Got my Mark IV! A few questions.

[Scottyyy]

Hey guys. I went today from the post office to pick up my Mark IV. I bought it from WretchedESP86 on this forum and it looks like it's in good condition. Haven't turned it on yet as I have a few questions. You'll have to excuse me for asking such stupid questions, I'm still quite new to these large amps. Firstly about the power cable. It's a 1994 B version I believe, and from what I've read the IVb's come with a detachable power cable? It seems like mine is attached however:

http://i32.tinypic.com/315ol1h.jpg

Also, what is the power socket for in the top left, seeing as the power cable is coming from underneath? Secondly, the amp came with a fan:

http://i25.tinypic.com/2i6kyea.jpg

However, I don't know what to do with it.
Where does it plug in to get power, and where should I put it?

And finally, how do I find the serial numbers on Mark IVs?
edit: nevermind, found the serial I think - the sticker under the ground switch says IV-006441

Can't wait to turn it on and try it out - but I want to get these few niggles sorted first.

Thanks

 

[ryjan]

That is a "B" version short head. The "A" version had the detachable power cable. The plug above it is a through power for plugging other gear into and is not needed for normal operation. I have the medium head so mine may be different as far as fan placement but my fan is under the tubes and centered between the preamp and power tubes. That does not look like the factory fan. I wonder if your amp was born a combo and somebody converted it to a head.

 

[GD_NC]

Funny. I had the exact same fan question when I got my Mark IV a couple of months ago. There is a very small switched outlet between the transformer and the wall of the case to accommodate the fan. It's hard to see, but it's there. If everything is working correctly the fan should be controlled by the power switch. Low Speed with Tweed and Higher Speed with Full.

The fan on a shorthead mounts on a metal bracket attached to the front baffle (in the middle of the u shaped cut out) in the center of the case. Should sit right below the tubes.

The outlet on the back is just an unswitched auxiliary. Just there for convenience.

 

[Scottyyy]

That is a "B" version short head. The "A" version had the detachable power cable. The plug above it is a through power for plugging other gear into and is not needed for normal operation. I have the medium head so mine may be different as far as fan placement but my fan is under the tubes and centered between the preamp and power tubes. That does not look like the factory fan. I wonder if your amp was born a combo and somebody converted it to a head.

It was originally a head, but it was converted to a rackmount then back to a head. Sorry, should have mentioned that. Where does your fan plug into? Is it safe to run it without the fan?

Thanks for the info about the power cables btw.

 

[ryjan]

As mentioned above, there is a place to plug the fan in next to the transformer. The front panel is removeable for easy access via velcro. While your in there I'd check all the connections since it was taken apart. I have never ran mine without the fan and I have no idea if its safe or not so I would choose to err on the side of caution. BTW congrats on a great amp! If you have any trouble dialing it in there's plenty of help to be had on this forum. Rock on.

 

[Scottyyy]

Yeah the grill is really lose, if I tip the amp forward it just falls out haha. Not sure how I'd go about fixing that.

I'll have a look for the fan input.

 

[ryjan]

Yeah the grill is really lose, if I tip the amp forward it just falls out haha. Not sure how I'd go about fixing that.

I'll have a look for the fan input.

Velcro.

 

[GD_NC]

Hey I just looked at the pictures again and noticed the fan bracket is already there. It's 4" (or so) horizontal the metal strip behind the tubes.

 

[Scottyyy]

Yeah the grill is really lose, if I tip the amp forward it just falls out haha. Not sure how I'd go about fixing that.

I'll have a look for the fan input.

Velcro.

Doesn't seem to hold it very well. Doesn't matter anyway.

I can't find anywhere to plug the fan in though. :?

 

[GD_NC]

It's really hard to see. Look in the 1/2 inch space between the transformer on the left (looking from the back) and the wall of the case. It a very small rectangular outlet (two prong). You probably need a flashlight to see it.

 

[Scottyyy]

Hey I just looked at the pictures again and noticed the fan bracket is already there. It's 4" (or so) horizontal the metal strip behind the tubes.

Ah so that's what it's for.

Also, I've just found these two cables which look like RCA:

http://i27.tinypic.com/149nvcx.jpg

There's two sockets right next to V4 where I think those would fit. What are they for and should I plug them in?

 

[GD_NC]

Reverb in and out. Should be two cable to attach to the reverb in the bottom. Just plug them underneth in near the first pre-amp tube. I think they are color coded

 

[Scottyyy]

Reverb in and out. Should be two cable attached to the reverb in the bottom. Just plug them in.

Cool thanks. I think I found the place to plug the fan in, but it's really hard to get to.

 

[kmanick]

Hmmmmmm...????
my IV is an "A" combo and the power chord is not detachable?

 

[GD_NC]

Hmmmmmm...????
my IV is an "A" combo and the power chord is not detachable?

Yes, There are variations of the power cord for both A & B.

I've seen A's with fixed and B's with detachable.

 

[Scottyyy]

I've installed the fan but it's blocking two of the power tubes so I can't put them in (two on the left)

 

[ryjan]

I've installed the fan but it's blocking two of the power tubes so I can't put them in (two on the left)

Power tubes? The fan should be pretty far away from the power tubes. Try to get a pic up so we can see whats going on. Or try to find a good pick of the back of another one so you can be sure you have it in the right spot.

 

[Scottyyy]

I've installed the fan but it's blocking two of the power tubes so I can't put them in (two on the left)

Power tubes? The fan should be pretty far away from the power tubes. Try to get a pic up so we can see whats going on. Or try to find a good pick of the back of another one so you can be sure you have it in the right spot.

It goes here yeah? It would make sense, as it fits nicely with the metal bracket to install it.

http://i25.tinypic.com/2mnkapg.jpg

I've unscrewed the screws at the top and I'm moving the amp around inside the chassis, I've moved the amp back a little and the power tubes seem to fit. Although, I don't think I'll be able to screw the screws on the top back in with it moved back this far.

 

[Scottyyy]

I've unscrewed the fan so it just sits at the back freely and I can get the power tubes in. Although, the two left ones are just touching the fan. Is this OK?

 

[GD_NC]

It looks like the fan is basically in the right place in your pics. I've only had Mark IV combo's so I can't help much on that.

I don't think it matters if the fan is very close to the tubes. But I think having the fan touching may cause problems.