ba662

[Karl ALEXANDRE]

	Well, i finally fixed my problem with some un-scietific manipulations.
	 
> What value output resistor are you using for the 3080? Remember it
> outputs current and not voltage. 10k to the 5V3 rail should be OK. Then
> put this into your follower. A fet is probably better here, source
> follower.

	You'll laught, but my knowledge in OTA and transistors being poor 
	i did the followig :
	
	i reduced r124 and r125 to something small enough to get a very few
	milivolt at the 3080 input. The other input of the vca is connected
	via 1M resistor the the cursor of a trimer, the two others terminals
	are connected to ground and 12v.
	The ota output is connected to the base of the npn via a 10k resistor. 
	The npn colector is connected to the 12v. The emited is charged with 
	10k to ground.

	It more or less works, sometime it clips (but softly), with a low 
	cutoff frequency i can hear some high frequencies at very low level
	(i don't know where they come from). The overall is very noisy.
	
	My question, which one of these two alternative is the best : 

	1 - Reduce the input swing of the ota and boost the control current ?
	2 - Raise the input and scale down the control current ?

	
	I'll try other ota, but as i'm not skill, i burn them :) I never burnt
	an opamp, but i burned ton of OTAs. They are very expensive (in my situation)
	a 3080 cost me  1.5$, a 13600 or BA6110 cost me 2.5$
	
> How are you triggering accent and slide on your clone? I am hoping to
> use velocity CV to control these on mine.

	The sequencer part is a 8051 with2 back ram and rom, basic midi circuit, nothing
	to be proud of.
	The code is inspired by the description of the sequencer I found on a 303 site.
	This description included an ascii chronogram of the slide an gate signals. 
	As i don't have an original 303 i can't compare, but it seems to be ok. I get 
	the feeling, but not the quite the sound. I compared it the rebirth, but it 
	seems that the rebirth sequencer is not the same as the original. I download
	the user manual to have a clue about the note duration.






						Karl.

PS: OTA clipping is certainly not wanted, but sounds great (fat soft crying sounds)