My AmpegV4B quit on me at a show Fri. night

Jaguar · #1 07-12-2010, 04:34 PM

It was a hot humid night outside,but I didn`t notice it was that bad inside the club.I just had it re-tubed and re-capped.I`m hoping this will not be too costly.

Jefenator · #2 07-12-2010, 04:51 PM

I wonder if the tech might have goofed something?

Here's hoping it's minor and can be made right for free (or cheap).

JimmyM · #3 07-12-2010, 04:56 PM

was it not working before or was it a case of "if it ain't broke, don't fix it" but you fixed it anyway?

Jaguar · #4 07-12-2010, 05:03 PM

Quote:

Originally Posted by JimmyM

was it not working before or was it a case of "if it ain't broke, don't fix it" but you fixed it anyway?

No it was working great.The tech is quite famous as far as tube amps go,so I`m hoping he doesn`t charge me.I only gigged with it three times before this happened.

JimmyM · #5 07-12-2010, 05:05 PM

well it sounds minor if you had it recapped and retubed. i'm thinking maybe one of the new power tubes went ka-flooey. that's the one problem with new tubes these days...sometimes you get a dud.

Jaguar · #6 07-12-2010, 05:06 PM

Quote:

Originally Posted by JimmyM

was it not working before or was it a case of "if it ain't broke, don't fix it" but you fixed it anyway?

Oh,now I understand

When I got it, it still had the original tubes and caps and hissed and scratched a little.

JimmyM · #7 07-12-2010, 05:10 PM

ok, just checking you weren't one of these guys who replaces everything out of principle

took me 3 times to get my svt right, btw. every time the tech fixed one thing, something else would go bad. sometimes it happens. but mine was completely blown out and had been sitting in a garage for years. so not the same situation as yours. i predict you'll get off much easier.

Jaguar · #8 07-12-2010, 06:33 PM

Quote:

Originally Posted by JimmyM

ok, just checking you weren't one of these guys who replaces everything out of principle

took me 3 times to get my svt right, btw. every time the tech fixed one thing, something else would go bad. sometimes it happens. but mine was completely blown out and had been sitting in a garage for years. so not the same situation as yours. i predict you'll get off much easier.

I just asked him to make it tour ready in case I did some short travel stints.Good thing I was close to home.

Jaguar · #9 07-23-2010, 07:27 PM

My amp is fixed.Apparently it got so hot that an original soldered joint on a resistor came loose from heat and vibration. $20
I think I will clip a fan on the back when I use it from now on.

coreyfyfe · #10 07-23-2010, 08:22 PM

Quote:

Originally Posted by Jaguar

My amp is fixed.Apparently it got so hot that an original soldered joint on a resistor came loose from heat and vibration. $20
I think I will clip a fan on the back when I use it from now on.

They do get pretty toasty without a fan. The courtesy outlet on the back works, and the anchors for wrapping the power cord can hold a clip on fan if you angle it right. Or you can pull the B-string move and mount one in the amp in front of the tubes/transformers. In one of the V4 threads he posted a pic where you can see the mounting.

JimmyM · #11 07-23-2010, 08:59 PM

can't say i ever had a problem with heat from a v4b. my guess is it was a fluke. still, after having it happen, hard to blame you for wanting a fan on it.

beebassdude · #12 07-23-2010, 09:21 PM

Quote:

Originally Posted by Jaguar

My amp is fixed.Apparently it got so hot that an original soldered joint on a resistor came loose from heat and vibration. $20
I think I will clip a fan on the back when I use it from now on.

i had this exact issue happen to me 2 weeks ago with my V4. no fan + playing for 1.5 hours + amp getting hot = solder joint comes loose. i had my tech re-solder every joint he could find inside just to prevent this from happening to any of the other joints (and i have a '71 V4 so everything inside is pushing 40 years old).

im thinking of adding a fan to the back as well, kinda silly these things didnt come with fans and the SVT's do.

craig.p · #13 07-23-2010, 09:26 PM

Heat rises. Move the handle to the bottom and the rubber feet to the top, and run the amp inverted.

**B-string** · #14 07-23-2010, 09:34 PM

Quote:

Originally Posted by coreyfyfe

They do get pretty toasty without a fan. The courtesy outlet on the back works, and the anchors for wrapping the power cord can hold a clip on fan if you angle it right. Or you can pull the B-string move and mount one in the amp in front of the tubes/transformers. In one of the V4 threads he posted a pic where you can see the mounting.

Thanks for remembering! If you look very close you will see I also moved the OT forward a little. My only complaint with this killer amp is the output tubes are just to darn close to the OT.

beebassdude · #15 07-23-2010, 09:43 PM

im also trying to install a fan on mine as well. how should i go about doing this? just buy a fan and clip it on the back and point it at the tubes or is there a correct way or more efficient way to do this?

**B-string** · #16 07-23-2010, 10:03 PM

I used a piece of aluminum sheet to make a L bracket. Used one of the preamp cover studs, double nutted. If you have the back you will notice the tubes are too close to mount on the rear. The filter caps will block the airflow if you mount on the tone stack cover (where the the 6K11 is). Blowing back from the front seemed the best and worked very well. The fan is angled some so the airflow will get to all four tubes (and the Output Transformer).
Note: Do not mount directly on top of the preamp cover unless you want to induce some noise.

beebassdude · #17 07-23-2010, 10:08 PM

Quote:

Originally Posted by B-string

I used a piece of aluminum sheet to make a L bracket. Used one of the preamp cover studs, double nutted. If you have the back you will notice the tubes are too close to mount on the rear. The filter caps will block the airflow if you mount on the tone stack cover (where the the 6K11 is). Blowing back from the front seemed the best and worked very well. The fan is angled some so the airflow will get to all four tubes (and the Output Transformer).

what you just typed was close to chinese for me. i felt like billy madison watching eric play the violin. lol

anyway you could post a picture? that would be sweet. thanks dude.

**B-string** · #18 07-23-2010, 10:17 PM

Here is another view:

By the way it is a 117vac fan wired to the main power switch.

johnk_10 · #19 07-23-2010, 10:18 PM

hmm. none of my V4's ever got that hot. i mean, they get very warm like any tube amp, but not nearly hot enough to desolder anything.

still, a fan wouldn't hurt any tube amp.

**B-string** · #20 07-23-2010, 10:23 PM

Quote:

Originally Posted by johnk_10

hmm. none of my V4's ever got that hot. i mean, they get very warm like any tube amp, but not nearly hot enough to desolder anything.

still, a fan wouldn't hurt any tube amp.

6550's were hotter than the 7027's. Figured why take chances.
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