I am considering adding a tube buffer to my system. I would place it between my 990 and my 7500. However I was wondering would just adding it to the main speakers be sufficient or should I look to add one to all channels? Obviously if my only concern was 2-channel listening I would just add it to the mains, but I do listen to a lot of multi-channel SACDs. I was wondering if just using a tube buffer on the mains in this mode would cause some disparity when listening to multi-channel. Also, if you do add it to all channels does that include the sub as well?

Another question is in regard to tubes (I have never been a tube owner), I understand they take sometime to warm up before the function properly. Therefore, do you just leave them powered on at all times or do they warm up relatively fast? Which is better for longevity, powered on or power cycling them?

I am planning on going with the Yaqin as it seems to have good reviews and a reasonable price for an experiment.

Any feedback on this subject would be appreciated.

I can't speak for the tube buffers since I've never used them. In any event, I would think a tube buffer would be wasted on the subwoofer channel.

Almost all of my system is tube based, and I have never found that tubes need any more of a warm up period than perhaps 5 minutes at the most. Tube power amplifiers actually reach optimum operating temperature faster than solid state power amplifiers because of the bias drift inherent in solid state designs as the heat sink temperature stabilizes. The bigger the heatsinks, the longer the stabilization period.

I would not leave tube gear on at all times. The constant emission from the cathodes shortens tube longevity more than any turn-on power surges might. Some tube gear has surge limiting in any event, so this is not an issue. Ironically, the older tube designs which used tube voltage rectification had built-in surge limiting by virtue of the fact that the rectifier tube required a finite amount of time to warm up before it passed current.

Mdrconsult,

I am a former owner of a Model 990 but current owner of two Yaqin single twin triode tube buffers and one Musical Fidelity X10v3 tube buffer. I used all of them in a 5.1 home theater system with my 990. If you are purchasing a Yaqin tube buffer, make sure to purchase the Pacific Valve and Electric Company version. This one uses a single 6922/6DJ8 tube vs. the Yaqin twin 6J1 tubes found on eBay or Grant Fidelity. There are many 6922/6DJ8 variants that the 6J1 tubes just doesn't have. You will find that the Yaqin when using the right tube in your system will sound better than the MF tube buffer. Will there be a disparity if you only use one Yaqin just for the front mains. Probably depends on the resolving power of your home theater system. I use Magnepan IIIa for front and rears. So I can definitely hear the timber and warmth differences with and without the Yaqin in place. Maybe your ears won't be as critical and try out one before purchasing another. Don't waste your time adding your subwoofer to the tube buffer, it actually muddies the bass on my Velodyne HGS-12. You probably can get away from purchasing a third Yaqin just for the center channel just because the center channel will not be the same as the front or rear speakers that you use as in my case. So there are already compromises. In terms of warm up, the Yaqins actually only need about 10-15 seconds to fully warm up while the Musical Fidelity needs close to 30 seconds. But you will find that everything will stabilize within one minute. Also, I shut off my Yaqins when not in use. It will increase their life expectacy for the tubes. Hope this answers your questions.

Slbenz

Tubes Rule!!!! I use my 1070/Anthem MCA 5 II for HT and surround sound. I move the speakers wires for my Alons from the HT amp to my Vac PA100/100 when I want to listen to 2 channel music.

My Tube Preamp is the ARC SP16-L. The current production of Vacumn tubes for audio Sucks. The Russian and Chinese tubes do not sound good at all.

Back in the day, the USA, England, Germany, etc. make great sounding tubes for Audio.

I am telling all of you, should you use tubes amps/preamps, Dacs, etc, make sure you get tubes from the 1960's and 1950's and maybe 1970's.

There are NOS tubes that cost a lot of money. Try finding tubes that are litely used and test well!

For my Preamp, I use 1960's short plate Mullards make in the Blackburn plant. When I compare these to the EH 12AX7 tubes that came with the preamp, the decison with clear, Mullard kills the Russian tubes.

For my Amp, I use Tung Sol 1957-1959 5814A (12AU7) tubes. These are military tubes and they are warm and full, way better than the current crap out there.

Now I await some older KT88 output tubes for the amp. These tubes are so hard to find. I am lucky to have found some.

Modern amp/preamps with good transformers and good old great tubes give you satisfaction, unlike Solid State and Op amps!

IMHO , to achive good sound like tubes with Solid State, you will need to spend thousands of dollars.

Sad too say, the great names such as Mullard and Tung Sol are now owned by New Sensor and they put out lousy sounding , good looking Russian tubes.