NOS???

[Ant]

Hi All,

I'm relatively new to the site due to the fact that a few mates of mine have asked me to repair their valve amps. I was up until about 10 years ago, a TV repairman and I gave that up on when they became cheaper to buy/replace rather than fix.

Anyway, the few valve amps I repaired were very much done by the expert help I received on this site - thanks to all.

To cut a long story short, I'm finding all of a sudden that I'm getting more requests to repair more and more amps just by word of mouth. This is good and I suppose a bit flattering but I don't feel totally comfortable as this is not my area of expertise. This doesn't mean however that I won't take on the challange!

I just posted this thread to ask if any of you would recommend any reading (especially sites) where I could brush up on the theory side of things? e.g. Just read a post on this forum talking about "NOS" tubes - What the heck is a NOS tube? I'm feeling a bit out on a limb here so any pointers then please put them to me (along with a short explaination on "NOS"

[myfoot]

N ew
O ld
S tock

Supposedly tubes that have been laying around for years and are brand new/never used .

[Alex R]

Hiya. I've almost always worked on guitar amps (and hifi, and jukebox, recently), and like you I'm discovering (after putting up a website in my case) that there is quite a demand for this kind of work in the UK musical community, and not many people to supply the service. Which is good news. I'm always having problems and thinking 'I bet an ol' TV repairman would know the answer to that'. So ask away, and the expertise will go both ways I'm sure.

[Earl]

Hey Ant - MPO is that if you're gonna work on tube type amps, you can get through a significant percentage of problems with fundamental DC voltage checks, or resistance checks. This aside from the typical crusty pots. jacks. bad connections, etc.

http://www.tpub.com/content/neets/ is an excellent website that covers about everything, and starts from ground zero. I like this series, as it has a lot of excellent tube theory in it.

[Marc]

other links

Hey Ant - MPO is that if you're gonna work on tube type amps, you can get through a significant percentage of problems with fundamental DC voltage checks, or resistance checks. This aside from the typical crusty pots. jacks. bad connections, etc.

http://www.tpub.com/content/neets/ is an excellent website that covers about everything, and starts from ground zero. I like this series, as it has a lot of excellent tube theory in it.

Ant,

Earl's link was chock full of amazing stuff, not just electronics. Two other sites to look for tube related reference I'd reccomend are geofex.com the tube amp debugging pages and Aiken amplification for theory.
There are many others out there but those two will get you started off really well.
The london power books are also good if you get into building your own gear, which will happen if you keep at it. sooner or later some guitar slinger will come to you looking for their holy grail.

Marc

[Satamax]

Ant, as Marc said, the tube amp debuging page is amazing, realy, it's all you need to know to repair old valve amps. http://www.geofex.com/ampdbug/ampdebug.htm

I know Fcuk all in electronics, besides ohm's law, and i can get by most of the times. Never given any of my amps to repair, and i repair amps for friends and few customers from time to time. Thought, i'm trained as a guitarmaker. And i'm completely stumped by solid state, i've had this marshall 8080 colecting dust for years because i'm unable to find the problem with theses blacks multi legged warts or green pcb. At least a valve i shake, if it's rattly, i know it ough to be microphonic.

Bye.

Max.

[stokes]

Ant,a great book is the Jack Darr book,which can be downloaded for free at
www.pacificrecone.com/Jack Darr Book.html It covers a lot of tube amp info as well as solid state stuff,might be good for you too,Max.Like you I am also short on the solid state info,mainly due to a lack of interest in it,but one day I'll read those chapters.You will have to type in the link to connect.