Four Hour Tube Amp Warm-Up

All tube amplifiers sound OK after 30 minutes. But if you listen carefully sound is getting better during 2-3 hours. Especially it is true for not feedback circuits. I also paid attention that this difference gets bigger after I tweaked and improved sound quality my 300B amplifier. I had McIntosh MC30 and Marantz 8b amplifiers. All of them benefited from couple of hour warm up.
Another fact, in recording studios all used tube equipment is switched on in start of the day and switched off in the end of the working day.

I am really sorry to hear your system requires such an extended warmup. For tube equipment this is simply rediculous. I have owned a PrimaLuna integrated amp for over 10 years in my home office.

Ditto

I may have never discovered it’s sweet spot.

When did we switch from amps to women?

My experience with warm up time has been so variable over thirty years, variability in comments not surprising to me. I've found system presentation or voicing, tube types and qualities, especially power tubes in amps, standby ability, number of tubes in entire system, AC quality, cabling, on and on ad nauseam, all have bearing of when system kicks in, even mood plays role. I just wonder if there is some point of stabilization applicable to every single little thing in our systems, and ourselves for that matter?

With -20 degree wind chill factors during recent listening session even thought about how temp could be affecting AC cabling exposed to these temps, specifically, could temp of wire affect sound quality? Obviously heat is of concern here, does more heat mean quicker warm up times, cold or cooler longer times? This meant in relation to all parts within components.

I only know every listening session has a point where things just kick in, assuming nothing breaking in. I only find consistency when my system is in static mode, meaning nothing changed over certain length of time.

1/2 hour to an hour should do it

Just wondering if this holds with the experience of other tube ampers.

@bolong No. It takes our amps about an hour. About 25 years ago our amps took about 3 hours but component improvements have changed that.

Since I initiated this thread things have changed for the better. Now my set up is sounding very acceptable after an hour warm up. Tweaking has helped.

All the power cables are Anticables, and they are all plugged directly into the wall now except for the cables to the Jay's Audio redbook transport and the Denafrips Terminator DAC  - those cables are still plugged into the Shunyata power conditioner. Running the Terminator in oversampling mode is now better.

Speaker cable is now vintage cloth covered Western Electric tinned multi-stranded 10 gauge wire which is complementing the Primaluna's and the Cornwall 4's with no loss of detail and good PRAT. The bi-wire jumpers are vintage 16 gauge Western Electric pink cloth wire which seems to slightly tame the treble. I tried it with 10 gauge WE jumpers, but the treble ran a bit hot that way. This may or may not be logical from an electrical engineering standpoint since the bi-wire terminals all theoretically end up in the same places internally but..whatever.

I have also been re-burning CD's from .flac to .wav (in JRiver) and think they sound better perhaps because of less computing in the signal chain and therefore slightly less noise.

Also discovered a 12au7 tube that was microphonic. Replaced it and now the background is much blacker. Also reinserted some vintage 12au7 Amperex "Bugle Boys" into the signal positions, and this has helped quite a bit. The Primaluna's do not like "alien" 12au7's, but just the Bugle Boys as signal tubes are doing fine.

Also, built some floor attached angling guides for the speakers so that they can be pivoted predictably and in perfect unison relative to each other and the back wall, and the distances between them can be exactly gauged relative to my listening chair. This has improved sound-staging quite a lot.

Tweak City over and out.

Same here... With the little soundartist el-34, 4hrs is needed to sound best.

@bolong +1; a weak tube can take a long time to warm up properly.

bolong +1; a weak tube can take a long time to warm up properly

Where is @tubebuffer these days?
As Confucius say, “Man with strong tube, need little time to warm up.”

After making some adjustments it is down to about a 2 hour warm up now.

Time has passed and the Sophia Electric EL34's are probably technically burned in now. I would say that about an hour and half use/warmup blooms them nicely. However, a couple of weeks ago I accidentally left the tube amps on for 7 hours unattended. When I got home that night and started playing I was taken back to the real, real "bloom." What can I say - there is this everyday operating dimension and then there is the dimension slightly beyond. I am hopeful that electrical theory will one day catch up.

Never experienced anything like that with pure tube amps. In fact I always find them quick to warm up. I once had a hybrid electrostatic headphone amp (grounded grid EL34 with solid state CCS outputs) that took like an hour to sound its best -- but I'm pretty sure that was from the transistors. 

@bolong I have to agree. 20 mins gets them up and running (same time needed to "warm up" my turntable bearing) but they do open up as the hours go by. By the time I’m turning the things off after 4+ hours, they’re at their sweetest and most three dimensional. This seems to hold at any time of the day too, so I don't think it's related to cleaner power as the day winds down. 

My experience is as a result of having a Vinyl / CD Source, along with ESL Speakers and Cabinet Speakers, is that with CD used as the first medium and an ESL, the Sweet Spot is usually quite present before an Album Side is over.

With Vinyl as the first medium and an ESL, the sweet spot is quite present on the second side of an Album and will be max'ed not too long after. I put some of this down to the Cart' findings it optimised condition as well.

Using Cabinet Speakers the Sweet Spot will appear at almost the same time line for both Vinyl/CD. The sweet spot can start to be noticed after a few hours. I put this down to the Drivers Suspension becoming optimised. When using the Cabinet Speakers I have conditioned myself to use CD as the first music as a Background music, prior to sitting in front of the system.

With the price of Vintage Valves, it is not a nice experience to have them wasted in use for Warming up other devices as well, to get them to an optimised function.

A 'cheapo' integrated amp' to drive the Cabinet Speakers for a period of time would be the most cost effective, preserving Valves for best SQ replays. 

Will try that. Thanks