Got an Ampeg V4

[karter2000]

Hi all,

I've got the use of a fairly-old Ampeg V4 (see attached picture) from a good friend. The problem is, I've never owned an all-tube amp before, and I could use some tips! How do I set the speaker impedance switch at the back? I have two 8ohm 2x12 cabs.

Any other tips would be greatly appreciated!

PS Based on the picture, how old is the amp?

Thanks,


Lyle

 

[Basslice]

Early 70's. My guess is 71-74. Look on the back to see if it was made in Linden, NJ or if it was after the sale it will likely say Division of Magnavox. I think Magn took over Ampeg in 74. You can search the details on the net.

Unless you hav the 2 - 8 ohm cabs hooked up strangely, you should select the 4 ohm. I assume you are plugging one cab to the speaker output and the other to the EXT speaker output.

Enjoy the amp. It should provide you with some good times.

 

[will33]

Two 8ohm cabs hooked up in the usual configuration, parallel, that means anything other than a special made series cable makes a 4ohm load. If you're using 1 cab, set the switch to 8ohms, if you're using both, set the switch to 4 ohms. Unless I'm issing something weird about the V4B's speaker outs.

Edit: also don't power it up without some speaker being plugged in. Powering up some tube amps without a load (speaker) hooked up can damage them.

 

[Basslice]

Will is absolutely correct. I meant 4 ohm with two 8 ohms. I will correct my ealier post. Also, here are some links to the original manuals:

http://www.ampegv4.com/manual.php

 

[NoHomework81]

No doubt someone will differ with me on this one, but I think it should be mentioned...

It is my understanding, after speaking with several amp techs and a considerable amount of internet searching, that the proper Standby and Power up routine to use on this amp are:

Note: this is assuming that the power and standby switches operate in the original manner. Down is disconnected, or an open circuit, and, should be best thought of as OFF.
Down = Off for these instructions.
I really felt the need to clarify, so many posts have people calling standby disengaged, engaged, off, on, etc. and they never actually describe what's going on.

When first turning on the Amp (amp is cold)
- Standby and Power should OFF (down)
- Turn power ON
- Leave standby OFF (I believe this keeps high voltage out of the tubes while they warm up.)
- Wait at least 30 seconds (as per my amp tech)
- Turn Standby ON (Allows high voltage to the power tubes, and you can play normally now).

When taking a break with the intent to come back and play later, don't use Standby as an "I'm taking a break" switch. Just turn the volume down. There is no need to remove voltage from the tubes, and the additional cycling on and off of the high voltage to the tubes can shorten their life. It's just not necessary.

Someone else may have a better suggestion for turning off the amp, but I've always just turned the power Off first, then the standby. There may be a good reason for doing it the other way, but I haven't heard it yet. I've always felt that Standby was simply a better routine for powering on by delaying the addition of high voltage to the tubes and capacitors until the tubes had a moment to warm up, thus extending the life of these parts.

edit: If you can't switch the Ohms selector with your fingernail, anything you can fit into the little groove on the black plastic slider will work. If there isn't a sliding switch, you'll need to find out from the owner how to set the ohms for the amp.

 

[karter2000]

Well, I used this amp in rehearsal last night.....I now know why everyone says there's nothing like a tube amp. This thing had major balls (for 100w), and I was only using one of my cabs (8ohm Musicman Audiophile 2x12). I had the volume about 10-11 o'clock, and I got this nicely overdriven, yet deep sound.

The only problem I had was one of the speaker outputs wasn't working (which is why I only used one cab). My other cab is an Avatar 2x12, could I daisy chain the two cabs using the Avatar's in/out 1/4 jacks to the Musicman?

Thanks,


Lyle

 

[coreyfyfe]

You can definitely daisy chain the cabs. I believe that the "ext amp" jack on these older ampegs is wired in series and not parallel like the newer amps, so just make sure you're using the "speaker out" when you daisy chain the cabs.