Enjoy the benefits of a premium membership!
Upgrade Account
-
TalkBass has been independent since 1998. Add your voice.
Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
Join free Log in
Want zero display ads or expanded classifieds tools? Compare plans.
Double Bass Cheapest easiest way to boost input impedance?
- Thread starter krfoss
- Start date
Rule of thumb: parallel impedance is ALWAYS lower than the lowest impedance in the circuit. That makes for an easy reality check if the number you calculate is higher than the lowest Z.
Always On High Pass Filter | Broughton Audio
A standard Broughton high pass filter with the bypass switch removed. This design allows a more compact layout, fitting on a single pedal board rail, or even mountable underneath a pedal board. The high pass filter is a 12 dB per octave low frequency filter. The knob controls the cutoff...
www.broughtonaudio.com
$70 USD
I doubt you’ll notice any improvement with the Realist. Realist products usually work great with 1M or more. Some people do prefer 5 or 10M for the Full Circle. Idk if you’ll hear a difference with it, but i would guess it’ll be subtle if noticeable at all.
Provided you’re pickup likes likes 1 Meg Ohm this will work and tye Broughton has a variable HPF, but if your amp’s input impedance is already set at 1 Meg Ohm (most are these days) that function of the box is redundant. To the best of my recollection the Mark Bass Little Marks are one of the few bass amps that has a 500 K input impedance.Always On High Pass Filter | Broughton Audio
A standard Broughton high pass filter with the bypass switch removed. This design allows a more compact layout, fitting on a single pedal board rail, or even mountable underneath a pedal board. The high pass filter is a 12 dB per octave low frequency filter. The knob controls the cutoff...
$70 USD
Last edited:
Aren’t these line matching transformers for microphones?This is what I use when necessary...
Line Matching Transformer
Line matching transformer connects a balanced low-impedance microphone output to an unbalanced high impedance input.www.shure.com
It works just fine with one of these:
American Recorder Technologies XLR Male to 1/4" Female Mono Adapter Nickel | Guitar Center
Shop for the American Recorder Technologies XLR Male to 1/4" Female Mono Adapter in Nickel and receive free shipping and guaranteed lowest price.www.guitarcenter.com
(NFI)
Primarily used to connect a bass to a mixing board or a microphone to a guitar or bass amp. I know they alter Impedance I’ve just never used one on a piezo pickup.
Last edited:
I have tried the above setup, it works the same with my piezo/pre-amp system as it does with my mic (clear). Just need to have the necessary cable adapter. Fwiw, I also frequently use it with wireless dongles.Aren’t these line matching transformers for microphones?
It does work, resulting in a generous boost. Note though, I am not much of an electronics guy. What is recognizable to me is the increased headroom, probably between 20% and 40% on the volume dial (that's usually how much I have to turn the volume down to keep the same balance).
Edit: This may be important, the inline devices I am using are by AT and named "Impedance Matching Transformers". I don't know if that is exactly the same as a Shure "Line Matching Transformer". I DID accidentally picture a Shure "Line Matching Transformer" in my early post, although its description does indicate it matches impedance, so it may be the same kind of device. Here's the one I'm using:
Invalid Link Removed
Last edited:
FWIW, I've never found that impedance higher than 1-2Meg was beneficial to the Realist. I always end up having to back off a lot more low end or roll up the HPF when I use higher impedance than that. I have a Grace Felix and I've used a Radial PZ-DI at 1Meg and 10Meg. The HPF is ALWAYS rolled up for 10-20Meg. I've also experimented with a 5Meg input on my Strobostomp Mini, which requires the HPF to keep the bottom clean. I rarely use much HPF at 1-2Meg (I have a Trickfish amp and Trickfish and MXR preamps w/2.2Meg).
I know every player, bass, amp, and room are different, but you might find that you create new problems to solve if you go much higher than 1-2Meg. Or, it might be exactly the thing you need for your particular setup.
Aren’t these line matching transformers for microphones?
Yes.
With a mic plugged into the low impedance XLR side, the line matching transformer (LMT) translates something like 150 ohms to a higher impedance that will work with the input of a musical instrument (MI) amp.
If you turn the LMT around, it translates the relatively high impedance of an instrument to the lower impedance of a mic input. FYI, the input impedance for the mic inputs for my old mixer is about 2k.
The transformer itself does not present a specific impedance at the input and output of the LMT. Rather it translates the impedance from high to low or low to high. AFAIK the translation amount is a fixed ratio that is related to the turns ratio between the two windings in the transformer. The impedance on the output is impacted by the impedance on the input and vice versa. AFAIK the idea is to get as close to matching as possible.
To use the LMT with a piezo and MI amp, the low impedance XLR side should be plugged into the amp; so the LMT translates the impedance of the amp higher. This is why you need a 1/4 to XLR adapter on the low impedance side. If the amp has 1 Meg input, the LMT will translate the impedance to a higher value that is more suitable for a piezo.
I actually used Shure A95U to plug a Realist original and copperhead into a mixing console. AFAIK, the load presented to the pickup was < 1 meg, but I thought it sounded fine. When used this way, the LMT does essentially the same thing as a passive DI.
Last edited:
It it's kind of a conundrum isn't it. The only pickup I've ever needed higher than 1 Meg Ohm was the Fishman BP-100.
When Ampeg introduced the B-15N in the early 1960's they set each of the inputs at a higher impedance than 500K
Primary input on Channel 1 is set to 5.6 Meg Ohms, the Secondary input is 1.2 Meg Ohms, and the Channel 2 input is set
to 2.2 Meg Ohms. Walter Woods set his MI-100-8 to I Meg Ohm based on readings he got from a pickup Don Underwood
sent to him by request. I must admit to using the HPF on the Grace very sparingly and the input impedances are both on the
medium setting. With my bass, the Ehrlund EAP pickup, through the RedEye Twin into any of my amps. I don't even concern
myself with that the Meg Ohm reading on the what ever bass amplifier I happen to be using. The HPF is rarely an issue either.
Just my take of course.
When Ampeg introduced the B-15N in the early 1960's they set each of the inputs at a higher impedance than 500K
Primary input on Channel 1 is set to 5.6 Meg Ohms, the Secondary input is 1.2 Meg Ohms, and the Channel 2 input is set
to 2.2 Meg Ohms. Walter Woods set his MI-100-8 to I Meg Ohm based on readings he got from a pickup Don Underwood
sent to him by request. I must admit to using the HPF on the Grace very sparingly and the input impedances are both on the
medium setting. With my bass, the Ehrlund EAP pickup, through the RedEye Twin into any of my amps. I don't even concern
myself with that the Meg Ohm reading on the what ever bass amplifier I happen to be using. The HPF is rarely an issue either.
Just my take of course.
Your first example is good for a microphone. The issue with most acoustic pickups is that piezo pickups are hi-z and are often too high for a typical amp to produce ideal sound.This is what I use when necessary...
Line Matching Transformer
Line matching transformer connects a balanced low-impedance microphone output to an unbalanced high impedance input.
It works just fine with one of these:
American Recorder Technologies XLR Male to 1/4" Female Mono Adapter Nickel | Guitar Center
Shop for the American Recorder Technologies XLR Male to 1/4" Female Mono Adapter in Nickel and receive free shipping and guaranteed lowest price.
(NFI)
I do have a mounted Sennheiser e-604 mic and this device of course does work for that mic. But my Vic's Model C piezo system does have a similar volume increase.
Stock input impedance is 1Meg, but Broughton will customize the input impedance on request
Based on the amps I’ve owned and gigged with there’s some kind of synergy between the Meg Ohm input load and the preamp voicing
that makes for a good Double Bass amplifier. Walter Woods had that figured out, so did Euphonic Audio, Acoustic Image, Genz Benz (Shuttle) Gallien Krueger (200MB’s,MBS) and Phil Jones. (Super Flight Case, Flight Case, and Briefcase)The common thread here is that they’re all out of production. The GR Bass (AT Cube Acoustic), Traynor (SB series) and Genzler Magellan series are fortunately still avaliable.
that makes for a good Double Bass amplifier. Walter Woods had that figured out, so did Euphonic Audio, Acoustic Image, Genz Benz (Shuttle) Gallien Krueger (200MB’s,MBS) and Phil Jones. (Super Flight Case, Flight Case, and Briefcase)The common thread here is that they’re all out of production. The GR Bass (AT Cube Acoustic), Traynor (SB series) and Genzler Magellan series are fortunately still avaliable.
Fdeck! I had one and it was super.
Then a thief stole it from me along with my Gallien Krueger amplifier and my Headway preamp :-(
Then a thief stole it from me along with my Gallien Krueger amplifier and my Headway preamp :-(
Boo, that’s a crime against all bassist everywhere!
I found reference to this on another TB thread:
Double Bass - Any reviews of the Triton BigAmp Piezo DI?
BigAmp Piezo - Triton Audio
Looks interesting.
Double Bass - Any reviews of the Triton BigAmp Piezo DI?
BigAmp Piezo - Triton Audio
Looks interesting.
Attachments
Last edited:
Trying to optimize the input impedance is opposite of low hanging fruit IME. It is tiny fruit way up high on the tree. That is, unless you have a fairly obvious lack of low end and signal strength. In other words, if you have a nice strong signal on open E (or B or C if applicable), then you have the correct impedance IMHO.
For those wanting something a bit better, the Fire Eye stomp boxes are a good option. The Bright Eye is the cheapest option, but even that is $175 now. I have one, and my experience is that its added value really depends on what else you have in your signal chain.
For those wanting something a bit better, the Fire Eye stomp boxes are a good option. The Bright Eye is the cheapest option, but even that is $175 now. I have one, and my experience is that its added value really depends on what else you have in your signal chain.
