The right way up for Tubes in an amp chassis..

[Jacew]

Re: The right way up for Tubes in an amp chassis..

Well, Marshall was one of if not the first high gain amp -so maybe it makes sense that they were learned this made their amps dissipate heat better plus they wanted the weight in the bottom because they were designing stacks in a tall narrow head early on.

But I firmly believe that the oscillation from a fan that is hard coupled to the chassis will cause issues with solder joints before heat on the components will on a well designed amp -I have upside down Fenders that have the original components from 60 years ago.

I don't think 100plus watt 6550 amps have a choice thought -gotta have a fan.

Fender's original inverted arrangement comes from the desire for the controls to be on the top or angled and making more room from the speaker or enabling a smaller overall cabinet - I don't think heat was a concern in their original designs.

I've never had a heat problem though -except solid state amps ironically, but I buy quality proven amps, keep my valve amps dialed and keep the amps ventilated (not against the wall).

Yes. Solid states are much more prone to the problems. Tubes are very good at dissipating excess heat compared to those, needing huge extra cooling systems to work.

Tube amp combos really need to have back open enough for ventilation and can havepossible issues with vibration. I prefer heads partially because of that. (Just never found to really like open back cab in terms of tone anyway)

 

[NegativeEase]

Re: The right way up for Tubes in an amp chassis..

Yes. Solid states are much more prone to the problems. Tubes are very good at dissipating excess heat compared to those, needing huge extra cooling systems to work.

Tube amp combos really need to have back open enough for ventilation and can have possible issues with vibration. I prefer heads partially because of that. (Just never found to really like open back cab in terms of tone anyway)

I like many open back models for clean tones, always prefer closed for cleanish to dirty typically.

I had a Peavey Roadmaster head with a fan in the late 80s that sounded like a damn jet winding up.

My Marshall JCM 800 50W 2204 was loaded with 6550s and I would push it really hard back then -probably my favorite high gain amp I've ever owned -and with 6550s instead of EL34s it would get the kind of hot that the OP/TS is talking about, but it was never an issue -even after a 2 hour gig

 

[dave74]

Re: The right way up for Tubes in an amp chassis..

The fan in my Dell laptop is more annoying than the fan in my triple.
Mesa did it well at least. It's probably as small as they could get away with and still meet the safety standard.
I feel no vibrations at all through the chasis or parts. Still though I'd rather be without it, just one more thing to collect dust.

 

[NegativeEase]

Re: The right way up for Tubes in an amp chassis..

The fan in my Dell laptop is more annoying than the fan in my triple.
Mesa did it well at least. It's probably as small as they could get away with and still meet the safety standard.
I feel no vibrations at all through the chasis or parts. Still though I'd rather be without it, just one more thing to collect dust.

Yeah, if there's any amp with a fan that hasn't bothered me it's the Mesas.

 

[Jacew]

Re: The right way up for Tubes in an amp chassis..

How do you even hear the fan when playing? Or does the fan motor cause noise in tube amp?

 

[dave74]

Re: The right way up for Tubes in an amp chassis..

Only time it bugs me is when I stop playing and try to hear if that was someone banging on the door downstairs or the woman/kid yelling for me to "turn it down!".

It's usually neither, nor do I usually care anyway lol.

 

[SoPhx]

Re: The right way up for Tubes in an amp chassis..

Non-issue. My 66 year old 5C3 Deluxe agrees.

 

[beaubrummels]

The right way up for Tubes in an amp chassis..

I have a JTM45 with tubes up, a Traynor with tubes down, a VOX with tubes sideways I believe? Or maybe they’re down (can’t see inside very well), and a ‘57 Twin RI and a SuperReverb with tubes down. I’ve run them all for hours and hours in the studio and never experienced any parts failures.

The only amp that’s a problem is the VOX. It’s so noisy they actually had to document the noise problem in the manual saying “it’s normal”, and they even added a switch to change how it operates to make it ‘less noisy’. That is a design flaw to me.

But when you think about it, they are consumer items. They are made to a price point. They don’t expect them to last forever. They want you to buy it, use it, then buy a newer model.

 

[Mincer]

Re: The right way up for Tubes in an amp chassis..

I have to say, Mesa did great with their fan. Mine has the tubes facing down, with the heat rising. The fan is on, but even after 20+ years, it is silent, and you can't hear that thing at all.