test in GC was with the stompbox and I bought the rack mount.
So I really have no way to compare the two unless I find a stompbox one in a pawn shop and buy it.

[rogeryu_ph]

Off and On.
Although my test in GC was with the stompbox and I bought the rack mount.
So I really have no way to compare the two unless I find a stompbox one in a pawn shop and buy it.

CodeMonk hi,
So now that you already both have the rack and stomp version, did you compared both version? does it really no differences between the two? using it the same way like both on the loop or both straight to the amp input. Just curious......
Sure the stomp version is way much cheaper as earlier said on how you acquired it, Lucky you   

Roger

[CodeMonk]

No, I don't have the stompbox version, only the rackmount one.

The rackmount I got at a pawn shop.

The stompbox one I ONLY TESTED in GC.

[DougH]

I got the rack-mount on ebay a few yrs ago for $35. Be careful about "on & off" comparisons with it because the bypass is not "true" and sounds positively awful and muddy compared to a normal dry signal (oldest trick in the book...). Use an external bypass/loop box to do the comparison. Switching the "bypass" switch (or whatever it is called) on the bbe on and off will sound like day vs. night. A true comparison with a real dry signal will not sound near as different.

[rogeryu_ph]

No, I don't have the stompbox version, only the rackmount one.

The rackmount I got at a pawn shop.

The stompbox one I ONLY TESTED in GC.

Oh I did not quite or totally got your earlier story 
Anyway, I just finished STM's schem on Enhance LO HI eq stage plus the Time Alignment stage as suggested.
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I still can't comment on the test results I made the reason maybe I don't still grasp enough on what to expect or how the BBE Sonic Maximizer effects and it's processed sounds might be. Also, STM's review indicates needs for the the third stage which is the Hi Freq expansion or expander module if I got it right.

Thanks,
Roger

[Mark Hammer]

Mark hi,
I got the downward expander noisegate from you man and again thanks. Do you have an EXCITER schem or project to share? I browse on your hammer.ampage.org site but to no avail.

Thanks guy,
Roger

Jules Rykebusch's "Harmonic Sweetener" project appeared in Electronic Musician magazine somewhere in the late 1980's.  You can find the circuit here: http://www.harpamps.com/schematics/harmswtn.pdf

It does a decent job for very little money.  A couple of considerations:
1) "Exciters" provide harmonics of existing medium-order harmonics.  That is, they result in more upper-order harmonic content by producing lower-order harmonics.   Okay, say we have a fundamental of 500hz.  4000hz is a low-to-medium order harmonic of 500hz.  If I somehow take that 4000hz and torture it to produce 8000hz and 16000hz, then I have essentially added upper-order harmonic content of the original 500hz, by taking medium-order harmonics and deriving lower-order harmonics from them.  Clearer now?

What this means is that the cutoff for the highpass filter needs to be set so as to keep those medium-order harmonics, while keeping the lower-order ones out.  What counts as medium-order depends on the nature of the input signal.  Mandolin will be different than voice or bass.  So the corner frequency of the lowpass filters you see on the bottom left of the schem need to be planned around the nature of the input signal.  As shown, they are designed to reject content below around 7.2khz.  Is that low or high enough for your needs?  I can't say.  Which is why RG and I indicated on that diagram (I tweaked it, RG redrew Rykebusch's original schem from EM) that one might consider sticking in a variable highpass aspect with a dual-ganged 10k pot.  Note that the stock circuit uses 4 poles of highpass filtering for nice steep rejection of undesired content.  The variable aspect we suggest only affects 2 poles in that first section, simply because it is easier to find dual-ganged than quad-ganged pots.  Allowing more and less frequency content through to the second 2-pole section via variations in the first will yield a less steep rolloff, but in practice I found it to have a useful impact on the resulting sound.

2) The stock circuit shows a pair of red LEDs used for clipping.  It also shows a 1M feedback resistor, which gives a gain of 100.  That may be great for eliciting clipping from the LEDs, but you have to wonder what it does for the noise level of all that nonmusical content above 7.2khz (and below, because 4-pole filtering is not THAT steep) that doesn't get clipped.  Indeed, as I noted in 1993 ( http://www.harmony-central.com/Guitar/Faqs/faq/faq.effects.misc.txt ), this is a circuit that needs to be fed with a relatively noise-free source.  If the LEDs are swapped for a pair of 1N914s, then the amount of gain needed in the clipping stage can also be reduced, which ought to, in principle, result in less noise at the 10k Mix pot.

Of course, what the "exciter" part contributes is not just the added harmonics resulting from clipping.  Even if there were no diodes of any type, we have carved out the content from the top of the spectrum and boosted it, so this sidechain is acting like a general treble booster, with a mix control that allows us to blend in the amount of treble-boosted content we want.

So, here are the suggested mods to make this a more usable circuit

• Change the 4k7 resistors in that first filter stage for 2k7 resistors in series with a 10k dual-ganged pot.  That is the two resistances that change the filter frequency will vary from 2k7 to 12k7.  That will provide tunability.
• Change the LEDs to 1N914s, and replace the 1M feedback resistor with a 150k resistor in series with a 250k pot, wired as variable resistor.  Change the 10pf cap to something around 27pf.  The pot will provide your Drive.
• If the result does not yield enough treble for your tastes, you can increase the value of the feedback resistor on the inverting stage just before the Mix control from 10k (unity gain) to perhaps something higher like 12k, 15k, 18k or even 22k.

:

It's a nice simple, decent, circuit that adds some nice crispness to many sources.  Like all such effects, though, the amount of effect it adds depends on the high-frequency content of both the signal source feeding it, and what you feed the resulting signal to.  If you were looking for a way to make acoustic strings sound a little crisper, or add a little more snap to mic'd drums, this will do a nice job.

[frank_p]

Jules Rykebusch's "Harmonic Sweetener" project appeared in Electronic Musician magazine somewhere in the late 1980's.  You can find the circuit here: http://www.harpamps.com/schematics/harmswtn.pdf

Is it true that the Harmonic Sweetener is an "equivalent" of the DOD FX85 Harmonic Enhancer  ?  I use this box quite often and I was wondering what was the schematic and how the thing works. Never could find what was the circuit of the DOD.  I've read in the reviews at Harmonic Central that the "Sweetener" was comparable.

But as you say Mark, this kind of effect will convert noise from other sources into severe hiss.

I like to use it with a woofy amp or muddy fuzz and a Les Paul.  If you use a fuzz that have a long sustain it can give you a really raw "solo" tone.   

Ho, and thanks for the mod infos and explications Mark !

[Mark Hammer]

Is it true that the Harmonic Sweetener is an "equivalent" of the DOD FX85 Harmonic Enhancer  ?  I use this box quite often and I was wondering what was the schematic and how the thing works. Never could find what was the circuit of the DOD.  I've read in the reviews at Harmonic Central that the "Sweetener" was comparable.

Franchement, je sais pas.  "Enhancers" and "exciters" are said to work differently, but then nobody seems to abide by any strict rules regarding what gets called what (consider the number of things called vibrato or tremolo that are actually the opposite).  You can produce additional harmonic content in many ways.  The diode clipping used in the Sweetener is one way, but in an Aphex schematic that Sir Giles sent me a while back, they used an octave-doubler circuit to increase harmonic content (an OTA modulated by a highpass-filtered copy of the input signal).  Some "enhancer" circuits I've seen use other methods.  here's a japanese DIY schem posted at the Experimentalists Anonymous site:  http://experimentalistsanonymous.com/diy/Schematics/OOP%20Japanese%20Electronics%20Book/harmonic-exciter.gif  It uses a state-variable filter and a single diode for clipping of one half-cycle.
Here another that inserts some phase-shift and high-pass filtering without any clipping whatsoever: http://experimentalistsanonymous.com/diy/Schematics/OOP%20Japanese%20Electronics%20Book/phase-exciter.gif

So, what does the FX85 use?  Aucun idée.

Note that the general principal behind the Harmonic Sweetener (HS) can be extended in interesting ways.  cast your mind back to the Voodoo Labs Sparkle Drive and the assorted DIY attempts to mimic that.  What you have there is essentially a clean signal and a distorted signal that are blended together.  Same thing in the HS: distorted and clean signal blended together.  What makes them different is what gets distorted.  By inserting some highpass filtering, the HS distorts only part of the signal, not all of it.

But you know.....that rolloff could be moved down a lot more.   Indeed, a person could have a single pedal that serves as both Sparkle Drive substitute AND Exciter.

[frank_p]

Well thanks again Mark.  I guess that the combination might be infinite when you consider what kind of effect you apply to what part of the signal.  You could pass your entire life at trying multiple options.  So yes, it may be hard to tell.

Here is a gutshot of the DOD:

[Mark Hammer]

I can't see the picture at work (I assume you posted to photobucket?), so I'll try and take a look at home later tonight.

[frank_p]

Exactly, OUKI !

[Mark Hammer]

OK, I can see the picture now, and from thelooks of what is and isn't on the board, it looks more like an "enhancer" (dynamic boost of existing upper frequency content) than an "exciter" (synthesis of additional harmonic content based on what is there already).

Looking at the chip complement, I see a CD4007, which is the standard chip DOD uses for solid-state switching.  That leaves us an NE570 compander chip for whatever dynamics processing it does, plus 4 op-amps (TL062 and 1458).  Do you see any diodes on the board, because I can't spot any.  So, in the absence of diodes, I'm gonna guess that it employs some sort of highpass filtering that allows a massive boost to the upper treble content on transient peaks, but cuts back on them quickly so that the hiss that might normally accompany such high-end boosting does not show up in the output signal in a manner that you will easily hear.

The best test of this hypothesis is to see if the values of the averaging caps on the compressor and expandor side of the NE570.  These are the caps between pin 1 and ground, and between pin 16 and ground.  When the chip is used in symmetrical compress/expand mode, the two caps should be equal so that the envelope signal which dictates the time-course of the dynamic changes is equal for encode and decode.  When the two caps are different values, or are designed to have different discharge times (e.g., via a parallel resistor), that suggests that the expansion is intended to NOT track the compression identically.  If the expandor half decayed faster than the compressor half then whatever additional treble content was created between the compressor and expandor halves would have a faster than normal decay time.  So, that extra treble would appear at the moment of picking or striking whatever object is the source of the signal, but would disappear quickly.

That's my best guess.

[frank_p]

OK Mark, I'll reopen the box tomorrow to check around the NE570 and for the diodes also (perhaps even tonight, later...).  For what I remember for the diodes, there is only one at the bottom right of the PCB (picture), just next to the electrolytic cap.  And ,wow , thanks for all the explanations...  Nobody gave me some relatively clear one about what was happening in there and since I have it.  Lately I just tough it was a static highpass filter...

[Eb7+9]

Check here for an implementation that follows the response of the NJM2150 BBE chip.  It includes both LO and HI boost controls, it has increased maximum boost capability, and its central frequency is tuned down a bit as this worked much better with guitar signals.

http://www.aronnelson.com/gallery/main.php/v/STMs-Circuit-Ideas/BBE/

interesting - the amplitude response to frequency looks somewhat like that of the Dyno-my-Piano filter ...
btw, you may want to try a small cap to ground on the input of your circuit
thx for posting

[rogeryu_ph]

OK, I can see the picture now, and from thelooks of what is and isn't on the board, it looks more like an "enhancer" (dynamic boost of existing upper frequency content) than an "exciter" (synthesis of additional harmonic content based on what is there already).

Looking at the chip complement, I see a CD4007, which is the standard chip DOD uses for solid-state switching.  That leaves us an NE570 compander chip for whatever dynamics processing it does, plus 4 op-amps (TL062 and 1458).  Do you see any diodes on the board, because I can't spot any.  So, in the absence of diodes, I'm gonna guess that it employs some sort of highpass filtering that allows a massive boost to the upper treble content on transient peaks, but cuts back on them quickly so that the hiss that might normally accompany such high-end boosting does not show up in the output signal in a manner that you will easily hear.

The best test of this hypothesis is to see if the values of the averaging caps on the compressor and expandor side of the NE570.  These are the caps between pin 1 and ground, and between pin 16 and ground.  When the chip is used in symmetrical compress/expand mode, the two caps should be equal so that the envelope signal which dictates the time-course of the dynamic changes is equal for encode and decode.  When the two caps are different values, or are designed to have different discharge times (e.g., via a parallel resistor), that suggests that the expansion is intended to NOT track the compression identically.  If the expandor half decayed faster than the compressor half then whatever additional treble content was created between the compressor and expandor halves would have a faster than normal decay time.  So, that extra treble would appear at the moment of picking or striking whatever object is the source of the signal, but would disappear quickly.

That's my best guess.

Geez, you're a veritable adonis than me 

[rogeryu_ph]

Guys,
By incident, i found other forum design for BBE Sonic Maximizer..... Can I linked that forum thread so us to verify....I need your permission first to linked it isn't?

Roger

[DougH]

I don't think the schematic will do you much good without the source code.

[ClinchFX]

Back to the original topic, I haven't thoroughly investigated the Sonic Maximizer, but I believe you'll find that it shifts the phase, depending on frequency.  This is not unlike the Bose "equalizers" that had to be used with Bose 802 and 901 speakers to make them sound good.

[rogeryu_ph]

I don't think the schematic will do you much good without the source code.

Here's the thread and source code
http://freestompboxes.org/viewtopic.php?f=13&t=395

Roger

[frank_p]

I don't think the schematic will do you much good without the source code.

Here's the thread and source code
http://....org/viewtopic.php?f=13&t=395

Roger

Jack, I think the link is not opening correctly. Might be only on my side...

P.S. Your avatar is similar to one of my guitar only mine is the ugliest one I've ever seen. Imagine a blend of the Brit flag and leopard fur...