AC30TBX versus AC30CC

Discussion in 'Amps and Cabs' started by Teahead, Feb 26, 2008.

  1. Teahead

    Teahead Member

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    All things being equal with regards to speaker choice and tube selection, what are the differences in these two amps? I don't mean the features, or construction, forget about those, I only want to hear what sets their sound apart to your ears. The TBX being the UK made Korg RI and the CC being the current Chinese RI.
     
  2. thudle

    thudle Member

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    I'm going to piggy-back on this thread....any others who can comment?
     
  3. Teahead

    Teahead Member

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    With equal valves I find the TBX and CC to have almost identical noise floors. Build quality also appears equal to me, but then I have no understanding of that side of things anyway. I can say I've had my TBX break down loads of times, but yet to see a CC break down once.

    In terms of tone, I hear the TBX as having a looser low end and slightly less preamp gain at equal settings, especially on the Normal Channel. The CC sounds and feels more focused throughout, dispite having that touch of extra gain to it's sound.
     
  4. Lyle Caldwell

    Lyle Caldwell Member

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    Everything Echoplex said is spot-on. The TBX is awful in comparison.
     
  5. Lyle Caldwell

    Lyle Caldwell Member

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    You're lucky - the TBX has a noisy power transformer and ground loops built into the PCB layout.
     
  6. phyrexia

    phyrexia Member

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    Admittedly most of what I know comes from what Lyle's said over at the Plexi Palace, but it seems the TBX AC30s are plainly inferior to the CC.
     
  7. CWFurst

    CWFurst Member

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    I've always felt that the knobs and buttons always felt flimsy on the CC's. Is this just because I could have told myself subconsciously that they are bad because they are new and made in China? I have a TBX and I've often wondered if I should buy a CC. I like the features that they have but I always hear guitar players slamming those things. Anyway... Sell me on one!
     
  8. archtop

    archtop Member

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    I prefer the sound of the TBX amps I've played a lot more than the CC amps I've played. I'm not a fan of master volumes generally, so perhaps another factor is that the TBX is laid out like a vox should be in my mind (with no master). I have enjoyed playing through the CC when it was supplied as backline at a gig. But I was playing it at a volume where the master volume didn't really seem to get in the way.

    If I had to buy one or the other, I'd probably choose the TBX. But I've actually gone a different route though, and a friend has built me a handwired AC30 on a Weber chassis, with the Vox handwired series transformers and sozo caps, and it just sounds incredibly good. :drool
     
  9. jhp612

    jhp612 Member

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    I went through the same dilemna picking an amp. I went with the TBX after finding itcrazy hard to find one. They both got that vox chime, but i felt the TBX just had some muscule the CC didnt have. It "sounds" more vintage to me as well to get those U2 tones, thats just my opinion tho... I would never give my tbx up for a CC... never
     
  10. µ¿ z3®ø™

    µ¿ z3®ø™ Member

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    i like both the CC and the TBX.

    if i had a choice, it would be for the TBX.
    to me, it has much greater touch response than the CC and i marginally prefer the sounds i get from the CC.

    i've never heard one of the modded CCs and my understanding is that some of the 'arms length' feeling i get playing a CC is addressed by some of the mods.

    the TBX amps also had some wicked custom colour tolex happening. a buddy of mine has a red one and a purple one, both w/ AlNiCo celestions. seriously sexy looking amps.
     
  11. Lyle Caldwell

    Lyle Caldwell Member

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    The TBX had serious design flaws.

    Ground loops built into the board, running the input signal past all the power and PI stages before getting to the first preamp tube, a random approach to ground paths, crappy board quality/cheap traces, terrible serviceability (you have to remove everything to remove anything), a noisy power transformer, lower wattage resistors than the circuit needs, unreliable filament wiring for the preamp tubes, a really cheap cabinet, a wasted tap on the OT, and no RFI filtering on the inputs.

    The CC addresses every one of the above complaints, and sounds (stock) much more like a JMI era AC30 than a TBX.

    Cons of the CC:

    1) Due to EU regulations, Vox can't sell the old cotton fabric grillcloth, and the new fabric doesn't look as nice.

    2) The knobs don't look as nice - I do wish they had used solid shaft pots with setscrew knobs, but the new pots are reliable.

    3) The switches on the top panel have cosmetic surrounds that are really tough to remove should one need to replace a pot.

    4) The early runs of CCs had a mistake and used a .22uf cap on the effects loop send instead of the 2.2uf called for, and the loops on these early CCs lose low end as a result. Since fixed in production, and an easy repair if you have an early CC.

    5) For some strange reason, Vox used 100K plate resistors on V1 instead of 220K. Easy and inexpensive "mod". In that one regard, the TBX circuit is "more authentic" than the CC, but the TBX gets other things drastically wrong, so it's kind of a moot point.

    Cons of both the TBX and the CC:

    The damn bright cap is too damn bright. Stock on the top boost channel is 120pf - 68pf or no cap at all sounds better.

    I'm only considering the stock form, or with very simple easy mods. With full mods, the CC still sounds better than the TBX, as the ground scheme is better and the input signal never comes near the PI or power section. But the CC requires fewer mods than the TBX in order to sound "like a JMI".

    The CC master volume when on 10 is not negatively affecting the tone. It's the same simple circuit as Matchless used.
     
  12. Lyle Caldwell

    Lyle Caldwell Member

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    The TBX is also massively overfiltered compared to the JMI. 50/32 compared to 16/16. The CC offers a choice between 22/22 and 44/44. You won't hear the difference between 22 and 16, but 50/32 is just drastically stiffer and harder than the JMI spec.

    When comparing them, remember that most CCs are new and don't have much speaker break in time yet, compared to the average TBX which is as much as 16 years old.
     
  13. Teahead

    Teahead Member

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    Thanks guys, Lyle especially. That's about as comprehensive as it gets and from one of the best voices on the subject. I've listened to and played the CC plenty and can definitely hear and feel improvements over the TBX, although I still prefer the TBX, if only because I have played one for so long.
     
  14. starfly59

    starfly59 Member

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    With all due respect to Lyle's great knowledge of these amps, I figured I would offer my 2 cents based on my experience. I don't have Lyle's technical knowledge of circuits or his experience and I have not tried out his modded AC30CC which I hear are absolutely amazing. I highly recommend checking with him about having your CC modded - the Plexi Palace guys rave about his work.

    So....

    I really became dissatisfied with my AC30CC2x and eventually sold it after finally repairing it for the last time. It had more issues breaking down than any amp I've ever had. The fuses blew quite a bit, I had a bad transformer, some cold solder joints, it ate tubes like no other, the reverb stopped working, blah, blah, blah. I found the master volume to be pretty weak until you got past 12 o'clock (compared to a Matchless SC30's and my Valvetech Hayseed 30's MV). Just didn't have that vox mojo that my buddy's TBX and JMI did. I've since used these CC's on the road as different venues have rented them for me. They got the job done, sound good, and I would take it over any Fender DeVille that I sometimes have been provided. BUT...I've had a couple TBX's rented for me too, one running greenbacks, another blues, and they both sounded/felt quite a bit better to me than the CC's (more touch sensitive, more low end response, and just more of that vox mojo I desired). My favorite was an early 1990's fawn limited edition anniversary AC30TB with greenbacks and a THD Hotplate attenuator - man, what a tone!!!

    If I were to go back to a Vox reissue, it would either be a TB/TBX or a Lyle-modded CC.
     
  15. Lyle Caldwell

    Lyle Caldwell Member

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    Oh, I guess I should mention another con of the CCs: really cheap tubes. I advise all my clients, regardless of whether I mod their amps or not, to dump the stock tubes (hang on to the Tung-Sol 12AX7s some CCs ship with now) and get a full set of JJs. The stock power tubes are all pretty crappy, and the stock GZ34 is notoriously bad.

    Granted, these are cheap tubes which have been shipped thousands of miles before they get to any of us, but still, they fail a lot.

    With JJs, the amps are very reliable.
     
  16. Bradders

    Bradders Member

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    (said in a whisper....)

    erm......

    I love my TBX

    thanks - I mean, sorry. erm..........well.......


    sorry.......(sound of me getting my coat.....)

    :AOK
     
  17. xhavepatiencex

    xhavepatiencex Member

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    I have an ac30cc2 which I just recently put a mercury magnetics OT into and I love it, I also changed the coupled caps, tubes and bright caps and its really a night and day difference between the stock amp. I don't have to much experience with playing other ac30s though. I am very happy with my cc though and it still has the wharfedales!
     
  18. jezzzz2003

    jezzzz2003 Member

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    Well Ive owned both and both are great amps!
    The TBX had greenback 25's and the chinese CC had wharfdale's
    I unfortunately didnt have them both at once but to me, they were both very similar and just sounded madly good. just like a great AC-30 should.
    Dont corksniff the chinese makes theyre absolutely awesome.
     
  19. Weathered

    Weathered Member

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    I've played numerous TBX's, and own a CC. My CC has had a little bit of work done to it (changed coupling caps to Mallory 150's, changed speakers to Greenbacks) and it has some serious grunt. To get the tone I love from an AC30, the TBX would have to be run nearly wide open, which is too much for pretty much any venue I'd play. For me, the CC is the better amp, but it all comes down to personal preference.
     
  20. benjisaynomore

    benjisaynomore Member

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    TBX has the MOJO baby! I love mine. I have played both extensively. For me it's all about the clean tone to boost with pedals. The clean on the TBX loves pedals and has something hard to describe the CC does not.

    It could be called, MUSCLE, RESPONSIVENESS, TONE STRUCTURE, etc. It just is superior IMHO in that regard. If looking for the OVERDRIVE tone from the amp itself CC is superior, otherwise TBX is the cat's pajamas.
     

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