freestompboxes.org

Hello all,

I'm facing an issue with my Fender princeton reverb silverface. When i hit the strings (especially low strings), the amp cracks. It appears at 4 on the volume knob. It cracks only when hitting strings. Level is right, no loss.
I've changed all tubes with JJ. Also changed speaker (bought a Weber 10125). But the problem remains.
So, could it be a cap problem, or tube socket problem?

thanks,
regards,

Ed.

Ed22 wrote:I've changed all tubes with JJ. Also changed speaker (bought a Weber 10125). But the problem remains.

Now you know it's not the tubes or the speaker, but this is an expensive form of debugging.

Ed22 wrote:So, could it be a cap problem, or tube socket problem?

If you don't feel comfortable working on the inside of the amp, do take it to a tech. If the problem only occurs at 'higher' volumes with the bass string, maybe a solder joint has let go or another connection is broken.

Thanks modman,

that's true, changing tubes ans speaker is expensive. but there were probably some original tubes in it, RCA. the same for the old crappy oxford that came with those amps. I use this amp for gigs and these changes are inevitable.
thanks!

regards,

Ed.

Sounds like a loose solder joint - as Modman suggested. Fender amps sound great but they have some notoriety for solder joint problems. I would suggest (if you are VERY CAREFUL) checking the soldering on the boards. Before starting, make sure that you are comfortable working with high voltages...if not, take it to a technician. IF you are OK with this, then drain the caps and start checking the PC boards.

Modman seriously appears to be on the mark with this one. When you play, the vibrations rattle the loose connection, causing the static/crack sound.

claskowski,

thanks for your message,

regards,

Ed.

Hi,

I've finally found the cause of the problem. It comes from the reverb. when i disconnect the reverb (the 2 RCA cables) the amp works fine. reverb connected, there are those cracks at about 4 on the volume knob.
So there is a problem either with the reverb transformer or the reverb tank.
What could i do to check these two parts?

thanks,
cheers,

Ed.

I had a similar problem with an old traynor amp. I found a ceramic cap leading to the reverb had broken off and caused all kinds of crackling and noise. Check for broken connections and bad solder joints. Be careful.

Ok. i've checked solder joints and components leading to the reverb, but everything seems OK...
I've opened the reverb tank and i found nothing suspicious, no broken wires...

maybe the RCA cables...

thanks,

Hi,

i've tested the amp with another reverb tank. The problem remains.
So i suppose it comes from the reverb transformer or a solder joint (if that's correct this solder joint is REALLY tricky!)

thanks,

Ed.