Vibro Champ XD Amp Crew

[RubyRae]

I finally got a new amp, and after realizing I could not get the money together this year for my hand wired Princeton Reverb...I settled on a new Vibro Champ XD. I am really happy with this little amp, and feel it was the best $189.00 I have ever spent. This amp will keep me busy for months to come. After just 3 hours playing it last night I found some incredible sounds.
Love the Tweed setting, Blackface, and British. Between the 16 voices, and multiple effects, there are so many combinations, let alone tweaking each one to your liking.

I contemplated getting the Super Champ XD, and I think i would have been happy with that too, but at 2/3 the cost I pretty much had my mind made up prior to playing them both. For me, the 5 watts was appealing in what I was looking for. Once I played it, it simply reaffirmed how sweet the Class "A" vintage tone can be. Super warm and lush, with great overdrive and bite.
The stock 8" speaker sounds good to me, tho i may try something different down the line, possibly a Jensen, Weber, or Emminence...who knows. I highly doubt I will cut it to upsize to a 10", but would never rule out an extra cabinet to see what it sounds like.

All and all, you can not beat this amp for the money. The amp produces some serious warm, smooth, and natural vintage tones we all love, despite the fact that it is a modeling amp. The tubes are nice, and the amp runs HOT...'does wasted heat account for so much tonal warmth?' my guess would be yes, and well worth it. This amp is magical to me.

Who else knows this? What mods have you braved so far? Thanks!

[davechen]

I'm in! I've had mine a year, and it's great fun to play with. Lots of knobs to fiddle with. I thought about getting the bigger Super Champ XD, but after playing with the VCXD realized that it's plenty loud for me on my couch.

I kind of go back and forth between the tweed and blackface voices with a bit of the chorus+reverb.

I'd definitely be interested in hearing about how a new or external speaker works out for you. I haven't done anything to my amp.

[timmer114]

Count me in, I love my VCXD. I tested it side by side with the SCXD for a good hour before I purchased it. The VC just sounds better to me, I think it's because we can really push the tube at lower volume, and that it's class A.

Mine is a little noisy with the hum idle, I guess I can live with it though. Sometimes I debate taking it in to exchange it for a different one, but I reckon being class A most of the VC's have that hum no matter where you plug it in or what it's near.

I love channels 1, 4, 7,8,9 and 11. Sometimes I mess around with 2 and 3 but find that 4and 8 pretty much cover my needs.

Do your guy's VC's have that hum also? It's not enough to be irritating, but it's enough to make recording difficult..

I am tempted to make a 10" baffle out of some plywood and stick it in there, I think a 10" would just fit. I see SCXD speakers in the 20 buck range on ebay all the time, it would be perfect in this amp.

[RubyRae]

timmer, I remeber reading some of your posts prior to me buying mine. I really barely had the money to get it, so the SCXD was not much of an option at the time, but this amp was exactly what i was looking for. I didn't want 15 watts, and the super warm tones from this 5 watt class A was perfect for me. My 15 watt amp will be the Princeton Reverb when I save up the money this year. In the meantime I am overjoyed with the versatile sounds of this amp. I really don't think I will mess with my speaker (as far as upsizing to a 10") Mainly I don't want to do the work...but I will certianly entertain the thought of a new 8" speaker and eventually new tubes. I am content with the sound as is. Regarding the noisy idle hum...it is strange, sometimes I hear it, and sometimes I don't. So I thought it was just certain settings, but last night I really tested it out. I turned off all other sounds in the basement to keep the room quiet. Basically yes there is a very light hum, buzz, noise, whatever...but it really doesn't bother me or interfere with the sound of the amp in my opinion. I need to have my ear fairly close to the amp to hear it when idling. I wish I had another VCXD to compare it to, but I think what I hear out of mine is typical of all, and not a problem for me. I don't even think it would hinder my recording. *Cheers* to sweet vintage tone at a fraction of the cost! I'm with you on the settings too, love the Tweed, Blackface, and British.

[teleporter]

Just got mine today from Musicians Friend. I used to have a Champion 300, 30 watt solid state but stupidly traded for a G-dec. Did a lot of research and decided the Vibro Champ would fit the bill. I was a little concerned that only 5 watts wouldn't give me the sound I wanted but after only 30 minutes of playing around with it I am very pleased and looking forward to seeing what sounds I can squeeze out of it.

[Anwar]

Count me in too! I just picked mine up a few days ago. I was a little worried that it may be noisey but it is dead quiet unplugged from the guitar. I went and got those new SCN Fender ModShop noiseless pickups and now......you guessed it! Totally!!!! Yea single coil transparency, bite expressive dynamics but 0 hum!!!!!!

Now I just need to work on chops. If I get anything else it will be a microphone in case I sit in at a Chicago blues club in like 6 months or something. This is great stuff!

[the_rising]

Just got mine...love it so far!

Anyone care to share any settings they've had good luck with?

I'm playing a '62 reissue Strat and would like to get a nice, warm blues rock tone along the lines of SRV (obviously) and John Mayer.

Thanks!

[don jon]

Ok so I'll join the club as well. I loved the VCXD the minute I plugged into it at the music shop. The only downfall to me was the 8" speaker and the lack of low end. So I had to swap the speaker for a 10". I found the perfect fit with a Weber 10F150 and even kept the original baffle intact and cut a new one covered with custom retro upholstery (see pics).

I also did a minor mod by removing the stock OP Amp in V1 and installing an 8 pin DIP socket. After trying several OP Amp replacements I found the Burr Brown 2132 (per Bill M's suggestion) to be most to my liking. It cleans up the distortion voices and lowers the operating noise.

I tried using my Yellow Jacket adapter and running an EL84 in it......mistake. It sounded awful. I did put a NOS Mullard 12AT7 in the pre-amp/phase inverter spot which added a little glassiness to the clean voices.

My favorite voice is the acoustic #16 with my Tele. It is just so much fun to play around with and adds a great percussive quality to your pick attack!

[RubyRae]

Good look don jon. The only thing you need now is a 'blue' light to match that grill. Tell me what you think you gained, and the overall sound that the 10" Weber gives you...I have been thinking about trying one at some point.

Also how did you cut out the board to make it larger, do you just use a jigsaw? And last how difficult was the mod you did? was it worth the work, and the sound much better? You mentioned it taking care of any idle hum the amp had prior...I was thinking about some new tubes, and found a JJ pre amp tube at my house the other day that I think is still new, but it is not an AT7...thanks for sharing. Great amps. I truly love mine more and more each day, and play it at least 2-3 hours a day.

[don jon]

Originally Posted by RubyRae

Good look don jon. The only thing you need now is a 'blue' light to match that grill. Tell me what you think you gained, and the overall sound that the 10" Weber gives you...I have been thinking about trying one at some point.

Also how did you cut out the board to make it larger, do you just use a jigsaw? And last how difficult was the mod you did? was it worth the work, and the sound much better? You mentioned it taking care of any idle hum the amp had prior...I was thinking about some new tubes, and found a JJ pre amp tube at my house the other day that I think is still new, but it is not an AT7...thanks for sharing. Great amps. I truly love mine more and more each day, and play it at least 2-3 hours a day.

Well the speaker (obviously) made the biggest difference in the sound of the amp. The Weber 10F150 is voiced similar to the Eminence made stock Fender speakers. But the extra size and magnet weight added bigger round bass and even enhanced the warmth of the highs while adding just a little to the top end response. I feel the speaker was a good but not amazingly good improvement. I mean, when it comes down to it, it's still a 5 watt amp pushing a 10" speaker. The amp simply isn't designed to create big volume. And in hindsight, the 8" speaker is still adequate and is a great fit for the amp. However the 50 watt 10" is a bit warmer and rounder. As far as volume and headroom it made no noticeable difference (not that I was trying to get headroom from a 5 watt amp lol!). But all the gain and distortion from this little amp comes from the Op Amp and the digital chip anyway, not the tubes or the speaker.

For the modded baffle I just cut it out myself with a jigsaw and used an upholstery stapler to attach the cloth I found in the sale bin at Wally world. That cloth was actually the most satisfying mod I performed on the amp. I think it looks sweet. Not to mention I did not want to cut up the original baffle. I used a new piece of pine lumber about 1" thick because I like to keep all my original parts intact when I am modding my gear if possible.

As far as the Op-Amp swap I will say this. I am a tinkerer. It is hard for me to leave things alone, and I haven't met a warranty that has lasted more than a week! So if you are like me swapping the Op-Amps is an interesting experiment. And it was also educational as it helped me understand the circuit. But if you are not a tinkerer, and you are thinking about doing the swap because you want a big change in the amp's tone, you will be disappointed. While the Op-Amps in positions 1 - 3 (1 especially) did affect the distortion level, noise floor, and volume of each voice, it was usually way too much in one direction or the other as I tried chips from different families. And I settled on the BB 2132 only because it had a bit smoother break-up while not losing a noticeable amount of volume. It was not a jaw dropping difference that turned a not so good amp into a great one.

Bottom line: The speaker was worth the $90 and work to the baffle as it added some depth and a little bottom end to the amp. If I had the desire to mod the amp further I could probably get it to push a little more volume all around but that is not what I bought the amp for. The speaker did what I wanted and rounded out my frequency response nicely without flavoring the amp's voices. The Op-Amp mod was not worth performing unless you just love to do stuff like that. The difference is minimal, and have you ever de-soldered and 8 Pin DIP? Sheesh!!! It sucks. Overall the amp is very impressive out of the box for the money and size of it. And the design is such that it is not very mod-friendly. Even the speaker is a tight fit which requires that you leave off the little tube cage. If you are happy with it now I would let it be.

And now that you mention the blue jewel light, I think that would be an awesome addition! Thanks for the advice.

[RubyRae]

thanks for the info. i sounds like the speaker would be a cool consideration down the road. i once hooked my vcxd up to my hr deluxe to see what it sounded like thru my stock eminence 12", and the result was crapola. it actually sounde thin and just weird...i didn't fool around with it long enough to work out any decent sounds, but it was a fun experiment.

true story tho, the other day i found a JJ ax7 pre-amptube, and i really have no idea where it came from. i had been getting some funny, and unpleasant fret buzzing and the amp just seemed to be noisier than usual. i put the JJ tube in to replace the fender stock tube, and i was literally floored with the sound and spank of the amp. not sure how, but it cured the fret buzz too.
i know it sounds bizarre, but i was in heaven with the sound difference, and now i realize what a solid difference a tube upgrade can make.

i may try the 6v6 sometime too, but i am happy with the amp, and never get bored dialing in some gain and levels to my favorite voicings. it has been some of the most fun, and productive playing i have had in years. this little amp never ceases to amaze me.

[timmer114]

I often wonder how the SCXD speaker would fit and sound in the VXCD..

Another thing I wonder about is the cathode bias, if changing the resistor size would warm that up a bit, what the effect would be..

Hrmm...

[don jon]

Originally Posted by RubyRae

thanks for the info. i sounds like the speaker would be a cool consideration down the road. i once hooked my vcxd up to my hr deluxe to see what it sounded like thru my stock eminence 12", and the result was crapola. it actually sounde thin and just weird...i didn't fool around with it long enough to work out any decent sounds, but it was a fun experiment.

true story tho, the other day i found a JJ ax7 pre-amptube, and i really have no idea where it came from. i had been getting some funny, and unpleasant fret buzzing and the amp just seemed to be noisier than usual. i put the JJ tube in to replace the fender stock tube, and i was literally floored with the sound and spank of the amp. not sure how, but it cured the fret buzz too.
i know it sounds bizarre, but i was in heaven with the sound difference, and now i realize what a solid difference a tube upgrade can make.

i may try the 6v6 sometime too, but i am happy with the amp, and never get bored dialing in some gain and levels to my favorite voicings. it has been some of the most fun, and productive playing i have had in years. this little amp never ceases to amaze me.

I actually love the EH 6V6 my VCXD came with. I did immediately swap the 12AX7 out for a 12AT7. Which is a much more appropriate choice as the tube is actually not a pre-amp tube but a phase inverter. But anytime I buy an amp I swap the pre-amp tubes for Tung-Sol, NOS Mullard, Sylvania, or Phillips. That always makes a huge improvement.

[timmer114]

I swapped my EH tube out for 1950s Magnavox 6v6, it made the sound a little rounder, but I wouldn't say it's nessecarily better than the EH.

The EH is a really solid tube, good all around sounder. But if you do swap the 6v6 out, you will hear some difference with other tubes, which I was happy to find out. I was afraid that any tube swaps on this amp would be of little use if you wanted to audit some different sounds.

All the 12ax7's I have tried in it have sounded pretty much the same. What did the 12at7 do for your sound Don? Or I should say how did it change it?

Edit - I scrolled up and saw your glassiness comment, I might have to try a 12at7 out.

[timmer114]

Really love my VXCD, amazing practice amp. When my Wife was out of the house yesterday, I ran up the volume to about 6 and remembered how much better this thing sounds when you push it a bit.

I tried a Jensen CR8 in mine, it's a bit shrill, I went back to the stock speaker which I think is very underated in these amps. Still though, thinking a 10" would be great in this thing. I am tempted to make a pine cab out in the shop, put some snakeskin tolex on it and stick a 12" in it lol, but even stock the little thing is pretty heavy, not sure I want to lose that portability.

Still leaning toward using the stock SCXD 10" in there. It's voiced the same, I wonder if I would pick up a little bottom end..

[don jon]

Originally Posted by timmer114

Really love my VXCD, amazing practice amp. When my Wife was out of the house yesterday, I ran up the volume to about 6 and remembered how much better this thing sounds when you push it a bit.

I tried a Jensen CR8 in mine, it's a bit shrill, I went back to the stock speaker which I think is very underated in these amps. Still though, thinking a 10" would be great in this thing. I am tempted to make a pine cab out in the shop, put some snakeskin tolex on it and stick a 12" in it lol, but even stock the little thing is pretty heavy, not sure I want to lose that portability.

Still leaning toward using the stock SCXD 10" in there. It's voiced the same, I wonder if I would pick up a little bottom end..

The SCXD 10" would definitely be a bit cheaper than the Weber I sprung for. And you are right, those Eminence made Fender Specials are great speakers for their purpose. I didn't like them in my HR Devilles but I love them in my Blues Deville and the VCXD. Even in the Pro Jr. all the Blues Jr.'s I owned they sounded great until you pushed them too hard. They are really voiced perfectly for this small tone machine. I swapped out for an old Utah alnico 8" which was a great speaker for the old Champs. But it sounded buzzy and thin in the VCXD.

If you found an SCXD speaker on the Bay you could probably get it for $40 or less, and it is a tight fit but it will go in the cab. It is probably the same exact speaker that Fender puts in the Pro Jr. and the Deville 410. Also about the 12AT7. It cleaned up the overall voice of the amp and added a glassy tightness to the overdriven voices. The "pre-amp" in the VCXD is actually three Op Amps, so swapping out to lower gain valves does not lower your volume or gain like in most tube amps. The power tube is not just there for show though. I tried using my Yellow Jacket and running an EL84 in it for fun. That was a mistake that sounded like a fried transformer pushing a de-coned speaker.

[timmer114]

Thanks for the info Don.

I like that with the SCXD speaker, with 5 watts in front of it, I wouldn't push it too hard that it would fart out.

I'm still considering the Op Amp mod, but I know what its like pulling them, it's a pain and I'm not sure if it's worth it, but then again if I put a socket in there, I could always try some diffferent amps. Did it quiet that hiss? This is my 2nd VXCD, my first one had a bad tear on the bottom of the tolex that bugged me enough to exchange it. But.. it was much quieter than my 2nd one, I mean dead quiet. If an op amp swap would quiet that hiss some, I'll do the mod for sure, but I think it's just cheap transformers that cause that hiss..

[Jack Knife]

Originally Posted by don jon

I did immediately swap the 12AX7 out for a 12AT7. Which is a much more appropriate choice as the tube is actually not a pre-amp tube but a phase inverter.

Actually not. As a single-ended amp, there is no phase inverter in the circuit. The 12AX7 is just a driver tube, it amplifies the signal before sending it to the power tube. You'll still see the effects of different tubes' amplification factors but there's no PI functionality here.

And only half the tube is used so definitely don't buy a matched tube as a replacement!

Not harping, just didn't want anyone to get the wrong idea while upgrading.

[don jon]

Originally Posted by Jack Knife

Actually not. As a single-ended amp, there is no phase inverter in the circuit. The 12AX7 is just a driver tube, it amplifies the signal before sending it to the power tube. You'll still see the effects of different tubes' amplification factors but there's no PI functionality here.

And only half the tube is used so definitely don't buy a matched tube as a replacement!

Not harping, just didn't want anyone to get the wrong idea while upgrading.

Hi Jack,

Thanks for the correction. I was mistakingly calling the 12AX7 a phase inverter. That is due to my amateur misinterpretation of the official schematics. Here is a more accurate description of the function of the tubes in the VCXD from the mod master Billm I found on another thread:

"All of the preamplification, all of the voices, and all of the effects come from a digital signal processor. After the DSP is done, one stage of the 12AX7 (in the Vibro Champ) is a buffer from the solid state stuff and a driver for the 6V6. The other side of the 12AX7 is not used, as you noted. It is not a phase inverter because single-ended amps don't need one.

The Super Champ XD uses one stage of the 12AX7 as the aforementioned buffer/driver and the other one as a phase inverter, since it has two 6V6s in push-pull.

The tubes are there for the power stage only. They add some warmth and sweetness to the tone, but many owners will attest that they sound just as good from the line-out jack, which is a pure digital output." Billm

So it appears that some of the pins of the 12AX7 are a buffer for the DSP and Op-Amps and drive the 6V6. The schematics were confusing me. But it was apparent that the 12AX7 was not a pre-amp in the tube-amp sense of the term because all the gain and distortion comes from the IC's and DSP while the tubes act to simply warm and buffer the signal.

My bad.

[Jack Knife]

No problem and again, I wasn't trying to criticize. I know a lot of people like modding their stuff, as do I, and I didn't want anyone to go out and spend extra on a balanced PI tube to put in their VCXD.

PS - I totally dig the '60s hippy look of your amp with that custom grill cloth That's from *ahem* back in my day and we used to do stuff like that all time LOL