Members 1001gear Posted January 13, 2018 Members Share Posted January 13, 2018 or snakeoil spam? [video=youtube;Bo9W_nRFDpg] They sound good for the most part. Like. Link to comment Share on other sites More sharing options...
Members 1001gear Posted January 13, 2018 Author Members Share Posted January 13, 2018 this too. [video=youtube;vMq2J-i0z2M] Link to comment Share on other sites More sharing options...
Members Mikeo Posted January 13, 2018 Members Share Posted January 13, 2018 or snakeoil spam? [video=youtube;Bo9W_nRFDpg] They sound good for the most part. Like. There's so many of these lil mini/micro amps out now. 2 bills. I don't know how they do it. On my list for a purchase is a Quilter Mirco Pro Combo. I'm not sure if I'd dig the bigger version better than the smaller 8" combo. IMO, they sound classic old school good. They are not like super cheap, assembled in the USA. I'll probably want the travel bag and the larger foot switch. I've been looking at em for over a year. [video=youtube;mSmhP4VHvC8] [video=youtube;-jchh9AChAc] Link to comment Share on other sites More sharing options...
Members WRGKMC Posted January 14, 2018 Members Share Posted January 14, 2018 It uses a Class D power section which can be built very small. I have one of those 350W Ampeg Portaflex heads which is small and lightweight.I'm not sure its real world wattage is nearly as loud as what the manufacturers boast however. Wattage is based on using a test tone of 1KHz and pushing the amp till it begins to distort. That's not the same thing as pushing a full frequency signal from an instrument. If I compare it to other heads I own running side by side its quite obvious Its real world "Usable" wattage range is lower. I made a comparison running an old school 200W SS head along side the Ampeg using identical speakers so I could hear both at the same time. I could dial the bass down on the Ampeg to a thin tone and get it louder but when I dialed a tone I'd actually use playing bass was about or slightly less then the old school 200W. My conclusion is the Class D heads, while being incredibly loud for their small size, produce tonal "footprints" about half the size of older transistor amps and maybe 1/3 that of a Tube head. I'm sure if I compare that Class D head to my old 100W V4B head it would piss all over it. The other thing about class D heads is they are extremely sensitive to overheating. Most have fans to keep the circuits cool and thermal breakers that remove power till the circuits cool. When they do blow the circuits are more difficult to diagnose and repair and spare parts used are unique to the manufacture. You see un-repairable class D heads littered across EBay likely from people pushing them to their limits. Another reason for buying a head twice the wattage you think you need then running them around half power to prevent overheating. Lastly, a Class D amp is what you call a Switching or Pulse Width Modulation (PWM) amplifier. The audio signal is used to modulate a PWM carrier signal which drives the output devices then a low pass filter is used to remove the high frequency PWM carrier frequency. The problem with this design is audio frequency response. It can work well in bass amps where there isn't much treble frequency. In order to get more treble (especially upper harmonics on a guitar) you have to multiply the carrier frequency well above the highest audio frequency. Components have to be free from impurities which cause them to overheat. The higher the frequency, the more expensive the components become and the more cooling is required. it becomes. A typical guitars frequency response may be from 100 to 5Khz with harmonics well above. Because the carrier signal is above the audio the amp wont have the upper harmonics of either a normal SS amp or tube amp. After listening to a couple of demo's, it was pretty obvious the top end is neutered and the most you'll get is maybe a 4K roll off on the top end. That can be all someone may need of course. You typically mix lower mids from one guitar with another guitar using the upper mid ranges in a recording or live band mix to get them to blend. Vox amps are noted for staying out of the way of vocals, snare and cymbals etc. I do like the tones they get. This one surely doesn't have the top end of a typical Fender/Marshall amp. Comparing it like they do in their ad's to an AC15/30 is misleading too . Yes you may be able to roll the treble off those amps to give them the megaphone tones this amp produces but you sure wont be able to dial up the bright jangle tones those amps are capable of producing. Link to comment Share on other sites More sharing options...
Members 1001gear Posted January 15, 2018 Author Members Share Posted January 15, 2018 It uses a Class D power section which can be built very small... ... Vox amps are noted for staying out of the way of vocals, snare and cymbals etc. I do like the tones they get. This one surely doesn't have the top end of a typical Fender/Marshall amp. Comparing it like they do in their ad's to an AC15/30 is misleading too . Yes you may be able to roll the treble off those amps to give them the megaphone tones this amp produces but you sure wont be able to dial up the bright jangle tones those amps are capable of producing. Interesting amp info. The question is directed at the optical triodes though. Korg seems to have started "printing" 'em and they supposedly are real triodes. So, reliable? Sound like 12ax7? And not discussed but can you now put a tube amp on a tiny board? Tranny sold separately. Link to comment Share on other sites More sharing options...
Members WRGKMC Posted January 15, 2018 Members Share Posted January 15, 2018 Vox/Korg does some very cool things with their SS designs. They are one of the few companies thinking outside the box and developing new circuit designs and not simply using the same old amp designs and sticking it in a new cab. Several of their amp use a 12AX7 as a power tube. It doesn't put out enough wattage to drive a speaker of course because its only a low gain preamp tube but they use it to drive clean power transistors so it gives you the saturation of higher wattage tubes which is something guitarists want. Other manufacturers often use preamp tubes in the preamp section to get channel overdrive and the power sections. yet others may use power tubes with a solid state preamp like Music mans and Peavey Hybrids. I couldn't find much on this amps Nutube preamp other then it's claim to work using a Fluorescent light design that's supposed to work like a Triode. [ATTACH=JSON]{"data-align":"none","data-size":"full","title":"AAAA1.JPG","data-attachmentid":32142288}[/ATTACH] The design would allow it to run cool which is essential running it in a small box with a Class D amp which needs to run as cool as possible. A regular tube even with a starved plate voltage commonly used in SS amps having a preamp tube would still need the heater lit which would cause too much heat. My concern is this. Allot of gear in my business over many decades have used all kinds of Fluorescent designs, mostly for displays. They all suffered from the same issues. They were good for maybe 5 years or so then they would either fade out or burn out. Lifespans were unpredictable. Technology changed and they switched to liquid crystal and touch screens like you have on Cell Phones. Looks like they've adapted it to work for audio some how but this device looks like its soldered into place. If it has a similar lifespan to other Fluorescent designs its not like you'll be plugging in a new one like you would a regular vacuum tube. Depending on how it fails its conceivable the amp could go dead in several years too. This is the risk you take when using new technology. Unless its been out awhile you don't know the long term effects and on a low cost amp like this its essentially a disposable unit that's likely too expensive to repair once the warrantee has run out. Maybe the Fluorescent design is expected to be much longer because its essentially the number of hours the lamps burn ( just like Fluorescent lamps in a home) I'm not completely knocking what they are using, but the advertisement is a bit misleading. I doubt the unit actually amplifies a signal. It simply reacts like a tube possibly adding coloration or compression. It shouldn't be confused with actual Vacuum tubes that get their mojo running higher voltages in the 200V ranges. Like I said. I really like the Vox stuff. They are innovative and interesting and usually produce excellent results. At my age I probably wont be around to see how these work out long term. Its the test of time that gives gear its reputation. Vox's history was not very good back in the day. They had many failures in the past due to poor designs. The new company seems to be avoiding many of those mistakes, even with their reissues. I have some of their multi effects units. They do an excellent job modeling amps and even things like string touch sensitivity is superior to many other manufacturers. You have to figure the that develop the technology for their Korg Keyboard is likely being utilized in their guitar gear too. Link to comment Share on other sites More sharing options...
Members 1001gear Posted January 15, 2018 Author Members Share Posted January 15, 2018 Don't understand much about them but they do say they operate from 5 to 80 volts and very little current. [video=youtube;8MJ8XEzkfnY] Link to comment Share on other sites More sharing options...
Members 1001gear Posted January 15, 2018 Author Members Share Posted January 15, 2018 [video=youtube;6Azl1vzoLpA] Link to comment Share on other sites More sharing options...
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