Let's Design "DIY AUDIO's Versatile BASS PREAMP"

[thomgun_lc]

Hi Guys,
I have an Idea, how about if we design a versatile bass preamp?
Probably this preamp should have 3-4 Parametric EQ ( BASS-MID-TREBLE / BASS- MID BASS-MID HIGH- TREBLE), MID SCOOP/ SLAP Button. WE also can Vary MID CUTOFF, Bright/Ultra Low Switch, If Possible, add some Compressor.

Now, Let's talk about First STage of this Preamp.
Using FET?Or OPAMP? in buffer/inverting?

Let's build together this bass preamp, awaiting your opinion.
Thanks

[engel dela pena]

http://albertkreuzer.com/pics/el/pre...eamp_sch21.gif
how about this one?

[regiregi22]

So, basically, if I hook it up to an standard amp (see gainclone), I would have what is called a "bass amplifier"? Like the one I hook to my big speakers cabinet for playing bass?

It would be very interesting to made one for my bass

[Brett]

Originally Posted by regiregi22

So, basically, if I hook it up to an standard amp (see gainclone), I would have what is called a "bass amplifier"? Like the one I hook to my big speakers cabinet for playing bass?

It would be very interesting to made one for my bass

That's all that's inside my bass heads - a preamp and a poweramp. A single gainclone won't go very loud, probably not even enough for stage monitoring in most cases as they're <60W.

[regiregi22]

Originally Posted by Brett

That's all that's inside my bass heads - a preamp and a poweramp. A single gainclone won't go very loud, probably not even enough for stage monitoring in most cases as they're <60W.

But keep in mind that ours are REAL watts, not those high comercial numbers. We use to overspec the PSU, use big heavy transformers, put big capacitance or even regulated supplies (I use one). And the main chip with a good bypass and a short signal path.
All of this paired with 2 cabinets of high efficiency and power, and a high enough preamp signal.........and I think you are ready to wreck

[wahab]

Originally Posted by regiregi22

But keep in mind that ours are REAL watts, not those high comercial numbers. We use to overspec the PSU, use big heavy transformers, put big capacitance or even regulated supplies (I use one). And the main chip with a good bypass and a short signal path.
All of this paired with 2 cabinets of high efficiency and power, and a high enough preamp signal.........and I think you are ready to wreck

On stage, 200W for a bassist is the minimum, as it s not even enough to
sound as loud as the guitarist s 50W amp s...
2 X 200W should do it...

[Brett]

Originally Posted by regiregi22

But keep in mind that ours are REAL watts, not those high comercial numbers. We use to overspec the PSU, use big heavy transformers, put big capacitance or even regulated supplies (I use one). And the main chip with a good bypass and a short signal path.
All of this paired with 2 cabinets of high efficiency and power, and a high enough preamp signal.........and I think you are ready to wreck

I've never tested a pro amp that measured under spec (some MI stuff is a bit exacggerated, but not all), I'd rather have a SMPS rather than lug weight around due to silly audiophile excessiveness in the PS and considering the processing and EQ that's often involved in getting the tone you want, 'short signal path' means nothing.
Oh, and years of experience tells me that 60W is nowhere near enough except for very small pubs with low allowable SPL.

[Nigel Goodwin]

Originally Posted by regiregi22

But keep in mind that ours are REAL watts, not those high comercial numbers.

As Brett has already said, guitar and PA use real RMS watts (as do any decent HiFi gear as well), it's only cheap junk and in-car stuff which uses wildly exaggerated specs.

There are various 'gain clone' type bass combo's about, 60W is enough for sensible playing - even in large rooms, where the PA should be doing the power anyway, the combo is only monitoring.

[regiregi22]

Originally Posted by wahab

On stage, 200W for a bassist is the minimum, as it s not even enough to
sound as loud as the guitarist s 50W amp s...
2 X 200W should do it...

But this depends heavily on the size of the place where you are playing, how many musicians are, what style of music are you performing or what level of loudness are you willing to achieve.

Brett, I agree with you that is not needed any of the inconvenients of the audiophile reasons, so better go with an SMPS. buying an SMPS you can solve it. And don't need the diode bridge and smoothing caps.
For playing when you are practising, is OK because you dont have to carry it.

BTW, I play alone at my home the bass, and have it connected to the input of an EMU 0404 USB (high impedance instrument input, nice preamplifier). Then it goes to a gainclone with a regulated supply and big caps, 300va transformer. Then to my big boxes.

It sound really really good, I can't complain at all despite the fact that I can only control the tone of the sound by the instrument's onboard pot. Maybe too much pure and audiophile for me to really like it. That's why I need a bass preamp

[Test Electrix]

Even if you had just the preamp you could DI in to the venue PA? I think that should be a big consideration in to the design (though saying that I have a Hartke 3500 head powering 4x10" and 1x15" cabs)