JHS - Treble Booster ( Hornby-Skewes )

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Re: JHS - Treble Booster ( Hornby-Skewes )

Postby gilmour_pugliese » 06 Jul 2011, 09:53

I've built this booster, converting it to NPN mode (2N5089 transistor)... 68k instead of 62k, 1M pulldown input resistor, and replaced the 100k out with a 100kA pot and the 80uF with a 100uF (I haven't the 80u).
Compared with my Cornish TB-83 clone the HS with the original 22n/1n combo sounds good, less compression and a better cleanup, but a bit thinner when I turn down the guitar volume :slap:
I've tested the 68n in/4,7n out combo but it's muddy and fuzzy... Now I'll lower the out cap to 2,2n or 1n to see if the sound fattens a bit...

a 18v supply will improve the sound of this booster or not?

also, anyone has some info of this pedals?
http://www.treblebooster.net/

the HS models are all based on the original JHS boost (both Ge and Si versions) but I don't understand what are the differences between the various models (except the transistor type)... a different IN/out cap arrangement or more (different resistor value on collector= more/less gain, etc...)?
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Re: JHS - Treble Booster ( Hornby-Skewes )

Postby Electric Warrior » 06 Jul 2011, 11:05

Resistor values are different for the germanium version (same ones as in the Selectatone: viewtopic.php?f=19&t=13025). No idea what value the input cap is in these.
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Re: JHS - Treble Booster ( Hornby-Skewes )

Postby monkeyxx » 26 Oct 2011, 09:39

I just built one of these for fun...going after sort of a Marc Bolan wild hair trying to get at the super ripping saxophone guitar tones Electric Warrior was referring to with my MK I in line. I did it point to point with no circuit board or tag or standoffs, just a spaghetti mess hanging off of the footswitch and jacks. I have toyed with the idea of drenching it in silicone or hot glue, but it seems to be pretty stable the way it is. I built it in a small Raco electrical junction box for extra-ghetto looks. I did use mojo caps, though, I like the BC blues and have a lot of Mallorys. No knobs!! love it.

I used the .022/.001 cap combo at first, but the tone is so bass-light as to be comical and almost unthinkable in real use, so I added a switch that doubles the capacitance to .044/.002, based on Doug H's positive review, and it does sound a lot better and more useable, still somewhat trebly, and still with what I would guess is a distinctive to this circuit throaty rough and tumble type of growl.

this thing will REALLY overdrive your amp or anything that comes after it... I used a 300ish hFE BC182L but am open to suggestions of good NPN transistors to try out. It responds well to the guitar volume knob, not cleaning up like a fuzz face, but actually going down quite a bit in level as you turn the knob. if you're slamming your amp or a fuzz yes you get the cleanup behavior..gain staging. It's like this unit makes your guitar go to TWELVE, it's beyond eleven. But you can simply back it off with a quick turn of the guitar volume...pretty cool. It really is a hoot having all these old school pieces of gear lying around to mess with and play the old sounds on.

with the doubled in and out cap values, after the MK i tonebender, it does get a pretty dern nice classic tone, not sure if it's quite T Rex, though, think I'm missing parts of the equation still, and I don't know if I'll ever know what they are.
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Re: JHS - Treble Booster ( Hornby-Skewes )

Postby Electric Warrior » 26 Oct 2011, 14:47

You're missing the Zonk II part. I built the Shatterbox.
Since the thread on the DAM forum I linked to is dead. Here's the schematic:

Image

Later incarnations of the Shatterbox have the 0.022 at the booster's input.
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Re: JHS - Treble Booster ( Hornby-Skewes )

Postby monkeyxx » 26 Oct 2011, 23:48

thanks I may have to give that thing a try, just for giggles


on the topic of the Hornby Skewes Treble Booster, in my findings transistor hFE is an important consideration and I'm not sure if this has been addressed. You mentioned it, Electric Warrior for your shatterbox. Anyway with a 300 hFE BC182LB, the treble booster with .022/.001 caps is kind of harsh and ridiculous, but the increased caps make it sound "ok." I put in a 180ish hFE 2SC828 and the sound smoothed out quite noticeably. Now the stock in/out cap sound is usable. (The bassier setting still sounds nice, too.) Putting it after a fuzz pedal gives that kind of silly "Satisfaction" buzzy guitar sound. Running it into a dirty amp sounds pretty good too, it's not so pinched and thin sounding with the lower gain transistor and it doesn't overload the amp's preamp quite as much. The pedal was way too hot with the 300 hFE as well. I can't imagine getting a useable sound out of the stock circuit with a 600 hFE 2N5088 or similar. Electric Warrior's post shows that the original transistors were in the 95-230 range so it makes sense. It's still loud with the 180 transistor, but more in line with say a Rangemaster's output. That circuit is sensitive to transistor selection as well. Compared to a germanium rangemaster this circuit is a lot grittier and raunchier...it's NASTY. I think I might reach for it the next time a guitarist says something like, "I need a really trashy guitar sound, what can you do"

here's my funky build :blackeye

trubble blaster update 007.JPG

trubble blaster update 012.JPG
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Re: JHS - Treble Booster ( Hornby-Skewes )

Postby Electric Warrior » 27 Oct 2011, 00:16

oh yeah, that's funky. I'm usually going for clean, but this one came out a bit messier looking than I intended:

Image

Image
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Re: JHS - Treble Booster ( Hornby-Skewes )

Postby monkeyxx » 27 Oct 2011, 00:26

haha that's funny! your version of "messy" is like me on my best days. Great looking build. I like the half point to point, half stripboard idea, I might copy that. Funny enough it seemed to make the build go a lot faster to me to do the offboard wiring and the circuit all at the same time. It looks like shit, but it's actually really sturdily built, now that I've got a bunch of glue in there holding the wad in its place. The soldering was all carefully done, and things are insulated where they need to be to prevent shorts. The two-screw-on-the-top box makes battery changes a breeze.
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Re: JHS - Treble Booster ( Hornby-Skewes )

Postby Electric Warrior » 27 Oct 2011, 01:08

I copied here:

Image

here's the layout:

Image

the original was built on a wider spaced vero, btw...
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Re: JHS - Treble Booster ( Hornby-Skewes )

Postby monkeyxx » 27 Oct 2011, 01:44

VERY coooool, thank you. I wish that wider pitched stripboard was more common, it looks so cool.
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Re: JHS - Treble Booster ( Hornby-Skewes )

Postby pedalgrinder » 27 Oct 2011, 04:43

It appears to me from looking at the schematic that this is unit is not a treble booster per say. But a high pass filter that is only letting the high frequencies through more and dropping bass content. Does anyone know of a treble booster that keeps bass content and purely increase's just the treble content??? Of what i can tell these are mainly just concentrated high pass filters. Thanks
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Re: JHS - Treble Booster ( Hornby-Skewes )

Postby monkeyxx » 27 Oct 2011, 05:36

isn't that the same thing functionally? does it matter?

on the other hand, I am also interested in your question because I don't know what an active EQ boosting circuit looks like on a schematic, and I'd like to learn. As far as I know, a classic Fender tube amp has an entirely passive (roll off only) tone stack that just alters the basic EQ of the amp that is set when the knobs are all at "10," and nobody is complaining about how those sound.
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Re: JHS - Treble Booster ( Hornby-Skewes )

Postby pedalgrinder » 27 Oct 2011, 05:47

to answer you question yes it does matter if you care i suppose but say you put a bass guitar but you only want the treble part enhanced and the bass frequency to come through you then have a problem. as only high frequency's will come through. What your not sure about is what is called high pass filters band pass filters and low pass filters. The fender amp your talking about in its passive circuitry has all three in it's passive circuitry to contend with the full frequency range. And may i say that all fender and marshall amps were first bass amps. It was the guitarist's that took the bass amps and turned them into guitar amps. Couldn't help myself sorry anyway the treble booster schematic you have here is just purely i high pass filter Which is no good for bass and i would have thought a few guitarist's would be losing bottom end from it also. Thats why i was hoping to find a schematic that lets all frequency's through and just enhancing the treble content or basically adding more db to it so you can purely adjust the top end with out affecting your full frequency range of your instrument. Hope that helps cheers [smilie=new_smilie_colors1.gif]
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Re: JHS - Treble Booster ( Hornby-Skewes )

Postby monkeyxx » 27 Oct 2011, 06:37

hmm I wonder though, doesn't cutting bass and then boosting the whole signal a whole bunch (like the Hornby Skewes circuit above) basically come out to the same thing as what you're suggesting? the bass comes up to unity volume or more with the added gain, and the treble is way above unity. This affects the character of the sound when feeding a dirty gain stage as intended. A bass boost into clipping will make a fuzzier tone (I think I remember) and a treble boosted tone into clipping will sound something such as "creamier" or more singing. When you're feeding a dirty stage, as intended, you don't hear an effect like these as a deep bass cut, you just hear it as a shift in tonality of the clipped signal. There are certain vocal qualities evoked that are not dissimilar to that of feeding a clipping stage with a stationary wah wah pedal (what's that a bandpass filter?)
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Re: JHS - Treble Booster ( Hornby-Skewes )

Postby monkeyxx » 27 Oct 2011, 06:39

I guess this wouldn't work well for a bass guitar for a lot of reasons, one being that most bass amps are set pretty clean, and have a lot of headroom? and with that in place, yes this effect will just sound like a huge bass cut. it's probably boosting frequencies that aren't much featured by bass strings, as well, I would guess, other than upper "air" harmonic stuff
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Re: JHS - Treble Booster ( Hornby-Skewes )

Postby modman » 01 Apr 2018, 14:18

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