m-theory Posted February 11, 2010 Share Posted February 11, 2010 Ok, this isn't nearly as impressive as cgil's HNAD, but, since I've gigged for nearly 30 years and have had only 3 previous "HNAD's" logged, this one is significant, nonetheless! I gig with three amps right now; a 7 watt el34 vlv jr conversion that's pure bliss at reasonable volume and works really well in small rooms, a 14 watt 2xel84 vlv jr. conversion that's tonal bliss at a decent stage volume, and a 50 watt el34, plexi-modded bassman that's just flat out killer for larger stages. I've got a 2xel34 cathode biased build in mind that will clock at around 30 watts, and should easily become my go-to for most gigs, but when I saw these new Jet City "20 watt" (I have my doubts...we'll see) heads for $299, I couldn't help myself. No, I really didn't NEED it, but you know something? So what. It's $299, not $2999. My first impressions? For $299, this is a pretty impressive amp. The gain is more than plexi but less than JCM800, and it's voiced ala Marshall, so it's definitely my thing. With the amp dimed, it actually has considerable gain, although not what you'd necessarily consider "Soldano gain." No death metal here, unless your pups are some ridiculous 18k monsters or something like that. Normal pups, both SC and HB, produce wonderful, singing lead tones with the amp dimed, that clean up real nicely with guitar volume rolled back. The amp is quite responsive in that way. Overall, I find it to be a rather bright amp, but that's not necessarily a bad thing. I'm finding myself running the treble and presence controls below noon, and the amp is still plenty bright. All tone controls are very effective. What I really like about the amp so far is that, when you're pushing it hard, and even with the lows rather high, it doesn't fold or get mushy. It stays rather tight and robust. It appears that the power supply is rather firm, as it carries the gain very nicely. Again, I'm sure that might change with very high output pups...my Lester wears something in the 7-8k range, I believe. so even with things dimed, the amp remains very articulate and clear throughout. Very nice. Granted, I don't have the matching cabinet. I'm playing it through a small 1x12 with a 100 watt celestion G12h, so it might have a very different character through the stock, matching cab. Build quality is actually very good, compared to some Chinese amps we all know and love. I'd actually say that it's better than my kid's blues jr., which I've also had completely apart several times. I took this new amp apart right away, because I just had to see what "Hand built" means in China, and I was pleasantly surprised at how well this amp is put together. I did find some less-than-perfect solder connections inside, as well as a couple of very tiny solder blobs floating around, but the lead dress was nice, and, all in all, it was pretty impressive for a $299 amp. Tolex, piping, amp corners, handle, etc., are all very well put together. Tubes are all chinese, and I'm sure things can be improved with an upgrade there, although for new production, a guy can actually do a lot worse than the lastest production chinese 12ax7s. Still, with as bright as this amp is, I think a JJ might be a good choice for V1, as well as output tubes. I'm gonna bring it over to my amp tech buddy when I have a chance, to have him plop it on the bench and see what makes it tick. I highly doubt it's pushing 20 watts, personally, and I'd like to measure that, as well as see where the bias point is set from factory, and see if the horse whisperer has any magical suggestions for this one. He's never done me wrong yet, and I run nothing bone stock, so I'm really curious to see what he might come up with for tweaks. All in all, I couldn't be more happy with this. I'm a one-trick-pony sorta guy, and this amp has that in spades. No gimmicks, no weird "trick" knobs that do next to nothing, nothing but really solid tone. I'm happy, and, to be honest, for $299, this is a no-brainer, imo. Link to comment Share on other sites More sharing options...
cGil Posted February 11, 2010 Share Posted February 11, 2010 HNAD! And congrats! No shame in good tone, ya know; regardless of the price of the wrapper. Have you seen my Savage Croaker? :-s Metal film resistors even. Impressive! And it's a Soldano design, too? Hey Mikey! You've been robbed again! Something tells me this puppy may not need much, if anything! But tell your buddy we're definitely gonna need to see a quicky schematic of this one anyway before we muck this place up with too much drool and slobber! Gil... Link to comment Share on other sites More sharing options...
K.E.B.1281734147 Posted February 11, 2010 Share Posted February 11, 2010 Nice review m-theory. I've heard good things about this one. From the pics it looks nice and clean. For $299 it looks like a winner. Watch out Epiphone! Link to comment Share on other sites More sharing options...
m-theory Posted February 12, 2010 Author Share Posted February 12, 2010 Everything in the amp appears to be of very respectable quality, including the iron. If I were to just look at the amp inside and out and play it, I would not guess it to be $299. The design is reportedly Soldano's Atomic 16. They're also producing a small amp, co-designed with THD and very similar to the Univalve, a 50 watt amp, and a 100 watt amp, as well as an isolation cabinet. Mike wasn't ripped off...he's part of the 3-owner group that launched Jet City Amplification. He designed the original Atomic 16 and also was directly involved in fine tuning the iron on this amp to more closely match the original. From what I've seen and heard of the JCA20H, he should be very proud. He's brought a very good amp to the market at a price that anyone can afford. It's entirely possible, based upon what I've seen and heard, that Jet City will set the bar by which all other Asian-built amps will be judged. Assuming that this is a direct copy of the Atomic 16, this is the schematic http://www.freeinfosociety.com/electronics/schematics/audio/soldanoatomic16.pdf Link to comment Share on other sites More sharing options...
twanger Posted February 12, 2010 Share Posted February 12, 2010 Congrats! And welcome to the club! For $299 it's a great amp. Apparently they're bringing out a model with a clean channel to go along with the amp the way it is now. It's possible price will be $399. I'll probably get that one too. I really like the tones available with these amps but I do miss a clean channel. Before they bring out the 2 channel version of the 20 watter they already have the 100 watt version and will be getting a 50 watt combo out. I think the company is only 5 months old now and they seem to be taking the market by storm. Many have called the JCA20H the newest model to join the "amp of the month club" meaning that it is only the current fad. But I think the naysayers missed the mark on this one. Well built, great tones and the only measure to be met for a classic is durability which, time will tell. For now, I, like many others are pleased with the product and believe it is and will prove to be much more than just another fad. Link to comment Share on other sites More sharing options...
m-theory Posted February 12, 2010 Author Share Posted February 12, 2010 LOL! You don't need no stinking clean channel! Just roll the guitar throttle back! With the gain and volume at about noon, I can get really nice "cleans" and great crunch just by twisting that knob. Although, with the gain cranked, I can only get respectable "cleans" with my strat. Lester don't play clean with the gain dimed. I think I'd read somewhere that the revised version of this amp will also have reverb, fwiw. One subtle thing that I really like about this design is that the tubes are mounted correctly, or at least the way that I think they should be mounted, in order to draw heat AWAY from the chassis, instead of drawing it TOWARDS the chassis. Small thing to some, but I think it's pretty big, especially in a PCB amp. Link to comment Share on other sites More sharing options...
cGil Posted February 12, 2010 Share Posted February 12, 2010 Found the Jet City website after I posted that. http://www.jetcityamplification.com/amplifiers/ Yep. Looks like Mikey's involved big time. Just from the look of it, I'd have to say it definitely raises the bar for Chinese manufactured amps. If I had one that I just had to mod, I'd probably start with a few 1/2w carbon comp preamp plate resistors to thicken up the tone a bit with some extra 2nd order harmonics. But only if it needed it. Might not! Gil... Link to comment Share on other sites More sharing options...
twanger Posted February 12, 2010 Share Posted February 12, 2010 I play a skinny DC Lester and he's dressed in P90's. No matter how low that volume knob goes Lester still growls. Turn up that knob and he growls, barks and snarls like he should. Guess that's why I like him, he never loses that bad attitude. Humbuckers do play nicer with the amp when rolled down but turn them up and prepare to sweep up the peeled paint! Poor frankenstrat sounds like it got neutered when it's plugged into the amp. So yeah, I still want a clean channel. Link to comment Share on other sites More sharing options...
MaxHart85231281734137 Posted February 18, 2010 Share Posted February 18, 2010 so what s the run over on the amp now? you put it through the ropes yet? Link to comment Share on other sites More sharing options...
TWANG Posted February 19, 2010 Share Posted February 19, 2010 congrats on the new amp.. I've only heard a very little about these so I get happy lots of reading day! TWANG Link to comment Share on other sites More sharing options...
m-theory Posted March 1, 2010 Author Share Posted March 1, 2010 Ok, I've logged a couple of gigs with this amp now, so I figured I could write some kind of reasonable review. First gig was last Sat., after logging about 30 hours on the amp at home. On stage, it was rather thin, a bit brittle/harsh, and hard to dial in to a pleasing tone. At the beginning of the third set, an output tube failed, so I had to swap amps. I'm guessing that the harshness/brittleness of the amp may have been due to crossover distortion from that bad tube, but that's only a guess. It could also be that those stock Chinese tubes are just crap that can't produce fat, swirly, harmonically rich tone. I ordered all new tubes, 2 genolex gold lion 6bq5's, 2 JJ 12ax7s (including a "matched triode" for phase inverter), and a TAD 7025s for V1. I've read rave reviews about the genolex reissues and the TADs, so I thought it worth the extra cash to try them out. Big mistake. Don't waste your money on either, imo. I took the amp, with brand new tubes, over to my tech buddy's shop on Sat afternoon. He put the tubes up on his test equipment first, and found that the two Genolex tubes AND the TAD were barely even acceptable. The Genolex tested as "worn out." The TAD had such miserably low gain that it was barely above "trash can level." The two JJ's that I got online were very strong, and the one that was supposed to be matched, was, so that became the PI tube, as I'd envisioned. The other JJ became v1, and I tried the TAD in v2, thinking that lower gain there might not be a horrible thing. He supplied 2 JJ output tubes to replace the "worn out" brand new genolex tubes. Initially, we found terrible distortion on the sine wave, so he started tracing back, and found it to be in the preamp section somewhere. On further tracing, we found clean signal going into V2, but dirty coming out, so I suggested we swap that TAD for something else. He threw a good 12ax7 in that hole, and the distortion cleaned up instantly. The TAD wasn't just pathetically low in gain, it was just flat out no good. With all good tubes in it, he got the bias dialed in, checked the amp over, reflowed some solder joints that looked sketchy, and had me try it out. All went well with initial trials, so we buttoned it up, I paid the man, and headed out. The only "complaints" that he had over all was that he thought that the 50k trimmer for bias was a stupid value (recommended 10k there, and a slight re-design of the bias control circuit), and the PCB was solvent wet, which lent itself to bad solder connections that need to be reflowed. At the gig, with both gain and volume knobs at noon, the amp performed beautifully. Real smooth, rich harmonic "swirl," much more balanced tone, great crunch without caving in. The power supply is rather robust, and is thus able to take a hellacious pounding without getting at all mushy or soft. Those who don't get the output tubes to distortion would never recognize that or care, but those of us who DO push the amps that hard DO care. All in all, now that the amp is dialed in and has decent tubes on board, I'm very impressed. For $299, plus the $100 or so it costs to re-tube and bias adjust, it's well worth the price of admission. I will be tinkering with some cap values at some point, because it's STILL a bit bright for my tastes. I found myself running the mid, treble, and presence knobs all at about 11:00, and it still seemed bright to me, but I'm not exactly sure where the issue is, so I'm going to tinker with knob settings some more to zero in on that, before I start swapping parts. The amp clocked at just over 21 watts, with about 363v on the plates. Slighly over spec, but not nearly as bad as most 2x6bq5 amps run these days, so tube life should be very respectable. I'd guess I'll easily get a year on a pair of tubes, vs. 6 months on my other 6ba5-powered amp. Voicing on this amp, although overly bright, is typical marshall. Gain is higher than a typical plexi-type amp, but not nearly as high as a typical modern metal amp. All in all, a real nice sounding amp. Link to comment Share on other sites More sharing options...
TWANG Posted March 1, 2010 Share Posted March 1, 2010 I was happy to read that review because I tried one at GC and it sounded really crappy. I even told the salesman that my modded vj seemed tonally superior and nearly as loud as the in store model. So I'd guess the tube problem.. exacerbated by how many people come into gc snap it on for five minutes then turn it off.. is the big culprit. it seemed better as you turned it up.. but I ran into 'too loud for the store'.. *even with three kids on drums at the same time* before I ran into much 'I like that'. Nice to know that just a little attention can turn the jet city around! Link to comment Share on other sites More sharing options...
m-theory Posted March 1, 2010 Author Share Posted March 1, 2010 You really can't tell much about an amp until you get it on a stage, because you don't know how it's going to work in a band mix until you do so. 21 watts is actually quite loud. I used to gig a buddy's Maz Jr for a while and there were only a couple of times when I squashed that amp out and longed for a bit more power. In terms of actual db rating, you're right...it's not THAT much different than a modified Vjr, BUT, in terms of useable headroom, it's a VERY noticeable difference. The amp, in stock form, is not unlike any other modern mass-produced amp that's stuffed with today's crappy new production tubes off the shelf, in that, first and foremost, the amp will sound FAR better than stock with a simple tube upgrade. Overall, the build of this amp is quite good, especially considering where it's made. Not boutique level, obviously, but certainly a clear step above the typical chinese-built, cookie-cutter amp. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.