Q: VCO pitch range

Discuss mods, hacks, tweaks, etc.

Moderators: altitude, adafruit_support_bill, adafruit, phono, hamburgers

Please be positive and constructive with your questions and comments.
guest
 
Posts: 3155
Joined: Fri Feb 17, 2006 5:35 am

Re: Q: VCO pitch range

Post by guest »

if you end having to order online for the opamps
you could just tack on the other stuff as well
it would probably help get up to the minimum order anyways

User avatar
antto
 
Posts: 1636
Joined: Thu Apr 15, 2010 3:21 pm

Re: Q: VCO pitch range

Post by antto »

i got tlc272ip and sockets
but no desoldering wick.. damn i guess i'll try to desolder IC11, and probably damage it

guest
 
Posts: 3155
Joined: Fri Feb 17, 2006 5:35 am

Re: Q: VCO pitch range

Post by guest »

if you can get your iron
to touch all 4 pads at once
you can lift one side out first
and then do the other

User avatar
antto
 
Posts: 1636
Joined: Thu Apr 15, 2010 3:21 pm

Re: Q: VCO pitch range

Post by antto »

got wick and desoldered the 6562 .. it was very tough and i thought i burned it but it still works (i accidentally touched the plastic part of the TUNE pot, now the knob cap won't go in grr)
socket's in, tested LM358 - slightly better but still not good enough (the lowest 2 notes were off)
tested TLC272 - right.. it's audiably good (haven't measured the exact freqs or anything)

btw, i also soldered something like a sort of socket for Q8, tested a few transistors i had..
most didn't work (the square wave output is just a little queter and it sounds more like the sawtooth, sothe transistors didn't change anything..)
surprisingly i put a small guy with the label "A1267 GR" and :shock: sounds the same as my A733P

guest
 
Posts: 3155
Joined: Fri Feb 17, 2006 5:35 am

Re: Q: VCO pitch range

Post by guest »

glad to hear the tlc272 did the job

im a bit suprised to hear that q8 swaps
dont have much of an effect
id be curious to see a comparison of beta
for those transistors
as its fairly beta dependent
although not particularly Vbe dependent

User avatar
antto
 
Posts: 1636
Joined: Thu Apr 15, 2010 3:21 pm

Re: Q: VCO pitch range

Post by antto »

yup, thank you guest ;]

as for the Q8 i made a little thread here
since i found even more transistors which work as good (soundwise) as the 733P
i tryied to measure the hfe with my crappy multimeter but i guess i'm doing something wrong or the legs are too short

Locked
Please be positive and constructive with your questions and comments.

Return to “x0xm0dz”