[starkiller]

Just wondering if it would be all right to leave my dynaco 410 powered on all the time..

[Bill Thomas]

     Yes, there is nothing that would prohibit you from leaving the 410 on all the time, BUT there are LOTS of good reasons for NOT leaving it on all the time.

     First, it will be drawing *some* current while idling which will kick up your power bill a bit.  Second, it is MUCH more susceptible to Power Line "incidents" (spikes, lightning hits, etc.) when "always on."

     Is there some reason WHY you want to leave it on all the time?

Bill

[starkiller]

Well, its part of my garage system so doenst get used very often. When I have turned it on, last 3-4 times its blown both speaker fuses.  There is a brief burst of noise and then the fuses blow. I do have a C-J PV-3 tube preamp that has had some work done to it so am not sure if the preamp is causing a surge and thus the problem.  When i change the fuses and power it back on its fine.

[decal]

I think you shoud be asking,"what's wrong with my system" not "is it okay to leave it on all the time" but that's just me.

[starkiller]

i am, i am planning to get a fill-in ss preamp to try out and see if the problem is still there. already swapped out the ic's btwn the amp and pre to see if that was the problem.  just will be in the garage alot the next few days and need tunes

[Bill Thomas]

     I would be cautious!  While it is *possible* there is a problem with the preamp that is causing this, it isn't highly likely.  More likely is a problem with the 410.  I would look for any DC Voltage at the speaker terminals.  I would also try powering up the amplifier with the Input shorted using "shorting plugs".  If the speaker fuses still blow, the 410 is the culprit, NOT the preamp.

     Always remember Murphy's "corollary" regarding such things:  "In anything electronic, the expensive solid-state devices will always blow to protect the 50 cent fuse."  While this hasn't happened to you... YET, it is still likely that it WILL happen.  When it does, it can take out MANY solid-state devices at once, as well as cause several High Power Resistors to melt or break out in flames!  Still want to leave it on all the time?  Hope your Homeowner's Insurance is paid in full.

     Of course, this is just *my* opinion, but *I* wouldn't leave it unattended at all under these circumstances.

Bill

[starkiller]

Yeah, i am beginning to think i need to swap another amp in there first and see what happens

[avahifi]

A properly working Dyna ST-410 will not blow fuses at turn-on unless it has a problem, or possibly the associated preamp is putting out a big turn-on transient.

Safe operation is to turn on everything ahead of the power amp first, wait a few seconds, and turn the power amp on last. This will prevent the amplifier from amplifying any turn on transients or pulses from equipment upstream.

At turn-off, turn the power amp off first, wait while it plays down.  Then turn off everything ahead of it.  Again, this prevents the amplifier from being on and able to amplify turn off transients from anything ahead of it.

Heat and age the the enemies of electronic parts.  Keeping that big old amplifer on all the time will simply shorten its service live and increase your electric bill and make the "green" folks unhappy with you. 

It will also allow small problems that develop while you were listening and noticed to turn into big problems as the amp cooks away with a small flaw getting bigger until the magic smoke comes pouring out of many parts.

Regards,

Frank Van Alstine

P.S.  For those non-electrical engineers around here, the secret to all electronic parts is that they are filled with magic smoke under high pressure when they are manufactured.  If the part is overheated and fails, the magic smoke comes pouring out into the room and smells pretty bad. 

[starkiller]

Oh, THAT kind of magic smoke, was worried there for a second

Have decided to get a ss amp and preamp to check out the problem. Will also try the power up amp last and power down amp first and see what that does.

thanks!

[starkiller]

well, got the other amp and preamp in the garage. decided to try one more time with dynaco...fired up cd player, fired up preamp, fired up the dynaco---thump...and then that wonderfull white smoke that smells so good

Aaacckkk!  I didn't know I could move that fast to turn off a switch!

Back to where I bought the Dynaco and find something else...they have a SAE 2200, ATI 1502, Audire Crescendo, B&K St-1400II, Carver M-1.4 and 400x, Hafler DH-200, Harman Kardon 87 and Yamaha M-50.

Since all these are vinatage are there any recommendations?

[dB Cooper]

Yes, look into the options Frank Van Alstine (post above) has for doing a complete new amp circuit in your 410. (I believe his compaany still supports that chassis.) All of the old circuits, including whatever just blew up, get tossed and replaced with top grade new stuff. Look into it. It will look just the same on the outside and be dramatically better on the inside.

[Wayner]

+1 for making it into an AVA poweramp.

Wayner 

[dB Cooper]

It would be the best garage system EVER 

[Wayner]

Lucky Neighbors,,,,,,Invite them over for a beer when you crank it up!