New model Fender Bassbreaker 15 repair

[Enzo]

Here, try this. By the way, they were a tremendous pain to work on.

[printer2]

Did not call, was reading in another forum and the amp came up, I am a curious sort so I wanted to see the schematic. The searching paid off this time.

Thanks for the Princeton. Again, just for my curiosity. Barely a mention about it out there, just wanted to see why not.

[Enzo]

Princeton Recording was not a successful model. You don't hear about them because no one bought one.

[Palantine]

Has any of you run into the tick/pop noise (someone says "faint crackling") in stand by?
I did a search and find in another forum a guy to whom had the preap tubes changed by the tech at the store, BUT "the problem actually doesn't seem to be fixed" (his last post on the thread).
I also have a BB15 combo and I notice the same noise in stand by. The crackling intermittent noise disappear in ON mode (at least the last time I used).
This crackling noise seems to increase at every new switch-on (I mean day by day).
As far as I know the stand-by is sort of a fake "standby" because the amp is full working but the switch just cuts (mutes) the signal to the speaker.
Any idea? Solution?

[Justin Thomas]

It doesn't mute the signal to the speaker. It mutes the signal going into the phase inverter, to allow for silent recording. Which leaves the entire phase inverter & power amp to be making noise in Mute.

I wouldn't want to open one of those up unless it was with a grenade. It's got that folded chassis with multiple boards held together by jumpers. Good luck!

Justin

[Palantine]

It doesn't mute the signal to the speaker. It mutes the signal going into the phase inverter, to allow for silent recording. Which leaves the entire phase inverter & power amp to be making noise in Mute.

I wouldn't want to open one of those up unless it was with a grenade. It's got that folded chassis with multiple boards held together by jumpers. Good luck!

Justin

Maybe is an easy fix......many owners spot this problem.

[Palantine]

[QUOTE=Justin Thomas;555105]It doesn't mute the signal to the speaker. It mutes the signal going into the phase inverter, to allow for silent recording. Which leaves the entire phase inverter & power amp to be making noise in Mute.

I wouldn't want to open one of those up unless it was with a grenade. It's got that folded chassis with multiple boards held together by jumpers. Good luck!

Justin

Here we go!

Resistors are OK (236 ohm both), diodes measure 0,960 but are NOT resistive, electrolytics measure 40 and 41 uF......I'll change diodes for new ones and replace electrolytics with higher temperature class, but I see no reason to remove those Zener, since in my case they have not become resistive (no measure in ohm).
That said, I have redplating in one EL84, the closer to the speaker.
The redplating lasts two or three minutes after turning on the amplifier, during which I can hear pop corn and "faint crackling" noise in MUTE and then stabilizes and I have no more redplating. Switch the MUTE off and the amp play flawless.
Anyway I don't remember this abnormal behavior when the amp was brand new; every time I turn it on again, the noise and the redplating increases.
What do you think?

[nosaj]

[QUOTE=Palantine;556435]

It doesn't mute the signal to the speaker. It mutes the signal going into the phase inverter, to allow for silent recording. Which leaves the entire phase inverter & power amp to be making noise in Mute.



Justin

Here we go! [ATTACH=CONFIG]58163[/ATTACH]

Resistors are OK (236 ohm both), diodes measure 0,960 but are NOT resistive, electrolytics measure 40 and 41 uF......I'll change diodes for new ones and replace electrolytics with higher temperature class, but I see no reason to remove those Zener, since in my case they have not become resistive (no measure in ohm).
That said, I have redplating in one EL84, the closer to the speaker.
The redplating lasts two or three minutes after turning on the amplifier, during which I can hear pop corn and "faint crackling" noise in MUTE and then stabilizes and I have no more redplating. Switch the MUTE off and the amp play flawless.
Anyway I don't remember this abnormal behavior when the amp was brand new; every time I turn it on again, the noise and the redplating increases.
What do you think?

Check solder joints on tube socket an associated resistors.
Nosaj

[52 Bill]

That said, I have redplating in one EL84, the closer to the speaker.
The redplating lasts two or three minutes after turning on the amplifier, during which I can hear pop corn and "faint crackling" noise in MUTE and then stabilizes and I have no more redplating. Switch the MUTE off and the amp play flawless.
Anyway I don't remember this abnormal behavior when the amp was brand new; every time I turn it on again, the noise and the redplating increases.
What do you think?

Switch the two EL84 tubes and see if the redplating stays with the socket or the tube.

[g1]

Also swap the EL84's around, see if the red-plating stays with that socket, or moves with the tube.

[Justin Thomas]

That's the BassKraken 15. Wow, what an assembly! They're conpetibg with Mesa dor the most stuff in the tiniest package.

Jusrin

[Palantine]

Switch the two EL84 tubes and see if the redplating stays with the socket or the tube.

Well....yesterday I received the spare parts ordered.
Replaced electrolytics with new ones, replaced diodes with new ones (obviously same values), resoldered the cathode resistors (which were into the specs)....took me almost 3 hours from 5 AM (I was listening Dixie Chicks and James Taylor as the light of day came....).
Switched on.....the red-plating was still there with pop corn noise, but in the OTHER tube.....bad italian words everywhere!

I said to myself "calm down"; I switched the tubes and red-plating disappeared.

Now, really I don't know if the new components needed sort of break-in but with this configuration the amp works.
Swapped these tubes in favor of another duet of TAD EL84 CZ (nothing but rebranded JJ EL84 as the suffix indicate).....and still no red-plating and no pop corn noise.
Switched the two TAD and again: no red-plating and no noise.

I cannot conclude (realize) the amp is fixed, because in my opinion I did not spot the problem, but the amp works...at least till the next issue.
There is something strange happening in the 'power on' process; maybe an oscillation coming from the PI.....really I don't know.
Anyway and again, thanks Folks for your help!

[Helmholtz]

Could be an intermittent tube socket contact. Most probably grid pin.

[g1]

Also, re-solder the power tube sockets (if you haven't already).