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mid range "passive boost" circuit ?
mid range "passive boost" circuit ?
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Old 28th October 2013, 02:19 AM   #1
tonequester is offline tonequester  United States
diyAudio Member
Join Date: Oct 2013
Default mid range "passive boost" circuit ?

Greetings to all.

tonequester here, making my first post on this forum. I'm hoping to get some opinions coincerning a mid range "passive boost" circuit for electric guitar. As it concerns boosting of a signal, I hope that this is the right part of the forum to post this on. please, pardon me if it is not.
The circuit in question is a device offered for sale($112.00) by Villex. I spoke to the owner/designer about it, but he has such a heavy accent that it was hard to understand some of what he was trying to tell me. I got this much : he says that the circuit, which is built into an output jack, is designed to take advantage of the loss of signal strength, or inefficiency of the Stratocasters basic circuit. He says that it is NOT a bass/treble cut, as many supposed mid range "boosters" are. It is not an LC network. He says that energy is lost due to the loading of the pickups, and the impedance/reactance of the whole circuit. He also says that his jack uses "new magnetic materials", and basically conserves lost energy, and uses it to boost the mid range frequencies of the guitar.
The sound bit that his website offered, of course sounded great. He played the same "lick", first without the jack circuit engaged(it has a bypass switch), and then with it engaged, for each of the 5 positions of the pickup selector switch. The sound bite seemed to "prove" considerable boost of mid range frequencies with all three pickups each by themselves, as well as with neck and mid combined, and mid and bridge combined. The tone was pretty close to what I desire. I have heard others post(on other forums) who state that there is no such thing as a passive boost, period. I was actually of this opinion before talking to the owner/designer. Now I am wondering about his approach. The trouble is that I am not well grounded enough in theory to determine if his circuit is possible or not.
For some reason, his explanation(even though I didn't get the half of it) seemed to make some sense to me, and I got the feeling that he was quite sincere. As I questioned him pretty thoroughly, and made it clear that I did not want another bass/treble cut circuit, parading as a mid range booster, he assured me that this booster is the real deal. The guy even asked me what I thought he ought to do to help market it, and that he isn't very good at business.
So, if anybody would to "chime in" on this one, I'd be very thankful and appreciative. I have tried to Google this subject, but have had no luck. This is most probably because I lack the theory to even search the internet properly regarding this subject. Again, thanks to anyone who has an opinion. I would hate to spend the $112.00 only to find out that it IS some scam. If I wanted to "boost" the mid range by cutting bass and treble, then turning up the volume, I can do that comparatively cheap. tonequester out.

P.S., I apologize for the length of my post.
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Old 28th October 2013, 11:02 AM   #2
DF96 is offline DF96  England
diyAudio Member
Join Date: May 2007
Whether it is a scam or not could depend on whether the seller genuinely believes his own blurb. To boost midrange passively you need an LC circuit; even that will only boost voltage, not energy. He says it is not that - first warning sign. You say it uses "new magnetic materials" - second warning sign. It is conceivable that it just adds a capacitor and uses the existing inductance of the pickup.

Without a clear explanation I would steer clear. With a clear explanation you might wonder whether the price is appropriate.
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Old 29th October 2013, 05:03 AM   #3
tonequester is offline tonequester  United States
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Join Date: Oct 2013
Question mid range "passive boost" circuit.

Greetings, and thanks DF96.

I appreciate your reply to my post. I will definitely continue "researching" this subject, and will also contact the designer again before I spend $112.00 plus $8.00 shipping on the jack. The biggest problem with my first contact with the guy was just how hard it was to understand him, due to his thick accent, which sounded Russian. I believe that the use of the word power was not mentioned by him. I apologize for steering you wrong on that. He did mention signal loss in the guitars circuit through the impedance of the pickups, and capacitance, even through the guitar to amp cable. He did claim that his circuit was able to make use of this "loss". However, he did mention that his circuit used "new magnetic materials". This is one thing that I should have questioned him about, and will, if and when I talk to him again. I hope to get a few more responses here, before I contact him again, and as I said, I'm still trying to "research" this on my own. I plan to try a search of the Patent Office to see if there has been any kind of patent filed, or granted for such "technology". I really appreciate your time in posting, and respect your advice to be cautious. I'm glad to make your aquaintance here on the forum.
Best regards, tonequester.
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Old 29th October 2013, 07:47 AM   #4
Villex is offline Villex  United States
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Hello guys.
I am William Villex, designer of SJMB - passive mid booster.
I will be happy to explain to anybody how this booster works.
For 7 years of selling it I didn't have single return from any unhappy customers!
Respectfully, William
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Old 29th October 2013, 10:18 AM   #5
DF96 is offline DF96  England
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We await your explanation. Will popcorn be required?
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Old 30th October 2013, 03:22 AM   #6
tonequester is offline tonequester  United States
diyAudio Member
Join Date: Oct 2013
Greetings to all.

Tonequester here. I see that William Villex has joined as I suggested he should. I will email him and let him know that an explanation of his circuit is awaited on the forum. He is completely new to forums, and may be new to other things American, judging from his accent. Here's some exciting news as far as I am concerned however. He emailed me after I sent him word of, and advice to join this forum. He asked me for my shipping address so that he can send me his jack, no money up front. I had mentioned during our phone call, that IF I were to purchase the jack, I couldn't afford to do so for a couple of weeks. Mr. Villex must be pretty confident concerning his jack. He gave me the impression that he had integrity during our phone call, but he said that he "wasn't so good at business". I have to say that in my case, customer service is way up there at the top. If he is willing to trust me enough to send me the Strat-Jack, free to try, that's an unheard of start. One last thing, I want to say that I am in no way affiliated with him, or Villex, other than as a perspective customer. I will post a sound bite once I have installed the jack in my main guitar. If it sounds as good as the Villex web site sound bite, I'll be satisfied. I'm already very satisfied with his approach to doing business. tonequester out, for now.
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Old 30th October 2013, 10:51 AM   #7
DF96 is offline DF96  England
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Join Date: May 2007
I am sure people on here will be happy to help him express his ideas. There may even be some who share his native language, if that would assist.
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Old 30th October 2013, 11:02 AM   #8
scopeboy is offline scopeboy  Scotland
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Location: Glasgow
If you know nothing about electronics, $112 seems like a reasonable deal for someone to choose some components for you, stick them in a box and support you in wiring it up. There might only be $5 worth of components in it, you are paying for the time and effort involved in choosing the right components to shape the sound in a pleasing way.

I couldn't make a living selling gizmos like that even if the box were completely empty.

I'd bet it is some kind of autotransformer or tapped inductor.
"Sadly, audio is like that. It is about the only branch of electronic engineering where lack of knowledge is regarded as a more advanced form of wisdom." http://scopeboy.com/amps

Last edited by scopeboy; 30th October 2013 at 11:05 AM.
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Old 30th October 2013, 12:22 PM   #9
sreten is offline sreten  United Kingdom
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Location: Brighton UK
Originally Posted by scopeboy View Post

I'd bet it is some kind of autotransformer or tapped inductor.
Hi, +1, all it realistically can be, versions may vary, rgds, sreten.

Though I wonder if a transformer would reduce hum possibility.
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Old 30th October 2013, 07:12 PM   #10
Villex is offline Villex  United States
diyAudio Member
Join Date: Oct 2013
Hello guys.
From basic physics we know that:

"To get most power from energy generator, the load must match internal resistance of the generator"[/B]

We do that all the time when we match speaker cabinet with amp output resistance.
If they don't match, we loosing energy by either over load generator leading to internal lost of energy
or under load generator so not using 100% of it's capabilities.
We all do that when we match amp with speakers.
This is relatively simple to do with speakers and amp because they have practically only resistive component
of impedance. (Impedance is complex resistance that composed of R, L and C resistance or reactance).
Pickups are coils. Therefore the main component of it is inductive resistance. We actually should call
it reactance.

To get max energy from pickup we must match pickup output impedance with the AMP input.
AMP input is pretty much constant within guitar frequency range and is about 1.2 MΩ (megaohm = 1000 KΩ)
for the most AMPS.
In contrary pickup impedance changes a lot within it's frequency range.

Here is table of reactance for pickup that has 6 H (Henry) inductance.

on 41 Hz (low E on bass) ----------------------- 1.55 KΩ
on 82 Hz (low E on guitar) ------------------- 3.10 KΩ
on 659 Hz (high E on 12 th fret --------------- 25.07 KΩ

As for harmonics 15,000 Hz ------------------ 565.32 KΩ

As you can see they are much lower than AMP load and that's where energy is lost !

You may ask me very reasonable question: Why not to make pickups with higher inductance
and recover all that lost energy ?? The answer is CABLE. From very beginning Leo Fender
started designing pickups that are loaded with 500 pf cable. That's 10' cable. The longer cable
the higher capacitance. Cable can pass up to certain frequency. At that frequency it gives
resonant boost of this particular frequency and then sharp cut off.

Table for such frequencies:
for 6 H (Henry) pickup ----------------------- 2900 Hz
5 H ----------------------- 3200 Hz
4 H ----------------------- 3550 Hz
3 H ----------------------- 4100 Hz

I have tried to show you how mush energy is lost there between pickup and amp.
There is a lot of simplification just to make it understandable for most of you guys.
For those of you with high knowledge in theory and have some specific questions
I will be happy to answer.
Of cause I wouldn't explain how in particular I recover some of lost energy. That is my trade secret.
Respectfully, William Villex.

Last edited by Villex; 30th October 2013 at 07:24 PM.
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