Mastersound Compact 845 with Pvsane 845T

The Pvsane 845T is manufactured to the Amperex/RCA 845 standard with a rated filament current of 3.25A at 10V. If your amp uses "standard" 845 tubes, the Pvsane should be drop in replacements. What tubes are in the amp now?

I confronted the same issue when I was shopping for 300b tubes for my New Audio Frontiers amplifier which is often compared favorably with Mastersound. An amplifier can operate with a range of tubes but will only perform to its potential if the numbers line up. Your dealer probably knows the performance parameters your amplifiers requires of a tube. A modification could work for you but it’s chancy - every component in your amplifier was chosen for the way it works with the other components. Good luck.

Thanks for that,the existing tubes are the originals as supplied with the amp.When contacting mastersound they said an engineer had to physicaly look at the valve.Cant understand that. Any way all the specs have been sent to them will wait and see what comes back .Another problem has arisen.Cant Bias the right right valve .Using the bias socket at the rear of the am p I can only get it to read 5.8 Volts max,albeit continuing to turn it turns the valve red (Ugh )immediately turn it down again.Can only gage level through comparing brightness of tubes .Trying to get info our of Mastersound is a nightmare,Trouble is I am working in Abu Dhabi which does not help as there is not a abundance of engineers who can tackle this .Albeit Dubai Audio have kindly offered to look at it.Patience is a virtue.

Sorry for your troubles Patal. I’m very lucky to have a friend who is a gifted tech (even though you make me wait too long, K). So far, I have never found the tubes provided by any manufacturer to be right for me, so by all means, keep searching for upgrades. Just determine what your amp requires and then make sure the new tubes meet the spec. Tubes make a difference.