Ted Weber's 6V15 kit schematic w/ differences between it & 1960 JMI/Vox AC15 OA/031

[dchang0]

With tedweber.com's website rebuild (a big improvement), they removed the hidden 6V15 schematic that Ted was working on.

Here is a repost of the schem, with the differences between it and the original 1960 JMI/Vox AC15 OA/031 schematic highlighted. Sorry for the low resolution--the original was 72dpi.

The original values are not provided here.



Here's hoping they finally release the 6V15 kit for sale. It would make building AC15 clones a lot easier.

[dchang0]

Whoops, I noticed an error: C26 is also one of Ted's mods.

This is the new schematic--please ignore the previous one.

[Matt R]

No difference between this schematic and original JMI really. The c26 is in the original. The only differences would be the variable vibe/term speed and the higher cap values at the pi filter. Also the modulator tube should be a 12au7 not 12at7.

[MarkusBass]

That's interesting - in the other thread on Vox AC15: http://music-electronics-forum.com/t41160/ , the Brilliance capacitor is in series with the Normal Volume pot, and here it is parallel to the pot (as a bright cap). Both versions cannot be correct. Which one is correct?

Mark

[dchang0]

C26 (0.022uF capacitor) as shown in the 6V15 schematic is not in the original OA-031 schematic. The confusion arises from the fact that Ted Weber relabeled all the components. C26 on the original OA-031 schematic is a 500pF capacitor.

[dchang0]

Good catch! From the original OA-031 schematic, the Brilliance cap (C5, 250pF) is in parallel with the Brillance switch (SW5).

Ted's is incorrect. I don't know if he intended it to be that way or if it is just an error on his part. It's due for a highlighting to show the difference, though.

[dchang0]

Per MarkusBass' discovery of the Brilliance switch in series rather than in parallel, here is version 3 of this schematic. Thanks, Mark!

[dchang0]

Found two more differences. Ted's input jacks and tremolo depth are wired differently than in OA-031. Here's version 4.

[Dave H]

- in the other thread on Vox AC15: http://music-electronics-forum.com/t41160/ , the Brilliance capacitor is in series with the Normal Volume pot, and here it is parallel to the pot (as a bright cap).

In the original VOX circuit the brilliance capacitor cuts low frequencies but has no effect on high frequencies. In Ted's circuit the brilliance cap boosts high frequencies but has no effect on low frequencies. The two circuits are going to sound completely different.