[mchuckp]

SOLD

I have a mint condition Van Alstine Ultravalve tube amplifier for sale.  I'll rate it 9/10 (Agon Scale) simply because it isn't brand new.  I bought it brand new from Frank for $1699+shipping in April of this year.  Serial# is 1011.  Since I'm the original owner, you'll still have the remainder of the transferrable warranty (3 yrs from this past April).

There is absolutely nothing wrong with this amp and sounds excellent and hasn't moved from my rack since getting it.  Original EH tubes are still installed and have seen typical usage in the 4+ months that I've had it.  I've just decided to take a different gear direction.  I have all the original packing and manual.  Only thing to note is there is a small hole in the side of the box from UPS.  It didn't harm the amp.  I will patch this up nicely before shipping.

Save yourself the 30-day wait and some money as well.

$1350+shipping.  Paypal (+3%) or Money Order/Cashier's Check accepted.  Feel confident buying from a regular here on AC.  Please check out my positive feedback on Agon 'mchuckp'.

Best to PM me if interested.

Thanks,
Mike

[oneinthepipe]

That is a great price on a terrific amplifier. 

[Wayner]

Mike,

Do you know (and probably Frank does and should chime in) if this unit has the 5AR4 diode modification done to it, or maybe came from the factory this way? I don't know when Frank did the change in production, maybe yours is done, maybe not.

The sound or performance of the amp is not affected by the diode mod, it simply makes the tube happier, and extends it's life........

Wayner 

[mchuckp]

Mike,

Do you know (and probably Frank does and should chime in) if this unit has the 5AR4 diode modification done to it, or maybe came from the factory this way? I don't know when Frank did the change in production, maybe yours is done, maybe not.

The sound or performance of the amp is not affected by the diode mod, it simply makes the tube happier, and extends it's life........

Wayner 

Wayner, I don't believe I have this mod.  I don't know for sure.

[mchuckp]

SOLD

[BPoletti]

Here's the deal with the 5AR4 rectifier tube (as has been explained to me by someone who actually knows).  The 5AR4 warms up slowly.  This delays the high voltage from being delivered to the 4 output tubes until after they are warmed up by the tube heaters (IIRC, 6 volt circuit though it might be 12 volts).  This keeps the plate from being stripped and extends the life of the output tubes. 

Using a solid state diode instead of the tube rectifier ("diode") allows the high voltage to be delivered to the plates before they are warmed by the heating elements in the tubes.  This causes the coating on the plates to be stripped off shortening the life of the tubes. 

That said, I have had a 5AR4 go bad while the amp (Dyna ST-70) was operational.  It's quite ugly.