ARC VSi75

[ariess]

Question on break-in: does time when a tube unit is on but not playing anything "count" towards break-in time? I ask because I would like to break in my new unit, when it arrives, as fast as I can but I don't want to inflict on my family music playing at all hours of the day.

[joeinid]

On with no music playing does not count. Play it when you want and just enjoy the ride. Before you know it, even more beautiful music will be coming out. Life is not meant to be rushed but savored.

[microstrip]

Originally Posted by ariess

Question on break-in: does time when a tube unit is on but not playing anything "count" towards break-in time? I ask because I would like to break in my new unit, when it arrives, as fast as I can but I don't want to inflict on my family music playing at all hours of the day.

IMHO, you should have a signal during burn-in. Just get two 22 ohm 50 Watt power resistors and replace the speakers by this load when you are not listening. If you can not get the resistors use incandescent lamps having similar resistance when cold.

[ariess]

How long is burn-in? Doesn't ARC do burn-in before the customer gets it?

[Amado]

Originally Posted by ariess

How long is burn-in? Doesn't ARC do burn-in before the customer gets it?

600hours
But do like joe saids and enjoy the ride!!!

[ariess]

Just got my VSi75 in and hooked up.
Its a very nice piece of gear!
Initial reactions from listening. Music sounds more powerful, more present! I am looking forward to more exposure after more break-in time.

I can say more about its features relative to the VSi60 which it replaces in my setup.
It looks sharper due to the milled plate in front, the status screen and the silver perforated cover over the power supply. I really like the "bias" button which cycles through the bias reading on all 4 KT120 power tubes. The remote is nice, ARC finally going to a metal remote which feels more substantial. A big improvement over the VSi60 is the volume scale. I used to find that ~95% of my listening occurred within 2-3 volume steps. So you couldn't increase or decrease the volume by anything but a large change. The VSi75 has about 25 steps over those same 3 of the VSi60 which allows me to get what I want. No complaints some far. I am very impressed and pleased. My only regret is I have not heard of anybody else experiencing one yet with whom I could trade notes and tweaks (heck its still not even on ARC's webpage).

By the way, anybody interested in a lightly used VSi60, a recent build that uses 4 KT120 drivers?

[bakerman]

Congrats! It sounds like ARC made some nice improvements with this amp. Let us know how it sounds as you put more hours on it.

[ariess]

Two questions on my brand new VSi75:

1) The bias on the KT120's is 68, manual recommends 65. Are differences of this size worth correcting? Are they audible?
Does ARC purposefully set the bias high knowing that it will come down over time?

2) I know burn in time is 600 hours. How subtle is the change over this time? How much of that should come in the first 100 hours? (This unit has a lot in common
With the REF75 if that is a guide)?

[TMcD]

Check the bias after running it for around 30 minutes without any load, ie not playing any music and set it to 65. Running it higher will put a touch more load on the tubes and shorten their life.

During break in you might fine some inconsistencies in the sound as it cycles through the hours, it will improve a lot especially after 400 hours and will reach its full potential at 600 hours.

Enjoy it is a lot of fun!

[ariess]

Noticed a "feature" or "bug". When I run a source into a single-ended input (#1 in this case) I can hear it just as loud in the other inputs like 2 and 5 as in 1, less loud in 3 which has another source plugged in and quiet in 4 which also has another source plugged in. In this normal? I would have expected to hear nothing from this source in other inputs which are not the one connected. Is it just up to the user to make sure only one source is playing at a time?