VT-25 vs 45

[MartinV56]

Anyone here have any expirence with VT-25 tubes, which you liked? And in front VT-25 vs 45 tube ? Thanks, Martin:thmbsp:

 

[BrianC.]

Hello Martin. I like Hytron VT-62 and prefer the 10-derivative bright filament valves(10Y, 801A) to the 45. They retain the articulation of the 45 but have a magical, though wholly natural, "airyness" or "bloom". Good OPTs are more difficult to source though and need to be of the highest quality to reveal their full sonic beauty.

Brian.

 

[MartinV56]

thanks Brian, My next project is to make a SET VT25, the circuit which I think to use is the one of Sun VT-25, everything depends on the quality of the SOT transformer a very good iron, again thanks, Martin

 

[BrianC.]

I have had excellent results using CLCL filtering on the filament, the final L (common mode toroidal) mounted on the valve base tags.

Brian.

 

[Jack G]

I have some SETs based on 10/10Y etc. Nice amps if you have the speakers for them. Smooth, clean, and a sense of immediacy that nothing else matches. I've tried everything from Cunninham CX-310s to RCA 801As and lots in betwen by Sylvania, WE, Taylor etc. My favorite are the RCA 801As.
Jack

 

[BrianC.]

Yes, the 801A is THE valve for Lowther/AER' mine drives one of the above (TP-1).
I'm currently trying out a graphite anode GE VT-62
Final judgement is reserved but without doubt all that family bring unparalleled beauty of reproduction.

Brian.

 

[MartinV56]

Hi Guys, I am thinking to use the VT-25 Sylvania Brown base whose specifications are: Vplate=220V, Vgrid=-7V, Iplate=25ma, Mu=6, Rp=6Kohms. 10=VT25 with thoriated tungsten filament: Ef=7.5V If=1.25A, Mu=8, 12 watts. The circuit is the following one with some modifications:

Single Ended Triode (DHT) Clase A
2X VT-25- 2X6SN7GT (Drivers) Rectifier x Diodes 1N5821-E3 Vishay Semiconductors Schottky
The schematic is this:

B est Regards Martin