Tube amps and heat
Interesting thread. This subject...heat..is one that many a'philes should consider before purchasing the tube amp with multiple power tubes, IMO. BTW, BAT is one of the worst offenders in this regard with their tube amps. ( Not saying their ss amps are). A good general rule is to look for an amp that is lower powered and has as few power tubes as possible. Fewer tubes= less heat. Plus, IME, the lower powered tube amp most time sounds a lot better than its higher powered brethren. To the OP, depending on budget, I would suggest the new CAT JL5 Black Path amp...a superb peace that doesn't give off too much heat; or again if budget allows...a Jadis JA30Mk2, which is the amp i am currently using and it is magic. |
I’m in AZ as well and know what you’re talking about. I have summer and winter setups. My BAT VK55 is a heat monster and right now with temps reaching the nineties it’s reaching my limits for afternoon operation. If I don’t want to change speakers, I can switch to my VAC amp which runs much cooler but doesn’t sound quite as good. In my summer setup I use a tube preamp (VAC or Manley) with a W4S amp. I think you just need to find a tube preamp that mates well with your Bel Cantos. The PrimaLuna preamps are tube rectified which make more heat so that may not be the solution either. The Manley is really good for the money. I like it way more than the Audio Research preamps. |
A year round solution is to add two small fans to the top of the tube cage. See http://ielogical.com/assets/Audio/PrimaLunaAmpFans.jpg Fans are 60mm x 10mm 12v https://www.amazon.com/gp/product/B00KIDDEP2 powered from a DC 3v supply https://www.amazon.com/gp/product/B07663HSRN Center fans over each power tube pair. Mount w #3 machine screws atop a 1/4" nylon spacer. Wire so the fan is blowing up. Fans barely tick over and are absolutely quiet. It takes very little air to remove the heat. Amps sounds more consistent when kept within a consistent temperature range. Been doing this since the 70’s. |
To all the fan proponents, it’s a no go. AZ summers peak at up to 120 day time and stay 95 overnight. A/C systems run almost continuously. If one room generates much more heat than others which requires the thermostat to be turned down, then you run the additional expense of cooling the remainder of the house which doesn’t require additional cooling. Most houses have vaulted ceilings so there is no easy way to install an exhaust vent over equipment either. Any additional heat in the summer is your enemy! |
@rhljazz +1 More than a decade ago in the 95 - 100 degree heat of a Philadelphia summer, with a pair of popular Class A tube mono blocks that ran as hot as Hades, my wife put her foot down for the one and only time. And I use several (ceiling and floor) fans and the air conditioner. She never said to get rid of them, but that they were a DEFINITE no go in the dead of the summer, and to put them on hiatus until September |
Tube amps don’t need to be on all the time. 20 minutes is more than enough time to stabilize. Solar input for Arizona is around 8 KWh/m²/day. A 2400ft² roof is about 1.8 GIGAwatts per day. A refrigerator, computer, TV and all the other electric stuff generates far more heat than a tube amp. The San Fernando Valley has many days over 100°F and mid 20th century houses were not very well insulated. A 40w tube amp is about 0.2 kW/h. The additional heat when dissipated by the fans will not be noticed. |
Thanks guys for the suggestions. I've evaluated everything that has been suggested here. Rhljazz has hit it on the head. Maybe other appliances generate more heat but I doubt it. When you have small room with a 14 tube amp it's like putting a heater in the room. The past few days I've been using the BelCanto's and just maybe I've been concerned for no reason. The Bel Mono's are really close to the Prima Luna. Not quite there but close. In fact with a few tracks on my play list I thought they might be better. For me personally it seems easy to sway my impression of what I'm hearing. I can tell it's, different but sometimes different can be a nice change. Don't get me wrong I can tell if something is crap (for me) but in this case both systems are very nice. I guess I just got used to the Tube sound over the winter. I might still look for a fix, but a air conditioner in the window isn't one of them. As for fans and vents to take the heat away I've looked at that and for my room; not gonna work. Thanks again. Gary |
(most) Tube amps do have issues. Heat, tube life, tube matching, and the fact that iron core output transformers add a lot of chassis weight and distort the music that you don't realize until its gone. Check out Linear Tube Audio, which licenses David Berning's ZOTL design. I'm running ESL speakers with the ZOTL40 amp, which really puts out more than the rated 40 watts/ch. At least with my speakers, the speaker/amp handshake is just about perfect. If needed, it can be bridged as mono for nearly twice the rated output. The amp weighs less than 10 pounds, tubes last 10-20 years because they aren't run hard or spew a lot of heat. The sound is so clear and linear you think SS except you are hearing the beauty of the tubes, not the iron transformers. I run a quad of NOS Mullard XF2 EL34s, hard to beat. |
To all the fan proponents, it’s a no go. AZ summers peak at up to 120 day time and stay 95 overnight. A/C systems run almost continuously. If one room generates much more heat than others which requires the thermostat to be turned down, then you run the additional expense of cooling the remainder of the house which doesn’t require additional cooling.@onehole149 One of our customers lives in Guatemala City, and if you think it gets uncomfortable in Arizona, try adding some humidity to that. He does not like air conditioning (he could have it if he wanted, he's a millionaire and just the art alone in his house is worth more than everything I own), and has our largest amp which has 42 power tubes **per channel**. In his listening room, the amps can be on all day and night (I know because I've been there) and yet the room stays comfortable. This is because he installed vents in the ceiling above the amps. The heat rises, and a low power fan at the other end of the ductwork in the ceiling moves the heat out of the house. He has a light switch on the wall to run the fan. Its silent, inexpensive, draws very little energy and the amps don't contribute heat to the room. |
Running a DAC/pre direct to an amp, especially class D, can sound a bit dry and cold. I'm willing to bet if you put a tube preamp that is a bit warm blooded, may be a Conrad Johnson or older ARC model, you'll get that element that you feel you're missing. Regarding hybrids, I can recommend a Vincent SP-331 or SP-331 MKII for a bit more money. It has tubes in the input stage and delivers 150wpc into 8 ohms and doubles down to 300wpc into 4 ohms. Very underrated amp for its price. |
I had a pair of Golden Tube Audio power amps wired as mono blocks back in the day. I sweated my nuts off in summer and got tired of tube rolling and the associated microphonics of NOS room heaters, so I sold them used at The Sounding Board , formerly in Ridgewood NJ, where I sold the High End part time. Took a beating on my price... Pretty much stick to Solid State and Digital these days, except for my Cary LSI -80 |
I live in western India where summer temperature ( Highs ) is 40-46 degree Celsius (104 - 115 degree F ) everyday during day time , my tube amp is AES SuperAmp Signature 35 wpc with 4xKT88 , 2x E88CC and 2x6BQ5 . I have A.C. fitted in the listening room. I have three vents ( size 55 x 55 mm each ) with holes in the bottom plate of my amp chassis and installed a fan 50 x 50 x 10 mm ( 12 Volt ) over only one vent to push the air from bottom of the amp into the amp interiors . The other two vents are without fans. More ever on the top of the amp , under each power tube KT88, there are 6-8 small holes in the metal chassis around the tube socket , from where the hot air escapes upward brushing the glass of each tube. This arrangement keeps the heat of amp under reasonable control . I am thinking to add two more fans of 50 x 50 mm under the other two vents also , but not sure if that would be too much air to blow into the amp ! |
