[gryphongryph]

Hi, I am wondering if there will be a new version of the FET VALVE 600R HYBRID coming anytime soon ?
Also is it easy to change the tubes in the current amp ?
Thanks.

[tonyptony]

From what I understand, a number of running changes / updates have been incorporated into the 600R since its introduction. I asked Frank about it, and it sounded like bringing my early version up to the current would not be cost effective. So I'm guess the changes are significant.

[gryphongryph]

Interesting 🤔 you don’t happen know what changes have been done ?
Maybe Frank would chime in ?

[tonyptony]

I'm afraid I don't have that information.

[avahifi]

Changes to Fet Valve amplifiers over the years,

Changed to our own purpose designed metal chassis and complete internal layout design with new circuit board. Changed tube type used.

Went from Hitachi output mosfets to Exicon mosfets,

Upgraded to Exicon double die mosfets.

Added regulated power supplies for small signal circuits.

Added regulated output transistors power supplies.

Redesigned all internal circuits boards to provide adjustable regulated power supplies providing best performance independent of parts variations,

Major internal overall layout redesign improving noise and signal path quality.

We keep learning and making our products better but rarely announce design upgrades any more.

[gryphongryph]

Thanks Frank for replying, what tubes do the amps come with and is it easy to swap tubes, how long do the tubes normally last ?

[Tone Depth]

tube type:  https://avahifi.com/collections/power-amplifiers/products/fet-valve-600r-hybrid-amplifier

Thanks Frank for replying, what tubes do the amps come with and is it easy to swap tubes, how long do the tubes normally last ?

[avahifi]

The original Fet Valve amplifiers, built in Dyna 410 chassis metal, used 12AX7 tubes.

All built in our own dedicated chassis use 12AT7/ECC81 tubes.

We see several good years of service for the tubes as they are not driven hard and are fed from regulated power supplies.

Tube replacement is just plug and play.  Only if a replacement tube causes a heat sink to run much hotter then normal should the amp be returned to us for a check out and bias current reset.

Frank