DIY Stingray 3EQ Preamp

[xaxxat]

Originally Posted by domdec314

I'm thinking about having some PCB's made of this preamp. If there's interest I can probably order a bunch of them.

I'm interested.

[Andyman001]

Originally Posted by domdec314

I'm thinking about having some PCB's made of this preamp. If there's interest I can probably order a bunch of them.

I'll take a couple also

[EricssonB]

Originally Posted by EricssonB

Oh hey, it's the OP! Thanks for inspiring this. Been using the hell out of it.

I might take a few just to have on hand, depending on the price per unit. I'd probably run a few as experiments of different frequency routing, with a bunch of switches and stuff.

Whatever $20 gets me. What does $20 get me?

[eukatheude]

Great thread! I'll definitely try building this one. Is the best version the one you posted on page 3? Also, can i hook this up to a bass with active electronics?

[EricssonB]

Originally Posted by eukatheude

Is the best version the one you posted on page 3?
Wait, which one?

Also, can i hook this up to a bass with active electronics?
It would be the bass's active electronics.

Yeah.

[domdec314]

It'll be a month or two before I get around to placing the order. I'll update you guys when I do it.

[eukatheude]

Originally Posted by EricssonB

Yeah.

This one:

For the rest: I know, i was wondering if having an active bass going into it (sort of like having two preamps) could create trouble. Mainly i'd do that because my preamp doesn't have a midrange knob, and i could take advantage of the different frequencies anyway.

Whatever $20 gets me. What does $20 get me?

Get a breadbord for 5$

[SGD Lutherie]

Originally Posted by eukatheude

I know, i was wondering if having an active bass going into it (sort of like having two preamps) could create trouble.

No. Not a problem at all.

[eukatheude]

Originally Posted by SGD Lutherie

No. Not a problem at all.

Thanks. I'm definitely going to build this.

[eukatheude]

Another quick question: will 25k pots work the same?

[EricssonB]

Originally Posted by eukatheude

Another quick question: will 25k pots work the same?

The value of the pot is its resistance from signal to ground.

The tone pots route the signal from one cap/res path to another, so the degree of extremes will be reduced.

The volume pot like most is to ground, so your total output will be reduced by a factor of some fancy the result of some fancy formula. Tone loss? Meh. It's buffered?

Tired. That's the best I can offer. Doesn't seem too far off point.

[delta7fred]

Originally Posted by EricssonB

The value of the pot is its resistance from signal to ground.

The value of the pot is the resistance measured across it's outer ends. Sometimes the signal is applied to the wiper.

The tone pots route the signal from one cap/res path to another,

Well it does but it also is part of the tuned circuit so altering the value will alter the operation of the circuit unless you alter other component values to compensate.

so the degree of extremes will be reduced.

The way it works in this instance it will not reduce "degree of extremes".

The volume pot like most is to ground, so your total output will be reduced by a factor of some fancy the result of some fancy formula. Tone loss? Meh. It's buffered?

No, the output is buffered so as long as you stay between sensible limits will have little effect on the output voltage. It will however be more susceptible to loading by the cable capacitance (at some but not all settings) if you use too high a pot value.

[EricssonB]

Originally Posted by delta7fred

The value of the pot is the resistance measured across it's outer ends. Sometimes the signal is applied to the wiper.


Well it does but it also is part of the tuned circuit so altering the value will alter the operation of the circuit unless you alter other component values to compensate.


The way it works in this instance it will not reduce "degree of extremes".


No, the output is buffered so as long as you stay between sensible limits will have little effect on the output voltage. It will however be more susceptible to loading by the cable capacitance (at some but not all settings) if you use too high a pot value.

Yeah, that's bassically what I said.

[eukatheude]

In other words, will it sound, even if like crap? I just bought all the components needed except for the pots, which are harder to find 'round here if you don't want those ugly plastic things.

[delta7fred]

Using different value pots for the tone controls will alter the frequency that the controls operate at. I don't know if it will sound like crap as I don't know what pots you intend using and I have only built it with the values specified. If you want it to sound like a MM 3 band EQ then you really need to use the correct values.

The volume pot is not so critical, you could half or double it's value and probably notice no difference.

[eukatheude]

I want to use 25k's. I actually only have 3 of them right now for testing purposes, later i'll try with 50k's. By the way, i'm populating the perfboard. Does the "notch" on the electrolytic caps drawings indicate the positive or negative side? Please forgive the noobness, it's my first real electronics project beside some easy pedal mods and bass wiring.

[delta7fred]

Originally Posted by eukatheude

I want to use 25k's. I actually only have 3 of them right now for testing purposes, later i'll try with 50k's. By the way, i'm populating the perfboard. Does the "notch" on the electrolytic caps drawings indicate the positive or negative side? Please forgive the noobness, it's my first real electronics project beside some easy pedal mods and bass wiring.

Build it up and give them a try, it might be the sound you have always been looking for.

Nothing wrong with asking questions, far better to ask than assume you know and go blowing stuff up.

The Black bar on the electrolytics (on the layout) is the negative connections. If you look at your electrolytics that is the one that is marked with a "-".

[eukatheude]

Thank you. I noticed i forgot to get the 68nF cap in series (?) with the 50k bass pot at the electronics store, so i put the closest i had (100nF) in its place. In theory that should change the frequency at which the pot boosts-cuts? Also, will pots without a center detent do the trick?
Anyhow i'm halfway through soldering the components, took a break for diner. Now i'm going to finish the soldering and tomorrow i'll do the connections on the back.

[delta7fred]

Originally Posted by eukatheude

Thank you. I noticed i forgot to get the 68nF cap in series (?) with the 50k bass pot at the electronics store, so i put the closest i had (100nF) in its place. In theory that should change the frequency at which the pot boosts-cuts? Also, will pots without a center detent do the trick?

It will alter the frequency at which the cut/boost occurs, it will reduce the frequency (but it will still work ok). Change it when you get a replacement if you don't like how it sounds.

Centre detent pots just let you know where the centre is, they don't have any different/special characteristics.

[eukatheude]

Thanks. By the way, i didn't mention the electronics store didn't have any TL062's, but they gave me a TL072 which supposedly works the same, only with less noise. Curious to see how it ends up. Anyway, here's some pics: