I changed my tubes.

[Spudmurphy]

I realised that I hadn't changed the tubes in my Marshall since I bought it (in '87) so yesterday, I went out and got some EL34's and ECC 83's. (Electro Harmonix, and Sovatex)

There was hardly any room (in the combo) so it was easier to slide the chasis out of the case to change them. As I did so I realised that there was another ECC83 hiding behind one of the transformers, so tomorrow, I'm going to have to get another and slide the chasis out of the case again - ho hum !!!

At least it doesn't have as many tubes as a Mesa Boggie that was down my buddy's repair shop - I counted NINE output tubes !!!!!!!!!

Whilst in the shop Burke Shelly was there (Bass player from Budgie '70's UK Band)
and he said that he couldn't remember the last time he changed his tubes.

Anyway the Marshall retained its sweet sound and was worth doing.
Spud

 

[Sigmunds Couch]

I realised that I hadn't changed the tubes in my Marshall since I bought it (in '87)

A Brit calling a valve a tube. Who'd a thunk it?

I change my tubes in amps al the time. Last time with Electro Harmonix. Like these the best..

 

[Spudmurphy]

A Brit calling a valve a tube. Who'd a thunk it?

I change my tubes in amps al the time. Last time with Electro Harmonix. Like these the best..

Yup, and I'll be calling car bumpers "Fenders" (don't they try to make guitars ?)
and Car boots "trunks" ,
I've spent too long with my family from St Louis

 

[Adwex]

But do you get in a lift to get up to your flat?

Couldn't resist.

 

[Tim O'Sullivan]

Did you re-bias your 'valve' amp? It wil probably sound better if you do this!

 

[Spudmurphy]

But do you get in a lift to get up to your flat?

Couldn't resist.

lol

First time I went to St Louis I smoked.
I said to my cousin "I could murder a fag"
- now what a look he gave me !!!
Ha!
Spud

 

[Spudmurphy]

Did you re-bias your 'valve' amp? It wil probably sound better if you do this!

Hiya Tim

Not sure whether you need to do this?

My mate who gave me the tubes is an amp repair man and he didn't say anything about "re biasing".

The tubes were matched pairs.

PM me or post to this thread to educate this moron on rebiasing.
Spud

 

[blackspy]

I'd get a new amp repair man, if he didn't even suggest biasing the amp... Assuming, of course, your amp needs biasing.

 

[Spudmurphy]

I'd get a new amp repair man, if he didn't even suggest biasing the amp... Assuming, of course, your amp needs biasing.

I've known him for 30 + years so it'll be hard for me to see him go ha!

Nah, I'll mention it to him when I see him on the week end.
My Marshall handbook says nothing about it though, but I'll definately be checking this out.

Thanks

 

[Mick]

I've known him for 30 + years so it'll be hard for me to see him go ha!
.

Thanks

I know my mom for 36 years and she still gets on my nerves , sometimes.

Go and get a rebiasing for you amp it will sound better and will be more reliable.

 

[FoxMustang]

First time I went to St Louis I smoked.
I said to my cousin "I could murder a fag"
- now what a look he gave me !!!
Ha!
Spud

LOL, in some parts of the country you'd probably get arrested for a "hate crime" for saying that out loud

I know fag = cigarette, but I've never heard the phrase "murder a fag" before. Have to remember that one

 

[blackspy]

LOL, in some parts of the country you'd probably get arrested for a "hate crime" for saying that out loud

I know fag = cigarette, but I've never heard the phrase "murder a fag" before. Have to remember that one

I'd qualify as a mass murderer.

 

[Tim O'Sullivan]

Hiya Tim

Not sure whether you need to do this?

My mate who gave me the tubes is an amp repair man and he didn't say anything about "re biasing".

The tubes were matched pairs.

PM me or post to this thread to educate this moron on rebiasing.
Spud

Re-Biasing is an adjustment that should be made when new valves are fitted. Some amps such as Boogies and 5150's have a fixed bias. Marshalls on the other hand can and should be adjusted.

 

[SteveB]

In addition to what Tim said, amps also need to be re-biased if you modify the tube set, such as switching from 6L6's to EL34's (or vice versa). However, some of the newer amps actually have a 'switchable' bias to allow for this.. specifically, the Peavey Triple XXX and the JSX.. and perhaps some of their other tube amps.

 

[mhorse]

In addition to what Tim said, amps also need to be re-biased if you modify the tube set, such as switching from 6L6's to EL34's (or vice versa). However, some of the newer amps actually have a 'switchable' bias to allow for this.. specifically, the Peavey Triple XXX and the JSX.. and perhaps some of their other tube amps.

It's a common feature - Mesa Rectos, VHT's, Genz Benz amps, Laney GH's all have it. I'm sure I missed quite a few.

As far as biasing, some people (like the guy who runs JJ tubes business, but also some others) recommend modding fixed bias amps to make it adjustable on the basis that Rectos and 5150 and most other fixed-bias amps are biased too cold. If I understand correctly, that puts less constraints on tube characteristics. Can someone with good knowledge of tube electronics comment on that? It seems like everyone present perspective that benefits them the most.

 

[Spudmurphy]

I've learnt a lot from this thread.
I saw my mate again today, and got the missing VALVE! today
I'm going to fit it tomorrow as tonight I have a fireworks party (Guy Fawkes night for us Brits).
I mentioned the biasing to him and he said that the replacement valves were Very close specs to the originals. However he told me to drop the amp down to him and he would check it all out for me free gratis
- (He's a sucker for a jar of pickled onions at Xmas time and my Mam makes wicked pickled onions !!!)

 

[Spudmurphy]

Oh I forgot to mention !! Whilst there he showed me a valve that had literally melted - I tok some photos of it and will post them in the future - maybe start a "House of Horrors" photo collection !!!