Members echodeluxe Posted November 20, 2007 Members Share Posted November 20, 2007 a lot of people have written off ac30s and especially the ac30 custom classic as unreliable amps. ive had mine for a month (hardly a judge of reliability, i havent even gigged with it yet!) and i was impressed by the construction, the cabinet design, the way everything inside was laid out, etc... but tonight i encountered a problem that after a little research, i found out to be a problem alot of ac30cc owners have encountered as well. i brought mine to my shop to test it on the bench because ive been getting weird noises while tunring the amp on, and while idling. i figured something was loose, maybe a bad solder joint, something like that. well i took off the back panel and slid the chassis out of the cab to have a look at the tubes while i turn the amp on. when i flipped the power switch, there was a noticeable arc in the rectifier tube. it wasnt huge, but it was there. i flipped the standby on and it made a "BBBBZZZZZRRRRRTT" sound and idled normally. hmmm. i turned it off and gave it a few seconds. i tried turning it on again, and this time it (the rectifier tube) arced THREE TIMES and the amp turned off by itself. crap. now, this has happened to quite a few ac30cc owners and they figured they must have blown the power transformer, as the amp will no longer turn on. i figured they couldnt all be killing their transformers if they are for the most part running the amp under the right conditions. so i checked my fuses and found that my mains fuse had blown. HMMM. so i pulled the rectifier tube out and tested both sides (the GZ34 is a dual rectifier) and one of the sides was wayyyy off (bad). so, it seems that the rectifier tube was trying to pull too much current and the mains fuse was like "AAHHH NO WTF!!!" and blew. i did some more research and i guess the arcing and mains fuse destroying is a major problem with the Sovtek branded GZ34's (5AR4) rectifier tube. soooooo, stay away from the Sovtek rectifier. i have heard great reviews from the JJ GZ34 and i might replace it with that. the Sovtek's come stock so i recommend switching it out if you decide to buy an ac30cc or if you have recently purchased one. im going to do some more sleuthing tomorrow to see if there was anything else in the circuit that may have contributed and i will update if i find anything. i also saw some jumper wires that showed some slight burning around them on the PCB, as well as near some resistors in the vicinity. im gonna have to see if the current from the secondary runs through the circuit board (it shouldnt, theres no reason for it to) and if those burn marks are an artifact of the rectifier tube drawing to much current. sorry this is so long, im just trying to help my fellow custom classic owners gain some knowledge about their amps and to try to dispel the rumors that these amps are inherently unreliable. Link to comment Share on other sites More sharing options...
Members PurpleStain Posted November 20, 2007 Members Share Posted November 20, 2007 Man, i'm sorry to hear that. I've had absolutely no problems with mine. Link to comment Share on other sites More sharing options...
Members echodeluxe Posted November 20, 2007 Author Members Share Posted November 20, 2007 its no big deal, at least i can fix it. and its not an inherent problem with the amp itself so im thankful for that. Link to comment Share on other sites More sharing options...
Members Bluesman2514 Posted November 20, 2007 Members Share Posted November 20, 2007 Mine's been top notch too. incidentially, what speakers do you have in yours? Link to comment Share on other sites More sharing options...
Members Weathered Posted November 20, 2007 Members Share Posted November 20, 2007 Kudos for having the patience to check out the amp. A lot of people just assume because there were horror stories that they were bit, which is often not the case. Link to comment Share on other sites More sharing options...
Members echodeluxe Posted November 20, 2007 Author Members Share Posted November 20, 2007 Kudos for having the patience to check out the amp. A lot of people just assume because there were horror stories that they were bit, which is often not the case. thanks. the easy thing for me is i have some knowledge about amps and i have a shop. haha. its easy for me to troubleshoot and stuff. im just really glad that i found that the problem is not necessarily proprietary to vox amps. Link to comment Share on other sites More sharing options...
Members echodeluxe Posted November 21, 2007 Author Members Share Posted November 21, 2007 got some new fuses, didnt have time to test the amp again today. getting a few different rectifiers tomorrow and running the amp to see if the problem persists. Link to comment Share on other sites More sharing options...
Members thenakedarab Posted November 21, 2007 Members Share Posted November 21, 2007 a lot of people have written off ac30s and especially the ac30 custom classic as unreliable amps. ive had mine for a month (hardly a judge of reliability, i havent even gigged with it yet!) and i was impressed by the construction, the cabinet design, the way everything inside was laid out, etc... but tonight i encountered a problem that after a little research, i found out to be a problem alot of ac30cc owners have encountered as well. i brought mine to my shop to test it on the bench because ive been getting weird noises while tunring the amp on, and while idling. i figured something was loose, maybe a bad solder joint, something like that. well i took off the back panel and slid the chassis out of the cab to have a look at the tubes while i turn the amp on. when i flipped the power switch, there was a noticeable arc in the rectifier tube. it wasnt huge, but it was there. i flipped the standby on and it made a "BBBBZZZZZRRRRRTT" sound and idled normally. hmmm. i turned it off and gave it a few seconds. i tried turning it on again, and this time it (the rectifier tube) arced THREE TIMES and the amp turned off by itself. crap. now, this has happened to quite a few ac30cc owners and they figured they must have blown the power transformer, as the amp will no longer turn on. i figured they couldnt all be killing their transformers if they are for the most part running the amp under the right conditions. so i checked my fuses and found that my mains fuse had blown. HMMM. so i pulled the rectifier tube out and tested both sides (the GZ34 is a dual rectifier) and one of the sides was wayyyy off (bad). so, it seems that the rectifier tube was trying to pull too much current and the mains fuse was like "AAHHH NO WTF!!!" and blew. i did some more research and i guess the arcing and mains fuse destroying is a major problem with the Sovtek branded GZ34's (5AR4) rectifier tube. soooooo, stay away from the Sovtek rectifier. i have heard great reviews from the JJ GZ34 and i might replace it with that. the Sovtek's come stock so i recommend switching it out if you decide to buy an ac30cc or if you have recently purchased one. im going to do some more sleuthing tomorrow to see if there was anything else in the circuit that may have contributed and i will update if i find anything. i also saw some jumper wires that showed some slight burning around them on the PCB, as well as near some resistors in the vicinity. im gonna have to see if the current from the secondary runs through the circuit board (it shouldnt, theres no reason for it to) and if those burn marks are an artifact of the rectifier tube drawing to much current. sorry this is so long, im just trying to help my fellow custom classic owners gain some knowledge about their amps and to try to dispel the rumors that these amps are inherently unreliable. I've pulled everything my Tremoverb can muster from the JJ 5AR4's and they've given me no grief what so ever. From what the vendors I've ordered have said they're very dependable tubes. I've ran the stock Mesa GZ34's and have had no issues with them either though, and they may well be Sovtek. Link to comment Share on other sites More sharing options...
Members echodeluxe Posted November 21, 2007 Author Members Share Posted November 21, 2007 I've pulled everything my Tremoverb can muster from the JJ 5AR4's and they've given me no grief what so ever. From what the vendors I've ordered have said they're very dependable tubes. I've ran the stock Mesa GZ34's and have had no issues with them either though, and they may well be Sovtek. yeah im kinda thinking i might not wanna warn people away from the sovteks untill i inspect further. i did see alot of bad reviews from them though... it very well could be something in the circuit thats messing up the current to the rectifier. we shall see tomorrow. Link to comment Share on other sites More sharing options...
Members echodeluxe Posted November 22, 2007 Author Members Share Posted November 22, 2007 okay so i grabbed a mesa GZ34 (i didnt have much time, just picked it up from music unreasonable on the way to the shop) and plugged it into my amp, plugged in the new fuse, inspected everything, then turned it on. both cathodes heated up nicely, no arcing or anything. played through the amp for about half an hour, sounds the same as it did before and works great. amp seems to be running fine with no problems. im gonna grab a couple NOS tubes (mullard, couple others) to see if there is any other wierd arcing. if not, it would be safe to say i had a crap rectifier toob. yay. Link to comment Share on other sites More sharing options...
Members guitarman_nebr Posted November 22, 2007 Members Share Posted November 22, 2007 agreed the Sovtek's can have issues. Groove Tube branded Sovtek tubes will have been tested for performance though don't lose all faith in Sovtek. check this out. i put a JJ 12AX7 in V1, an RCA 12AT7 in V2, a JJ12AX7 balanced in V3, and a JJGZ34 Rectifier. also,I changed the speakers to Eminence Red Fangs. this darkened the amp a bit, but these tubes are reliable and the mids are now a presence.......... :-) Link to comment Share on other sites More sharing options...
Members echodeluxe Posted November 22, 2007 Author Members Share Posted November 22, 2007 right on man! im planning on swapping out one of my wharfdales for a red fang, but no one has responded to my red fang thread yet im gonna order som jj's for it as well, for backups and to see how they sound. ive got a "winged c" 12ax7 and some jj 12ax7's at home i can try... Link to comment Share on other sites More sharing options...
Members guitarman_nebr Posted November 22, 2007 Members Share Posted November 22, 2007 oh yea, i put a Matched set of JJEL84's in as well. i used to use the Red Fang on one side and a Wharfdale on the other. it was a great sound. so nice, i bought another Red Fang. lots of people use the combo of speakers. i wanted to see if two Red Fangs made even more improvement. if not, i bought the speaker at a good price, i won't lose much......if any. Link to comment Share on other sites More sharing options...
Members echodeluxe Posted November 22, 2007 Author Members Share Posted November 22, 2007 if i like the speaker and the combo of the wharfdale with it, im gonna get one of the vox 2x12's and do the same swap so i can have the 4x12's in an x pattern with two fangs and 2 wharfdales. Link to comment Share on other sites More sharing options...
Members TomCTC Posted November 22, 2007 Members Share Posted November 22, 2007 {censored}ty deal. I would rather gig a Valvetronix than an AC30.I've heard way more horror stories out of those than any other amp on the market. Link to comment Share on other sites More sharing options...
Members echodeluxe Posted November 22, 2007 Author Members Share Posted November 22, 2007 {censored}ty deal.I would rather gig a Valvetronix than an AC30.I've heard way more horror stories out of those than any other amp on the market. yeah its attitudes like this that give great amps bad reputations. like i said, i checked the circuit and it turned out to be fine. the problem was the rectifier tube. ac30s are quirky amps, there arent many amps like it, and the tone is unique as well. if this is your tone, this is your amp. most of the "horror stories" ive read about ac30's have been about the stock tubes, blowing fuses and not knowing why, and trannies going out. i would bet a million bucks that a rectifier tube was the culprit in the murder of most of those trannies. the ac30cc is build very well. i went through the circuit with a fine tooth comb and only found a handful of components that i *might* want to swap out for something better. but i could say that for any amp i go through. Link to comment Share on other sites More sharing options...
Members TomCTC Posted November 22, 2007 Members Share Posted November 22, 2007 yeah its attitudes like this that give great amps bad reputations. like i said, i checked the circuit and it turned out to be fine. the problem was the rectifier tube. ac30s are quirky amps, there arent many amps like it, and the tone is unique as well. if this is your tone, this is your amp. most of the "horror stories" ive read about ac30's have been about the stock tubes, blowing fuses and not knowing why, and trannies going out. i would bet a million bucks that a rectifier tube was the culprit in the murder of most of those trannies. the ac30cc is build very well. i went through the circuit with a fine tooth comb and only found a handful of components that i *might* want to swap out for something better. but i could say that for any amp i go through. I hear yah. If I were to get one, though, I would still opt for one of these: http://www.musictoyz.com/guitar/amps/voxamps2.php Link to comment Share on other sites More sharing options...
Members echodeluxe Posted November 22, 2007 Author Members Share Posted November 22, 2007 DROOOOOOLLLLL yeah those are nice. Link to comment Share on other sites More sharing options...
Members echodeluxe Posted November 30, 2007 Author Members Share Posted November 30, 2007 okay, update: the new mesa recto tube has been in the amp for over a week. no noise, no arcing, no problems. the sound is the same (a recto tube functioning normally should not have any affect on your tone whatsoever, you cork sniffers) and i havent blown any fuses. wahoo!!!! moral of the story? swap out your stock recto tube in your ac30cc just to be safe, and everything will be fine. if your vox blows and HT fuse for seemingly no reason, its probably the recto. Link to comment Share on other sites More sharing options...
Members Weathered Posted November 30, 2007 Members Share Posted November 30, 2007 yeah its attitudes like this that give great amps bad reputations. like i said, i checked the circuit and it turned out to be fine. the problem was the rectifier tube. ac30s are quirky amps, there arent many amps like it, and the tone is unique as well. if this is your tone, this is your amp. most of the "horror stories" ive read about ac30's have been about the stock tubes, blowing fuses and not knowing why, and trannies going out. i would bet a million bucks that a rectifier tube was the culprit in the murder of most of those trannies. the ac30cc is build very well. i went through the circuit with a fine tooth comb and only found a handful of components that i *might* want to swap out for something better. but i could say that for any amp i go through. Swapping the coupling caps to Mallories or Sozos = . Really improves the feel of the amp a lot. Link to comment Share on other sites More sharing options...
Members echodeluxe Posted November 30, 2007 Author Members Share Posted November 30, 2007 Swapping the coupling caps to Mallories or Sozos = . Really improves the feel of the amp a lot. nooooooooooo!!! waste of money!!!!!!!! blah. get any other caps with the same tolerance and specs for cheaper and i promise they wont sound any different than mallories or sozos. caps DO affect tone. but there is no brand that sound better, they are all the same. if they werent they would be terribly inconsistent. gah. yuck. Link to comment Share on other sites More sharing options...
Members Weathered Posted November 30, 2007 Members Share Posted November 30, 2007 nooooooooooo!!! waste of money!!!!!!!!blah. get any other caps with the same tolerance and specs for cheaper and i promise they wont sound any different than mallories or sozos.caps DO affect tone. but there is no brand that sound better, they are all the same. if they werent they would be terribly inconsistent. gah. yuck. BS. I don't want to get too into it, but I swapped the caps in one of my builds from Mallory to Mojo Dijon (their version of a Sozo/mustard) and the tone did in fact change. It's all in the construction as much as the tolerance - Sozo's are built differently than Mallories, and both are built different from each of the Sprague OD types (715P, 716P, PS). The story isn't just in the specs and tolerance. Link to comment Share on other sites More sharing options...
Members echodeluxe Posted November 30, 2007 Author Members Share Posted November 30, 2007 GAAAAAAAAAAHHHHHHHHHHHHHHHHHHHH Link to comment Share on other sites More sharing options...
Members utterhack Posted November 30, 2007 Members Share Posted November 30, 2007 moral of the story? swap out your stock recto tube in your ac30cc just to be safe, and everything will be fine. if your vox blows and HT fuse for seemingly no reason, its probably the recto. QFT Those {censored}ty rectifiers tubes are probably responsible for 90% of the "OMG AC30CC suxx it dide on me and I just took it back and am loudly blaming vox b/c I am actually a noob and have no idea wat teh troubles is and would rather bluster and act like i know what i'm talking about than learn something" posts on the entire internets. It's such an easy fix. I am surprised Korg hasn't just started sourcing a better part just to cut down on the bitching and moaning. Link to comment Share on other sites More sharing options...
Members guitarman_nebr Posted December 1, 2007 Members Share Posted December 1, 2007 the pre-2006 AC30cc's had issues. the newer ones have had some poor tubes. i have had that happen in Mesa's, VHT, and Carvin amps as well. my AC30CC has been a great amp!! it is a 2006 and i have put new tubes in it and swapped the speakers. reliabilty? absolutely no problems at all. my changes were to my preference, not issues. this amp is so much better than my DRRI. better clarity, better range of tone, and the AC30CC takes pedals much better. i am faithful to my Vox...... :-) Link to comment Share on other sites More sharing options...
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