New Blues Blaster Overdrive Distortion

[Ben Lyman]

Only had a minute to spare today and soon the Blues Blaster will be headed to San Diego

[PRR]

> isn't there any single op-amps equivalent to the 4558?

Read your history.

'4558 is a dual improved '741.

The "improvement" may have been significant when new but seems insignificant now.

'741 used to be THE op-amp. Many-many-millions sold.

Funny thing is: today a '741 is hard to source. Everybody and his brother-in-law introduced "improved '741". One popular improvement was putting two in one chip for less than double-cost. Duals now cost the same (even less) than singles.

So yes, you can find '741, and you can probably source TL071 (half a TL072). Won't save any money ('741 may cost premium), won't save any space.... it is useful to know how to safely "idle" half a dual chip.

BTW: grounding the output is usually very wrong. Depending on various factors, it is liable to dump LOTS of current through the chip. A happy dual chip pulls about 3mA. A ground-shorted opamp may pull 30mA, on top of that 3mA. Eleven times the battery drain, supply load, internal heat, for no good reason.

[pinkjimiphoton]

Only had a minute to spare today and soon the Blues Blaster will be headed to San Diego

that sounds pretty much as i expected it too. nice bro. nice playing, too. it does seem to have a good interaction with the guitar. your circuit is a little more transparent sounding, which to me is good, mine is a little creamier and thick, but pedal sounds smashin' to my ears.

[Ben Lyman]

Thanks Jimi! Colonel Grampa loves it, he played Inna-Godda-Davida on it and it sounded perfect for him.

I plan on making another for myself, gonna play around with everybody's suggestions on the breadboard first.

I wonder if the Blue Clipper is biased the way it is because Dan Armstrong was just doing what he knew how to do and maybe using an IC chip was kinda new to him.

[pinkjimiphoton]

try it with a fet based opamp like one of them ne553X like i used bro, you may like it. different sound, but good.
i think i'm gonna try one of these (yours) on my breadboard later, i really liked the demo... has a nice bite to it that's a bit different from mine, more of a nice transparent yet gritty overdrive like the way things used to be. i can dig it. and ya can literally almost build the entire thing on the back of a chip socket and stuff 'em in a 1590a.

time to whip out the old veroboard gizmotron and work up a layout. thanks ben!

[Ben Lyman]

Cool Jimi, I want to know what changes you make and how it sounds.
My main goal here was to make something fast with as few parts as possible, that's
why I started with the DA Blue Clipper.

I figure any beginner can make one of these and put it in a big enclosure easily with
room to spare, it's a good way to learn how to wire up a pedal with all the bells and
whistles: 3PDT w/LED, switched input jack, battery and switched DC jack.

Of course, I know a lot of you guys can easily squeeze this thing into a tiny
little box no problem.

I want to make my own soon but I have got to finish my Ge fuzz first. I also wanted
to make a Dan Armstrong Orange Squeezer but now I'm having second thoughts,
I don't know if it has weird, unorthodox wiring to it as well.

[pinkjimiphoton]

google up "mictester's really cheap compressor".... opto comp, couple parts, sounds great... so clean you almost can't tell it's on

[Keppy]

try it with a fet based opamp like one of them ne553X...

553x is worth trying, but is not a FET opamp. Actually the opposite, as FETS have very high input impedance and 553x has very low input impedance for an opamp (300k typical). Based on the ongoing discussion, maybe that's why you like it.

[pinkjimiphoton]

i like 'em mainly cuz a bud gave me a huge bag of 5532's and 5534's. other than that i just buy whatever's cheap usually. that said, i'll be using these ne's for YEARS still..
i bought a few of the oplxx whatever kinda chips i heard people rave about, and heard no particular difference.
i mean... we're talking distortion here
i still like 741's. great for a lot of things. and sometimes the best sounding.
but i'll agree in part with all of it... just disagree as a design absolute that ANYTHING ever has to be "just this way".... particularly when the objective is to distort the poo out of an electric guitar.

there's different ways to achieve similar goals. i argue form over function i guess, and prefer to worry about toneful more than correct.

[Ben Lyman]

I don't have any of those but I will try to get some next time I order. The only op amps I have are JRC4558, TL071 & TL072. I also tried a lot of different Ge and Si diodes and I think a big part of the sound that I like is coming from those HP/Motorola diodes