Treble booster question

[Kipper4]

Type "treble boost" into the search.  There are a number of TB threads here.   

Already done that Gus. Thanks but and i will probably do it again.

Whats this about transistors Smallbear? Pm me please with some more details.

I did the series resistor and cap to ground and its so quite now. Thanks again Its appreciated Dave.

I think i will make a note in my booky and use it in transistor circuits in the future.

i will make the huminator and whats more is i have a beavis drawing somewhere for a filtered power supply that i already use on my breadboard.
it's got to be similar to the huminator already?

Can i build the rangemaster and just use an AC125?

[Kipper4]

Omg I just stuck a J201 in the place of the 2n5457. this thing has some oumph (technical term) mind you it depends on how you set the trimmer.
Wow differant ball game there. Sweet overdrive. set the range to suit your sound too.

[mistahead]

After fiddling around and getting sub-standard results I gave up and bought the OC44 (is it?) metal can and their half-the-price japanese transistor, tested and packaged with the R's that suit the transistors ratings in the circuit.

I've tried all sorts of things in the Rangemaster - you can't lose as the base circuit is simple and cheap and the transistor COMPLETELY changes the game. You really want the mid/trebble switch on the input cap too - that gives it a lot more to work with.

[smallbearelec]

Most people who do an RM want a single device that hits a fairly narrow gain bucket, and we can and do offer various types at a price. However, if you are willing to do some experimenting, you can get superb results in the RM circuit by cascading two low-gain, low-cost devices as a Darlington pair:

https://www.smallbearelec.com/HowTos/GeDarlingtons/GeDarlingtonPairs.htm

The ideas in that article make use of devices that most people overlook, so they remain cheep and readily available for the moment. The pedal that I developed around them, the Oh My Darling:

https://www.smallbearelec.com/Projects/OhMyDarling/OhMyDarling.htm

is really cool. I would love to hear a shootout between it and any of the boutique RM clones out there.

[mistahead]

Low gain darlington pair?

Mind blown, why do all the best ideas seem so simple in hindsight...

[Thecomedian]

some of the intrinsic disadvantages of darlingtons.  the bias voltage typically adds together for a 1.2-1.4v requirement since voltage drops twice from Q1 VBE and Q2 VBE. I suppose this is actually one good thing about germanium darlington, since Ge is .2v instead of .65-.7v like Si diode junctions, afaik. However, this still does make biasing trickier.

I've also read DPs aren't as fast at responding as a single transistor.

if you do go for DP, try a high gain in Q1 and a low gain in Q2, then reverse them, and see if there's any noticeable sonic differences.

http://www.radio-electronics.com/info/circuits/transistor/darlington-pair-amplifier.php

[smallbearelec]

why do all the best ideas seem so simple in hindsight...

A heavy economic incentive--in the form of several thousand "remainder" devices--is good stimulus for "ideazz."

if you do go for DP, try a high gain in Q1 and a low gain in Q2, then reverse them, and see if there's any noticeable sonic differences.

Thanks for the article reference! The land-mine that I knew about when I started experimenting was the multiplication of leakage and noise, Q2 * Q1. I took R. G. Keen's suggestion and used the lower-gain/lower-leakage devices as Q1, figuring that those would also likely be lower in noise floor. That has worked well; I had no problems with biasing or hissiness. I was very pleased with the complementary Sziklai pair, because it makes use of low-gain PNP parts in the Q2 position.

[Lizard King]

The Tonepad Tubescreamer works as an incredible treble booster with the stock parts.  IMO.

[Kipper4]

i got some BC239's off the bay and made the greg fryer treble booster deluxe. Its nice.
http://www.paulinthelab.com/2013/03/greg-fryer-brian-may-treble-booster.html

I also experimented with the EHX LPB
i messed a little with it just to see how it would perform.
I subbed the 390ohm with a 330ohm (just what  had in stock)
Used a BC109 transistor. Then tried the BC239 a bit more gain there too.
Also modded the input cap with a parrallel 10nf/2u2 blend pot network. for control of the range. a bit Like in the Easyface


i was wondering if i put a parrallel cap say 47u with the 330 ohm coming from the emitter to ground like ive seen in some other circuits .
Would i get more gain with this mod?

[mistahead]

I found the LPB a little underwhelming, but I'm still boxing it up with a muff fuzz and naming it Katinka.

Tim Esc. had the utility boost, again play with the input cap and choose exactly the range of gain via NPN transistor choice and you've got something I rate higher than the LPB.

[Kipper4]

I tried the input cap blend technique in the front end of a fetzer and it just wont work. Totally ineffective.
Should i try to move the input cap after the first resistor (68k) and between it and the j201 gate.
Anybody tried this?
heres a link to the ROG Fetzer valve.

http://www.runoffgroove.com/fetzervalve.html

[Kipper4]

There i did it again !!!!!!!!
Think big go small.
I built a version of the rangemaster seen here (final schematic in pdf)
Although i've tried biasing it all differant settings reason being i used a 100k trim pot in the place of the 68k resistor.
Its got hum like almost as strong as if i go directly to the +9v terminal and thats on the input and it gradually gets worse the further on into the circuit i probe.

anyone ever built this
please help im stuck as to how to debugg it to.

http://www.seymourduncan.com/tonefiend/wp-content/uploads/DIY%20Club%20Project%204%20v03.pdf

[mattjames]

That schematic shows them using a 50k volume pot  .... I wouldn't even think it would bias with that and the other resistors being original.... I would go with the original 10k output pot..

[smallbearelec]

I built a version of the rangemaster seen here (final schematic in pdf)
Although i've tried biasing it all differant settings reason being i used a 100k trim pot in the place of the 68k resistor.
Its got hum like almost as strong as if i go directly to the +9v terminal and thats on the input and it gradually gets worse the further on into the circuit i probe.

It's possible that you have made a mistake in wiring and that you can make this build work as the OB (Original Builder) intended. However, the PNP/Negative Ground implementation of the RM is known to be troublesome; other posters have reported intractable problems with motorboating noise. I strongly suggest either building positive ground or finding an AC127 or other suitable NPN device. My suggestions regarding Darlington pairs also stand.

[Kipper4]

its highly likely i have made an error Steve.
I havent dismissed your idea with the darlingtons mate. I'm holding off for now until i know more about them.
The only darlingtons i keep are mpsa14's i think.
I need to do some more reading on them.
I might try the 10k pot in it too thanks for the suggestion and insight.
I just built the OB and even it was noisy with my goddam wallwart ,with batterys it was still noisy but workable.
I've yet to build the huminator.
Thanks guys

[Kipper4]

the Range master sounds good on SS amps but stick a dirt pedal in front of it into a tube amp and its amazing.
What a shame you cant put a range master (flat out mode) ie with no boost control on the output of a dirt circuit and put both in the same box.
I imagine it would be a nightmare with a + and _ ground circuit both in the same box.

What would be a good not to expensive npn germanium transistor to make a negative ground rangemaster so it could be bolted onto the end of a dirt box

[Kipper4]

I just bought some ACa67 to try in an npn style rangemaster for the bolt on trial

if you have an opinion dont be shy

[Gus]

Have you looked at this thread?
http://www.diystompboxes.com/smfforum/index.php?topic=101292.0
You can use a med power Si like a TIP29

[Kipper4]

thanks Gus i liked the revolution darlington style one. Makes a note of schemo on a piece of paper. (save for later)
everybody has there own ideas of what caps to blend between.
I like your designs too.
My filedmaster negative ground circuit still wont work i might dismantle it and reengineer for positive ground with a pnp and see what happens

[Kipper4]

is it possible to put a small 100r resistor across the power supply to help tame noise as advised before?
If so do i put it on the + or _ volt rail. Bearing in mind its going to be a positive ground circuit.
thanks