View Full Version : Which amp instead of Vibro Champ?
10-15-2008, 09:53 AM
I have a late model silverface VC that I have fixed up. I still have an 8" speaker in it....I would like a small amp similar to this that would work for small to medium gigs.
I was thinking of modding the amp, but even with new transformers, will it really be louder with just one 6v6? New speaker (has a Weber)?
Is there an amp I could sell/trade (so not too much money) if for with similar tone, but a little more volume? I usually run it between 5-6 so I don't need clean cleans.
I have an Allen Old Flame that I can run at 25w, so something like a Deluxe Reverb would be too much amp. I think a Princeton would work, but they are spendy.
I don't care if I have reverb or not. I just want Fender blackface tones with a little more volume then the VC.
Bring your VibroChamp into a store, plug into a 4X12 cab running 4 ohms, and crank it. The VC is surprisingly huge sounding - don't be scared off by the 8" speaker limitation.
I see you have an Old Flame - doesnt matter if it's the 12, 15 or 2X10 speakers, hook the VC into it for a sec and check it out (the ohm mismatch won't kill the VC for a short turn, but long term i'd get a Z-Matcher if you're going to stick with that getup). See how you like it!
You may end up only having to pony up for a 1X12 ext cab for your VC and tote that to gigs alongside your VC. speaker options are unlimited. Heck, you might feel adventurous and run your 8" and the 12" in parallel and have the VC drive both at the same time, like so:
Basically, see what your amp can do for you before moving to another amp whose signature you may not even like.
10-15-2008, 10:14 AM
Sound advice. I did have the VC set up to go through the OF before. It sounded great. The speakers in the OF are Web Sigs, so not super efficient...so I wonder if I was gaining any volume? The Sigs are rated at the same db whether 10 or 8".
I was thinking, since the amp is already modded cosmetically, that I might cut the baffle to house a 10" speaker. Perhaps a Weber Vintage series?
Currently, I've replaced the straps and handle ($20). I also switched to an aged grill cloth (had extra from a diff project). The speaker is a Weber Sig 8 ceramic (cheap). The tubes are a JJ 6v6 and Tung Sol RI 12ax7 (came with amp). I have a 5v4 rectifier (had it) running in it. I had to replace a back panel too($20). The amp was super cheap and in tough shape when I got it. I am not against further hurting the resale value.
I plan on eventually getting a blackface plate for it too. I thought about a different cab, but they cost more than the amp. Right now I have less invested in the amp then what they go for here and on eBay. What a great piece of gear!
The amp is somewhat limited by the small cab and speaker, so the idea of an extension cab would work. I don't think you'll gain a whole lot with changing to a 10, although if you did I'd recommend replacing the baffle with a new one, that way you can go back to stock easily. There are a few circuit mods that will help as well - I'd do a search here - there is a mod (I think by John Phillips) that changes the cap and resistor on the power tube grid for more headroom. The other mod I recommend is the Area 51 fixed bias mod kit. I'd say you can get maybe a 15% improvement in headroom of the amp with those changes.
10-15-2008, 12:10 PM
Wow, you've done a lot to that VC...... Well, likewise I have an Allen Old Flame, and with it's excellent Master Volume control, I've found it can work in a wide variety of situations. I put a low gain 12AY7 in the V1 position though, which has lowered it's total volume output, while sweetening up it's clean headroom tone a lot... most of the time, I run it's volume knob about 7-8 (which is still really clean, with my guitar volume knob around 3/4 of the way up). Then, I just use the Master Volume control to suit the venue. Works really well with the custom 2x10 cab I'm using.
However, if you really want to use your VC with just a bit more oomph, you could try this: (which is what I did with my 79 silverface Champ with no ill effects)
Since the VC and Champs have the same power tranny as the Princetons, they will take a single 5881 power tube, PROVIDING you use a Weber WZ68 Copper Cap to replace the 5Y3GT rectifier tube.
The WZ68 will draw no heater filament voltage, making less load on your power tranny. The WZ68 should provide added power to your 5881 power tube so it will sing better without overtaxing the whole amp.
Yes, the output transformer is the limiting component, but you will experience a slight increase in volume, but a better bass response, especially if you use a Weber 8F125 as a replacement speaker or use a 4 ohm 2x10 extension cabinet.
I also have a Weber Z-matcher that I've used with my Champ for all sorts of weird and wonderful hookups. I even ran it with a closed back 8-ohm 1x15 cabinet loaded with an Electrovoice 15L..... talk about monstrous Champ action. That was giggable with a polite drummer and full electric band. Email me if you want more particulars or photos.
However, I sold that wonderful "Giant-Killer" grab n' go Champ to fund other acquisitions..... The Allen Old Flame seems to do it all now......
10-15-2008, 12:13 PM
Find a Musicmaster Bass Amp, put the VC's chassis into it and drop a ceramic Weber 12" into the cab.
Hoooooo-BOY!!! You'll be blown away!!!
11-05-2008, 12:12 AM
WoW, first post here. I've been at HC for the last few years but wanted to spread out. Hello all.
I'm planning on building a Vibro pretty soon and saw this post while scouring the internet for info. Triode Elect. sells a kit, the transformer allows for 8 and 16 ohms so that could be an option if you want to swap it out. I plan on throwing in a Celestion Blue in mine, the WZ68 and 5881 power tube idea sounds pretty cool for more ummph. Anyone know if it changes the tone? I really wanted reverb and a master volume, but for the price and size, this and some pedals should do.
11-05-2008, 12:17 AM
That outta do it.
Those old ampegs are great. Awesome alternative to fender. The midrange is a little smokier and more usable than fenders. Warm and full. Sound great with strats.
11-05-2008, 12:43 AM
I've got a '74 VC that i often run into a cabinet with a 10 (copperhead) and a 12 (red fang), wired for 4 ohms. That thing gets loud. And it sounds positively huge. I've thought about building a head cabinet for it.
And get a Weber 8A125 or 8F125 for the VC's cabinet--MUCH better (and much louder) speakers than the Weber Sig8.....even though the Sig8 is more "accurate" to the original.
FWIW, my '74 was in a similar shape to yours when i got it. between the amp, the capjob and mod i had done to it (pull pot on the volume which taps the 2nd triode of the vibrato tube for more gain--it's like a mini marshall), the NOS tubes, the new chassis straps and back panels, i've got more invested in it than i'll ever get out of it.
Doesn't matter--i'll never sell it. It's a little screamer.
11-05-2008, 04:18 AM
I run a champ through a separate 12... great combo. I have on occasions hooked a 2x12 and a 2x10 to it and it sounds huge. That 8 is the limiter. If that is not enough then a princeton is the way to go.
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