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Omnisonic Volume Control anyone?
Posted: Fri Feb 22, 2008 4:49 pm
by Razor
I've seen these advertised on eBay:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... :IT&ih=004
The seller (who I think is also the manufacturer) claims that you can crank your amp up full and control the overall volume using this device, thus saving your ears and your neighbours' nerves!
Does anybody own one or have experience of them?
Considering getting one for use on my AC30...
Re: Omnisonic Volume Control anyone?
Posted: Fri Feb 22, 2008 7:24 pm
by jps
I made of of those, it is just a volume control in a box. It can come in handy if you need some more control over the level of your amp. Does the AC30 have a FX loop?
Re: Omnisonic Volume Control anyone?
Posted: Fri Feb 22, 2008 7:53 pm
by ric330
Wow that is cheap for attenuating. Never tried one but if it works well it would surely put some of the other attenuators which are at least 10 times that price to rest.
If you end up trying it out please let us know what you think.
Re: Omnisonic Volume Control anyone?
Posted: Fri Feb 22, 2008 8:17 pm
by jps
It is not the same as those attenuators that go between an amp's output and a speaker, this is just like the volume control on your amp or guitar, just in a small box.
Re: Omnisonic Volume Control anyone?
Posted: Fri Feb 22, 2008 11:17 pm
by sharkboy
Color me skeptical. I may be missing something, but if this happens in the effects loop, then it doesn't allow the user to get full color of the output tubes.
I use attenuators all the time- they aren't all that expensive (edit) to make. I've also used the Radio Shack volume control things as attenuators. In those cases, the simple description is that you are bleeding off watts from an energized series of stages. Though some frequencies are affected, you can reign in a great deal of volume while driving your output tubes into smooth or hard distortion.
If this works as I understand it, it requires your preamp to be in charge of the quality of the sound and the amplifier is not allowed to be as much of a tone component.
Re: Omnisonic Volume Control anyone?
Posted: Sat Feb 23, 2008 6:36 am
by Razor
jps wrote:I made of of those, it is just a volume control in a box. It can come in handy if you need some more control over the level of your amp. Does the AC30 have a FX loop?
Yes AC30 is one of the newer ones and so does have an FX loop.
I've read reviews on other forums about this product and they seem to say what is echoed here that if they don't sit between the amp's output and the speaker then they can't really give you the full tone as expected.

In fact some people claim it's false advertising on the seller's behalf!

Re: Omnisonic Volume Control anyone?
Posted: Sun Feb 24, 2008 12:08 pm
by ken_j
If your FX loop is parallel wired and has a mixer control you can get the same results for the price of two jacks. I have tried this with my Subway Blues and it works fine. It will allow you to distort the preamp tubes more at a low volume. In my opinion this makes a non-master volume amp act like it has a master control. That is all that the ebay item will do IMO.
Re: Omnisonic Volume Control anyone?
Posted: Sun Feb 24, 2008 12:37 pm
by ric330
Great points Mark and Ken,
I've been through a whole gamit of stuff and have gone back to low watt, point to point, with quality tubes and Trannys, and speaker to get great tube tone.
There's nothing that compares with a 15-22 watt well made tube amp pushed a bit. I just couldn't attenuate to get the same results with higher wattage amps.
I'm extremely happy with my Deluxe Clone ( not for everyone probably) but it does the trick stage, studio, or Jam session. I did convert to EL 84 like a Vox AC 15 and installed the Celestion Blue. This works for most everything. And If I need more volume I just mic it or put the 6V6's back in which the amp is already biased for.
This works for me but not everyone. I've heard numerous great tone at lower volumes with higher wattage amps.
You've just got to figure out what works for your individual set up.
I did try a Weber unit once through my AC 30 that worked pretty good. But ultimately,
I went back to my low watt tube amp.
Tony ,I hope you acheive that tone you are looking for - the journey is half the fun. If you find something that works well please post and let us know.
Either way the AC 30 CC is a great tone machine as is.
Re: Omnisonic Volume Control anyone?
Posted: Sun Feb 24, 2008 1:29 pm
by sharkboy
The best way of which I know to obtain the fullest output tube sound without screaming volume is Kevin O'Connor's ( londonpower.com ) power scaling, which is a system of reducing the power (usually) of the output tubes. This is a drastic oversimplification, but by interactively using some gain control into a power scaled output section, one can get very close to the same tone they would have out of full power.
Having an amp tech do this can be expensive. Kevin sells PS kits and also has a book that explains it (the only one of the TUT books I don't have- TUT4).
I have a couple of Weber attenuators and I like them a lot. I also use "silent" cabinets to allow me to keep from overdoing the attenuators. I will probably try power scaling in an amp before long.
Re: Omnisonic Volume Control anyone?
Posted: Sun Feb 24, 2008 1:45 pm
by ric330
Mark,
I've heard of this Power scaling idea and read a bit about it but don't know anyone who has used one.
If you do eventually get one, please post your findings as this is probably a subject many would be interested in.
Since you've read up on this - Does he make an outboard unit or only intergral to the specific amp?
Re: Omnisonic Volume Control anyone?
Posted: Mon Feb 25, 2008 9:53 pm
by soundmasterg
Kevin, I'd sugget to email Kevin O'Connor with any of your questions....he's very friendly. I believe he has versions that will fit into any amp that you can order as a kit. He also puts them in his amps. There is a forum dedicated to power scaling, and there are others on Ampage, Hoffman, webervst etc., who have used power scaling and talked about it.
Greg
Re: Omnisonic Volume Control anyone?
Posted: Mon Feb 25, 2008 10:15 pm
by ric330
Thanks Greg.
Re: Omnisonic Volume Control anyone?
Posted: Wed Feb 27, 2008 2:29 am
by sharkboy
Sorry, I was away for a bit (zoomed to LA to help my brother move.)
And, of course, Greg provided the correct answer. I will post my findings when I do try it out.
Re: Omnisonic Volume Control anyone?
Posted: Wed Feb 27, 2008 12:01 pm
by steve_hershberger
Build one yourself and save a few bucks - look here:
http://www.fortunecity.com/marina/newland/2081/id3.htm
I'm the guy who wrote up the instructions, built and photographed the box on the site above. That was started on another forum many years ago when the Hot Rod Deluxe and Deville amps started getting popular, but the main complaint was "they're too loud." Steve Dallman and I got so many requests from that forum thread that it resulted in the above website - which was put up as a "FYI/PSA" kind of thing. Some lurker(s) on that forum took the design and started selling them on e-Bay, and here we are today. Anyway, good for them. They've made some money. It kind of P'd us off at first, but it's no big deal.
The whole point is - it's extremely simple and cheap to build one yourself in less than a half hour. If you don't like what it does, you're not out much in terms of expenses.
And it does work as originally advertised - but it also depends on *who* is writing the ad too! I've read the e-Bay ads over the years from these various "manufacturers" and most of them are pretty outrageous. No, it's NOT an attenuator. It IS another volume control between the preamp and power amp stages in an amp that has an effects loop.
Mine works great in my old Hot Rod Deluxe, but I've never tried it with my Vox AC-30CC head. I'm not too familiar with that Vox circuitry yet so I can't say anything about compatibility at this point.
If anybody has any questions, please feel free to e-mail me and I'll try to help you out.
Re: Omnisonic Volume Control anyone?
Posted: Wed Feb 27, 2008 9:09 pm
by jps
That is exactly why I made mine, the HRD I had needed some taming. It worked well in the M/B DC-2 I used to have, also.