Double Bass Help: what preamp you recomend for my setup?

[Diego1977]

I have a Realist pickup on my double bass and I use a GK MB-150 head with a 2x10 Harktke cabinet.

What preamp do you recomend for me? and what beneficts I will get? (More focus sound? When i use my GK on stage as monitor, I will hear my bass more clearly? I will get a more rich sound?)

I was reading a lot about it and the best choice seems to be Radial tonebone PZ pre

Thanks !!!!

 

[drurb]

I have a Realist pickup on my double bass and I use a GK MB-150 head with a 2x10 Harktke cabinet.

What preamp do you recomend for me? and what beneficts I will get? (More focus sound? When i use my GK on stage as monitor, I will hear my bass more clearly? I will get a more rich sound?)

I was reading a lot about it and the best choice seems to be Radial tonebone PZ pre

Thanks !!!!

It's not clear if and/or why you need a pre-amp. If you are looking for a richer, clearer sound because you're not happy with your sound as it is, a pre-amp may not be the cure.

When using a pickup such as the Realist, it's good to load it with an input impedance between 1 and 10 Mohm. Your GK already does that. The second most useful function is an adjustable high-pass filter that many players use to tailor "boominess" on stage. The Radial has a only a crude version of that. Finally, there's tone-control. I'm not a fan of doubling up tone controls and I suspect the controls on your GK are sufficient. So, if you'd like to get the benefits of a high-quality, adjustable, high-pass filter along with optimal loading for the Realist, then I suggest you do what so many of us already have and go right here. You can read about it in detail here.

 

[Ric Vice]

+1
Since the GK already has a 1 Meg input impedance then you may not need anything at all. There was a time when there very few bass amplifiers that did that, but it's fairly commonplace these days. The links Les offered up lead to a very well thought product that's the "Swiss Army Knife" for bassists using a piezo pickup.
I've always ascribed to the "less is more" approach with little black boxes. If the pre amp in the GK has the EQ that you're happy with, than an additional pre amp in front of it is IMHO counterproductive and overly complicated. Unless, you're doubling of course. That's a bit challenging with only one set of tone controls. Just my opinion, some players love their little pedals.

Ric

 

[murrayatuptown]

This is interesting...for someone math-oriented (me included). I took apart a realist that must have gotten wet, as it was corroded & no longer worked. I measured the (electrical) capacitance of the individual pieces (2 piezo discs and cable/jack), and found that it was about the same as a guitar bridge piezo 'rod' pickup (the kind with string 'rests' built in, as opposed to the kind that is a round rod completely embedded and not visible externally).

All this 'blah-blah' just means that I expected the Realist to only deliver adequate frequency response for a guitar (lowest note ~82-ish Hz?) when plugged into a 1 Mohm input amplifier (or preamplifier). I guess there are always tone controls, as someone said...

That being said, the anticipated response seemed, in theory, to be a bit skimpy for the octave lower a standard bass goes to (41-is Hz), and ~31 Hz for a 4-stop neck extension. Maybe that's how they 'voiced' the Realist so it isn't too strong at the low end...

Anyway, my naive calculator-bent leads me to conclude a 2M ohm input impedance would seem more 'correct', also supported by another poster's recommendation of 1-10 Mohm. I had assumed one wants or needs flat response to at least the lowest fundamental pitch of the instrument, and can reduce the low end through tone controls. To 'starve' the low end by having too low an input impedance and try to get it back through EQ seems like a recipe for a very 'colored' sound, but I think if peopel can obtain a sound they like, few are concerned about the howany why, as long as they can 'get there'.

I didn't state measurement numbers above as it seems to cross a line regarding respecting someone's design (IP). I don't have any qualms about taking things apart...I can't help it, it's my nature...but I try to respect some kind of boundaries.

I hope this didn't put most readers to sleep.

I have an electronics background and made many mistakes fooling around with piezos and violin electronics...so venturing into the bass register, I already know what problems I didn't anticipate and have my 'pencil sharp'.

I ran into Francis Deck online and like his work (I haven't heard him play).

FYI, the B-Band three-pickup D1 has a 50 Mohm input impedance, and needs it due to the unique nature of their pickups/transducers. That's why other preamps on the market are not compatible with their pickups.

 

[Ric Vice]

This is in

Anyway, my naive calculator-bent leads me to conclude a 2M ohm input impedance would seem more 'correct', also supported by another poster's recommendation of 1-10 Mohm. I had assumed one wants or needs flat response to at least the lowest fundamental pitch of the instrument, and can reduce the low end through tone controls.

Murray Uptown,
Well, I'm certainly not an electronics whiz, and my current pickup the Ehrlund EAP and Pre Amp doesn't have those issues. When I used the Realist with a Headway EDB-1, my ears told me that setting it's variable input impedance switch to 5 meg ohms, sounded more pleasing that the 1 meg ohm position. Several players, including Chris Fitzgerald have commented on the 4 meg ohm input impedance of the PJB Super Flight Case improving the sound of the Fishman Full Circle.

Steve Rodby mentioned once in an article that he had a 2 Meg Ohm buffer pre amp, and found that to be the best tone for him. So I suspect that you are on to something here. It's commonly known that Fishman and F Deck set their buffer pre amps at 10 meg ohms, which would seem to cover all the basses (pun intended, it's baseball season after all).

Ric

 

[drurb]

This is interesting...for someone math-oriented (me included). I took apart a realist that must have gotten wet, as it was corroded & no longer worked. I measured the (electrical) capacitance of the individual pieces (2 piezo discs and cable/jack), and found that it was about the same as a guitar bridge piezo 'rod' pickup (the kind with string 'rests' built in, as opposed to the kind that is a round rod completely embedded and not visible externally).

All this 'blah-blah' just means that I expected the Realist to only deliver adequate frequency response for a guitar (lowest note ~82-ish Hz?) when plugged into a 1 Mohm input amplifier (or preamplifier). I guess there are always tone controls, as someone said...

That being said, the anticipated response seemed, in theory, to be a bit skimpy for the octave lower a standard bass goes to (41-is Hz), and ~31 Hz for a 4-stop neck extension. Maybe that's how they 'voiced' the Realist so it isn't too strong at the low end...

Anyway, my naive calculator-bent leads me to conclude a 2M ohm input impedance would seem more 'correct', also supported by another poster's recommendation of 1-10 Mohm. I had assumed one wants or needs flat response to at least the lowest fundamental pitch of the instrument, and can reduce the low end through tone controls. To 'starve' the low end by having too low an input impedance and try to get it back through EQ seems like a recipe for a very 'colored' sound, but I think if peopel can obtain a sound they like, few are concerned about the howany why, as long as they can 'get there'.

I didn't state measurement numbers above as it seems to cross a line regarding respecting someone's design (IP). I don't have any qualms about taking things apart...I can't help it, it's my nature...but I try to respect some kind of boundaries.

I hope this didn't put most readers to sleep.

I have an electronics background and made many mistakes fooling around with piezos and violin electronics...so venturing into the bass register, I already know what problems I didn't anticipate and have my 'pencil sharp'.

I ran into Francis Deck online and like his work (I haven't heard him play).

FYI, the B-Band three-pickup D1 has a 50 Mohm input impedance, and needs it due to the unique nature of their pickups/transducers. That's why other preamps on the market are not compatible with their pickups.

Murray--

I'm not sure how you arrived at your calculation. Perhaps you'll disclose what you measured. I don't think that's crossing a line at all. After all, there's so much more to the design than the electrical measurements of the piezos in isolation. Are you simply assuming that, because the capacitance you measure from the Realist is similar to a guitar pickup, the Realist would then only have reasonable response down to 81 Hz? I suppose you aren't making that assumption because you say that you made actual capacitance measurements. Did you account for the combination of capacitances, given how the disks are wired (parallel, I assume, so capacitances add)? Take a look here. Follow the links, especially reading this one. Perhaps you have already read that post that references the single-pole (-6 dB/oct) RC equation.

By the way, I doubt many rigs are flat down to 41 Hz, especially when you consider real responses in rooms. That's the fundamental frequency (not "pitch") of the instrument at low E. You can lose the fundamental frequency altogether and the pitch will be preserved (Google: missing fundamental and pitch). Also, you may be interested to know that the second harmonic is the one with the greatest energy on a double bass.

 

[wallawallabob]

I use a K&K Pure Sound with a BassMax piezo. When I use my own amp (Benz Benz shuttle) it doesn't seem to matter much. When going through a house board, the sound guy usually just grabs the cord and plugs it in and dials me in. Sometimes is hard to remember which channel it went, so I can make some tone changes with it, but mainly I use it for volume adjustments during the gig.

 

[Hoyt]

I really love my Series 3 HPF FDeck. The crossover and phase switch come in handy, and I did notice a slightly fuller sound with my K&K pickup. I've even tried it after my Schertler Stat B, and it seems to round everything out nicely. Definitely one of the best gear purchase for the upright that I've made so far.

 

[Stick_Player]

Realist, DPA 4099, EDB-1, PJB Super-Flight Case.

Groovy, baby!

 

[Ric Vice]

Realist, DPA 4099, EDB-1, PJB Super-Flight Case.

Groovy, baby!

Stick Player,
Glad it worked for you, but in my case the Realist was to hot for the Channel 1 input on the EDB-1, so I had to have it modified by Headway at the factory. We found out later that David Gage sells an attenuated cable for the Realist that solves the problem without modifying the Headway.

Ric

 

[Stick_Player]

Stick Player,
Glad it worked for you, but in my case the Realist was to hot for the Channel 1 input on the EDB-1, so I had to have it modified by Headway at the factory. We found out later that David Gage sells an attenuated cable for the Realist that solves the problem without modifying the Headway.

Ric

Too Hot? Interesting! The Realist is definitely hotter than what I can get out of the DPA 4099. Sometimes I use the phantom power from the EDB-1, other times I use the Denecke PS-1A for a full 48 volts to power the 4099.

But... was there distortion on Channel 1 from the Realist?

I am aware of the Realist Docking Station. Is this different than the "attenuator cable"?

I don't have this distortion problem, though - I don't think.

 

[Ric Vice]

Too Hot? Interesting! The Realist is definitely hotter than what I can get out of the DPA 4099. Sometimes I use the phantom power from the EDB-1, other times I use the Denecke PS-1A for a full 48 volts to power the 4099.

But... was there distortion on Channel 1 from the Realist?

I am aware of the Realist Docking Station. Is this different than the "attenuator cable"?

I don't have this distortion problem, though - I don't think.

Stick Player,
It wasn't distortion, it was such a hot signal that I couldn't get the volume on Channel 1 past 2 before it began feeding back. The cable is manufactured by Planet Waves, for David Gage. Here's the link to the product page on Gage's site. It's described as a "Padded Cable" for the Realist Transducer.

http://www.davidgage.com/store/product_info.php?cPath=53&products_id=491

I also found, that the Headway EDB-1 is a little noisy, with the DPA 4099B. It takes a great deal of gain on the Channel 2 input to get the required volume for playing through an amplifier. So having such a hot signal into the Channel 1 input, and a weaker signal into Channel 2 made it next to impossible to balance the signals with one another. Lowering the gain coming from the Realist fixed this problem. I would venture a guess that the 48v phantom gives you a quieter signal into Channel 2.

Ric

 

[Stick_Player]

Stick Player,
It wasn't distortion, it was such a hot signal that I couldn't get the volume on Channel 1 past 2 before it began feeding back. The cable is manufactured by Planet Waves, for David Gage. Here's the link to the product page on Gage's site. It's described as a "Padded Cable" for the Realist Transducer.

http://www.davidgage.com/store/product_info.php?cPath=53&products_id=491

I also found, that the Headway EDB-1 is a little noisy, with the DPA 4099B. It takes a great deal of gain on the Channel 2 input to get the required volume for playing through an amplifier. So having such a hot signal into the Channel 1 input, and a weaker signal into Channel 2 made it next to impossible to balance the signals with one another. Lowering the gain coming from the Realist fixed this problem. I would venture a guess that the 48v phantom gives you a quieter signal into Channel 2.

Ric

Thanks for the info.

I definitely have a weaker signal from the DPA v. the Realist. But it doesn't seem as drastic as your original problem.

I think I'll get the Padded Cable and see if there is any improvement. It's a continuous hunt when it comes to amplifying an acoustic instrument.