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Bat 150 SE replacing 6C33-B power tubes problems

BAT 150 SE 6C33-B power tubes were replaced with 8 pcs new tubes. 3 of the new tubes blew out the 3 amp fast blow fuses and internal sparks were seen with loud nasty sounds emmitted from mid range and tweeter sections. These amps only feed only the non-bass sections.
The defective tubes are now replaced with good ones. Upscale Audio did not hesitate to send me replacements. Since they are out of stock on current production Upscale sent me NOS without any extra charges.
Is it normal because the 8 NOS tubes are new that the sound is now harsh, metallic and not sweet as it used to be.
Does anyone have any idea how many music hours app. this can take ?
Any advice on this matter is really helpfull to me.
Thank you.
128x128terryakhan
trcnetmsncom
431 posts
 
Hello Terry,

Sorry to hear about your problem. Yes the 6c33 tube can be a pain in the neck sometimes but BAT has done a good job of seeing to it that the amp is well protected.

From what I've heard there is a HUGE supply of these tubes so there is no need to worry about a shortage for a very long time. I'm sure the amps will be sounding as good as ever in no time.

Best of luck,
Tom
jfrech's avatar
jfrech
1,816 posts
 
I have RCA red base 5692's in the 6sn7 spots in my 75se. Much sweeter sound. Also I replaced the 6v6, but can't remember the actual tube.

Good luck !
terryakhan's avatar
terryakhan OP
109 posts
 
I like to thank everyone for their advice about the 6C33-B power tubes promblems that I was having.
300 music hours have now passed both amps are singing like I have never heard before, just amazing what new tubes can do. I would like to mention that Kevin Deal suggested that I clean the pins of each tube with grade 400 sandpaper and by applying a thin film of Walker SST contact enhancer really helps.
All eight new tubes glow at the same brightness also, since some of them used to be deep red on the large vertical black plate.
THX Terry
trcnetmsncom
431 posts
 
Hi Terry,

I'm glad to hear all is well with your BAT 150se monoblock amps. I did however want to give you a word of caution about applying the Walker SST or similar type of products on the tube pins. There have been many reported problems of this causing tubes to fail and taking the amp with them in the process. I have NOT heard of this being a problem with BAT tube amps but I do feel a phone call to BAT to inquire about this would be reasonable.

All the best,
Tom
terryakhan's avatar
terryakhan OP
109 posts
 
Hi Tom, thank you for the heads up. I have contacted BAT about the SST and their response is 'use at your own risk/void warranty'.
SST appears to act as conductor between contacts and since it is in paste form it can also create electrical shorts if it gets in contact with any other components especially the high voltage parts as explained to me by my supplier. I have been using this product to treat interconnect and speaker connections.(low voltage) and just started with the tubes. I think the way the application of the SST is made is extremely important. As mentioned I touch the tube pins forming a tiny dot without creating any drips and never painting the entire pin. I will post any problems created by the Walker SST.
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