Vibro Champ volume issues (2024)

I have got a 64 Vibro Champ (no logo)yesterday and besides being near mint condition and all original the volume when turned to 10 is too low.The tubes are all original as they came in 64.

I haven't opened the amp but will need to make it louder for my needs.
Any suggestions? the speaker is the original custom made EV, look like there is no apparent issues...:hmm
Tremolo / vibrato works very nicely.:3zone
Just need MORE VOLUME from this little practice amp....

HELP please!!!
Thanks - Andreja

You say the vibrato circuit is working perfectly. Great that 12AX7 is fine and the photo resistor is fine.

I would check the 6v6GT because that is the easiest to check without pulling apart the amp. If swapping that tube doesn't help, check that there is no ground or loose solder anywhere by visual inspection. There is a cap that goes to that 6v6GT. Replace that and see if it helps. Check the voltage going to the 6v6GT. It should be 340v.but be aware that is 340v you're checking in there. Be careful what you touch. If you can't get anywhere with it bring it into an amp tech.

Here's the schematic

http://www.schematicheaven.com/fenderamps/champ_vibro_aa764_schem.pdf

J T said:

You say the vibrato circuit is working perfectly. Great that 12AX7 is fine and the photo resistor is fine.

Click to expand...

No photoresistor in a VibroChamp.

My first move would be to swap tubes with known good ones, at least V1, V3 and V4. V2 is the trem oscillatior, and won't affect volume.

If that doesn't do it, it needs to be opened up.

the speaker is the original custom made EV

Click to expand...

I've never seen an EV stock in a pre-CBS amp ever. Pix?

andreja marovic said:

the speaker is the original custom made EV...

Click to expand...

???

DrewB said:

Check the plate voltages on the tubes. If you have extremely low volume, I suspect a power-supply resistor has drifted way up. If that's what it is, you'll probably find the problem resistor connected to the plate of the output tube.

Click to expand...

This would be where I look after a power tube swap.

Worst case scenario - transformers.

For what it's worth, I love my '64ish Vibro Champ, but even after a thorough servicing, it's just not that loud, even on 10. I use a boost if I want to make it louder, and then it is capable of getting loud.

Do you have reason to believe yours is quieter than other Champs?

andreja marovic said:

I tried input N 2.Same volume as N 1.
Changed the old 6V6 for a NOS one....same.
Never owned a Champ before this one, I don't know how loud they can get, but I was expecting MORE VOLUME...I don't think that a swap of 7025 or 12 AX7 will have a input on the output volume...will probably need a look inside.

Click to expand...

Try a modern speaker swap. Weber makes great Champ speakers and that could easily increase the volume very substantially.

If you dont know how to discharge the caps and have some electrical understanding then make sure you update your Will before you start poking around in the chassis.

....or go to an amp tech.

Drawrein said:

See Also

How to increase volume of video online | Clipchamp Blog

Try a modern speaker swap. Weber makes great Champ speakers and that could easily increase the volume very substantially.

If you dont know how to discharge the caps and have some electrical understanding then make sure you update your Will before you start poking around in the chassis.

....or go to an amp tech.

Click to expand...

Thank you for this wise words....I have no intention of taking my hand from my poket while touching this small beast with the other one.The amp man is the last solution but a possible reality in near future.

Does the speaker holes work for Weber speakers? no need of drilling new ones?

https://taweber.powweb.com/weber/

https://taweber.powweb.com/weber/

https://taweber.powweb.com/weber/

A socket wrench for the nuts, speaker drops right in and solder two wires. That's it.

If soldering is beyond your abilities you could ask Weber to pre-wire the wiring harness for you. Then it's just plugging a RCA jack.

blauserk said:

For what it's worth, I love my '64ish Vibro Champ, but even after a thorough servicing, it's just not that loud, even on 10. I use a boost if I want to make it louder, and then it is capable of getting loud.

Do you have reason to believe yours is quieter than other Champs?

Click to expand...

My experience also. I have tried speaker swaps as well. They sound like they are about 3 watts, they are even too quiet for home use. I have several BF Champs.

Dave:bike

Wow, even 3 watts should sound half as loud as a 30 watter. My Classic 30 could move my drapes. If a true 3 watts is too quiet you must be wailing?

What about electrolytic caps? They may be getting toward their end by now if they are originals.

D

BC Audio said:

How much power is it putting out? Do you know how to measure it?

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No, I don't know how to measure the output.
But I suppose that 0ne 6V6 can make lot of noice.I own a AC15 HW and it has 2 EL84 and it's very poweful.2 6V6 in a Delxe are very loud also...
The actual output of my Champ is just too low from what I expect to have.

The electrolitics need to be checke out.Yes they are still the same from 64.

Wally said:

There should be a manufacturer's code on there....probably 465 XYY.....'465' is the code for Oxford and the xyy would be the last digit of the year 'x' and the week for the year 'yy'.

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Yep. Every BF/SF Champ/VibroChamp/Bronco I've seen had an Oxford stock.

hi andreja!

from my experience your amp should be so loud that you´re afraid to turn it up to "10" when you live in an appartment - with neigbours/wife/kids around.

a healthy v-champ should be fine to hang in a jam-session at moderate levels. bring a booster to be heard at your solo-spots and don´t expect to have the guys on the other side of the drumset hear exactly what you play - but still...

the old speakers were very inefficient, though. that´s part of their sound, but if you want a bit more volume i´d recommend a jensen c8r or similar.

still, your situation sounds like there´s something not quite right with your amp.

cheers - 68.