Electrovibe Chorus volume

[doublej]

so this may not really be trouble shooting, I have never had a uni-vibe and maybe this is how they work but on vibrato volume is full just with the effected signal. on Chorus I also get the effect but at a pretty decent volume drop. I have messed with the trims inside and have the volume maxed out. should I have a decent volume loss on chorus, not really perceived but obvious. I will get a pic as soon as I can

 

[Bricksnbeatles]

I’m not familiar with authentic univibe circuits either, but I’ve seen the volume drop mentioned by a few people on the forum

 

[NickC]

I can confirm, the volume drop is normal for this circuit.

 

[Bricksnbeatles]

R4 is the place, for those interested, to start tweaking for unity gain. I'll be tweaking this in my build so I'll be the guinea pig here.

Probably worth just using a trimmer

 

[doublej]

R4 is the place, for those interested, to start tweaking for unity gain. I'll be tweaking this in my build so I'll be the guinea pig here.

so I may sound like an idiot here but which one is R4, I couldn't find a doc with the locations. I just know its 47k

 

[doublej]

View attachment 15804

thank you!!

 

[Jonnytexas]

Quick question fellas. I gigged mine this weekend and the tone was glorious, but I did notice the small volume drop. Would R4 need to go up or down to increase volume?

 

[Jonnytexas]

Up.

The R1/R4 divider can be tweaked to allow more signal to pass into the circuit. Stock, it lets 68% of the signal get through. So if you find that you are having volume issues, you can tweak R4 up. For example, 100k goes to 82%, 250k to 92%, 2M to 99%, etc.

I'd maybe tack in a 100k pot and see what gets you to unity, or a volume in general that works for you, then replace with the closest fixed resistor

Ok, thanks, will report back.

 

[Jonnytexas]

One more question before I fire up the iron....should I go 2M? Then I have the volume pot to dial it back if it's too much. Also, if I was to use a pot to dial it in, I would use lugs 2 and 3? Sorry for the newb questions, Still learning

 

[doublej]

Up.

The R1/R4 divider can be tweaked to allow more signal to pass into the circuit. Stock, it lets 68% of the signal get through. So if you find that you are having volume issues, you can tweak R4 up. For example, 100k goes to 82%, 250k to 92%, 2M to 99%, etc.

I'd maybe tack in a 100k pot and see what gets you to unity, or a volume in general that works for you, then replace with the closest fixed resistor.

I know you didn't design the circuit but why would stock only let 68% through, I mean why would someone want a vol drop? is that how the original worked?

 

[forumimagedemarque]

Hello there, Just giving my little feedback on this topics. I was also finding that the Electrovibe had a low output level. Then I found your thread and tried to swap the R4 - 47k to higher value. Experimented with a 1M Pot, which I found still too weak. Then with a fixed 2M resistor : this one is definitely the way to go in my opinion. Make the Electrovibe goes from discreet to where I should have hopped it would go. I'd say it's going above unity around 2 or 3 o'clock. Allowing a slight boost of volume when maxed out. Hope this helps for future builders Anyway thanks to you for the tips.