Thank you Very much indeed!Here is the original hand drawn schematic, maybe @Dominic DeCosa still has his version that he can re-post.
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DIY Stingray 3EQ Preamp
- Thread starter Dominic D
- Start date
Simplest way would be to wire them as you normally would (series or parallel) and have the normal output wires go to the input of this.
Pickups =======> DIY Preamp ======= > Bass Output
[QUOTE = "EricssonB, post: 20568428, member: 190341"] O caminho mais simples seria conectá-los como você normalmente faria (série ou paralelo) e ter os fios de saída normais para a entrada deste.
Pickups =======> Preamp de DIY =======> Saída de baixo [/ QUOTE]
Obrigado pela resposta, mas a minha pergunta é por causa desta placa, há apenas uma entrada de sinal, eu simplesmente conectaria os fios em série ou em paralelo e isso faria o controle de dois como se fossem corret?
Pickups =======> Preamp de DIY =======> Saída de baixo [/ QUOTE]
Obrigado pela resposta, mas a minha pergunta é por causa desta placa, há apenas uma entrada de sinal, eu simplesmente conectaria os fios em série ou em paralelo e isso faria o controle de dois como se fossem corret?
[QUOTE = "JrMare, postagem: 20568471, membro: 310960"] [QUOTE = "EricssonB, postagem: 20568428, membro: 190341"] O caminho mais simples serial conecta-como você normalmente Faria (série ou paralelo) e ter fios de saída normais para a entrada deste.
Pickups =======> Preamp de DIY =======> Saída de baixo [/ QUOTE]
Obrigado pela resposta, mas uma minha pergunta por causa desta placa, há apenas uma entrada de sinal, eu simplesmente conecte os fios em série ou em paralelo e isso faria o controle de dois como se fossem corret? [/ QUOTE]
Desculpe, eu controlaria ambos, como se eu fosse apenas uma pickup porque eu só tinha um bilhete.
Pickups =======> Preamp de DIY =======> Saída de baixo [/ QUOTE]
Obrigado pela resposta, mas uma minha pergunta por causa desta placa, há apenas uma entrada de sinal, eu simplesmente conecte os fios em série ou em paralelo e isso faria o controle de dois como se fossem corret? [/ QUOTE]
Desculpe, eu controlaria ambos, como se eu fosse apenas uma pickup porque eu só tinha um bilhete.
Seems like this is closer to what you're trying to get. I think you will have to start drilling more holes for pots and knobs at this point, so you may want to reconsider putting this into a pedal-type unit like I did a few years ago.
Basically, the bass has four knobs now, so you will have to drill some holes or use concentric knobs, which I feel adds a few layers of extra work to the project.
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I understood, but I did not like the drill option, but I appreciate your intention to help. I'm going to end up swapping the preamp for an already ready with the controls set to 4 holes myself, I saw something in a se3p art.
FWIW GuitarPCB.com has a PCB that will work for this circuit, you would just need to change component values to match..
Thought I might toss this wiring diagram up for a blend pot addition. Cool preamp!
Here is another one.
Dropbox - IMG_7678.JPG
I like it so far. I would like to tweak it little bit. That's why I made it.
I hope someone could help.
I would like to tweak circuit board to have little more boost on highs.
Is this possible? (I have changed C8 to 1nf, I like it more with 1nf)
And maybe little more volume boost?
I read on this topic someone has changed C1 capacitor from 10uf to 33uf for more volume.
Any help would be awesome.
Dropbox - IMG_7678.JPG
I like it so far. I would like to tweak it little bit. That's why I made it.
I hope someone could help.
I would like to tweak circuit board to have little more boost on highs.
Is this possible? (I have changed C8 to 1nf, I like it more with 1nf)
And maybe little more volume boost?
I read on this topic someone has changed C1 capacitor from 10uf to 33uf for more volume.
Any help would be awesome.
Are you actually using this with a MM pickup, coils in parallel, wired directly to the input of the pre?
The thing about this pre is that there is actually quite a bit of treble boost, but that 2n2 cap across the input actually creates a resonant peak down in the low treble range then rolls off the treble response above this, which leaves very little high treble left to boost.
By lowering the value of that cap or removing it altogether, you are shifting that peak and roll-off higher into the treble region and actually leaving more there for the treble control to play with.
Having said this, remember that the big peak in the low treble is very much a part of the MM stingray sound, so shifting that around might start taking the "sting" out of your stingray!
The thing about this pre is that there is actually quite a bit of treble boost, but that 2n2 cap across the input actually creates a resonant peak down in the low treble range then rolls off the treble response above this, which leaves very little high treble left to boost.
By lowering the value of that cap or removing it altogether, you are shifting that peak and roll-off higher into the treble region and actually leaving more there for the treble control to play with.
Having said this, remember that the big peak in the low treble is very much a part of the MM stingray sound, so shifting that around might start taking the "sting" out of your stingray!
Yes, it is a MM pickup wired in parallel directly to preamp. I like the preamp, I will use it in original state anyway.
I just want to do some experiment to better understand this preamp. In sense which component gives boost, frequency peak etc. Just to do some mods to "see" what are the results and maybe go out of stingray "territory".
I can put it back to original state when ever I want.
Thank you for the input, I totally get it.
I have learned a lot on this topic, thank you all.
I just want to do some experiment to better understand this preamp. In sense which component gives boost, frequency peak etc. Just to do some mods to "see" what are the results and maybe go out of stingray "territory".
I can put it back to original state when ever I want.
Thank you for the input, I totally get it.
I have learned a lot on this topic, thank you all.
Yeah that cap between the input and earth (and how it reacts with a MM pickup) actually does more to create "the stingray tone" than any of the components in the tone stack! A cool mod is to have that cap switchable (to earth) with say a push-pull pot. With this cap removed (or switched out), the treble will sound far more natural. More like the original 70s' stingrays actually.
I've often wondered if that cap was actually a mistake. It makes no sense that an engineer would place a cap there, creating a peak and roll off well below most of the active treble's range. Back when schematics were written by hand, these little things happened a lot. I like to think it was perhaps a mistake on a prototype, and the RD guys actually liked the clicky bright tone, but who knows. Bass speakers back then rarely had tweeters, so a boost around 2-3khz would have been quite impressive sounding.
It would make more sense if instead of a 2.2n cap, this was a 2.2m resistor. It's common practice to earth a coupling cap with a 1 or 2 meg resistor. It's not really necessary with the pickup directly connected like this, but hey... And 2.2M resistors are used in the rail splitter, so it would make sense to use the same value for a bleed resistor on the front end.
Having said this, of course there's no bleed resistor on the output coupling cap. The vol pot does this job. (And the original 2-band has neither also.) So I guess we'll never know. It would be great to meet someone who worked at EB in the late 80's...
I've often wondered if that cap was actually a mistake. It makes no sense that an engineer would place a cap there, creating a peak and roll off well below most of the active treble's range. Back when schematics were written by hand, these little things happened a lot. I like to think it was perhaps a mistake on a prototype, and the RD guys actually liked the clicky bright tone, but who knows. Bass speakers back then rarely had tweeters, so a boost around 2-3khz would have been quite impressive sounding.
It would make more sense if instead of a 2.2n cap, this was a 2.2m resistor. It's common practice to earth a coupling cap with a 1 or 2 meg resistor. It's not really necessary with the pickup directly connected like this, but hey... And 2.2M resistors are used in the rail splitter, so it would make sense to use the same value for a bleed resistor on the front end.
Having said this, of course there's no bleed resistor on the output coupling cap. The vol pot does this job. (And the original 2-band has neither also.) So I guess we'll never know. It would be great to meet someone who worked at EB in the late 80's...
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Thank you for very useful information. I will mess around with that cap to see results. I wonder what will happen if I put 2.2m resistor instead that cap? On volume I am using 30k log pot. Will 30k volume alter sound of preamp?
Passinwind
I know nothing.
- Dec 3, 2003
- 23,054
- 45,931
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- Designer/Toaster Tech @ Passinwind Electronics
I just took a quick look in my LTspice model. That sub would make an absolutely huge difference in treble voicing.
I tried without C5 cap and difference is huge, like new set of strings 
. It is more hi fi sound, but I like it. I tried it with 1nf and 100pf. I will keep experimenting. With this cap you can make more suitable for some other kind of basses and pickups.
@RobbieK is absolutely right, this preamp has huge treble boost, but now there is enough treble to boost.
Thanks!
. It is more hi fi sound, but I like it. I tried it with 1nf and 100pf. I will keep experimenting. With this cap you can make more suitable for some other kind of basses and pickups. @RobbieK is absolutely right, this preamp has huge treble boost, but now there is enough treble to boost.
Thanks!
Ah, good ol' LTSpice. That sure did help get some of my
::bad flashbacks::
