Greetings Friends. A friend is the happy owner of a Vox AC15TB, 1996-2004 vintage. As I'm learning, there are many versions of the AC15 out there, with many opportunities for confusion. This may be the correct schematic, but it doesn't say AC15TB anywhere on it.
As I understand it, this version was built with one channel, and retains the Top Boost characteristics of earlier 2-channel versions of the AC15. The owner of the amp would like to rework this circuit to lower the treble frequencies, to achieve a tone closer to the Normal channel of a classic AC15.
My inexperienced-tech mind is leaning towards a simple removal or replacement of a Cathode bypass resistor (perhaps C12) to allow more of the lower freqs through. But a bit of research online points to a Cathode follower in the preamp circuit that could be adjusted in other ways.
Do you have any experience with this issue? Any advice, opinions, warnings welcome. Thanks for taking a look!
w
As I understand it, this version was built with one channel, and retains the Top Boost characteristics of earlier 2-channel versions of the AC15. The owner of the amp would like to rework this circuit to lower the treble frequencies, to achieve a tone closer to the Normal channel of a classic AC15.
My inexperienced-tech mind is leaning towards a simple removal or replacement of a Cathode bypass resistor (perhaps C12) to allow more of the lower freqs through. But a bit of research online points to a Cathode follower in the preamp circuit that could be adjusted in other ways.
Do you have any experience with this issue? Any advice, opinions, warnings welcome. Thanks for taking a look!
w
He's playing with treble on 0 and still too bright.
Here is a link to a webpage covering the Vox AC15TB and AC15TBX. Unfortunately there is no schematic.
Here is a link to a webpage covering the Vox AC15TB and AC15TBX. Unfortunately there is no schematic.
The TB option boosts the treble, the tone cut option is probably what you need. But wired in, not adjustable.
Fit a 4n7 400v capacitor between the drives to the output valve grids. See Treb Cut circuit ...
That'll take the nasty top parts off, or replace the speaker with a better quality speaker that gives a better bass response.
Fit a 4n7 400v capacitor between the drives to the output valve grids. See Treb Cut circuit ...
That'll take the nasty top parts off, or replace the speaker with a better quality speaker that gives a better bass response.
