Smoked my first carbon comp resistor w/soldering iron - Radio Shack, here I come

[Downhome Upstate]

   Oh, well. Anyone going to say 'welcome to the club'?

[Paully]

Welcome to the club, though I have to admit I haven't smoked one.  I usually put the LEDs in backwards.  Must be a nice Radio Shack, I can't remember the last RS I was near that had carbon comp resistors.

[Grainger49]

I just broke about 4 in a row.  They are delicate.  If you call the Queen she will send you another first class mail.  CC is the best here, carbon film is next. 

[Downhome Upstate]

Welcome to the club, though I have to admit I haven't smoked one.  I usually put the LEDs in backwards.  Must be a nice Radio Shack, I can't remember the last RS I was near that had carbon comp resistors.

Hey, Paully. Yeah, you're right. After 3 calls to different Rat Shack locations, I gave up. Decided to buy some stuff with the store credit I had with pcX, and threw the 220R 1/2 watt 5 percent'ers for the Seduction grid stoppers (like the one I smoked) in with the order. Gave me a chance to stock-up on quad-eutetic solder, solder wick, and make some shorting plugs while I'm at it.

[Downhome Upstate]

I just broke about 4 in a row.  They are delicate.  If you call the Queen she will send you another first class mail.  CC is the best here, carbon film is next. 

Hey there, Grainger. Yup. I was trying to un-solder one that was uncomfortably close to its neighbor when the body just kind of disintegrated. Had my soldering station on 700. Must have stayed just a wee bit too long.

[earwaxxer]

Because of my OCD I replaced the CC's with Tants. I do have some CC's waiting in the wings though, when I feel the need for a mod. From what I have read, the CC's have a nice 'tubie' sound to them. They are old school though, and not very reliable (that was the trip wire for my OCD).

[Paully]

All this talk of buying stuff from Partsconnexion is making me itch.  I suddenly need to solder.  Ok, what can I build that I really don't need?

[Doc B.]

All this talk of buying stuff from Partsconnexion is making me itch.  I suddenly need to solder.  Ok, what can I build that I really don't need?

My vote - think I'll put one of these in my A-80:

http://www.ebay.com/itm/Nixie-Bargraph-IN-9-Stereo-VU-Meter-Fully-complete-kit-/270989833877

[Grainger49]

OOoooooo, Ooo, Ooo, Ooo!  I may have to buy one of those!  Thanks for the link!  (sad when an engineer is so easily amused?)

[Downhome Upstate]

Definitely fits the bill !!

[Paul Joppa]

Welcome to the club, I've smoked several. Metal films are a good substitute, and I see no reason to reject carbon film either. I expect we will make the switch eventually.

Traditionally, the bulk resistance of carbon composite has been assumed to be best because it has no inductance beyond that of its length. (Film resistors usually have a small spiral of conductive material which has a bit of inductance.) But VoltSecond, a long term Bottlehead who doesn't post much these days but is an excellent EE with tons of relevant professional experience, reports that he's used metal films as gate stoppers on extremely high transconductance FETs with great success. That's good enough for me - the real world trumps even the best theory, every time.

[rock4016]

I've heard radio broadcasts come through an amp from using metal films as grid stoppers on high transconductance tubes, so it would depend on where the amp is used.

[Paul Joppa]

Wow - thanks for posting - it's always good to get more data! Much appreciated.

[rock4016]

I wish I could give more details, but I didn't build the amp.  I also know that Decware uses or used to use metal films(Dale/Vishay) as grid stoppers for the 6DJ8, which I would put in the high or higher than average gm catagory.  So we may be talking about "certain" brands of metal films on "certain" tubes, like a 6C45pi 

[coca]

I have had a lot of good results in using mills non inductive wire wound resistors in that position as grid stoppers.

Bernie.