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Post by rabidgerry on Jun 25, 2010 11:10:54 GMT -5
Oh yeah, the band I'm in, we had a Soundtech powered mixer, we just sold it on recently as it wasn't loud enough for us, but it was feature packed and didn't seem to be any trouble, despite some quite shaky pots and a set of very complicated effects selection switches (4 switches had to be selected in specific combos to aquire presets).
I liked it, but it was heavy!! I hope I win this Soundtech, I can't afford to really fight for it however so I hope no one else is interested in it.
[glow=red,2,300]edit[/glow]
Incase you read this message first, check back the previous page as my reply to your mamoth message is back there.
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Post by ashcatlt on Jun 25, 2010 11:30:08 GMT -5
10K is a bit higher than I'd expect to see at a mic input, but it's not way out of bounds. A while ago I googled for "typical" mic pre numbers and came up with a wide range: from about 100-2K.
Your idea with the passive DI is pretty good (you'll need two, right?) but keep in mind that the DI doesn't have an impedance of its own. The transformer inside "reflects" an impedance that is some multiple of the in-Z of the mic pre to which it's connected. This multiple is a function of the turns ratio on the transformer. In my research I came to the idea that it's typically something like 133. So 10K x 133 = 1.33M.
I could be wrong, but I suspect that the issue with the HC is that it's a passive filter without any active buffering on the output. It is, isn't it? Haven't looked at it in a while. Well, if it is, the load impedance will have some effect on that filter's behavior. Cutoff frequency, resonance, something might be thrown too far out of bounds by an in-Z which is too high or two low.
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Post by sumgai on Jun 25, 2010 13:14:41 GMT -5
rg, I'm still outside working, just came in for a brief respite..... gotta keep the other half happy, as we all know.  I'll get back at it this evening with more details, but for the nonce, I'd say "safe" is that no damage to any of your equipment will occur if you mistakenly mismatch input and output impedances. The only think you'll note will be distortion that you didn't plan on.  For purposes of testing which unit should be placed where in the chain, try to keep your signal as clean as you can (meaning, free of intentional distortion from any effects, etc.). It can get difficult to distinguish one kind of distortion from another when they're all mixed up together at the speakers...... That's it for now, but in the immortal words of the Governator - I'll be back! sumgai |
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Post by ashcatlt on Jun 25, 2010 13:56:16 GMT -5
You asked how to measure the Out-Z of the HC. I've never done this, here's what I've heard:
Get out your test tone generator and your multimeter. Set the test tone at 1KHz and run it into the HC. Measure and note the AC voltage at the output of the device - from tip to sleeve of the jack. Now find a pot with value somewhat greater than your expected impedance. Wire it across the output Jack with one outside lug to the tip and the other to the sleeve. Run the test tone and measure between the wiper and the sleeve lug. Turn the pot down until the AC voltage is half of your initial reading. Now carefully remove the pot from the circuit with turning the knob. Measure the DC resistance between the wiper and former sleeve lug. This will give you a "close enough" reading for the nominal out-Z at 1KHz.
Pretty sure you could use a computer as both test tone and voltage meter, but you'll need a meter for the resistance.
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Post by rabidgerry on Jun 28, 2010 8:44:15 GMT -5
10K is a bit higher than I'd expect to see at a mic input, but it's not way out of bounds. A while ago I googled for "typical" mic pre numbers and came up with a wide range: from about 100-2K. Your idea with the passive DI is pretty good (you'll need two, right?) but keep in mind that the DI doesn't have an impedance of its own. The transformer inside "reflects" an impedance that is some multiple of the in-Z of the mic pre to which it's connected. This multiple is a function of the turns ratio on the transformer. In my research I came to the idea that it's typically something like 133. So 10K x 133 = 1.33M. Well I have a stereo DI box so I wouldn't need two, that means its got two channels. I'm totally bewildered by the DI thing not changing the impedance, I thought thats what they did. Obviously not  or passive DI don't change impedance and active DI do. I could be wrong, but I suspect that the issue with the HC is that it's a passive filter without any active buffering on the output. It is, isn't it? Haven't looked at it in a while. Well, if it is, the load impedance will have some effect on that filter's behavior. Cutoff frequency, resonance, something might be thrown too far out of bounds by an in-Z which is too high or two low. I dunno what the HC is, people who have researched it claim a lot of things, but tend to never own one. I read something about it filtering then re-mixing parts of the signal bla bla bla all I know is it does something. Oh and I missed the dam SoundTech Equalizer, someone else outbid me and my tiny budget. I'll try my hand at others however. I'm not sure I can be bothered testing the impedance of the HC now. I have a tone generator built into my lead tester (made by behringer) but it sounds a little over my head. May be I will try......... |
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Post by ashcatlt on Jun 29, 2010 17:43:50 GMT -5
I'm totally bewildered by the DI thing not changing the impedance, I thought thats what they did. Obviously not or passive DI don't change impedance and active DI do. Now, I didn't say the passive DI won't change the impedance "seen" by the pickups, I said that it doesn't really have an inherent impedance of its own. You need to know the both the turns ratio of the transformer and the impedance of the mic pre to which it will be attached in order to know exactly what kind of load it's going to present. |
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Post by rabidgerry on Jul 1, 2010 11:48:37 GMT -5
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Post by rabidgerry on Jul 1, 2010 12:58:52 GMT -5
On my investigation it seems this KAM EQ152 is pretty much a Peavey PV215 in disguise.
and if it is, the unbalanced operation is 20kohm impedance. I ask is that to dangerous to plug into after it goes through a DI box?
Also, in the HC instructions using the HC into a DI is fine apparently, just thought I'd through that in there.
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Post by ashcatlt on Jul 1, 2010 15:30:00 GMT -5
It certainly isn't dangerous in the sense that you or any of your gear will be damaged in the process. I'm really just going by what you've said about the "requirements" for the HC and my speculation as to why they might specify such a window.
I don't rightly remember where I came up with the 133 x impedance factor for the passive DI, and I don't know anything about the one you're using, but if it's even close, you'll end up with over 2M when connecting to a 20K line input. This might mean that the HC won't work exactly as expected/intended. You can't know if it's a deal-breaker without trying it.
I think this has gone too far, and is leading to a bit of frustration on your end, so I'm going to come out with my opininion on the Harmonic Converger:
There's nothing magic about the Harmonic Converger. It's a 2 pole low pass filter with the ability to mix in the original signal to taste. Somewhere I found a frequency response chart for it. I use EQ ITB for much the same effect and it does usually work wonders in making my amp sims sound just a bit more realistic.
I can't see any reason you couldn't replicate this curve using the top few bands on that 15 band EQ and just take the HC out of the picture altogether. Your processor will have no problem driving this 20K line input, and you might end up with some hair left. You could at least try it. Maybe find a nearby music store with a good return policy to experiment with, then when you find out that I'm right, return the thing and buy something similar from your online discount outlet of choice.
Edit - can I ask exactly why it is you don't want to put the EQ before the HC? While I still think it would involve one superflous piece of gear, it would alleviate your concerns.
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Post by rabidgerry on Jul 2, 2010 11:00:23 GMT -5
Ok, here is where we are at, I had the best tone I could have without the HC.
I got the HC things got really good.
And now I'm fine tuning things due to the fact that I don't use the same sorta speakers either side of my stereo setup and since I make most of my patches up at home, I have a hard time matching them on my louder setup due to more and larger speakers, so to save me EQing everything from scratch on my GT-6 I figured use an external EQ to help match things and then I could set and forget.
The HC is now integeral to my setup, I'd never get rid.
The window I specified was something I asked the designer about and he told me what kind of impedance the HC was designed to have on its outputs. When I looked at the instructions last night again, it simply says; the HC was designed to see a relatively high impedance at its outputs, to interface with a low inpedance inputs, use a di.
I have read the thread your talking about with the graph display on it of a frequency chart for the HC, even this thread still suggests its not quite as simple as using an EQ.
So an extra EQ device is purely for me to be able to get closer to my home sounds, as when I play using the super loud set up I get insane bottom end and midrange, the GT-6 has global bottom end and top end settings so this allows some adjustment however more are needed in the mid range spectrum, hence EQ. I understand why you suggest to ditch the HC but I'd prefer not to since it delivered on what it was supposed to do and I don't wanna go fulling around with fizz elimination myself, it does it fine by itself.
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Post by rabidgerry on Jul 3, 2010 10:18:34 GMT -5
I might give your idea a try after all.......of course I need to get a 15 band EQ!!!!!!!!! So the few options I have on ebay I'm waiting basically to see if I can win one. This means I can retire the HC for home use since a rack system is to big for my living room!!
I'm gonna stress however the HC inpedance numbers I've been trying to meet where purely on the basis that the HC is designed to work with relatively high inpedance at its outputs and the negative effects that are said to occur pluggin it into too low an input may make it sound "too dark". So that may have been resolved by adjusting the amount of effect I have on the HC, and by turning down its mix pot I could control any negative effects, but hey who knows!
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Post by rabidgerry on Jul 5, 2010 10:46:56 GMT -5
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Post by ashcatlt on Jul 5, 2010 14:54:37 GMT -5
My guess:
There's 20K between + and ground, and 20K between - and ground, for a total of 40K between + and -. When you plug in a TS cable, the - is shorted to ground, leaving only 20K.
I've got a mono 31 band DOD graphic that I've been using for years. Mine's got variable LPF and HPF, which I have often used to "bookend" the audio signal. I've had a number of DOD pedals over the years, and their stuff is pretty much workhorse kind of gear. As long as it works when you get it, it should last you quite a while.
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Post by rabidgerry on Jul 15, 2010 9:24:18 GMT -5
Ok I'm pleased to announce my DOD Equalizer can tolerate the HC no problem with no affects either good or bad so all this impedance mayhem was not relevant after all.
ashcatlt my DOD only gots a LPF, no HPF, what frequencies should I turn down at the top end to bookend it so to speak?
I'm a we bit bothered the EQ has no XLR'S but sure nothing is perfect. I thought I was sold a dud when I read the back and the power supply said 120volts!!!!!!
UK its 240!!! I near hit the roof and contacted the seller to give him a chewing!! However I plugged it in and it din't blow up, so I'm confused. It heated up a bit though, ashcatlt does your DOD heat up much?
Also what does it say on the back of yours in terms of power supply? So confused it says 120 v - 100 v on my one.
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Post by D2o on Jul 15, 2010 10:19:37 GMT -5
RG … I’m no electrician, but plugging an electronic device that is designed for 120V into 240V is not jumping out at me as a great idea. A scene from a movie called "Leap Year" springs to mind ...
Can’t you buy an adapter of some kind?
D2o
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Post by ashcatlt on Jul 15, 2010 14:35:09 GMT -5
I thought y'all had funny shaped outlets where a US plug wouldn't fit. Aw well. I'm in the US, and never even bothered to look at the power requirements for the thing. I'll try to check it out tonight when I can get to it. Don't recall it ever being particularly warm, but it has always been racked up with everything else, so I didn't have much opportunity to feel it.
From what I recall of the HC frequency response, it cuts off at about 4-5K, with a little bit of a bump back up (dependent on the mix setting) around 8K. I'd start cutting above 4-5K and definitely kill everything starting around 10K on up. Of course, it's best to just use your ears and play around till it sounds right to you.
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Post by rabidgerry on Jul 16, 2010 10:12:55 GMT -5
I haven't yet distinguished whether or not my unit is 120v or not. I'm pretty sure it would have died in the "blown up sense" had it been fed 240v and not been designed to take it. At least thats what happens amps. I could by an adapter but the thing is, I'm gonna bust this seller up if he has sold me a unit not designed for uk voltage, so if I break it its his fault, for a start in the descrption it clearly says [glow=red,2,300]240v powered mainS!!!!!!!![/glow] I played it all last night, and GOD DAM!!! It cleaned up a lot of crap!! I was getting tonne and tonnes of rumble and thats all gone with everything down past 100k. Hi end sounded ok to me until later in the evening but I put that down to ear fatigue - what say ye all on this theory?  ? I had to reduce minmal amounts of 240k and 400k and bump up the gain a smidge (i mean a very small smidge) and bump up the 100k a tad since I'd taken a lot of the bass away already but need good bass back in the sound for body. I'll probably be tweaking little bits from now on. ashcatlt lemmy know what it says on your unit asap, if I have to buy an adapter I'm totally selling this thing on cause I don't need to buy a freakin adapter or had planned to spend the extra money and I was unknowingly bidding on a unit that clearly said it ran on 240v!!!! I have to admit, throwing a rack EQ between my amp and my effects unit is a good idea, since I bypass by 2 amps preamps by pluggin into the return socket I've no global EQ for adjusting to a room enviroment or whever I may be so i'm now able to have flexibility!! ;D [glow=red,2,300]edit[/glow] ashcatlt it didn't come with a power cord so I used one of my own with a 13 amp fuse in it. You guys have plugs with two prongs, are plugs have three and the middle is an earth, you guys run on 120, we run on 240!! |
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Post by ashcatlt on Jul 16, 2010 12:11:17 GMT -5
Well, I thought my EQ was here in the shed, but I guess it must be over at the studio. I'll be there tomorrow and try to remember to check it out for you. I'm pretty sure mine has an attached 2 prong power cable.
We have 3 prong thingies over here, too. For some reason we can't figure out, it's not required on most devices, though. I thought that the prongs on your devices were shaped and/or spaced differently, so that it required some form of adapter or modification to even fit one of our plugs in your holes (or vice versa). I guess since you're using your own plug, though...
I don't mean to get off on a rant here. You have to do what you have to do to get the tone you want. If it sounds good, it is good and all that. I've always wondered, though, why a person would use an amp/cab sim in order to get the coloration, filtering, and resonance of a specific guitar cab and then run it through some other guitar cab with its own coloration, filtering, and resonance. Just seems counterproductive to me.
Apparently this is not intuitive to most other guitarists, but I have always assumed that the best amplifier for an amp sim is something as flat and clean as possible - like a PA, keyboard amp, or even some bass amps.
Some of these things do put out some high-frequency hash which you wouldn't get out of a real guitar amp, and that's what the HC is for, I can dig that even if I wouldn't pay the price he's asking for the thing. I find myself wondering, though, if you're not using this new EQ to make up for some of the deficiencies in the cabinet you're using.
BTW - you can take out most of the "k's" in your post above. I don't think that even dogs can hear 240K, let alone 400K!
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Post by D2o on Jul 16, 2010 12:34:43 GMT -5
FWIW and all that ... (EDIT: WARNING - NOT WORTH MUCH! BAD THEORY FOLLOWS ; IGNORE IT AND SEE RESPONSE FROM JOHNH)RG, Is the image below what an adapter would need to look like if someone needs to plug into Ireland? If so, and you have been able to plug your stock electronic device into your stock wall outlet without such an adapter, I wonder if the device would likely have been designed to withstand the power supply commonly available through the outlet that it actually fits into (in your case, 240V).  You can see from the image below that you can’t plug a North American appliance into the outlet shape above … it won’t fit.  Does that theory sound reasonable? ... or is it just a weak and potentially deadly theory? D2o |
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Post by JohnH on Jul 16, 2010 16:29:16 GMT -5
If the unit says its for 120v supply, do not plug it into 240v!!!The shape of the plug does not relate to this. Some devices are designed for a range of voltages, maybe 100v to 240v (such as laptop power brick), but it will say so on the back. You can buy a small transformer however, to step 240v down to 120v. This is not the same as just a plug adapter however, which does not convert the voltage. You might find more insight in the owners manual, which if you don't have it, can be gotten here: www.dod.com/supportpages/lit.htmI tried to download it, but my pc refused. cheers John |
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Post by D2o on Jul 16, 2010 16:56:35 GMT -5
Thanks for the clarification, John.
D2o
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Post by lpf3 on Jul 16, 2010 17:03:39 GMT -5
I've accidentally plugged 120V power tools into 240V outlets (on jobsites).
They run really good for a little while.
Then they cost money.
;D lpf3
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Post by sumgai on Jul 17, 2010 1:30:09 GMT -5
The bottom line has already been stated - if the unit is plugged into twice the expected voltage, the lifespan drops to zero. Said lifespan may be mitigated by the fuse, but that just proves the point. If rg has been playing it, with any kind of power cord, on his home country voltage (240vAC), and it's still alive - then it's been modified from the orignal 120vAC to accept 240vAC, pure and simple. The eBay seller may or may not be the modder, doesn't matter. What matters is that whoever did the modding didn't complete the job by attaching some form of permanent label denoting the change - that's bad berries, in my book anyways. HTH sumgai |
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Post by rabidgerry on Jul 17, 2010 6:15:26 GMT -5
Ok I'm gonna check this out further, I'm really angry about this now.
Just info for yall, my EQ unit didn't come with a power chord, I need one of those chords that you use to plug in an amplifier with.
According to ebayer he has owned it since new, and since he's selling from the UK i'm assuming he's owned the unit and used it here in the UK. I'm e-mailing him right now. And I will also ask DOD.
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Post by rabidgerry on Jul 17, 2010 6:21:42 GMT -5
So confused now I've just read this "A front-panel rocker-type power switch shall provide visual indication with red marking. The power supply shall be internal with a thermally-fused transformer mounted in a low hum orientation. The transformer and primary side of the power supply shall be isolated from the secondary and electronics by means of a steel hum isolation shield. The power cord shall be detachable from an international standard IEC 320 power inlet receptacle. Unit shall be constructed to meet or exceed all applicable international safety and regulatory agencies. Unit shall be powered from 120 VAC 60 Hz (or 100 VAC 50/60 Hz, 230 VAC 50 Hz, 240 VAC 50 Hz). Unit housing shall be of all steel construction and shall be rack-mountable in an IEC standard 19" rack and shall occupy a 1U (1.75") rack space. An optional security cover shall be available. The unit shall be a DOD SR430QXLR or SR430Q Graphic Equalizer." on the link John H just posted to the maual for my model of EQ. The one listed is a newer version with XLR's but read what it says. www.dod.com/graphiceqs/technical/430ae.htm |
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Post by rabidgerry on Jul 17, 2010 6:31:16 GMT -5
the seller states he has used it with 240volts. I await a resonse from DOD.
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Post by sumgai on Jul 17, 2010 18:19:33 GMT -5
rg, Ah, I see it all now. As I interpret the literature, this thing apparently has a digitally controlled power supply that adapts to whatever is available from the wall socket. The idea was devised for the exact reason we've been discussing - there ain't no standards from one country to the next, and it's a genuine PITA to keep designing power supplies, one after another, for each country's requirements. So a "universal" supply was designed. The technology is not overly complex, but it does have a high-parts count, and that adds a bit to the price. Which explains why some manufacturers still don't use them. You should be able to use the thing with confidence. And didn't you just post that the seller is also in the UK, and he said that he'd been using it with no problems for some time? Seems pretty clear to me that this thing is either mis-labeled, or else DOD was modest in what to say on the label. But if it survives more than a few moments on 240vAC, then it's good, no matter what anyone else says. And the fact that it's working for you the way you intended is all the sweeter! ;D HTH sumga |
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Post by rabidgerry on Jul 19, 2010 7:47:22 GMT -5
rg, Ah, I see it all now. As I interpret the literature, this thing apparently has a digitally controlled power supply that adapts to whatever is available from the wall socket. The idea was devised for the exact reason we've been discussing - there ain't no standards from one country to the next, and it's a genuine PITA to keep designing power supplies, one after another, for each country's requirements. So a "universal" supply was designed. The technology is not overly complex, but it does have a high-parts count, and that adds a bit to the price. Which explains why some manufacturers still don't use them. You should be able to use the thing with confidence. And didn't you just post that the seller is also in the UK, and he said that he'd been using it with no problems for some time? Seems pretty clear to me that this thing is either mis-labeled, or else DOD was modest in what to say on the label. But if it survives more than a few moments on 240vAC, then it's good, no matter what anyone else says. And the fact that it's working for you the way you intended is all the sweeter! ;D HTH sumga Well I used it all Friday night and all Saturday afternoon and so far bingo!! I think your right also SG, and yes the seller did say he had it since it was new which I think could be near 10 years old and he said it worked fine. Its actually a really good idea I find. I've to correct a few things I've said in ealrlier posts, see next post. |
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Post by rabidgerry on Jul 19, 2010 8:10:42 GMT -5
I don't mean to get off on a rant here. You have to do what you have to do to get the tone you want. If it sounds good, it is good and all that. I've always wondered, though, why a person would use an amp/cab sim in order to get the coloration, filtering, and resonance of a specific guitar cab and then run it through some other guitar cab with its own coloration, filtering, and resonance. Just seems counterproductive to me. First up ash: Yes I agree do what sounds good to me, thats the best policey, I was only asking for a little guidance as frequency knowledge is something I'm just learning both live and for recording, I'm learning fast. I don't have a FRFR rig, so the next best thing or use I can do to help solve this is to plug into the return input on my amp which bypasses the amps pre-amp there for my amp sim is providing my pre-amp and the amp amp is providing the power amp. I don's use the speaker sims, and when I do its occasional. As you said about why filter stuff when your using amp sims and speaker sims to colour the sound, then I have to say why have an EQ on the pre-amp of any amplifier..........to tweak and refine. I will eventually move over to an FRFR rig or at least a stereo power amp and two 4 x 12" but when I get a job and get some money. At the mo I have to make the best of the gear I have happened upon over the past ten years. I ended up with the rig I have purely as, my Marshall was my first amp, then I found an extension cab for it allowing full 150watts, then last year I guy was selling a virtually new randal soldid state amp and 4x12" for £150 ($200) together which was so ridiculously cheap I had to buy it considering the guy was under selling by at least another £200. So I just ended up keeping it all and found running in stereo is good for me and helped guitar to beat our severly loud drummer!! Apparently this is not intuitive to most other guitarists, but I have always assumed that the best amplifier for an amp sim is something as flat and clean as possible - like a PA, keyboard amp, or even some bass amps. Totally, but I will get a PA at some stage, then keep one 4 x 12" and buy another and run amp sims without the speaker sims on. ;D Some of these things do put out some high-frequency hash which you wouldn't get out of a real guitar amp, and that's what the HC is for, I can dig that even if I wouldn't pay the price he's asking for the thing. I find myself wondering, though, if you're not using this new EQ to make up for some of the deficiencies in the cabinet you're using. BTW - you can take out most of the "k's" in your post above. I don't think that even dogs can hear 240K, let alone 400K! I made a massive error man, I mean to say 400hz and 240hz and when I said lowpass cutting of below 100 I mean hz again, I was still in OHM'S mode  I haven't fully cut of the 16khz, just dropped it by half. And to state one more time, the areas I have been working with on my EQ are not really affected by the HC, as before I got a HC I had the same problems, so I've got the HC and EQ for two different areas, but I can probably mimic the HC with my EQ now and use the HC at home on my other GT-6. SO for the record, I'm using to new DOD EQ to balance up my left and right amps, cutting all the unwanted rumble (of which I had loads despite dropping the BOSS's global bass) and also to cut bits and pieces through the low mid range to get closer to the sounds I have from my home set up which I think is the best for me!!! There I feel like I explained a bit better now  Hope it makes sense. Just wanna thank all those concerned for safety on that whole 240 - 120 volts issue, that why this is the best forum ever ;D |
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or passive DI don't change impedance and active DI do.
