Hello, I was wondering if someone could please shed some light on the subject of running a line out into another, larger amp. I have a Kalamazoo Model I with a line out, modified by Greg Heumann. If I run that amp, with the line out, to another harmonica amp, A BluesBox built by Randy Landry, will it sound ok? Will it sound horrible? The whole purpose of this is to get the tone of the Kalamazoo with more volume for the louder jams. I've certainly tried the line out into the PA, and that works great. I'm trying to come up with a solution in case that's not an option.
thanks in advance.
Last Edited by Minor Blues on Mar 21, 2016 12:13 PM
My understanding is you can run a cord from input 2 on the Kalamazoo to input 1 on another Kalamazoo or another amp. I'm not sure you will get a necessarily louder sound but you'll have a fuller, interesting variation.I am wondering if the amps are of different wattage/power will that make a difference?I'd like to try this too sometime. Perhaps people with better electrical knowledge will chime in on this thread.Can it be a lot louder this way? Like a 5 watt amp chained to a 25 watt amp? I have read you can get ground loop noises and phase problems with this setup though and I think the foolproof way to do it is with one of those A/B boxes like this one: http://www.radialeng.com/bigshotaby.php Not sure how much "louder" it ultimately is, though.
Last Edited by tomaxe on Mar 21, 2016 1:53 PM
It sounds like you're confused as to what I'm trying to describe. This is from Mr. Heumann's website:
Upgrades
These amps are great "straight out of the box". However there are some upgrades I've found to be worthwhile.
•Line Out - $49. Kalamazoos have great tone, and amazing volume for their size, but no 8W amp is going to win volume wars at a loud jam. The line-out is a high impedance signal accesible via a 1/4" jack, and the output is equivalent to that of a good microphone, so you can connect the amp to the house sound system (via high-Z input or DI Box) or another amp. This is no sterile-sounding pre-amp line-out. The signal is derived from the speaker side of the output transformer, so all the great Kalamazoo tone gets amplified. It really works! The Kalamazoo becomes an on-stage monitor but can be heard by hundreds, even thousands. A line-out is the optimal way to connect one amp to another. Using a "Y cable, "A/B/Y Box" or other cable splitter will cut the input impedance in half, doubling the load on your mic and altering its tone. The line out does not lower the input impedance at all. Cool, eh? (Thanks to Gary Onofrio, aka Sonny Jr. for his assistance in developing this circuit.)
Isn't this, in fact, a line out? Maybe I'm confused....
Try it! If the line out works on a PA (the XLR input) it should work on another amp. It works like a preamp pedal.. I have made a Line out on a champ and connect it to a Bassman. It sounded great. You have to be careful with the volume on the big amp from the beginning. Maybe you have to have the small amp (your Kalamazoo) on 3/4 of the volume you use to have . Then you turn up the big amp very vareful. If you get a loud hum there is some grounding issue and it's no good to continue.
Disclaimer. It have to be a real line out. Dont try to connect speaker jack to another amp.
Last Edited by arnenym on Mar 21, 2016 2:29 PM
re" input 2 on the Kalamazoo to input 1 on another Kalamazoo or another amp." this is a bad idea as it reduces the input impedance rather significantly - that will suck all the tone out of some mics.
You can ABSOLUTELY run the Kalamazoo line out into a bigger amp, I've done it many times. You will have to set BOTH amps a little lower in volume than you would if they were by themselves to avoid feedback.
@1847 - if there is some engineering definition of line out levels I'm unaware of them. I do know that, on something like a stereo receiver, a line out comes from the pre-amp circuit. I think SOME guitar (and even more likely, keyboard) amps may do this as well - however that would defeat the purpose on a Kalamazoo where the goal is Kalamazoo tone, just louder. The Kalamazoo line-out circuit I install, like most small guitar amp line outs - uses the output transformer output as its input, and a voltage divider network to reduce the signal level from something a speaker can handle to something an amp or PA input can handle. I've never bothered to measure the signal levels. I just know it works.
(I'm pretty sure you know all this too - I'm just trying to be as clear and transparent as possible. No rocket science here.) *************************************************** /Greg
Interesting info. Thank you. I am curious... let's say you had 2 kalamazoo amps, or two low wattage amps and you have no line outs installed. You can't just chain them with the guitar inputs, as Greg explained. Can you run them through a box like Lone Wolf's Terminator or The Big Shot and would it be significantly louder? I read somewhere that chaining 2 Kalamazoos would be a cool sound, maybe one with the Tremelo turned up....
maybe i am just paranoid, i killed a vintage output transformer just the other day. anyone who has owned vintage gear will typically grieve when a component wears out. like we have lost something of value, when in reality, everything eventually wears out and needs to be replaced.
i used both amps pictured above with the terminator pedal on sunday at a very loud blues jam. for the first song i used the champ by itself, no trouble being heard. the 2 nd song i had to kick in the other amp. worked like a charm.
one of the things i like about the lone wolf pedal is i can use a long mic cord. then 2 long cords to the input of the amps, which can be separated.
There are many ways to use two amps with one mic, and each has advantages and disadvantages.
1) Daisy-chain (mic in Input 1 of Amp 1, jumper Amp 1 Input 2 to Amp 2 Input 1 2) “Y-Cable” to split mic’s signal into 2 3) A/B/Y box to split mic’s signal into 2 4) Mic into pedal (that is always on) - THEN “Y-Cable” to split mic’s signal into 2 5) Line out from Amp A to Amp B 6) Mic amp A into Amp B
#1 is the least efficient as it will run the signal through multiple resistors and therefore rob the most tone from the element.
#2- works fine but the mic will see both amp’s input impedance in parallel. If both amps have 100K input impedance, the mic sees 50K ohms. If they both have 1Mohm inputs, the mic sees 500K. If the two input impedances are different, the actual formula is R1*R2 / R1+R2. Crystal and ceramic elements are much more sensitive to drops in input impedance than dynamic elements (like modern vocal mics, or vintage Shure controlled magnetic or controlled reluctance elements. )
#3 - these boxes are available in 2 flavors - passive and active. Passive means it works exactly like the Y cable, except that you can switch from one amp to the other or both with a tap of your foot. Active boxes actually “receive and rebroadcast” your mics signal - so it only sees the input impedance of the active box. Note that you could ALSO run your mic through any pedal that you like while it is ON- and it will have the same effect of isolating your mic from what’s downstream. In other words, if you go mic to delay pedal to Y cable or passive ABY box, you’ve solved the impedance dropping problem.
#4 - The pedal regenerates the signal so this gets around the impedance-lowering issue of 1, 2 and 3 above
#5 - - Many amps have line out circuits. These are electrically isolated from the mic so once again too-low input impedance is not a concern. However this usually adds to the overall gain of the system - you will get more volume but you probably have to turn both the 1st amp down from the max you set it at when playing it alone in order to avoid feedback.
I have yet to lose an output transformer or power transformer in close to 100 amps I have owned. As a rule every amp I buy went immediately to the tech for a full service/cap job reguardless of how well the amp functioned. My buddy in Georgia has lost two OT's in the last month because he is not a believer in servicing 50 year old amps that are working ok.
I know there are other issues that can take out an OT, but I am proof you can avoid it. The output transformer is the heart and soul of an amps tone, and you will not find a replacement like the original.
A replacement OT can sound great, but it won't sound like the original.
Last Edited by Harpaholic on Mar 22, 2016 10:53 AM
i am not sure what took out my tranny it may have been a combination of things. i just had my amp serviced, the caps were ok. i had a bad preamp tube socket, and i was running a 8 ohm speaker, the connection to the speaker was loose as well.
magnetic components made trannys for valco in the 50'S they claim they make them the same as they did back then. so in some cases it is possible to get an exact replacement.
what the heck am i supposed to do with the old one? i could have it rewound at mercury magetics. ---------- .
That loose speaker most likely fried that trany. I always solder mine at the speaker and make sure my jacks are tight and clean. I did blow one of the OT's on my Silvertone Six Ten at power up. That amp had recently been freshened. Those particular OT are notoriously small. Bummed me out big time. Mojo Tone had a replacement.
I wonder if you can keep that Kalamzoo tone if you line out to one of those powered speakers I keep getting spammed about? Seems like those things go on-sale every other day.
That would be pretty interesting, if it worked. A 60 yr. old made in the U.S.A. antique plugged into a piece of Chinese plastic.
@Greg There actually is an engineering definition for a line level audio signal. Its -10dBV ... you can google it and get the details but it amounts to about 1 volt peak-to-peak.
The following is not for you Greg, I know you already know this. Just thought it might help others:
I've modified several amps in my time to add line outs with a simple voltage divider across the speaker output. I have an oscilloscope so I can check the level to make sure its close to 1Vpp at the volume I expect to use it at. But if you don't have one, just start with something reasonable like a 1:10 ratio on the resistors (little resistor on top, big resistor on bottom. Then connect the line out on your amp to something that expects line level. Slowly turn up the amp and listen for distortion. If you have too much level, distortion will be heard quickly. If this is the case, increase the big resistor to reduce the level. The last thing you want is an amp with a line level output that is too hot - someone plugs it into a PA at a gig and blows the input on the sound board and is very unhappy! Another thing to remember with this kind of DIY line-out is that the line-out level will vary with the volume of your amp. Keep this in mind if your on stage using your amp as a monitor and using the line-out into the house PA.
I also sometimes put a capacitor across the top resistor (the smaller one). This rolls off the high frequency response. Every amp is different, you'll have to experiment with values to see what sounds good.
Lone Wolf's Terminator pedal will do the do for you. I've only run two amps through at home (it works great), but I did use the Terminator to run one line through my Kalamazoo I and the other into the p.a. at a gig and it worked great. I ran a Lone Wolf Harp Break from Terminator to p.a. for a little grit. Worked like a charm. ---------- Ricky B http://www.bushdogblues.blogspot.com RIVER BOTTOM BLUES--crime novel for blues fans available at Amazon/B&N, iTunes, iBook THE DEVIL'S BLUES--ditto HOWLING MOUNTAIN BLUES--Ditto too, now available
