KATANA - Speaker Swap in Katana 50 combo

Started by Elantric, April 21, 2017, 02:02:50 PM

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Elantric

https://www.thegearpage.net/board/index.php?posts/23976465/



Michel347 wrote>

That's it, I loaded the new speaker, holly molly, now my KTN50 has balls, talk about thump in the chest.

This weekend will be a lot of fun, less for the wife :)

admin

#1
CAUTION - If ANY Speaker (+) wire or (-) wire touch each other - or Chassis ground while powered ON -  - you fry the Katana Power amp

( BTW - this is true for ANY Solid State Power Amp, and many Tube Power Amps too.

mike349

#2
hi, could anyone be a pal and take a quick measurement if you own a katana 100w combo

for the spade tabs found on a katana 12" speaker, could anyone tell me in millimeters how wide each of the spade tabs is, as shown highlighted with red arrows in the picture below

please note: it doesn't have to be exact ... i'm just hoping to know roughly how wide they are, thanks!


mike349

#3
i finally got a katana amp  ;D

the larger spade tab (positive, with red wire attached) is approx 5mm
and the smaller spade tab (negative, with black wire attached) is approx 3mm

lionheart

#4
For the more pedantic among us (such as myself) the larger speaker terminal takes a 5.2mm size female spade connector and the smaller is actually a 2.8mm female.

The 2.8mm are dead easy to get hold of on eBay (by the bag of 20 or so) and from most audio spares websites but the 5.2mm are an absolute pain to find - odd as they are the standard terminal / connector size for Celestion, Eminence etc.

I found a UK based online seller called V & U Electronics (AKA vuelectroniccomponents on eBay) that stocks the 5.2mm type in packs of 4 by mail order.

I can only assume Boss deliberately mismatched their terminal sizes to avoid phase issues when fitting speakers to amp in the factory.

admin

#5
Quote from:  lionheart on October 15, 2018, 12:57:16 PM

I can only assume Boss deliberately mismatched their terminal sizes to avoid phase issues when fitting speakers to amp in the factory.

Correct

FWIW - most Japanese guitar amps have similar arrangement ( Yamaha)


gumtown

#6
Quite common with Automotive speakers too.



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admin





^^ Installing a Jay Mitchell Donut in Katana 50
http://theharleybentonclub.proboards.com/thread/1877/boss-katana-50?page=13
Quote



Cut it slightly overlarge so that it stays put.  I did also pop some foam in the two slots at the top but considered they were more for heat loss than for acoustics so took 'em out again.

Just played through the Kat and, lo and behold, that directionality is greatly reduced; not so much difference between standing up and sitting down which was my main area of worry.  I even ventured to push my treble past 9 o'clock and didn't suffer the consequences.

This has to be one of the best bang for buck mods I could ever do to an amp. Taking the postage out of the equation (I don't know whether Yodel will actually deliver for 99p!) it must have cost me about nothing or less than nothing.
As far as I can see the bass just pushes on through as though there was nothing there. I guess that's long waves for you. But I reckon there must be some top disappearing as I am able to use my treble knob far more than I used to be able to. I used to pretend it wasn't even there!

I wonder if there are any other shapes that people have tried to tweak the response? Star shapes? Slots either vertical, horizontal or concentric? Personally I'm happy to live with this for a while and try it at band practice. It will be nice to really open up the volume and see how it seems.
What I'm finding seems to be exactly what Jay Mitchell who invented these things says, "A 12" speaker has huge variations in its response above ~1200 Hz within just 10 degrees of the speaker's axis. With the 3/4" foam doughnut in place, the on axis response and the response at 40 degrees off axis are almost identical. This is a huge improvement.

Jay Mitchell wrote>
If you think about the subject of directivity, you'll easily recognize that there are two ways of saying the same thing: when you say a speaker becomes "beamy" at high frequencies, you're also saying that its on axis response is much brighter than its off axis response. For example, if you equalized the response to be flat on axis (a hypothetical exercise, as that's never what you actually want from a guitar speaker), you'd find that the response off axis falls off pretty rapidly at higher (> 1200 Hz) frequencies.

The reason for the preceding paragraph is to point out that making directivity more consistent over frequency requires that either the on axis or off axis response change. The foam doughnut causes a change in the on axis response, while leaving the off axis response alone. This means that, if you've tweaked your tone with the speaker aimed at your ears, it's now going to sound darker, and you'll need more treble, presence, and/or midrange, depending on the design of your amp's tonestack and other tone-altering circuits. If you're placing your amp on the floor facing the audience, the response you hear will change little or none, but the response the audience hears will now match what you've been hearing all along."


I had been tweaking my sound off-axis and then hating the beaminess directly in front so I switched to tweaking my sound on-axis but could never really get anything that wasn't too toppy and as nice as my previous off-axis sound...and it sounded wooly off-axis. Now I can get those tone knobs working as they should when on-axis, getting a nice tone and then don't lose that tone when I stand up or move around. Early signs are exceptionally good.



maxbo

I bought a celestion V30 speaker and when it came to swipping it I had the issue where the speaker spades are too big to plug the black cable. Is there any adapter that doesnt require welding that I could buy, I've been searching for days unsucesfully.