7199 glowing purple?

[GLF]

I have a 7199 that is glowing purple, I do not know what brand of tube it is, the only markings are 7199. Is the tube safe to use.
? Thanks.

Andrew

 

[fdegrove]

POPE COLOUR.

Hi,

I have a 7199 that is glowing purple,

This could be due to the tube being slightly gassy.

In time the getter should burn these gasses off, so for the time being it should be safe to use it.

If it is really leaking it will die on you though, worst case: a blown bypass cap and cathode R.

Cheers,

 

[GLF]

Ok, Thanks. Will see what happens, I am going to replace the input board on this ST-70 anyway.

Andrew

 

[fdegrove]

ST70.

Hi,

If memory serves me correctly, the Curcio mods don't use this 7199 anyway.

And if later on, you want to kick the Maggies real good with monoblocks I still have some aces up my sleeve.

Cheers,

 

[GLF]

Re: ST70.

And if later on, you want to kick the Maggies real good with monoblocks I still have some aces up my sleeve.

Cheers,

What would these aces be? I have a line on another power transformer for about $50 US. Was thinking about making some MK4 wannabees.

Andrew

 

[fdegrove]

ACE OF BASE.

Hi Andrew,

PSU mods is what I had in mind...especially with the Maggies in mind...

While it may seem a bit mysterious at first, a Class AB amp having to drive current hungry speakies like the Maggies can do with a beefed up B+.

Keep in mind SY's remark that the Maggies are power hungry and you'll see the point.

Cheers,

 

[GLF]

Fdegrove,

Could your PSU mods be done to a ST-70 or would I need the mono blocks?

Right now I am torn between a few options

I could go with the Curcio or welborne mod.

But I also have the chance to pick up another power transformer, and I know someone who could help me build the chasis for the mono blocks.

I am a college student, so I have a limited budget, so I dont want to put money into something I will not use for that long.

The amp is in what appears to be great condition. I have had it running for about 10 hours since I got it and it has worked great, no noise or hum to it at all. So I think it might be ok to leave alone for a while. Well, besides the selenium rectifier which should come out friday.

Do you think it would be worth it and try for the mono blocks, or just do the input mod to the amp now and leave it?

Andrew

PS. I must say that I like this place a lot better then AA. There is some good information over there, but the amount of crap far outweighs the good stuff.

 

[fdegrove]

BEER BUDGET MODS.

Hi,

Could your PSU mods be done to a ST-70 or would I need the mono blocks?

Doesn't matter, no need for monoblocks.

I could go with the Curcio or welborne mod.

My vote of confidence would go to Joe Curcio.
Why?
I read the articles in Glass Audio, all I need for a profile really...I trust the man and his judgement...entirely subjective I admit, so the choice is yours.

Well, besides the selenium rectifier which should come out friday.

Ahemmm...what's wrong with those?...I often whish I could find some.

Do you think it would be worth it and try for the mono blocks,

If you were to stretch the budget even further than maybe...

PS. I must say that I like this place a lot better then AA.

Great...I provide most of the crap around here anyway....

Hope we have you around for ages,

 

[Colt45]

"Ahemmm...what's wrong with those?...I often whish I could find some."

when (not if) they die, they release posion..
not to mention that Si is superior..

 

[Morse]

Hi GLF;

RE: your original question about the purple glow, is the glow a diffuse bluish glow spread throughout the interior of the valve, or is it only on the interior of the glass and/or plate(s)?

If it's a diffuse glow, it's a gassey valve as Frank already noted. However, it could just be that impurities in the glass are fluorescing via electron excitation. In other words, if the glow is only to be seen as a sharply defined blue or purple light on the surfaces of the glass envelope and/or plates of the valve, it's just fine.

All the best,
Morse

 

[fdegrove]

SE RECTS.

Hi,

when (not if) they die, they release posion..

Which is why you wont find any anymore.

In the case of the SS tube replacements, they are usually encapsulated though.

They provided a behaviour that had all the advantage of tube rectifiers, slow turn on and no HF crud.

Modern diodes such as Schottkys would be better still but the B+ will rise as well...hence my remark on the SEs.

Cheers,