MV60 bias lights always on after installing KT-88 tubes, please help

[antaresbluespirit]

Hi,

If you back to the MV60 story using EL34 , you 'll understand that this unit is not prepared to be fitted with 6550 neither Kt 88 since internal components have to be change and correspond to the SE version upgrade (resistors)

In the Other hand Cj does not advise KT120 in the SE version instead of 6550 since the tube heating current consumption increase by 30% VS 6550. and may cause some reliability troubles at the end...

Regards

Raymond

[Big Dog RJ]

Not the case once the MV60 has been upgraded to the SE version Raymond.

When I had the MV60 back in 2012, I was using EL34's. Then in 2013 I got it changed over to the SE version fitted with 6550C's, sounded quite good and used it for a while. Then JF mentioned to try out the new KT120's and said although the KT120's do require a slightly higher current capacity to drive these new Pentodes from Tungsol, the upgraded trannys on the MV60SE will have no issues accommodating these tubes. Infact, not only will it sound fuller, more dynamic and solid bass but also it will last longer since the KT120's will be cruising along...

And boy! Was he right! The MV60SE sounded like a completely different thing altogether. It had way more power and drive compared to an ordinary 60w stereo amplifier, and it drove my previous Quads ESL 2905's effortlessly with the ACT2 as the preamp. I used this particular combination for many years thereafter before changing over to monoblocks once again and then upgrading towards the CLX's.

With the MV60SE, it's a special kind of amplifier where CJ incorporated the high grade Transpectral transformers that are only found in the Premier line-up of amplifiers. The MV60 was the first MV series amplifier to install these upgraded trannys that are capable of much higher current, and with these transformers they can easily accommodate the new KT120's but not the KT150. This is quite a different tube with much higher current capacity required.

With the MV60SE it is safe to use: KT88, KT90, KT120 and 6550 series output tubes with no issues. They all have varied sonic Signatures and it's a personal preference to find the type of sound you prefer. Once you find it, it's definitely a marvellous thing!

Cheers, RJ

[Truth71]

Safe to use KT 120's in a Premier 11A?

[AnotherJohnson]

https://www.conradjohnsonowners.com/vie ... php?t=2015