Hot Rod Deluxe Problem

[Enzo]

Sorry, I didn't mean it that way. I must have had some other amp in my mental picture. I had not remembered the impedance switching of the external jack. I was recalling amps where the main jack has the cutout and the external has none. It was to be a visual clue. But not in your amp, as it turns out.

[tmlesko]

Wouldn't it be wise to wire in a 4" computer type fan inside these amps?

Tom L.

[Mars Amp Repair]

well,
it sounds like the classic over heating & unsoldering of the + & - 16V dropping resistors as Enzo mentioned.
Many have seen my posts on a solution which has proven over many repairs to be valid.
Just replace the 470ohm 5watt dropping resistors with 750ohm 5 watt (I use the special pc mount 7 watt type) & problem solved.
Someone else on the forum was experimenting with installing the 3 legged regulators which would be as valid a solution.
glen

[Test Tube Newb]

I got two major problems with my HRDLX

First is that the reverb never has worked on it....all the springs ar intact and hooked up to the wires correctly...if i crank it and really pinch a note hard i can get a little bit of the echo but by no meant full reverb...

the second and more recent problem is that my amp has gone silent...It faded to nothing while we were playing the otherday. I'm guessing the power tubes...everything is still lit and nothing looks different there is just no sound (no guitar no static no hum no nothing)..last thing...our drummer was using my amp to keep his bass drum from sliding....im guessing this could have knocked some things around?

any help guys?

[52 Bill]

First is that the reverb never has worked on it....all the springs ar intact and hooked up to the wires correctly...if i crank it and really pinch a note hard i can get a little bit of the echo but by no meant full reverb...

the second and more recent problem is that my amp has gone silent...It faded to nothing while we were playing the otherday. I'm guessing the power tubes...everything is still lit and nothing looks different there is just no sound (no guitar no static no hum no nothing)..last thing...our drummer was using my amp to keep his bass drum from sliding....im guessing this could have knocked some things around?

any help guys?

Why not start a new post for your problems.
Until then, check the tank with a meter and check the speaker with a battery.

[jazzdavid]

Hot rod deluxe Play then i hear crack and i have no sound!

well,
it sounds like the classic over heating & unsoldering of the + & - 16V dropping resistors as Enzo mentioned.
Many have seen my posts on a solution which has proven over many repairs to be valid.
Just replace the 470ohm 5watt dropping resistors with 750ohm 5 watt (I use the special pc mount 7 watt type) & problem solved.
Someone else on the forum was experimenting with installing the 3 legged regulators which would be as valid a solution.
glen

Hi

I hear some cracks in my Hot rod. Sometimes when i turn on my amp i have no sound and for second i hear crack and i have sound. Sometimes i play something then i hear crakck and i have no sound!
I replaced 470ohm 5watt dropping resistors not for 750ohm 5 watt, but for 470ohm 10watt- My friend told me that it would be better, but actually i have still that problem. Any ideas?

[52 Bill]

Sounds like a bad tube or a broken solder connection somewhere. Try different tubes first then check for bad connections.

If it is a loud noise, I'd start by checking the soldering on the tube sockets on the lower pc board. This is a fairly common problem. Also check to see if the tube sockets are holding the tubes in tight.

With the amp turned on and the back panel off, you can tap the pc boards with a plastic or wooden stick, to see if you can make the noise happen.

[jazzdavid]

Sounds like a bad tube or a broken solder connection somewhere. Try different tubes first then check for bad connections.

If it is a loud noise, I'd start by checking the soldering on the tube sockets on the lower pc board. This is a fairly common problem. Also check to see if the tube sockets are holding the tubes in tight.

With the amp turned on and the back panel off, you can tap the pc boards with a plastic or wooden stick, to see if you can make the noise happen.

Thanks man. I will try it, but actually i don't have any other tubes for testing. Can i check my tubes with in other way? Maybe just tab with sth on tubes?

[Ronsonic]

Hi

I hear some cracks in my Hot rod. Sometimes when i turn on my amp i have no sound and for second i hear crack and i have sound. Sometimes i play something then i hear crakck and i have no sound!
I replaced 470ohm 5watt dropping resistors not for 750ohm 5 watt, but for 470ohm 10watt- My friend told me that it would be better, but actually i have still that problem. Any ideas?

Those amps are full of dubious solder joints. Reflow everything bigger than a 1/2W resistor and be done. Everything along the control panel needs reflowed. Needs. Even and especially the mounting brackets, "wing" on the pots and the input and looping jacks. All of it. Do the tube sockets as well.

Diagnose any other problems after that is attended to. It'd be like trying to get your car running right with bad spark plug cables. Nothing else will help until that's done.

[Mars Amp Repair]

Hello,
I know the 750ohm resistors are harder to find. The 470ohm 10watters will work fine, they just cause much more current to be sinked by the zeners than is even close to necessary for the load.

As for testing w/o tubes, the tube most likely for causing your noise (if it is a tube) is the higher gain tubes on the right most from the rear. theory being that even if the highest gain tube is noisy, it won't be as noisy in the lower gain positions.

Try just removing the right most tube & see if the noise goes away. If it does it could still be a circuit issue, but now swap one of the other 2 tubes with it (try swapping the driver tube one closest to the power tubes) & see if the noise goes away or lessens. Do that with the other 2 until by process of elimination you find the noisy culprit...glen

[Robert M. Martinelli]

Why not start a new post for your problems.

What Bill said....

Or, better yet, use the "search" function before doing so...chances are you will find something useful even before having to start a new thread. This will help in keeping the forum "tidier" and easier to consult, and to keep you from opening new threads on issues that have been already dealt with... (in this case the dreaded HRDDRS, Hot Rod Deluxe Dropper Resistors Syndrome ).

Cheers

Bob

[jazzdavid]

Those amps are full of dubious solder joints. Reflow everything bigger than a 1/2W resistor and be done. Everything along the control panel needs reflowed. Needs. Even and especially the mounting brackets, "wing" on the pots and the input and looping jacks. All of it. Do the tube sockets as well.
.

Thanks for answer. I look on those joints and looks perfect! I didn't find any solder joint looking broken. Are you sure that i should reflow all those?

[Jazz P Bass]

Thanks for answer. I look on those joints and looks perfect! I didn't find any solder joint looking broken. Are you sure that i should reflow all those?

Do it now or do it later

[Zipslack]

Is it just me?

Is it just me, or does it seem that most repairs come down to dirty pots and jacks and bad solder joints? I seem to have about 75% or higher incidence where the entire repair consists of cleaning pots and jacks and finding bad solder joints/traces. I've gotten to the point where I automatically clean stuff and then re-flow all jack and pot connections and then test before I even start to get to the "down-and-dirty" troubleshooting. Most of the time, the troubleshooting isn't necessary after that. Has anybody had this experience, especially on newer (<10 years) amps?

[Jazz P Bass]

I consider it basic service.
Yeah, you kind of lose your TS skills.
Then along comes a doosie!