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Post by ozboomer on Oct 28, 2010 1:35:24 GMT -5
I'm trying to work out if something I'm hearing is something weird with my hearing, if it's some strange law of physics or if I've just been playing guitar too much and I'm going deaf... I have a particular Strat that I'm playing.. and in short, it just sounds too "boomy". I have it connected into the computer and I'm looking at the signal coming through a filter VST (EasyQ) and into a Spectrum Analyzer VST (SpectrumAnalyzer, duh). When I play an open bass E string alone, I hear the sound as boomy. The filter has a flat response and the spectrum analyzer shows some peaks at ~50 Hz, at 63 Hz, around the 80 Hz mark (duh, open E = 82 Hz or something) and further peaks at 125 Hz, 250 Hz, etc, etc. Now, if I set-up EasyQ to work as a high-pass filter with a cutoff frequency at 8k, say, I still hear the sound as boomy, even though the spectrum analyzer shows a much lower level on the frequencies below 8k; it even shows the slope of the response matching the 12db/octave of the filter. The tone controls on the monitor speakers aren't set to a constant "bass emphasis" or anything.. and yet the behaviour is not exactly the same with other guitars, although, the effect of 'constant boominess' is still there to some degree. Given that the behaviour is somewhat constant, I can understand how, for example, Keith Richards would remove the 6th/E string from his guitars, so he wouldn't get that overpowering "bassy" sound, so maybe I could try that? ...or would that make a mess of the set-up on the neck/guitar? Perhaps I should go to a hybrid set of strings and use a lighter 6th/E string.. but again, I expect that will alter the tension/load on the neck. I *do* notice that I CAN get a bit better/less boomy sound when I use a guitar that has a "bass cut" control, like in my SimpleMod-b wiring project. Any suggestions on what is going on with my crazy hearing!?
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Post by gumbo on Oct 28, 2010 4:46:08 GMT -5
Boomy, Huh??? .....and your name is? ?
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Post by cynical1 on Oct 28, 2010 8:52:58 GMT -5
The "boomy" that I'm usually fighting on the bass is usually located in that 125hz to 250 hz range. Odds are that's what you're experiencing.
The "~50 Hz, at 63 Hz" spikes could very well just be noise.
Just a few quick questions so I have an idea what's what...
What's the configuration on this Strat? ...as in pickups, string gauge, mods, what positions the "boominess" is most noticeable...stuff like that...
Also, is the "boomy" sound still there in a DI recording or just through an amp?
And, related to the last question, what amp are you going through?
And finally, you mentioned that your other guitars suffer a similar, but not as obvious "boominess"... What are you using for playback...and is it more or less obvious from your monitor speakers or through your amp?
Happy Trails
Cynical One
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Post by ashcatlt on Oct 28, 2010 11:27:40 GMT -5
What are you using for an interface? Have you tried recording the thing and then playing it back through the EQ? It's quite likely that you've got your system set up to monitor directly off the input, so you're not actually hearing (only) what is coming through the VST.
cynical1 is probably right about the 50Hz being noise. It sure is exactly the same frequency as your wall power, ain't it? There are some subharmonics generated, and if you're playing more than one note at a time you can get some combination tones which might be lower than the fundamentals. Even 80Hz is a very low frequency, and doesn't really sound like a note so much as just mud. The note we usually think we hear when playing the low E is actually the first octave harmonic up there around 160Hz. I (and many, many other engineers) high-pass guitars routinely in the area around 100-180Hz, and sometimes even higher.
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Post by ozboomer on Oct 28, 2010 11:44:03 GMT -5
...usually located in that 125hz to 250 hz range... "~50 Hz, at 63 Hz" spikes could very well just be noise. Ya, there's a lot of that going on right across spectrum in that area.. This guitar has had no changes at all.. although, it is a wonky copy. Monterey MST-5SGR they call it (see www.montereyguitars.com/electric.htm#). Farly standard everything, it appears to me... With 9-42 strings, nothing weird in terms of set-up, although the trem. bridge is set-up to be flat on the guitar, rather than having the float on it. I have no clue as to the innards as I've never opened it up.. but the 5-way sounds a bit scratchy and the tone controls do the normal thing, as does the volume control (obviously no treble bleed on this one - and I've had all these controls maxed-out when playing, so the "bassy" sound isn't coming from a turned-down volume). I would say the "boominess" is always there, whether going through the computer or through an amp. The actual signal paths run like this: Recording: Guitar -> BX-600 mixer (no tone controls) -> UCA-202 i/f -> Computer -> Cakewalk/Audacity (or VSThost -> VST plugins) -> UCA-202 -> external computer powered speakers... and Live: Guitar -> Frontman 15R amp. ..and I'd probably say the "boominess" is more obvious when going through the computer thing, I think and not so much when going through the amp... but this is after me trying to listen now, after just waking-up at 3:15am(!) I'm thinking that it might ultimately be a question of what's (not) happening with the VSTs (or my ears), as the VSTs show the bass components of the signal being (largely) removed but I don't hear anything different. If I do it with the same plugins but at higher frequencies, I can see the signals being cut out AND I can hear it sounding different... which is backwards, to what you'd normally expect, with reduced top-end response as one gets older, I know... ...and no, I'm not full of ink when trying to do these tests(!)...
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Post by cynical1 on Oct 28, 2010 11:53:39 GMT -5
As I read this, you hit your amp after going through your computer. I know this sounds obvious, but what are the settings on your soundcard? I mention this as most sound cards have a default, and if you ever bumped up the bass to cover headphones or a set of PC speakers that may be a contributing factor.
HTC1
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Post by ashcatlt on Oct 28, 2010 12:29:22 GMT -5
I still think that part of the issue with the computer thing is that you're not hearing only the post-VST signal. You've got some of the pre signal coming out the speakers, so you're not hearing exactly what the VST is doing. It sort of makes sense that you'd notice more difference in the top end. Our ears are a bit more sensitive in that higher range, and there's proportionally more energy in the low end for the dry signal to mask the EQd one.
Are you plugging the guitar directly into the low-Z line input on the mixer? This would tend to attenuate a lot of the high frequencies, and might make it come across boomy. Doesn't explain what you hear through a guitar amp, but you should really buffer the guitar before hitting that mixer.
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Post by JohnH on Oct 28, 2010 14:35:53 GMT -5
A few thoughts:
When I do test recordings with no amp, I go through a pedal of some kind, in an 'off' mode so it acts as a buffer, then straight to a pc line in, or maybe via a mixer. As stated above, you need a device with a high impedance input after the guitar.
Lowering pickup on bass side will......reduce bass!
Your amp, is maybe set up to try to make big deep Fender sounds out of a small speaker, so may have extra boom built in. How about taking your guitar into Billy Hydes and pretend you are a serious buyer for a new amp? a pleasant couple of hours can be spent that way, and you might walk away with a new amp! - or at least try some differnt ones.
John
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Post by ozboomer on Oct 28, 2010 19:11:47 GMT -5
To add a bit further information, here are some pictures and sounds... a sound sample - the first example is the VST filter OFF; the 2nd example is with the VST filter ON. The 2nd portion has been amplified somewhat in Audacity, as the attenuation dropped the sound level... but is the 2nd example significantly different by the time it reaches your ears? The arrangement with the VST filter bypassed (red 'B'): The arrangement with the VST filter NOT bypassed (blue 'B'): Notwithstanding a bit of clipping, maybe it's just my ears... but the recordings seem to sound more-or-less the same to my ears, in terms of "boominess". Maybe my ears are just weird... but I can get rid of the 'problem' when I use the "bass cut" on a SimpleMod-b -fitted guitar. I'm just confused that the VSTs show "yes, I'm doing it" but my ears say "no, not really"... and the VST is certainly giving a different response to what the guitar wiring does... which is what you'd expect, probably. Still need to check-out your suggestions, ash... -John, the permanently confused one
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Post by cynical1 on Oct 28, 2010 19:48:17 GMT -5
The first cut sounds over-saturated. The second one is dropped significantly and, as you said, was brought back in Audacity.
I am struck with the thought that something is going on here that we are not catching. Both tracks are very bass heavy.
What does the guitar sound like if you go straight to the amp? Is it still bass heavy?
I don't know what what vst plugins you're working with, but if you can find the Kjaerhus Audio Classic Series VST Plug-Ins still lurking out there it might be worth grabbing. It's only around 3MB, so it's definitely worth the effort to find it. I understand that Kjaerhus has gone the way of all things, but this was a free pack they used to offer. The EQ is not bad, the Master Limiter is pretty good...and there's the other obligatory stuff in there too.
My thought is that playing with the EQ might help you out.
Happy Trails
Cynical One
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Post by ozboomer on Oct 28, 2010 22:24:18 GMT -5
...the Kjaerhus Audio Classic Series VST Plug-Ins still lurking out there it might be worth grabbing. Heh... The first VSTs I collected, those ones... and the graphic EQ from that set was the first thing I tried using to cut the low end out... but I get other issues with the graphic EQ; in short, the EQ bands are 'not quite right' where they need to be, given the standard response I'm seeing in the spectrum analyzer - that is, the EQ bands run at 20Hz, 63Hz and 200Hz... let alone that the silly sliders don't seem to 'lock' when you select the "Link" button, whether you have a mono or stereo sound source... or more accurately, they "link" the sliders only sometimes... I have to check that out more... Now, this was an interesting exercise... and I think it might be part, if not the whole problem. Basically, it might be something with JohnH's lead loading... or see his JFET Buffer and buffer cable posting. I have been using a (cheap) 5m lead between the guitar and the mixer input.. or directly to the UCA-202 interface.. or to the amp... and when I plugged that lead from the mixer, directly into the amp, I heard the same sort of "boomy" sounds. However, I then used my old Roland 2.5m synth lead (one of the non-noisy ones!) and Oooo! did it brighten up the sound a mite! So, I'll try that old/short lead into the mixer a bit later and see if we don't get an improvement in the sound. I'm guessing that what might be another contributing factor... Maybe the pickup output on the Monterey guitar is "low" (in keeping with them trying to make it a 'vintage'-style guitar)... compared to the output delivered from my Bullet which has the pickups installed described in my posting Probably MIJ Strat Pickups... and Their Use. They may only be ~5k in the resistance test but they seem to have a bit more *Oomph!* and they may have enough grunt to better overcome the capacitance in the longer lead, as the Bullet doesn't suffer from the "boominess" factor as much as does the Monterey. Funny, this... as I've been getting frustrated with all the silly levels and combinations of things I'd been using lately. I originally had: Guitar (and its volume control) -> vAmp2 -> BX-600 Mixer -> UCA-202 -> Cakewalk. That gave me no less than 7 points where I needed to adjust input level. Pffft! So, it motivated me to start on an old project to have a go with one of JohnH's buffer/booster circuits... which I'm in the middle of constructing now. So, even more reason to get on with my soldering, eh? Oh... and even more important, I guess -- to realize that there IS a reason why some guitar leads run at $60-$80 instead of $6. I guess I'm living in the past or something but I guess this issue with sound/cable loading/etc almost justifies spending *something* more than $6 for a lead... I think I'll have to play with my head a lot more to overcome THAT lil' obstacle... and lash out some decent $$$ on one cable. *mutter, mutter*... How much would *you* (working musicians) pay for a 5m cable? Thanks for the pointers, though... They've obviously identified a significant factor...
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Post by ashcatlt on Oct 28, 2010 23:35:55 GMT -5
Wow that's weird! I think there are a number of things going on here, and I don't know exactly how much any single one is contributing to the specific issue you're trying to address here. We haven't yet asked which pickup you're using? Is it at the neck position, or closer to the bridge? We also haven't mentioned much the frequency response of your playback system or the acoustics of your listening environment. Have you tried moving around the room, or comparing to other recordings with which you are familiar? I have to say that on listening through the studio headphones I've been using for 15 years (which have a known deficiency in the very low end of the spectrum) this actually sounds pretty good on it's own. It would need some hi-passing to fit into a mix with things like bass and drums and other low register instruments, but it's pretty okay on it's own. Before I downloaded, listened to, and analyzed the file, I looked at your screen shots and thought that it looks like you're high-passing right around the point where most guitars stop providing meaningful signal. Especially when you've got a passive guitar plugged into a low-Z mixer input, I wouldn't expect you to hear anything above 8K except noise. So, if you pull out all of the wanted signal with the filter, then gain it back up to get the sample somewhere near volume matched with the "before" sound, you'll end up back with the same sound. Of course, that only works if this filter shelves out below the graph. A true high-pass should show a smooth curve down to 0 Hz, but I suspect your filter cheats and just plateaus off at a straight line once it's attenuated to a certain point. If you look at that plugin, you'll notice that it's got a parameter there marked "Range" which is set to 24db. I don't know for sure if that simply determines how far the graph shows, or if it describes the boost/attenuation limit for the filter. When I run frequency analysis in SoundForge, I find that when comparing the "After" to the "Before", there is a bump to the frequencies around and above 8K, with a bit of a dip just below there, and then it comes back up very close to exactly the same. If I was correct about the shelving action, though, this bump should be somewhere close to 24db, and it's really only like 5db. Which leads me back to the idea that somehow this is not representative of only what is coming out of the EQ plugin. That somehow you've managed to record a mix of the dry signal with the filtered signal. Whether this is a software malfunction or user error (or some combination of both) remains to be seen. Did you record the file and then apply the processing, or did you apply the processing during the recording somehow?
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Post by ozboomer on Oct 29, 2010 3:16:16 GMT -5
We haven't yet asked which pickup you're using? Is it at the neck position, or closer to the bridge? We also haven't mentioned much the frequency response of your playback system.... Well, I'm generally trying these things out using the middle pickup or the bridge+middle combination. Playback environment? Ohhh, it's nothing flash -- Photo: 1023x545, 210k -- but it is more-or-less consistent. Hmm... This is where I see the "personal taste" thing coming in, I think. You like the sound of it, c1 is thinkin' it's a bit "bass heavy". Some of the original thinking I'd made before posting the question was about how I can fiddle this raw sound to better sit in a mix... hence, I was trying to use the VST filter to get rid of the "extra low end"... but I kept finding that the VST did something "in theory" (by what the software was showing) but when it came to listening to what was coming out the speakers, it didn't sound too different... hence, confusion reigns. [...some ashcatlt techy observations and musings...] Ya, I'll go and check that out.. There's so many "re-plugging" of inputs to outputs, etc in VSThost that I'm certainly not 100% sure that what we hear at the speakers and/or in the recordings is just from the VSTs and there might be some original signal in there too.. VSThost has its own, built-in "record what you hear" -type of thing and that's what I used to make the initial recordings. Thus, the filter processing, for example, happened at recording time; it's not like I applied any "off-line" processing. Off to investigate some more...
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Post by cynical1 on Oct 29, 2010 8:24:13 GMT -5
I didn't say I didn't like it...I just found it to be a little thicker then what it sounded like you were looking for...
The best way to track this down is process of elimination. It comes down to eliminating as many things from the chain as you can, then adding them back in until the boominess re-appears, then you've found your culprit.
This is why I mic everything whenever I can...
HTC1
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Post by JohnH on Oct 29, 2010 14:24:42 GMT -5
Hi Oz - I had a listen to your sounds. Actually I quite like that thick sound, I wouldnt mind having it on a switch. But its not a classic spanky Strat sound!. Not ideal for practicing your 'Chicken Picken' but might be just fine for 'Humongously-scary-giant-Ostrich Picken'! A also grabbed the mp3 and entered it into Audacity to look at the frequency response, and you can see the strong overall fall with frequency of the order of 10db per octave from the low E upwards. I did a similar check on a couple of my samples where Im just having guitar, buffer, pc line in, Audacity, and I see a series of peaks at about the same level up to about 700Hz. See my LP scheme thread - these sound quite bright, even from an LP. Id recommend a similar test, since it eliminates most of the processing variables. The buffer can be a switched-off pedal (non true bypass), or a JFET type of circuit. cheers John
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Post by gumbo on Oct 30, 2010 6:04:31 GMT -5
Down Here, that's " Humongously-scary-giant-Emu Picken'! "
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Post by ozboomer on Oct 31, 2010 0:35:53 GMT -5
A bit of joy to report today... As this "boominess" was getting on my nerves.. and following some discussions with some of our learned GuitarNutz colleagues, I decided to try getting back to basics with the connections today (details to follow)... ...and as I've mentioned previously, I finally got stuck-in and finished constructing a simplified version of JohnH's JFET buffer/booster (that has no variable output and only a 2x to 3x gain) this afternoon... Now, after combining these two notions... well, the results are like chalk and cheese... Really. There is still some work for me to do, methinks, regarding the application of VST effects... but to start with, I made a simple demo recording. For the first portion, the signal path was: Guitar -> UCA-202 interface -> Audacity. The second portion signal path was: Guitar -> buffer/booster -> UCA-202 interface -> Audacity. Note that this was done with the same "troublesome" Strat that I was using at the time I started this thread... and also note that I have purposely not fiddled with the levels of the recordings (too much!) to illustrate the change in output level -- Beware! the 1st portion is quiet, the 2nd portion is significantly L-O-U-D-E-R! soundclick example - a demo of me (poorly) playing the troublesome Strat, before and after including the buffer/booster. Not bad, eh? ...and other than some design time and a couple of hours of soldering, etc, it cost less than A$20, with die-cast enclosure included. Once again, we bestow our undying gratitude to JohnH for his significant contributions to us all John Edit 1-Nov-2010: JohnH posting reference was wrong. Fixed.
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Post by JohnH on Oct 31, 2010 3:21:50 GMT -5
Nice work - and that buffer/booster is giving a good clear output and a useful but not exessive boost.
One thing I just did that is instructive, is to import your MP3 back into Audacity, and use the normalise effect to set both parts back to the same level - then you can really judge the change in tone. But both samples seem to have put paid to the boom, and the buffered one is also preserving all the zing of your Strat output.
Now youll have to be called . aka, 'oz zinger'!
cheers John
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Post by cynical1 on Oct 31, 2010 10:21:29 GMT -5
Man, night and day. Very nice work. +1 for the transition. The one thing I noticed in your first .mp3 file was the amount of noise. ...not to be rude, but it sounded like it was recorded downstairs from a tap dancing school across from the "L" tracks. For those of you not from Chicago - The "L": See Blues Brothers for example.With JohnH's magic box the sound is stunning, and the noise is gone...like you moved out to the country... Your guitar sounds much better and the boominess is history. I'm going to have to read up on that little device. Good work. Happy Trails Cynical One
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Post by ashcatlt on Oct 31, 2010 11:07:27 GMT -5
I haven't listened yet because it wouldn't do any good here on my phone. I did notice that both links seem to go to soundclick. I was hoping to get a look at that pedal, but...
There pretty much has to be a couple of capacitors in the signal path there. I'd guess that JohnH would have chosen values which wouldn't interfere with the normal guitar range, but they would be filtering some of the subharmonics and subsonic junk. More importantly, one or both of of those caps could be changed (either permanently or in some switching arrangement) to help taylor the bass response.
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Post by ozboomer on Oct 31, 2010 12:47:57 GMT -5
Even though JohnH has explained this style of thing a few times, for completeness, I'll add my take on the design here, albeit an express version ( hey, it's 4:20am and I'm enthusiastic about getting the details OUT there )... The design:The wiring (note the jack/power connection details are not shown) :Photos:Notes:- The voltage at the drain on the JFET has been set to 5.3 Volts
- The 5k trimmer I have in there is very sensitive. I wasn't brave enough to take it through its entire range (heck, I didn't want to risk blowing it up)... but barely a slight turn on a screwdriver shifted the voltage at the drain from 5V to 6V; it took a minute to get it to 5.30V.
Enhancements (maybe) :- Include a power LED on the enclosure (although, I fear the current drain on the LED would be more than that on the buffer/booster)
- It might be handy to have a bypass switch in the circuit... but I think I'll always have it 'in-circuit', at least for recording
- JohnH's original design(s) had a variable level for the output; I specifically was trying to get rid of all the extra level controls in my application of the circuit, so I dropped that feature here
More details and background are available in JohnH's posting JFET Buffer and buffer cable. Hope this helps, folks. John
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Post by ozboomer on Oct 31, 2010 12:54:32 GMT -5
Oh... As c1 says, the noise in my original recordings has always been a bind... but I haven't checked that detail out with the buffer/booster in-circuit through the VSTs yet.. I'll grab a bit more ZZzzz first John
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Post by JohnH on Oct 31, 2010 14:48:06 GMT -5
nice build and write up (+)! Thats a good building block for other circuits too. On the cap values, the input side will deal with anything audio range, and roll off below that, the output impedance is about the value of r2, ie 10k in this case. With the 330nF cap, it is fine for drivng any kind of high impedance input, and with a guitar, lower impedance inputs down to about 50k. Below that, a source follower buffer on the end and a larger output cap might be advisable, to get output Z down to about 2k.
cheers
John
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Post by ozboomer on Nov 2, 2010 0:42:24 GMT -5
As this lil' buffer/booster makes my recording life closer to a joy now, I've been re-working all the connections in/out of the computer this afternoon... and I found a little something of interest... ...Which leads me back to the idea that somehow this is not representative of only what is coming out of the EQ plugin. That somehow you've managed to record a mix of the dry signal with the filtered signal. Have a look at the picture on this web page for the Behringer UCA-202 Audio Interface, which is what I'm using at the moment... and you'll notice a little switch (or a label, at least) at the top-left corner of the unit that says "Monitor OFF - ON". So what do you think!? It was turned ON, so the input was being copied directly to the output. I woke-up to this when I had everything turned off on the PC - mixers, audio software.. even the soundcard was taken out of the computer's configuration and I could still hear the guitar being amplified some when I played it... So, turning that monitoring OFF, I now only hear what's going through the computer/VSTs, etc. What comes through the computer speakers certainly sounds more "lightweight" now... but I still have to deal with where I'm getting distortion sometimes... and how I can control that (guitar volume, primarily, I think, as the ASIO driver for the UCA-202 doesn't have any level controls, just off/on)... but seeing that what Audacity was recording was all 'internal' to the PC, I'm not sure it really explains the "boominess" in the recordings... although it WOULD explain the "boominess" I heard when I was listening through the computer speakers.. Anyway, I thought I'd better just make a mention of what I found... and let my lack of understanding(!) be a lesson to (older) younger players John
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Post by JohnH on Nov 2, 2010 3:47:41 GMT -5
Hi oz - I had a look at that interface unit, and one thing I see from the manual:.... www.behringer.com/EN/downloads/pdf/UCA202_P0484_M_EN.pdf....is that it has an input impedance of 27k. The booster seems happy driving it, but this fairly low impedance would explain the more muted sound when you plugged the guitar straight into it. Similar would likely occur if you put the guitar straight into the BX600 mixer. Actually, I just did a v simple spice model of a 10k output driving a 27k load through a 330nF cap. You lose a about 3db of signal overall, but is is very linear across the frequency range, down to below 50Hz, before you lose more than an extra 0.5db. In other words, its working well. John
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Post by ashcatlt on Nov 2, 2010 11:44:01 GMT -5
Well, that's a step in the right direction! I think there must be some similar kind of bypass thing happening in software, but I don't know where to tell you to look. I don't use Audacity or VSTHost, and I'm not sitting at your machine. These things can be frustrating sometimes. Stick with it, and you'll get it figured. Something I noticed in the manual is that some of the specs (max input/output, THD, crosstalk...) are specified in dbV. This indicates that it's intended to integrate with consumer level equipment with nominal levels at -10 dbV - about 0.447V Peak. This is likely where you're getting that distortion from. If you have a manual or a link for your mixer we could check to be sure, but it's probably set up to run at pro levels with nominal (0db on it's VU/led meter) at +4dbu - 1.737V Peak, about 4 times as much. Note that these are different scales - the big "V" and the little "u" denote different reference levels. (Line Level via wiki) What's important, though, is that your interface wants no more than 2dbV. Not sure if this is the point where the analog circuitry starts to clip out, or if it represents 0dbfs (yes, another db scale - digital full scale, this is the top of the digital meter "all bits on"), or possibly both. 2dbV is 12db above the nominal level at -10dbV, or about 4 times the voltage. So a level reading 0 on the VU of the mixer hits that threshold. JohnH hasn't specified his circuit for a nominal level, and it's hard to say what exactly you'd be getting out of it without knowing a bit more. That pedal is capable of getting very close to 9V with a suitable input and proper gain settings. A hot humbucker would be able to hit 1V or more without any gain. You might want to look into tacking on a "recording pad" at the end of that buffer circuit. Maybe make it switchable so you can still use the booster to push the front end of an amp when desired. This will have an effect on the output-Z of the booster pedal, and I'd have to defer to JohnH for appropriate values.
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Post by JohnH on Nov 2, 2010 14:46:35 GMT -5
If you are getting clipping in the chain, then maybe some control of the gain is needed. The 100k volume pot on the output should work, unless the clipping is generated by the booster itself.
Thus circuit is capable of a voltage swing of about +/-3V peak, and has a gain of about 3, depending how the trimpot is set, which is determined by the need to bias the JFET correctly, which is quite a variable item.
I think this is a good little box, but now you are on a roll, maybe what you really need is an even simpler x1 buffer instead? Thats what I use on every active circuit I build, and its the 'source follower' JFET design which you can see several places on my buffer thread. It has no gain, so its not a booster, but it has just as high input Z, lower output Z and greater output voltage swing headroom, and possibly lower current draw. It will give you the same tone as the booster.
John
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Post by ozboomer on Nov 2, 2010 21:24:02 GMT -5
If you are getting clipping in the chain, then maybe some control of the gain is needed. The 100k volume pot on the output should work, unless the clipping is generated by the booster itself. Ya, but the intention was to get away from having to deal with multiple controls of level and gain when I mainly want a clean, higher-level signal. ...and given that I will be/have already refitted my guitars with some sort of "treble bleed" mod, I'm just as happy to drop the volume on the guitar a little if there's some clipping/distortion of the signal, I think. Yes and I was already thinking of that(!)... but going the breadboard route for now, just 'coz it would be an experiment rather than something I need right now. I opted for the buffer/booster ("buffster?") as all my guitars were just too low-level that I couldn't get anything recorded without a lot of volume (and that meant noise, too)... so I've solved that problem now. Anyway, one thing I was going to check.. According to some of the other discussions elsewhere about JFET buffers/boosters, this circuit would probably draw maybe 0.5mA (I know, I know - I could just measure it.. Pfft!). If I did one of my mods above and added a "power-on LED", I'm trying to remember.. but I think the current would need to be maybe 5mA to drive a 3mm LED. D'you think it's a silly idea to add it in and cut the life of the battery by 10 times!? It's just that in the half-a-dozen times I've used the box since the weekend, I've left the silly thing plugged-in (and therefore, ON) for probably a few hours more than necessary (distracted me)... and having the LED in-circuit would help alert me... I think. O'course, I could just let myself get used to how the box works, I guess...
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Post by JohnH on Nov 2, 2010 21:47:39 GMT -5
I think you can get away with much less than 5 mA, especially wit the bright little blue ones from Jaycar. But I agree about the benefit of having the LED being moot - and I dont build them into my boxes unless there is a foot switch that does something, and I want a visual indication. If I put in an LED, I also add a 2.1mm Boss-style power socket. I also add an extra resistor and cap to decouple the pulse of switching the LED from the signal circuitry. You probably have seen this before, but this overdrive is basically two of your boosters and a buffer, end to end, with a volume control, footswitch and LED. guitarnuts2.proboards.com/index.cgi?board=fxschemes&action=display&thread=4987&page=1John
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Post by ozboomer on Nov 4, 2010 4:24:34 GMT -5
I think you can get away with much less than 5 mA, especially wit the bright little blue ones from Jaycar. I was having a look at their web site... but all the blue/3mm LEDs I could find there wanted 15-20mA or something... or so the web site said(?) Anyway, even without the LED display, how will I know that the battery is giving-up? (other than the obvious indicator of -silence-)... I'm guessing that maybe the sound will distort with low-level signals..? ...or if I use an alkaline battery, quick, sudden silence will be the indicator then as the alkalines tend to go flat.. *Bang!*, don't they? Also, I think I'll make the executive decision and put a switch of some sort in this box -- After seeing how I'm liking to use it, I think I'd probably leave the lead plugged-in all the time, so I really would do better to have a switch on the box... but I'll keep experimenting some, too -- There's probably a "good" and "better" way to do the switching...(!) You betcha.. but I tend to be a clean freak in terms of the sound coming from my guitars, hence I went searching for the simpler boosters and such... ...but y'can never have too much info on all this (at least, until you start getting confused). Fanx! again... John
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