Lovetone Meatball

[PMowdes]

SonusFluxa wrote

I got it filtering but not 100% the sounds that I think it should achieve, so I put it on the back burner to work on when I have the time.

I did notice though that the input is grounded on this layout. This is an adaptation of Sabro's layout, and if you look at them side by side, you'll notice this one is missing the cut under D1. That should at least get you passing a signal.

I also ended up removing the moog switch and bridging the cut under the TL074, as well as using switches in place of some of the rotaries a la Sabro. Again, it's not 100% ( I think some of my wiring is still fucked up), but I at least have sound passing. Let me know if any of this works, or you notice anything else! This would definitely be a sweet one to have completed.

Good call on the missing cut.  I appear to have a signal now but it is clean, and only if the colour is switched almost off.

Seems that the led responds to the intensity dial as well.

Any ideas what i'm supposed to be adjusting the trimmers to???

[Ciaran Haslett]

Unless I missed it in the notes....R21 (220K) is missing from this layout.


You can squeeze it in to the right of VTL1 in the 2 holes right above pin 14


Hope this helps

[PMowdes]

Ciaran Haslett wrote

Unless I missed it in the notes....R21 (220K) is missing from this layout.


You can squeeze it in to the right of VTL1 in the 2 holes right above pin 14


Hope this helps

Thanks Ciaran

I had just arrived at the same conclusion.  On Sabro's layout there are two resistors R15 and R21 which aren't on JohnK's layout.

I'll check them on and see what happens

[Ciaran Haslett]

Didn't even get as far as the PSU...you're right!!  Another 22K forming the Vref.  It can go here

[PMowdes]

So I soldered in the missing resistors and now I just get a clean signal which doesn't change much with any of the settings.

I think that I have an issue with the sweep switch ( VTL1 should go to sweep switch B2 if I've read Sabro's layout correct)

I also think that I might have mounted my Vactrols upside down.  Should these be negative towards the bottom of the board??

[Ciaran Haslett]

Negative at the bottom yeah.

The schematic shows the cathode of all vactrol LEDs going to B-2 and C-1.  Looking at the layout of the Sweep rotary...is B-2 pin 6..NOT pin 7?

[Ciaran Haslett]

Just re-read the thread and can see you spotted that already RE the Sweep rotary.  Also compared the layout to Johns gut shot and you can see the 2 missing resistors to the right of the ICs AND the Sweep 7 wire clearly connecting to to pin 6.