The Amp Garage

hi again, think i found the reason for the 17.4 V issue. In the original 63 vibroverb schematics R 37 is a 6.8 k. They have replaced this in the new model with a 39 k. If I replace this one with the original used 6.8 k, i get the 17.4 V at the driver cathode. So they just replaced the resistor with ...

btw,

i have looked in the schematics of 63-vibroverb, which was the original of this amp,
and it tells also 17.4 V for TP17.

i attach it here.

cheers

thanks Stevem,

i will check these.

cheers

thanks stiltamp,

may be they have really used 17 instad of 71.
ok i keep on searching for the reason for the distortion ...

cheers

Hi sluckey, thanks for your reply. Indeed I'm measuring something over 70 V (about 75). Also I found no reason for a difference between 17.4 and over 70. The cap from the anode of the tube before is well, also the other resistors around have their values. However, I'm having terrible distortion when...

Hello, we have a Fender Custom Vibrolux Type CSR 8 Serial Number AB007538. The device has a terrible distortion in both channels. We find at TP17 instead of 17.6 V DC about 70 V DC. This is the cathode of the driver tube, last stage before power tubes. I have attached the schematics as a pdf. Custom...

Don't agonize over impedance matching for this. The airbrake is a resistive load, speakers are inductive. What this means is that a speaker's impedance varies a lot depending on the frequency. Look at some speaker curves and you will see this. The actual impedance of an airbrake is sort of an avera...

http://ampgarage.com/forum/viewtopic.php?t=8733 thanks lot. i think it would work just to add a 25 ohm /20 watt resistance in serie to the 25 ohm resistance between switch position 4 (bedroom). this would raise the 25 ohm original to 50 ohm in position 4. this should lower the -11 dB original to ab...

vibratoking wrote:Take a look at the original Airbrake design in the Trainwreck files section.

thanks for responding.
do you have the url perhaps?

cheers

hi,

how can i mod a dr z brake lite to reach lower bedroom level?

thanks for a tip.

cheers