We now have retube kits up in the online store for the 90's AC30's and for the new chinese AC30CC's, C2's and the AC15CC's and C1's. We are definitely fans of the old VOX amps and of the 90's reissue AC30's which are pretty good too. Probably one of the most overlooked VOX amps until about 2000 were the 1964, 1965 and 1966 AC50's but the word has gotten out and the prices on these just keep escalating at an alarming rate! These are great sounding amps with all the sparkle of the AC30's but fatter with more punch and headroom. Plug a Strat or a Ricky into an old AC50, strike an open chord and you will know why The Beatles sounded the way they did!
So climbing out of the Wayback Machine, Korg has owned VOX now for quite a while and in our opinion they did a very nice job with the 90's reissue AC15's and AC30's. They have a nice vibe and we've been able to A/B them multiple times with original AC30's and for a PC board amp they compare pretty favorably. We have tubed a number of the Rose reissues and we prefer the Korg reissues over the these.
Then there are the expensive hand wired AC's from 2002 and if you really want the traditional sounding AC and money is not an issue then the AC30HW is a nice addition to any players arsenal. It has the vibe and the build quality.
We first heard the chinese AC30CC Custom Classic amps in January 2005 at the NAMM show and our first impression was favorable. I can't say that we were not disappointed that Korg had gone to china because I'm one of those guys who would rather not support their brutal oppressive government... But we're talking tone here so my mind was open. They sounded good but didn't bowl us over, with single coils they had a pretty good chime. We were looking forward to getting the first one thru the studio here so we could have our way with it, and it only took a couple months before our victim showed up! We thrashed on it for a while and laid it face down to open her up. It sounded ok, but quite sterile with a real brittle high end and it was really missing the personality we heard from the NAMM demo amps.
The first thing we noticed was the speakers were hard wired and needed to be unsoldered to remove the chassis. An inconvenience but no big deal. The insides were typical consumer PCB's. The plate voltage clocked in at 330 volts and the stock sovtek EL84's were out of match by about 7mA and on average were running slightly over 100% which is fine for a cathode biased amp. It took a little cooler grade of the JJ EL84's to get to the same bias point and we finished it off with a nicely balanced tube for the phase inverter in V3 and a couple ECC83S's.
The difference was actually a little less than we expected to hear but it was still very noticeable and the amp warmed up and we were getting a much more tolerable tone with single coils. The high end didn't take your head off anymore and being able to dial in some more high end allowed us to get back some of that VOX vibe we were missing.
So the verdict on the CC amps is mixed. We have lots of customers who just love them where others buy them and a week or two later when the honeymoon is over they either sell them or start looking for tonal improvement with tubes and speakers. They are a bit like the YCV Traynor amps which I call "fence sitter amps". The majority of players who buy them are on the fence about keeping them unless they can be made to sound better.
The CC amps were fairly short lived and replaced by the "C1" and "C2" Custom series amps. The AC15C1 received an additional ECC83 preamp tube and the AC30C2 was stripped of it's GZ34 rectifier tube in favor of solid state diodes. All in all the "C" series amps are leaning more towards the classic VOX sound than the CC series.
We retube a lot of the CC, C1, C2 and hand wired series VOX amps using the gold pin ECC83S's which seem to get the best sparkle and chime from the amp, they are very smooth so a word of caution here, if you like smooth they are great but if you like a little grit and slightly dirtier tone then stay with the non-gold pin tubes.
Any of the VOX combo amps are torture chambers for tubes and it's almost guaranteed that no matter what tubes you use you will find a note somewhere that will cause a mechanical rattle sound. If the tubes are not nice and snug in the sockets then all of the speaker vibration can cause a tube to intermittently loose contact in the socket causing a static like sound. You can usually cure most or all of this by doing what we call "rolling the pins". You do this by very carefully holding the tube by the pins and rolling it back and forth between your thumb and index finger. The mission here is the very slightly (emphasis on "slightly") tip the pins in toward each other which will make the tube a tighter fit in the socket. Be careful not to bend the pins in too much or you will crack the glass! A little is all it takes.
Even if the tubes are a nice snug fit any EL84 will be prone to rattling in a torture chamber (Combo amp) as will the preamp tubes but to a lesser degree. Our EuroDamper tube damper rings will quiet down most any EL84 or preamp tube and you can find them here. The Custom series amps use the thin wire tube retainers and although some of our customers have slipped the damper rings on over the tubes and the wire retainers, we recommend either leaving them off or replacing them with spring and cap style retainers like the one pictured below. This way the springs can fit on the outside of the damper rings.
The new hand wired Heritage series ACHH amps are definitely a big step above the CC and C1/C2 series amps in tone and vibe even though they are chinese made amps. These do not have the sterile sound that we hear from so many of the CC amps that come in. The build quality looks good so lets hope that it stays that way! These respond very well to the JJ's and the new JJ EF806 gives a real thick tone with a lot of character.
We get a lot of questions about whether or not the AC amps need biasing. The answer is no for all the VOX amps that use EL84's because they are cathode biased which is why we always like to know if you're looking for headroom, moderate or an earlier breakup so we can choose the proper grade for the power tubes. The old AC50's are an adjustable bias amp so if you happen to be the lucky owner of one then you need to bias the amp when you change the power tubes.
I know I'll get hammered if I don't mention the Valetronix amps and pre's so yes! We retube lots of them and we use a certain grade of matched triode ECC83S's that we especially like and the results are quite nice. A much warmer tone with a lot better definition and smoother distortion. So you can email us about these or call us.