Vox AC30 build into a trainwreck rocket

[JoeCon]

Dave G,
"..a simple 8 knob control panel." What?? 8 knobs simple? More time spent playing with the knobs than playing music. How about Vol-Tone-Master...done. Keep it simple lad!

Greg,
About the RJ Rocket Booster being boomy the Rocket was known by some here as a Fat Bottom Girl. Many have recommended changing the .047 coupling caps to .022. If you've bypassed the 2nd stage with a cap try something small like 1uF rather than another 22/25uF.

See ya!

[renshen1957]

Dave G,
If you've bypassed the 2nd stage with a cap try something small like 1uF rather than another 22/25uF.

See ya!

Hi,

I would suggest that 470nF would be closer to the mark for the 2nd stage in the preamp.

Best regards,

Steve

[gktamps]

Thanks, JoeCon!
Greg

[JoeCon]

Steve

OK I'll try that in my next build. Really cuts out that "fat bottom."

[renshen1957]

Steve

OK I'll try that in my next build. Really cuts out that "fat bottom."

Hi,

I used this value also to put the sparkle back into the Vox AC30 builds that use 2k2 screen resistors instead of the 100r that Dick Denney originally used.

Best regards,

Steve

[Gaz]

Steve

OK I'll try that in my next build. Really cuts out that "fat bottom."

Hi,

I used this value also to put the sparkle back into the Vox AC30 builds that use 2k2 screen resistors instead of the 100r that Dick Denney originally used.

Best regards,

Steve

Kevin O'Connor, is that you?

[renshen1957]

Steve

OK I'll try that in my next build. Really cuts out that "fat bottom."

Hi,

I used this value also to put the sparkle back into the Vox AC30 builds that use 2k2 screen resistors instead of the 100r that Dick Denney originally used.

Best regards,

Steve

Kevin O'Connor, is that you?

LOL

[Gaz]

You know, the 470n (or thereabouts) bypass cap is really a good trick, and I'm surprised you don't see it more often. Then again, you can easily overdo it (see: Hiwatt).

[dave g]

The drawing I posted displayed 1uF bypass caps on the second and third stages, but with the disclaimer that I have not built or tested the preamp and it was something I scribbled down in 10 minutes to illustrate a rough concept :p I think things like exact values always need to be tweaked by ear, so all the values I chose are really just my estimates of the order of magnitude that the component's value should fall into.

I'm thinking about building a two channel amp like this in the near future - if anyone else ends up doing the same, it might be fun to run wild with the preamp design and post what we all individually come up with.

[Curranproducer]

OK I popped in the .047 coupling caps into the circuit, as well as the 33k input resistor. I also upgraded the resistor/cap combo on the power section to the bigger wattage pieces. only got to goof for a little bit and I think there is a HUGE change in the tone between the lower resistor on the input 68k to 33k and the tighter lowend of the .047 from the .1uf on the couplers before the power section. i am still going to upgrade the 1k5 and the 100R resistors in the power section to the higher wattage of the trainwreck schematic. I don't know if that is going to change the tone of the amp at all BUT what the heck!!! I still dont have the PPIMV installed but that is comingin a few days I think