My debut into the vacuum world: Yarland FV34B

[Sethman]

Hi all, this is even my debut here in this forum.

Just today I got from a friend a Yarland FV34B, doing my debut into the vacuum world (soo amazing, I will never go back to transistors), with tubes already changed:

x2 preamp 12AX7 Electro Harmonix
x4 amp 6L6Y RCA

Btw I wish to change the amp tubes with a set of KT88 that I prefer far far more than the 6l6y.

It's possible to do that if I keep the 2 preamp?

There's no way to modify the bias so I've to buy a matched set of KT88 right?

And last but not least any kind of modification suggested that heavly improve the FV34B?

I'm sorry if I'm shoting all those questions already but I feel like a kid in a new magic world

[Eli Duttman]

Stick to the 6L6s. KT88s will put too much pressure on the power trafo. Also, the O/P trafo primary impedance for KT88s is approx. 1/2 that of 6L6s.

From what I see on the WWW, the amp works with EL34s and KT66s (roughly = 6L6GC).

The EH 12AX7 is (IMO) no better than mediocre in HIFI service. Installing the Sovtek 12AX7LPS in those "holes" is an inexpensive way to improve "tone".

Without a schematic, it's difficult to make rational recommendations about tweaks. As the owner, is a schematic available in the documentation packet? If so, scan and post it.

[Sethman]

I dont have the schematic, actually I'm searching into the web in case someone has it.

This is the amp btw: audiocostruzioni.com

What I can report is that the old owner and our official national distributor told me that this amp is fully compatible with El34, KT66, KT77, 6l6, 5881, KT88.

Maybe someone else here know deeply this amp and can share more info/suggestions.