R.G. Keen Austin Treble Blaster

Some like 'em and some don't, but I bet everyone has at least a couple — Analog Delay, Digital Delay, Reverb, Chorus, Flanger, Phaser, Tube Overdrive, Transistor Overdrive, Fuzz, Octave Fuzz, Tremolo, Vibrato, Compressor and the list goes on!

R.G. Keen Austin Treble Blaster

Postby Clanger on Tue Aug 04, 2015 11:42 am

I made myself one of these several years back and it has been in constant use ever since.

Recently I experimented with increasing the input decoupler cap for a wider frequency range boost. This was interesting and fun and a very usable sound.

However I then wondered if at some point the 10n output cap might be limiting the lower response, - anyone tried increasing that?

Cheers Clanger.
"Please feel free to copy this information and use it to make friends and influence people at your favourite social gathering" - Doyle
Clanger
Knight
 
Posts: 1554
Joined: Sun Aug 07, 2005 10:00 am
Location: A planet far far away

Re: R.G. Keen Austin Treble Blaster

Postby pdf64 on Tue Aug 04, 2015 10:28 pm

I then wondered if at some point the 10n output cap might be limiting the lower response

It depends what device/s are next along the line, and their input impedance. As long as it's around or above 250k, then no.

I wasn't keen on the circuit as a treble booster, but as a variable gain full range boost, it's a pedalboard essential.
I use a 1uF input cap in series with a variable 100k resistor as a gain control, and a switch on the emitter bypass cap to bring the gain right down.
The output feeds a transistor buffer with 470k input impedance, via a 22nF cap.
My band:-http://www.youtube.com/user/RedwingBand
pdf64
Knight
 
Posts: 1242
Joined: Thu Dec 14, 2006 9:55 am
Location: Staffordshire UK

Re: R.G. Keen Austin Treble Blaster

Postby Clanger on Thu Aug 06, 2015 12:05 am

Hi pdf,

Thanks for the reply, that makes sense.

I love it as a treble booster and also in full range mode. I think I had about 470n at one stage, which made me sound like Carlos Santana, but was so full range that it masked the high end boost for those wailing solos.

I've settled on 15n for treble boost mode, which stops it being too shrill. I've half a mind to add a switch to give me both options. - 15 or 470.

Quite apart from the boost, it does great things to the actual sound. Underrated pedal IMHO.

I assume you're using the 100k pot in the normal place in the circuit? If so why 100k instead of the recommended 10k?
"Please feel free to copy this information and use it to make friends and influence people at your favourite social gathering" - Doyle
Clanger
Knight
 
Posts: 1554
Joined: Sun Aug 07, 2005 10:00 am
Location: A planet far far away

Re: R.G. Keen Austin Treble Blaster

Postby pdf64 on Thu Aug 06, 2015 7:16 am

My 100k variable resistor gain control is in series with the input cap.
It is additional to the output volume control.
I found that without attenuating the input signal somehow, when used as a full range boost, my LP seemed to overdrive the circuit too much and sounded unpleasant.
I got the series input resistor idea from some of the 'improved' fuzz face type circuits, eg the Mike Fuller mods noted on Geofex http://www.geofex.com/Article_Folders/f ... fffram.htm
My band:-http://www.youtube.com/user/RedwingBand
pdf64
Knight
 
Posts: 1242
Joined: Thu Dec 14, 2006 9:55 am
Location: Staffordshire UK

Re: R.G. Keen Austin Treble Blaster

Postby Clanger on Thu Aug 06, 2015 4:25 pm

Ah, yes, I also did a Fuzz face with that mod.

I see the text says part of the problem can be the low impedance input loading the pickups. I've never noticed that problem myself on the treble blaster, though thinking about it I've only used full range with the strat.

I've found that 5nf treble boost works really well with Gibson humbuckers, but sounds shrill on a strat.

Must try the 470nf full range with the Gibson, it may show the problem you're talking about.

I've been having fun using diferent Ge trannys, they can all sound good, not just the holy grail ones.

Cheers,

Clanger.
"Please feel free to copy this information and use it to make friends and influence people at your favourite social gathering" - Doyle
Clanger
Knight
 
Posts: 1554
Joined: Sun Aug 07, 2005 10:00 am
Location: A planet far far away


Return to Effects and the Signal Chain

Who is online

Users browsing this forum: No registered users and 1 guest