Do tube amps really sound much better when warm... ??

othomas2 · Post by **othomas2** » Thu Nov 05, 2009 6:53 pm

Usually I pick up the guitar, switch on the amp and play straight away... in 10-15 stints.

Today i left the amp to warm up and it sounded so much better than I'd been giving it credit for... Probably the reason why I've been so happy with the amp during recording & rehearsal sessions and not so much when messing around at home. I just wish I could crank it now !!!!

What could be described as the differences in sounds between hot and cold ? what brings the science ?

O

kim · Post by **kim** » Thu Nov 05, 2009 6:59 pm

i always let my amp warm up for a moment when i turn it on, does make a difference yes, to me i just feel like it just sounds more ... proper.. don't know how to describe it but yeah..just, the texture is better and just sounds more the way i want it not all sterile.

laterallateral · Post by **laterallateral** » Thu Nov 05, 2009 7:03 pm

I think this may vary from one amp to another.
My 77 YBA-1 definitely sounds peaky until it's been on for like 15 minutes.
My bandmate's more recent Classic 50 sounds good right from power up.

Maybe this has something to do with old Vs. modern. Maybe it has something to do with EL84s reaching optimal operational conditions earlier than EL34s...

But I've definitely noticed this with cretain amps. It's not fairytales.

chisa · Post by **chisa** » Thu Nov 05, 2009 7:09 pm

theoretically they shouldn't sound any better the longer they are on.

kim · Post by **kim** » Thu Nov 05, 2009 7:13 pm

with more drive and gain they do though, just sounds warmer and fuller and nicer textures and stuff happening.

laterallateral · Post by **laterallateral** » Thu Nov 05, 2009 7:18 pm

The longer they're on, as in better and better over an indefinite period, definitely not. But from cold to warmed up, in my experience definitely sometimes. I don't know enough about tubes to know why that is or if it's even about the tubes for that matter but this is one thing I can't file in the malarkey bin.

Reece · Post by **Reece** » Thu Nov 05, 2009 7:23 pm

i imagine it might be true for larger amps.

tiny terror is good to go 10 or 20 seconds after turning it on. I usually flick on the standy switch and tune up though so it's usually warming up for a minute or two.

chisa · Post by **chisa** » Thu Nov 05, 2009 7:46 pm

most amps don't actually need a standby switch either

laterallateral · Post by **laterallateral** » Thu Nov 05, 2009 7:48 pm

You seem to know a lot about this.
Can you explain why most tube amps don't need standby switches?
I'm not trying to be snarky BTW, I'm genuinly interested.

chisa · Post by **chisa** » Thu Nov 05, 2009 7:56 pm

if it is a rectifier valve amp the standby supposedly damages that valve, most el84s don't need standby either - i forget why, i read a big essay some amp maker did on the subject something to do with how the valve warms up. the only amps that need standby switches are large 6l6, el34, etc non-valve-rectifier amps. i'll see if i can find the article and post it here.

i think mike knows a bit about amps so he might be able to clarify it a bit more.

Dogma Hollow · Post by **Dogma Hollow** » Thu Nov 05, 2009 8:12 pm

The explanation I heard about why tube amps sound better hot than cold was this:

Usually with electronics, heat is the enemy. But with tubes, some heat is good for tone, as long as it's not excessive. When you heat a glass tube, it expands slightly, thus slightly increasing the vacuum inside the tube. Somehow (I forget how the guy explained it, but he was a fuckin' amp genius so I didn't know better than to question it) this results in better tone, and a nice, natural compression. It made sense at the time, I just wish I could remember the details.

This is why I will never own a 100 watt amp unless I'm running a full stack...which I'll probably never do. 4 tubes just don't heat up as much as 2, and 50 watts can get ear-bleeding loud enough. Plus 100 watts is only 25% more volume, so it's a waste on all levels to me.

Will · Post by **Will** » Thu Nov 05, 2009 9:24 pm

I've had the opposite experience on occasion - too much heat makes the amp sound grungy and overly compressed.

Freddy V-C · Post by **Freddy V-C** » Thu Nov 05, 2009 10:08 pm

I don't know whether amps sound better after they've warmed up or not, but we've supported a band who were obsessed by it. They wouldn't let any other bands use their amps, but it was really difficult to find anywhere to plug our own amps in because they left them plugged in and turned on all night to 'warm up.' I can understand that amps might sound better when they have warmed up, but do they really need THREE FUCKING HOURS to warm up? [/rant]

chisa · Post by **chisa** » Thu Nov 05, 2009 10:37 pm

Freddy V-C wrote:I don't know whether amps sound better after they've warmed up or not, but we've supported a band who were obsessed by it. They wouldn't let any other bands use their amps, but it was really difficult to find anywhere to plug our own amps in because they left them plugged in and turned on all night to 'warm up.' I can understand that amps might sound better when they have warmed up, but do they really need THREE FUCKING HOURS to warm up? [/rant]

if that happens to me i just turn them off and tell them it'll have to wait. fucking corksniffers. being on standby isn't good either leads to cathode poisoning or something like that. you only need put a large amp on standby for 30 secs then it is good to go.

Rayjaysonic · Post by **Rayjaysonic** » Thu Nov 05, 2009 10:42 pm

I like to warm my amp up for a bit, starts sounding good (to my ears but could just be fooling myself) after 15 minutes or so. A studio I frequented a while back had a Gas Cooker Valve DI box and the guy who owned the place swore by turning it on at least an hour before it was used. Great piece of kit, bloody expensive but probably the nicest DI box ever made.

Progrockabuse · Post by **Progrockabuse** » Thu Nov 05, 2009 10:58 pm

Rayjaysonic wrote:I like to warm my amp up for a bit, starts sounding good (to my ears but could just be fooling myself) after 15 minutes or so. A studio I frequented a while back had a Gas Cooker Valve DI box and the guy who owned the place swore by turning it on at least an hour before it was used. Great piece of kit, bloody expensive but probably the nicest DI box ever made.

as used by Richard Thompson

Post by **Mike** » Thu Nov 05, 2009 10:59 pm

chisa wrote:theoretically they shouldn't sound any better the longer they are on.

This isn't the first time you've alluded to science without actually backing this up - enlighten me please.

I do know physics and I believe the reverse to be true.

chisa · Post by **chisa** » Fri Nov 06, 2009 12:43 am

Mike wrote:
chisa wrote:theoretically they shouldn't sound any better the longer they are on.
This isn't the first time you've alluded to science without actually backing this up - enlighten me please.

I do know physics and I believe the reverse to be true.

well once the circuit has reached working temperature which is about after 15 seconds it won't sound any different. why do you think it being on longer makes it sound better?

chisa · Post by **chisa** » Fri Nov 06, 2009 12:45 am

here's the article i was talking about

http://psg.com/~dlamkins/lamkins-guitar ... dby-switch

laterallateral · Post by **laterallateral** » Fri Nov 06, 2009 4:15 am

That was an interesting article. I think this establishes that no damage will be done to tubes if they are allowed to to reach operating temperature before submitting them to high voltage but it does not account for what Will was alluding to. Could it be that even tough the circuit reaches maximum temperature after 15 seconds, that it is the tubes' glass envelope expanding over sustained heat that cause amps to sound different after being on for several minutes?

I actually paid attention to how my amp sounded tonight. Immediately upon power-up and then, after being played for about 10 minutes. With no tweaks to the settings either on the amp, on the floor or on the guitar. I gotta say, if this is all corksniffery then call the short bus cause I saw a difference. Cold, my amp sounded peaky in the highs and seemed overly responsive to my playing dynamics. Almost like a bad EQ job. After a few minutes, this subsided and it seems the top end became smoother, more compressed. I also noticed clearer low frequency response at that point. Hey, maybe my amp is fucked! But maybe there's more to to this cause alot of people's amps seem to be fucked in this particular way.