Sunn 350b

[Shaolinmarine]

I have an" old" Sunn 350b that has just been completely reworked but it still has an old problem the tech couldn't fix. When the volume is tuned up 3/4 - full it shuts down. No sound. Then within a few seconds it comes back on but does this repeatedly. Any ideas for what can cause this? Evidently he talked to numerous techs and no one had any ideas.

[edbass]

Originally Posted by Shaolinmarine

I have an" old" Sunn 350b that has just been completely reworked but it still has an old problem the tech couldn't fix. When the volume is tuned up 3/4 - full it shuts down. No sound. Then within a few seconds it comes back on but does this repeatedly. Any ideas for what can cause this? Evidently he talked to numerous techs and no one had any ideas.

No offense to your choice of techs, but your amp is a pretty straight forward hand wired point to point amp. You might want to take it somewhere else...

[MONOLITHLOUD]

Originally Posted by edbass

No offense to your choice of techs, but your amp is a pretty straight forward hand wired point to point amp. You might want to take it somewhere else...

Agreed! I tried to locate a schematic for you but to no avail. Otherwise I would try and help.

[edbass]

The 350B is just a 2000S with a SS rectifier instead of the GZ34's, I don't have a schematic handy but they are available on the web pretty easily.

[MONOLITHLOUD]

Originally Posted by edbass

The 350B is just a 2000S with a SS rectifier instead of the GZ34's, I don't have a schematic handy but they are available on the web pretty easily.

Great, Ill check it out.

[OneWayPunk]

Originally Posted by Shaolinmarine

I have an" old" Sunn 350b that has just been completely reworked but it still has an old problem the tech couldn't fix. When the volume is tuned up 3/4 - full it shuts down. No sound.

Not sure what your problem is but damn...where are you playing that you need to turn a 350b up 3/4 to full on? I have never had mine above 5 on the volume knob, brutally loud.

But back to your problem, it's probably a heat failure in one of the components, check the dropping resistors in the power supply. It could be a failing solder joint as well. A good tech should be able to fix that.

[Sartori]

Originally Posted by OneWayPunk

Not sure what your problem is but damn...where are you playing that you need to turn a 350b up 3/4 to full on? I have never had mine above 5 on the volume knob, brutally loud.

Methinks the OP is in a very loud band. Possibly doom. I can easily see a 2000s/350B being turned up 3/4ths of the way in a doom band.

[D.M.N.]

Originally Posted by OneWayPunk

Not sure what your problem is but damn...where are you playing that you need to turn a 350b up 3/4 to full on? I have never had mine above 5 on the volume knob, brutally loud.

I run my 2000s at about half power when I'm playing with my psych blues band.....and that's quiet for us.........

But idk, I probably need mine serviced, as it's loud at 5, but not brutally, it's pretty bearable. Hm....

[quincy_j_clomo]

hey. just wanted to let you know, i had the same exact problem with my v4 a while ago. my friend ended up reflowing all of the solder joints in it, and it hasn't had a single issue since. sometimes, it really is that simple. good luck.