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View Full Version : questions for folks with vibro-champs re: vibrato and gain

exhausted
11-03-2008, 04:57 PM
when your vibrato is disengaged, does the overall gain of the amp decrease as you turn up the intensity control?

i'm measuring voltages and my voltage at the cathode of the V1B stage increases as the intensity control is turned up.

i'm trying to figure out if this is normal but i don't have a reference to compare to as this is my only single-ended vibrato amp.

all my wiring looks good and my voltages are fine according to the schematic (bearing in mind slightly higher wall voltage).

any help is appreciated.

http://picasaweb.google.ca/exhausted1975/MarshAmpsFenderVibroChampClone#

some pictures of the build. it's the same effect regardless of the extra 15K i added at the intensity control to ground.
Axekisser
11-03-2008, 05:34 PM
Well known and documented with the VC.

The Trem is bias modulation and that effects the volume and bass on the amp. If you have the trem on or off you'll get a reduction in volume and bass when turning the intensity up. I just turn the intensity down to keep the bass and volume up.
exhausted
11-03-2008, 05:38 PM
ok, excellent, thank you. i was searching and searching and couldn't find anything on this particular bit.

i was sure i had everything correct but needed this last bit of confirmation.
trisonic
11-03-2008, 05:53 PM
Another tip is to turn the Bass and Treble controls down when you get it distorting - just sounds nicer to my old ears. Do a search for John Phillips' name he contributed a number of posts on how to get the best out of a VC

I like them, many think they are toylike but they are very handy to have around.

Best, Pete.
exhausted
11-03-2008, 05:56 PM
Another tip is to turn the Bass and Treble controls down when you get it distorting - just sounds nicer to my old ears. Do a search for John Phillips' name he contributed a number of posts on how to get the best out of a VC

I like them, many think they are toylike but they are very handy to have around.

Best, Pete.


thanks. will do. yeah, it's only been alive for a day but i widdled the bass down to about 3 when i had it driven. it'll take me a while to learn the amp as always. i'm happy so far.