Harmonic Converger "Test Drive"

The Harmonic Converger Story

“Necessity is the mother of invention”

As far back as I can remember, I have always been interested in electronic circuits and how they work. In fact, I got started in electronics years before I took up playing the guitar. Once I started playing electric guitar in earnest, the electronics aspect became even more important to me, as it seemed I was always fixing mine or other band mate’s amps, guitars or fuzztones ;o). Later, I discovered that I could actually modify amps & effects to make them sound better, or just more like what I heard in my head. Although I have since become a lifetime pro musician (since 15 years of age), I have never lost my love for electronics, and am constantly experimenting & designing new circuits to help me get “the sound in my head” - the Harmonic Converger is one of those circuits...

Like most guitarists, I was very excited when digital modeling appeared on the horizon because of it’s amazing potential & promise, not to mention the thrill of eliminating a lot of heavy & bulky equipment. I was quickly disappointed however, when I heard the typical lack of urgency & presence, coupled with an abundance of “insect-attracting” fizz which sounded totally disconnected from the rest of the tone - that’s when I came up with the term “orphaned highs”. It almost seemed like an “evil miracle” that they could somehow lose the presence while exaggerating the fizziness.  At first I got depressed, but then I got *mad* and became consumed with the quest to regain what digital modeling seemed to have lost - the sound of a focused, cohesive, natural tube amp response which was totally believable in a mix, and without all the tell-tale fizz. I tried various types of EQ and filtering, and although it helped, I found it was the TIMBRE of the frequencies more than the frequencies themselves, which needed to be addressed.  Have you ever noticed that a distorted guitar can sound great thru a 4x12” speaker array, while sounding absolutely awful direct into a digital recorder, even with MASSIVE amounts of EQ and filtering? This is because those output tubes & speakers are accomplishing much more than simple EQ changes - they are actually changing the TIMBRE of those limited frequencies they reproduce. Also when tubes are driven into saturation, there is a very distinct timbre change in the upper midrange/high frequency response which is very satisfying to the human ear - major guitar amp companies go out of their way to highlight this characteristic (can you say Mesa or Soldano), while it is almost nonexistent in the digital modeling domain. The Harmonic Converger was designed to address these issues in a uniquely effective way.  Like a good tube amp, the HC is not a totally “neutral sounding” device - it imparts it’s own character or timbre to the tone, which is how it makes the sound more believable and amp-like.

Like all my other circuits, the HC was designed solely for my personal use - the thought of building them for other people *never* even entered my mind at the time (I used to think of it as my “secret tone generator”). But a couple of years ago, I was reading a lot of posts about “fizz” & “bogus high end” on the modeling boards & Harmony Central user reviews, so I started thinking “All these people want the same thing I want - a more believable, amp-like, & less fizzy tone from their modelers and preamps”. You must understand that at the time I thought I was the only one bothered by this stuff, but when I saw how many people were complaining, I decided to mention my Harmonic Converger on a popular board to see if people would be interested in such a device. Despite an aggressive deluge from detractors, people were very interested indeed. I have continued to experiment & refine the design of the HC, as it is still an extremely important tool in my “tone arsenal”. To hear what other users of the HC are saying, check out the Harmony Central User Reviews under “Effects/Radtone/Harmonic Converger”.

Cheers,

Hadley Hockensmith (Radley)

Who: Administrator, Perdikament, Radley

This test drive was a joint effort by Administrator and Perdikament (the testers) and Radley (supplying the HCs and advice on their best usage) to see, hear and experience the long-awaited Harmonic Converger which was discussed over a year ago on the line6 boards and then (more recently) on the Boss GT Central boards. This was basically a way for two trusted resources on the Boss GT Central Forum to give honest feedback on this unit which has received so much attention over the past 12 months. This review was put through the paces (so to speak) with honest intentions on finding out if this thing did what it was stated to do. Radley had no part, whatsoever, in the review's content or findings. These findings are solely the findings of Perdikament and Administrator.

There have been ups and downs, delays and changes along the way, but Perdikament and the site Administrator received the Harmonic Convergers approximately on July 8, 2005. The testing was done separately and the reviews of each tester are their own views. There was not pre-determined "outcome" for test drive. Everyone just decided to let the chips fall where they may. The following is the result of the test drive.

Administrator (The scoop)

I received the unit on Saturday, July 9, 2005 because I was not there to sign for the unit which required signature. I picked up the unit and directly went to Radio Shack because the HC (Harmonic Converger) came equipped with RCA input jacks. I found what I was looking for and the necessary connections could be made. Now to the laboratory! Muhahahaha. The Unit is silver with 4 RCA jacks and a 3-way toggle switch with no labeling anywhere on the unit. A pure prototype. After reading Radley's documentation* I realized that the RCA jacks on the LEFT were INPUT jacks and the jacks on the RIGHT were their OUTPUTs. The top left jack is input 1 and the top right jack is its output. The remaining jacks are there to support stereo operation for recording and live use..

The top position is the default HC position, the middle represents a Bold setting and the bottom toggle settings represents the darker setting. I first tried the TOP setting and go for the basic setting. BUT... before doing this I played with my Gibson Les Paul Standard through a Boss GT-8 for a good 10 minutes to get used to the tone. After playing around, I hooked up the HC in the headphone jack of the GT8 and connected directly in to a MOTU 828MKII which then goes to 2 Genelec monitors. I played pretty loudly. I also have Auralex all around my studio so the lows are punchy and the sound is tight. Let's see what happens now...

The first words out of my mouth were "Wow! I can't believe this thing does what Radley says." I played with the HC and got lost for about 30 minutes. Totally lost track of time and listened to how my modeler turned into a new type of sound machine. I then switch across all 3 toggles and quickly learned that the bottom setting is just not for me. Too dark; too muffled. Sounds kind of like throwing a blanket on a speaker. This is just my opinion. The center toggle was much to my liking, but the high end is very pronounced and the attack is very bright. I could probably EQ this out, but I found the top position (normal position) to be the one I decided to stay with for the rest of the evaluation.

What happened?! The tones indeed lost their high end brittle fizz. The sounds are very warm and the punch and character of the HC truly captured my attention. Even more interesting was that the speaker cabinet sims came to life! The Custom Cabinets I created and the use of the Tone Modifier in the FX really sounded different from before. They sounded much more realistic. Prior to the HC, each one seemed to offer sounds which resembled post EQ changes. Now they indeed sound like speaker cabinets. The mic sims (57 (on axis and off) dynamic and condenser mics were less pronounced than before. I don't know if this is a good thing or not but the 57 on-axis sounded the best to me. This little device changes my COSM modeler very much. The results in the studio were very favorable. But what about live? Everyone knows that you can tinker with settings only to find out that they sound like shit when you play live with the band. Off to practice... let's see what else happens here.

Damn! Again! I was totally amazed at the tone. I was looking for some hole in this unit. Although there are some, there are just too many good things associated with the way the tones are changed/altered. The amp sims now sound more like I am playing through a real live rig. It is smooth, punchy, defined and warm. But what is disappointing? Anything?

With this being said, the Harmonic Converger is simply a HUGE improvement for the my XTL and GT8. I cannot say how much better (to me) the unit now sounds. Especially when removing the unit from use and hearing what used to be there. Another cool thing - no batteries! Never a worry about getting that dim red light during a show knowing that you have to scramble for a new 9V battery. One word of warning for everyone. My recommendation is to NOT just put the HC on your unit and consider yourself done. I would highly suggest building all of your patches again from scratch, or simply continuing to tweak the current patches to get the best tone. If you do not do this, you are missing out on a hidden gem! Being able to choose the mic, speaker, effect settings, eq, etc is totally exciting. Especially with the HC running in the circuit. Good sounding patches only get better. Dialing in time becomes a fraction of what it was before. Why? I am not quite sure, but it is! I can get pro sound within a matter of minutes from the main amp controls. It used to take a lot longer to dial it in to sound acceptable Not anymore.

The unit simply from the device aspect did not seem to meet my needs.

1. The toggle. Personally, I would prefer a different type of switching device. Possibly one which does not protrude.
2. I believe that guitarists are 1/4" Hi-Z animals, not RCA. I would prefer to have 1/4 inputs.

The RCA jacks on the HC immediately needed converters. I needed the following to get the unit properly hooked up:

• Stereo 1/4 jack to 2 RCA to accommodate feeding the HC
• RCA - 1/4 mono jack (male) to accommodate going into a PA or DAW

There was quite a bit of time, phone calls and instant messaging going on about all of the various ways to use the HC. Using the Regular Outputs, the Effects Loop or the Headphone Jack All sounded quite different both in tone and level. These were determined to be impedance issues. Event the XTL had different impedance levels than the GT8 did. This would be a problem if going back and forth between different COSM modelers. After discovering that the Headphone Jack was the best in tone, we also decided it may be the best application use as well. Using the Headphone jack still allows users who prefer the 4-Cable Method to use the HC without jumping through too many configuration options. I go directly into the PA and get my monitor to feed my guitar reference to me when I play live.

	Rhythm patch first with HC and followed without HC
	Lead patch first with HC and then followed without HC
	Clean patch first with HC and then followed without HC
	Patch with HC1 (bright, normal, dark) Bright - First break Normal - Second break Dark - Third break Patch with HC2 (bright, normal, dark)
	Example of a tweaked patch for HC use (Regular Channel and Solo Channel) Another example of a tweaked patch for HC use (Regular Channel and Solo Channel) Notice that the quality of this patch should sound much better than the prior patches because I built this patch around the HC. I took advantage of the HC when building the patch from the ground up. There is not a difference in quality with these MP3s. They were recorded with the same quality settings as my other MP3's. Here is the SYX file

Please let me know if I can provide any additional information, clips, syx files for reference. I will be glad to do what I can.

Perdikament (The Scoop)

Ok Ladies and Gents..... Gather 'round, I have a little story for ya'll.

It all started back a few months ago when there was still snow on the ground here in good ole' Connecticut. I was reading the posts on Radleys Harmonic Converger.... Anything with a name that cool has gotta be a good thing. Welp, after reading the flames on the Line 6 board. I was a bit hesitant to "bite". * Thanks for the funny reads though to the Line 6 boyz, I love a good flame war.*

Anyhoo, I (being the nice person that I am, and ever trying to help others) I decided to give Rad the benefit of the doubt. I always do, until I'm proven wrong, it's just my 'policy'. Well, Rad I think realized that this might be the place to do such a "Test Drive" as we as a group here on GTCentral are very knowledgeable and more mature than 'other' boards on the net. Facts are facts...so let's get on with the goods.

First Impression:

Holy friggin' shit, this thing not only works but is a godsend. I absolutely cannot live with out this unit in my rig, nor play another note without it!!! Seriously, folks it does everything claimed to and much more. It turns a $450.00 modeling unit into a $20,000.00 multitude of amps. NO SHIT, FOR REAL.

While I personally find a few design flaws in the unit, which can be easily fixed, the tone and feel is there...period. Especially for any HI-GAIN users out there.

The design flaws IMO would be the use of RCA jacks (which BTW I agreed to) but it is a pain in the Arse for sure...adapters adapters adapters... Also the toggle switch is thin and 'will' no doubt break at some point...especially to the gigging guitarist. I have found a solution to the stage problem however. What I am doing is running the HC at the very end of the hook up. Since I use the 4cm I can not run the HC in the GT8 FX loop Live, so I simply run my 20 foot cord to the HC and place it on top of the amp...I will eventually Velcro it to the back of the amp.

Sonic Boom: After the initial first impression:

Well, the truth of the matter is the fact that while the first impression is very important...the old adage of 'time will tell' is the only true measure of anything. And even at this point it is a fairly new unit to me and has only a few short hours of play. But, sonically my only complaint, if I have one and I think I may...{depends greatly on the reference point}.... Let me explain, while the HC is ON it seems to me that it takes away some of the edge or crispness of the low end. Especially heavily distorted power chord riffage. It's not completely evident until you hear the same clip with the unit OFF. While there is no question that the same clip sounds better with it on and wouldn't be noticeable without an A/B comparison it is still there. Which could probably be rectified by some EQ adjustments. However, what you might give up edge the unit makes up for in sonic reality in the fact that it makes everything as a whole sound much more real.

Also, which is a huge benefit of the unit, especially for GTx users, it makes tweaking patches so, soo, sooo much easier... There is no longer a need to tweak 10 different settings to try to smooth out any fizz and find the proper EQ/Tone control balance... It actually makes the tone knobs much more useable and realistic...not to mention the MIC and CAB sims more alive and realistic. It ends the "battle of brittleness" in your search for tone and tweaking. Smooth, Creamy & Rich is where this thing brings ya...

For all the High Gain users, it is a must...especially if you’re going into Actives or a PA or doing direct recording... Everything from heavy riffage to searing leads will benefit greatly from this unit.

Playing Live:

I have had a few times now using the HC with my live rig which consists of a Marshall MODE 4 and the GT8 used in the 4cm. The HC didn't seem to do quite as much to the sound thru the MODE 4's 4x12 cab as it does for direct/full range set up...however it does make a noticeable difference. I still sit in the mix real well (probably even better) but I have to say also that I took alotta time in fine tuning my live patches to sound good with out the HC....and we do play extremely loud. I can say that the leads definitely sound better and cut thru better... Heavy power chord riffage thru the amp wasn't affected quite as much as direct recording or thru my studio monitors. I think that the MODE 4's cabinet is voiced for extreme low end and detuning stuff so it helps 'round out' the sound. Still, the improvement is a good thing, and I wouldn't want to gig with out it.

Playing it at home thru the Vibro-King it definitely helps a lot. I have always been enamored with the VK's tone, but now it's even better. I really never thought that would have been possible. but it's the truth. It works fantastic. I have come to one conclusion regarding the HC and AMP vs. a PA type set up. In a full range system such as: Active speakers, PA, Direct Recording, this unit is a must. With a traditional amp it helps a lot. I would venture to say that if you are playing thru a GOOD tube amp or a GOOD head/cab setup if you take your time in setting up patches and you are good at tweaking and dialing in tone then you can slide without this unit... HOWEVER, with the unit it cuts tweaking time to a fraction of what you’re used to. Furthermore, if you have all the 'good' gear then I would feel safe in assuming that you seriously value your tone and this will make it sound better, no question.

Tweaking:

It cuts down on tweaking time ten-fold. Not only that, where I used to have to tread cautiously with the preamps Treble and Presence I find myself laying right into it and cranking it up. The tone controls now act as they should. Adding treble used to be a nightmare to get the right balance before the tone got into Fizzy and Thin territory, now it's creamy with bite, the presence adds air like it should, opening the sound rather than thinning it out like a middle aged man. (BTW, I may be middle aged but I still have all of my hair).

What I think about what is happening under the hood:

Well it's real hard to say, I will try to explain it as best I can with no electronics experience. I would say that this is certainly NOT merely a high-pass filter nor a notching EQ type device. Even if it really is, it doesn’t seem to be just that... What I would say that it does, is rearrange the upper harmonic structure in some way...thus removing the fizz while adding a more real sounding, and a more sonically pleasing sound. I wouldn't say that it is just stripping away certain frequencies... It almost seems like it is 'de-fragging' the sound and putting all the frequencies where they should be...in a smoothed out fashion, Kind of' like the sound 'should be'. I tried for a while to 'match' the sound with a few different VST EQ's and while I got kind of close it was still not 'right', nor as good as the HC. I put the clips thru a frequency meter, and to my astonishment the meter was reading almost identically in both with the HC and without it. There was a very slight increase in the 4kHz and up with out it on (but minimal) and with it on there was about the same increase below 100Hz. This is why I say it's rearranging harmonic content rather than EQing it.

Why It Took So Long:

Well this test drive went thru several stages. The reason being is the proper way to hook it up took some figuring out in order for it to work properly, well the way it was designed to. The proper way is to hook this baby up via the Headphone Jack Output. Why you ask? Because the headphone jack is low impedance and ALL the other outputs {Loop & Main Out(s)} are high impedance. What a difference that makes. I was a tad skeptical at first and a bit bummed but only because it seemed a little out of the norm, plus I was having good results via the Loop and main outs. But in all honesty the ONLY way to really hook it up is via headphones, which after I did some research is 'probably' the best way to hook it up to anything anyway. See, the more impedance you add to a circuit the more (for lack of a better word) "distant" and less 'in-your-face' it sounds. If you have ever owned an amp that you can switch impedance on you will notice that the lower you go the louder, tighter and more up front it sounds...same principal at work here. There is less resistance, which means a truer signal. Impedance also effects the low end, the more resistance the more muddy the low end becomes especially when you start having impedance mis-matches. Why the outputs are High Impedance is beyond me and "Sir Rad". the Harmonic Converger is designed to work with a low impedance signal.

Now you may wonder and think what the "F", I got to use the Headphone Jack that makes hooking' things up even more complicated....well not really, and there is a benefit to this. What you can do is take the headphone signal and split it to two signals...one to the amp and one direct to the Board... Because the signal will be de-fizzed it will be a lot easier to dial in a killer sound out front without the use of a Mic. Your sound guy will love the fact that with a few simple EQ tweaks he can get a good sound from you, and he won't have to battle brittle high end fizz.

The Proof Is In The Puddin':

The clips will demonstrate just how well this works. What I did was take the headphone out, One side went thru the HC and the other went direct. I used two separate tracks to record the exact same thing at the same time. Then I just cut and pasted them to one track back to back, the first is thru the HC, the second is direct. Both tracks are mono and are not doubled, all levels are identical. I went with a lot of distortion because that's where the unit shines the best. I think that you'll find the tone to be more organic and more real sounding. You don't necessarily have to like the tone, but you will hear the difference, and it will apply to anything you put thru it.

I will be willing to add additional clips with other type tones for people who are interested in a particular style/sound. I stuck with 2 clips with a lot of gain on them because I feel like it shows what the HC does best.

Perdikament's Riff 1

Perdikament's Riff 2

Radley (The Scoop)

My HC "Test Drive" response

I am very pleased that both Ken & Bryan appreciate the sonic enhancement the Harmonic Converger adds to guitar tone, and I again want to thank these guys for taking the time & going to all the trouble to make this “Test Drive” review possible - we had a lot of obstacles and slowdowns, but I believe this review is very accurate & fair as a result. It is important to note that the least accurate frequency reproduction of mp3s is the upper-mids & high end, and this is where the HC does most of it’s timbre transformation - a live test is always more accurate. It is also important to note that my role in this “Test Drive” was simply to be a consultant to help Ken & Bryan understand & get the most out of the Harmonic Converger, not to affect their opinions or what they have chosen to write about it, pro or con. Having read both Ken & Bryan’s reviews, here are my comments:

Developing a unique product like the HC is fraught with many decisions - decisions affecting performance, sturdiness, ease of use, reliability, appearance etc. Although I continually look for ways to improve both my circuitry and design, I do feel that the current model is solid and dependable. The special short shaft toggle was chosen for better durability - the lower the profile, the better - the small size does not indicate that the switch is fragile (the shorter the shaft, the less chance of damage or breakage). I have used these exact switches for many years on my amp & effect mods without a single complaint or replacement. Other totally recessed rotary switches are available, but they don’t seem as “user friendly” (some require a screwdriver for adjustment). We must always keep in mind that the HC is *not* a stomp pedal, nor should it be treated like one - ideally, after the preferred HC setting is chosen, it should be permanently mounted in a location where it is not subject to being stepped on or dropped (duh). The RCA jacks are just as easy & reliable as their 1/4” counterparts - you just need to use dedicated RCA to 1/4” cables instead of 1/4” to 1/4” (I *never* use adapters - very clumsy & unreliable) I like to use cables with right-angle RCA's as it makes for a cleaner, more compact setup.

Having said all this, I am open to changing certain aspects of the physical design to:

1) 1/4” jacks
2) Some type of “recessed” rotary switch (if I can find one that’s high enough quality)

These changes would not effect the sound of the HC the slightest bit - it would still sound as good as the ones used for the “Test Drive” results & mp3s.

I hope you all enjoy the “ride”!

*** A quick note about using the Headphone Out to drive the Harmonic Converger:

One of the things we started noticing during the testing phase, was that although all HC results were a noticable improvement, they fluctuated somewhat depending on the source driving the HC. After a lot of experimentation, we realized that the HC performs at it’s optimum with *every* modeller by simply using the stereo headphone out (instead of the loop send or the main outs). This has proven to give consistantly excellent results in every test, and it also frees up the other outs & loop for seperate uses. This routing is easily achieved by using a stereo 1/4” cable (from the headphone out) which “Y”s into 2 mono plugs, which feed the HC. Also, since the headphone outs are always very low impedance, this means there is no signal degradation when using longer cables.

In Conclusion: The Harmonic Converger driven by the headphone out is “a match made in heaven”. ;o)

Hadley Hockensmith (Radley)