Axe Ultra ART SLA2 Beyma 12GA50

[Edge59]

I recently bought a pair of Beyma 12GA50 FULL range speakers to try in my floor monitors since I am on a budget and cannot afford to buy the high end stuff yet. I have a pair of Peavey wedge monitors that had Black Widow 12's and a crappy horn and a half diminished crossover. I disconnected the crossover removed the horn (I am going to put a cover over the open area where the horn was), and found them to sound great for mild drive and clean sounds. When going to more saturated tones, there was a harshness that I do not like with high end speakers (YES, I have the speaker sims on) I tried my EV SRO Alnico 12's and my EVM12L's, they sound awesome with saturated tones but lack in clarity when using the cab sims without extensive re-EQing. So I want to get somewhere in between the Beyma's and the EV's and still use my Sims. I found on the net a filter that is very easy to put together, its called a Zobel filter which consists of a 10 ohm resistor and a .01uf cap they are wired in series. Well I tried it but I only had a 16 ohm high wattage power resistor which is fine for the kind of power I'm running ART SLA 2, so it was still a little harsh, brite and grainy in the top and upper mids with those values. I eneded up using a .047 uf 600 volt paper in oil cap and the 16 ohm resistor with the resistor end attached to the negative speaker terminal and the cap end to the positive terminal. I took the wedges out to a small jam last night and was very pleased with the results, smooth overdrive and good clarity in the clean highs. This is a good option for those who are on a budget and have a pair of wedges they don't mind altering. They also have a pretty decent low end that I am having to EQ out slightly so I don't cause earthquakes. BTW, there is no crossover and the filter only removes the extreme harsh high end.

 

[DADA]

I have the exact same set-up. Therefore could you please post a schematic and some pics of the stuff and its connection.
I do not mind a bit of experimenting at all.

This is much appreciated!

 

[Edge59]

[attachment=1:c9yup95j]Beyma 12GA50 Zobel Filter.JPG[/attachment:c9yup95j]
Do not use an electrolytic cap. I used NOS Sprague Paper In Oil caps that I got off ebay. You can use Angela or Jensen caps too. I recommend the PIO caps, they are much more musical to my ears, but its always good to check the actual value of NOS caps with a DVM to make sure they are still within tolerance [attachment=0:c9yup95j]Beyma 12GA50 Zobel Filter.JPG[/attachment:c9yup95j]

 

[DADA]

Thanks!

What will happen with the resistance (ohmage) on the amp connection. I mean normally its 8 ohm for the Beyma's connected on the ART SLA 2. What is the new value?

Why didn't you use an PEQ in your AXE-FX set-up for your saturated tones?

Thanks

 

[Edge59]

I found some old Sprague paper in oil caps (PIO), which are known to round off or smooth out the top end harshness, and a 25 watt finned aluminum 15 ohm resistor in series.

 

[Edge59]

With the cap in series with the resistor it does not change the resistance of the speaker, it adjusts how much of the cap filters the treble. And I do use the PEQ, but it did not take off the harshness as well as this filter does for me, and I do use the PEQ and other filter or G-EQ when needed. When I used my EVM12L or EV SRO Alnico, there was no harshness, but lost some important highs when using the Cab sims. So I wanted to get the smoothness of the EV with the full range of the Beyma's. I found the Zobel filter on the net. It called for a 10 ohm resistor and a .01uf cap and is used in a full range hifi stereo setup for music playback, It was designed to smooth out harshness or nasty distortion that takes away from the sweeter musical nuances. It sounds very good with the ovderive/distortion settings this way. I have 16 ohm resistors and the .047uf sounded best after trying different values. It works for me, YMMV. I will see how it goes, it does not seem to cause any problems, and the article said there have been no reports of any. I am still trying to find the URL again, when I do I will post it here. It just sounds more where I want the tone now, between the smoothness of my EV's and better definition without the harshness I was getting at medium to high gain settings with the Stock Beyma's. The high gain settings are more like a guitar cab now with the smooth articulation I like from the EV's, the Full range of the Beyma's and NO top end harshness that was there before. It did not take anything away from the lower gain tones either. I Hope this helps EDGE59

 

[DADA]

Does this have any implication on the volume output of the amp?
Could you give me an exact product info on the parts used?
What is the exact wattage load of the resistor you use?

Thanks

 

[Edge59]

I will need some time to get that info together. The parts are in the cabinet and I need some time to open it up to see what the part numbers are. As far as implication on volume output, I have not heard any audible drop in volume, the only test equipment I have are my ears and others to test that , the sound is so much better that I don't have a problem with it. As I said the 16 ohm resistor is not paralleled with the speaker, it is in series with the cap and acts as a tone filter, (high end rolloff, similar to a fixed guitar tone control), if the resistor itself was in series with the voice coil it would add resistance and sure there would be some audible changes in volume and probably loose some definition, but this circuit as you can see in the pics, the resistor is in series with the cap, not the voice coil, and the RC network is in parallel with the voice coil and only removes the harsh top end I was experiencing. It works for me, doesn't mean it's for everyone, I thought I would share the results for those who are interested. It sounds best so far to mine and others ears that are hearing it. When I get a chance I will record a clip or 2 for you to hear. I will see what I can find on part numbers when I can. I will also test the circuit on and off the speaker again to see if there is any audble volume drop, but I don't recall any.
EDGE59

 

[DADA]

Edge59,

Opening up your cabs and the clips is not necessary. Just ordered the following:
- Power Resistor 15 Ohm, Ceramic, 11W
- Russian PIO (Paper in Oil) capacitor. Known for a smooth MID and HIGH without loss of bass response. 47nF 500V
The cost is a laughing 8 euro's

Will let you know what mine experience is!

Greetings and thanks for the idea and info

 

[Edge59]

Hi DADA!

Great! Yes keep me informed if you would. I would like to hear you results. It should be interesting in the least. Anything that helps get you that tone is what its about. It is somewhat subtle but effective. You could try different values of Caps, but I just wanted
to get rid of the extreme harshness that my ears were hearing with mid to heavy saturation without loosing the high end clarity for clean patches. Let me know how it goes for you.
Edge59

 

[DADA]

BTW is there a specific side of the capacitator to connect to the + of the speaker?

Just to be sure

 

[Edge59]

Yes, as in the pic or schematic diagram posted. The cap end needs to go to the positive terminal. The resistor end goes to the Negative terminal. Oh and the other ends of the cap and resistor of course are soldered together as in the diagrams. Your connection between the power amp and speaker is still the same as before, you just have the RC network (Cap/Resistor in series) going across the - and + terminals. My PIO cap has a metal casing outside that basically is a shield for noise for audio circuits, the dielectric end is where I connect to the positive terminal, (The site that I got it from said to do it this way, if I can find the site again, I will post it for reference.) the shielded end (not negative) goes to the resistor, relative to ground as a noise reducing method, but it has always been a general practice. Again they are NOT bipolar but in the old days they actually had a preferred end for noise reduction if any, it basically shields the signal to ground kind of like how shielded guitar cables work. Plus if there was any high voltages present and you touched the metal casing, you would know it, if it was wired the other way! ;/ BTW! I would test the components for their actual value to be sure they are not out of tolerance to the point where the resistor is pretty close to its stated value as the cap. DO this individually before you solder the parts together. If you have a resistor that reads 1 ohm or 100 ohms, you will have some problems. A cap can be shorted out and read like a wire is in its place if its shorted inside itself, open-no reading or out of tolerance, like a .047 says .022 or .01, .1 etc, will probably be too off for the desired effect, but say a .047uf cap is showing .050uf or .039uf they will probably still work within a usable range, but the more/less the values drift far from its specified rating the more your tone will change as well, and if its too far, in extreme cases it could either short the output or not have an effect at all. I use my DVM and set it accordingly to see if I am close and safe before using the parts and firing the amp up. They are usually within about 5% of their stated value. Also some of the new PIO caps with the metal shield have a clear plastic coating so you have less of a chance to get fried, but with these caps being used on a speaker, you will not see that kind of voltage at all. As you probably know to set the DVM in the 1k or so range for the resistor and to capacitance in the uf or if you use nf range conversion setting if you have that option. I rarely have new components show up bad, but as a safety precaution to your amp and speaker, I always do this.
EDGE59

 

[DADA]

Well i did the experiment today.

I did not liked it. The high freq are still their and the lower mid went down. Maybe the wrong values of the capacitor and the resistor. Or maybe the russian cap did not do the job. So I rest this case. Thanks for your help anyway.

BTW I found that the ARTS SLA already has a Zobel network in the output stage to stabilize the amp. http://gnu.295.ca/~peak/audio/sla-1.html
That is maybe the reason for the some odd values you are using for the Beyma's. Putting the specification of the beyma's in a design program http://www.carstereo.com/help/Articles.cfm?id=36 the Beyma's having a D.C. Resistance 6,2 Ohm and Voice-Coil Inductance of 0,6 Millihenries resulting in the following values: Capacitor = 10 Microfarads and Resistor = 7,75 Ohms.

Maybe I will try these values one day but the ART already has a zobel so I am not sure if it will work. But as for now I have better results with my ART Dual Tube EQ sitting between The AXE-FX and the ART SLA 2.

 

[Edge59]

Hi DADA, Hmmm. I have the SLA2 and it did make a difference with my setup... strange, sorry you spent money that did nothing you liked. I am curious about your Art tube EQ. So it helps reduce the extreme bite your hearing with your setup?
Thanks again,
Ed

 

[DADA]

As I said I am always in for an technical experiment and 8 euro's is just a laugh. I loved the idea so I tried it.

In my patches I am EQing most of the harshnish away and the ART Dual Tube does the rest.

Well the ART does not make the Dual Tube EQ any more. Which is a pity. The reason to choose for this "parametric" EQ solution is to be possible to change the the sound on stage on the fly without needing to get in the Axe-FX menu and just to SEE what the settings are. See it as a hardware Global EQ were editing menu's is not needed.

Here is some more info:
http://www.artproaudio.com/downloads/ma ... tubeeq.pdf
http://www.harmonycentral.com/products/91608
http://www.canadapromedia.com/sales/art/dualtubeeq.htm

I bought mine secondhand for Euro 150 in a very new state.

 

[Edge59]

Hi DADA, Sounds like a real nice piece of gear! I have been looking for one, but have not seen one used... I am curcious to find one. I like the idea of on the fly EQ-ing. Thank you!
Edge59

 

[Edge59]

Art Dual Rube EQ

Hi DADA, I just picked up a Art Dual tube EQ! It is in excellent condition! I am messing with the settings now. I now have Version 11 software for my ultra. Have you swapped out the tubes yet? I am curious if it would make much difference?

Thanks,
Edge59

 

[DADA]

Hi DADA, I just picked up a Art Dual tube EQ! It is in excellent condition! I am messing with the settings now. I now have Version 11 software for my ultra. Have you swapped out the tubes yet? I am curious if it would make much difference?

Thanks,
Edge59

Edge59,
To be honest, I forgot about this thread. But this is great news.
I bought it hardly used, so I did no tube swap. But I opened the thing and there are very high grade tubes in it. Can't remember exact the type but they are Philips.
Back then I had a call with ART and they told me that the Art is very forgiving. But I advice to buy ony topgrade tubes. This thing is studio grade and is still used in studio's so put in the best tube you can get. For on stage my basis setup is that it has no influence at all and put it in bypass sometimes even off (tube spare). Only when I need a quick EQ on all my patches I take it out bypass and use it. So I use it as a global EQ just for on stage and only when it is really really necessary. You can really polish you sound with it but do not over EQ. It is a very powerfull EQ and I advice you to give it a lot of play time to get acquanted how it works.

Regards