Pickup and Computers?

Most of my Ukes have builtin preamps and equalizers, but they won't drive my computers mic input. I have one of those clip on pickups that I bought to address the two ukes that don't have pickups and it does work with my computer mic input, not very loudly.

I tried to find out what the spec's were for the input and outputs but I guess no one seems to publish the specs? As an old electronics tech I'm used to dealing with specs and such. I don't know if the issue is impedance or levels or ??? What?

I want to play my ukes into my computer and record them and use the equalizer to 'shape' the sound. Can anyone tell me how to do this without buying a amplifier to do this?

As far as I know, you have to buy a device that is built for that. I have the iRigHD which works for my Mac, iPhone and iPad. I know there are other devices. I guess you could build one, if you had the specs for one of those devices.

JackLuis said:

Most of my Ukes have builtin preamps and equalizers, but they won't drive my computers mic input. I have one of those clip on pickups that I bought to address the two ukes that don't have pickups and it does work with my computer mic input, not very loudly.

I tried to find out what the spec's were for the input and outputs but I guess no one seems to publish the specs? As an old electronics tech I'm used to dealing with specs and such. I don't know if the issue is impedance or levels or ??? What?

I want to play my ukes into my computer and record them and use the equalizer to 'shape' the sound. Can anyone tell me how to do this without buying a amplifier to do this?

Click to expand...

You possibly need to use your "Line Input" rather than the microphone input. If your machine only has a single input socket it may be configurable from within "Settings" to use it as one or the other. Other than that, you'll need an appropriate pre-amp to get the levels up (or maybe use a microphone?)

There are USB-input devices available for very little money that'll take a jack input and present themselves to the OS as an audio source for your application of choice to use.

As you say, it can be very difficult to find "real" technical specifications for a lot of equipment these days

The concise answer is revealed when reading about a topic that is called:

impedance mismatch

I have answered this very topic and/or discussed it in over 100 different threads in the past 3 yrs, all of which can be found if you search for the word

impedance

in the search box of the forum.

Many other folks besides me have also contributed to these threads.

There is some learning involved and some new words to understand, but once you do, you will know what to buy, WHY to buy it, and HOW to use it...



RECORDING is different from LIVE AMPLIFICATION, even though impedance issues need to be considered for each.

Not sure if this will help.
http://scotthelmke.com/Mint-box-buffer.html

Can you input an instrument output directly into a computer? No, you cant.

All instrument pickups need an external preamplifier to boost the signal to "Line Level". which is what your computer wan't as an input. The signal from your instrument is a weak analog signal which needs to be amplified and converted to a digital signal for you computer to process it.

You at least need a preamplifier, depending on whether your computer has a built in analog to digital converter built in you need a converter. Even if your computer has a converter built in they are usually not of high quality so your better off with an outboard one.

You need a preamp/converter device.

Anthony

Cheap but decent USB Audio Interfaces available from Behringer/Focusrite/Presonus/others will give you a couple of mic/instrument inputs with adjustable gain and impedance switch.

Thanks for the help guys. I had presumed it was an impedance mismatch, but wondered why my clip on worked w/o preamp but not my Uke's built in preamp/eq?
Since I will be using my mic input I don't need a A/D converter (USB adapter), though it may help. I have been using a Microphone for recording directly into my computer. The signal is a might low and I generally have to amplify with my video software by 25-35% to get a decent level so the resulting video can be played at ~25-45% volume and sound good. Lots of the video's I see on the UU Seasons have very variable audio levels. That may be my hearing problem though?

The Mint Box schematic was useful, but it is designed for a passive pickup, with a high output impedance and no preamp, which isn't my problem. My ukes have preamp/eq built in., except for two. I could build a kluge like it easily but after 40 years of electronic kluge building I'd prefer to just buy something ready made. I really don't want to have to build a printed circuit board to use the surface mount parts I have in the garage.

I'll probably just keep using my microphone and call it even.

Maybe invest in what are known as headphone amps, I have one made by Joyo, just have it in front of your mic to record more sound.

This is the one I bought. - https://www.amazon.com/Guitar-Ampli...=2025&creative=165953&creativeASIN=B01H8G1YKS

You really will be better off buying an audio interface for your computer both for your mic and your uke. Apart from the impedance mismatch issue that Booli mentioned, the direct audio input jacks on computers tend to be noisy and if you are planning to multitrack at all, you will get problems with latency - the time lab between playing the instrument or speaking into the mic before the computer picks it up. An interface and the brands mentioned in an earlier post, Behringer, Focusrite and Scarlett are all reputable and have inputs that are matched to the output of your mic or pickup. They then digitise the sound and send it to the computer via a USB link. They are much lower noise (less background mush) and are also low latency so you can overdub further tracks without problems. Even the entry level ones will have at least two inputs with XLR sockets for a microphone and 6mm Jack sockets for an instrument which is switchable for high or low impedance inputs (usually labelled guitar/line)

I have tried recording directly to a computer via the input Jack in the past and have never really had satisfactory results. The resulting recording always had a lot of background noise and dealing with it degraded the quality of the recording even further so you really are better buying the proper tools for the job.

I use the Focusrite Scarlett. Inexpensive, plug & play, and works great.

Any piezo-based pickup has near-infinite high-impedance (like 10 million ohms) and near-infinite capacitance that requires extensive care in grounding and shielding, otherwise the signal will be overwhelmed by EMI/RF.

'line inputs' are typically 100k ohm
'guitar inputs' are typically 10k ohm
'mic inputs' are typically 250 - 1k ohm

There's more to know, butlikely this is the wrong audience for a deep dive into impedance, inductance and capacitance.

Booli said:

Any piezo-based pickup has near-infinite high-impedance (like 10 million ohms) and near-infinite capacitance that requires extensive care in grounding and shielding, otherwise the signal will be overwhelmed by EMI/RF.

'line inputs' are typically 100k ohm
'guitar inputs' are typically 10k ohm
'mic inputs' are typically 250 - 1k ohm

There's more to know, but likely this is the wrong audience for a deep dive into impedance, inductance and capacitance.

Click to expand...

Yeah this is not the place to discuss specs but thanks for the input. That makes sense of why my Uke preamps/eq don't work, but still my clamp on head piezo works pretty well. The piezo must have pretty good output to take a 10:1 mismatch and only be ~ 6-12 Db down?

It does stimulate my inner geek to wonder about the mechanical energy transfer and the efficiency of Piezo conversion. Especially since it is designed to be clamped on the head stock. All the magic numbers!

uke1950 said:

Maybe invest in what are known as headphone amps, I have one made by Joyo, just have it in front of your mic to record more sound.

Click to expand...

I have a cheaper copy of the Joyo and while it works I lack a 1/8-1/8" patch cable Until I can get by Fry's. The controls are so sensitive it's hard to make it work with headphones, or a computer speaker kit.

Considering the latency issue of the analog verses USB digital interfaces I can see why a USB A/D converter should have less latency and make it easier to multi- track with less offset in the spliced composite audio.

JackLuis said:

Yeah this is not the place to discuss specs but thanks for the input. That makes sense of why my Uke preamps/eq don't work, but still my clamp on head piezo works pretty well. The piezo must have pretty good output to take a 10:1 mismatch and only be ~ 6-12 Db down?

It does stimulate my inner geek to wonder about the mechanical energy transfer and the efficiency of Piezo conversion. Especially since it is designed to be clamped on the head stock. All the magic numbers!

Click to expand...

pardon me while I speak tech for a moment...

Aside from the aforementioned issues, for the typical voltage output of the average piezo disc pickup, the output voltage is likely around 1mV, and you need at least a 20x voltage increase using something like an LM386 op-amp or JFET circuit (like the Scott Lemke above) to raise the signal above the noise floor with any integrity worth amplifying any further and to have a signal-to noise ratio with enough dynamic range to make it worthwhile, otherwise when you amplify the piezo output, you are also amplifying the noise and EMI/RF.

When you play around with the various iterations of Ohms Law applied to AUDIO, you will see that you get a gift in how the impedance matching 'appears' to become a linear ratio instead of a logarithmic one, once you pass about 400mv.

While a 20x voltage increase helps, this is not linear in the audio signal output and you really need about 150-200x linear voltage increase to get a signal level that is AT LEAST around -20 db, otherwise there's just too little to work with that has any audio fidelity.

I have built a few circuits from scratch myself and also reverse-engineered a few others and rebuilt them with modifications.

My conclusion is that a passive resistor network will have better audio fidelity with a near-flat frequency response curve, and most of the active circuits out nowadays are a lot like putting lipstick on a pig, save for a few exceptions.

However, most of the public is conditioned to believe the hype, which is endlessly regurgitated as fact, and then the hive mind is duped into thinking that the Belcat preamps sound better than anything else, so ALL the uke makers start including them in their 'electro' models.

IMHO, these Belcat preamps are the perfect example of how an LM386 can sound really bad, yet with $1 in parts and a slight wiring change, can rival some of the more expensive preamps in the sound and noise isolation.

OTOH, Mi-Si, Fishman, LR Baggs are examples of the better way to implement these kinds of circuits.

It has been a long time since I've recorded anything with my computer, but I always found a mic is far better than any pickup. Even cheap mics sound better than pickups, in my opinion.

I have a Blue Snowball mic that worked great for me directly into the computer. Very nice sound quality.
https://www.amazon.com/Blue-Microph...=1471309042&sr=8-2&keywords=blue+ball+usb+mic
You can check it out at the link above. There are a lot of reviews too.
Levels were never and issue with that one.

jer said:

It has been a long time since I've recorded anything with my computer, but I always found a mic is far better than any pickup. Even cheap mics sound better than pickups, in my opinion.

I have a Blue Snowball mic that worked great for me directly into the computer. Very nice sound quality.
https://www.amazon.com/Blue-Microph...=1471309042&sr=8-2&keywords=blue+ball+usb+mic
You can check it out at the link above. There are a lot of reviews too.
Levels were never and issue with that one.

Click to expand...

before we retread this well-worn path about recording microphones, yet again, might I suggest that anyone interested please first go back and read this thread from May with 101 posts on this topic

http://forum.ukuleleunderground.com/showthread.php?120478-I-d-like-to-buy-a-mic

also, had one done the search for 'impedance' this would have been one of the 114+ search results near the top of the list.

also #2 fellow UU brother Ricdoug has offered extensive and expert examples (with photos and links to vendors) of PA systems and battery-powered amplification, that HE HIMSELF has used in THE REAL WORLD, countless times here on UU and one only needs to search his post history to find all the goodness that will answer 99% of the questions on THESE topics...

but if the 'Ferris Wheel into Oblivion' needs to churn I shant try to stop it, but you can bet that I will NOT be on that ride again.