Two Amps Died the Same Way — HELP!!

[Punkrot]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

Not knowing whether they are seperate diodes or a diode block I can't be sure but probably just component failure.
I've got a mate who has a small battery/AC portable amp. It has a power regulator /charging section. That section has a diode block on it for the AC to DC. It failed twice over the space of a couple of years. I ended up putting a higher ampage type in which appears to have stopped it breaking down.
It's something I've come across often, doing electronic repairs. Components [ especilly in power supply sections ] being under rated for their handling capacity.

Are you handy with a soldering iron? That should be a fairly easy fix.

I soldered the pickups into my guitar, so I can probably handle it.

I'm just worried that it will happen again, since my other amp died the same way just a few months ago. I figure it's either the hot and muggy weather stressing the gear out, or something with my electrical supply. Do you know if either of those factors could cause this kind of failure?

 

[Punkrot]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

It sure seems like the rectifying diodes on heater supply for those three valves, are shot [preamp tubes V1, V2 and V3]. There's nothing much else there to go wrong.

Also, do you think all three diodes died? That seems pretty weird and unlikely to me, but I'm definitely not an expert.

 

[GoldenVulture]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

Also, do you think all three diodes died? That seems pretty weird and unlikely to me, but I'm definitely not an expert.

Engl's best guess is that "the rectifier diodes may have been damaged," and that the amp will work once they're replaced. [/QUOTE]Silly me, obviously not a Diode block
There's four diodes there and maybe only one or two have failed. None the less the others may be damaged and fail if not replaced. It would be best to replace all four. Diodes are pretty cheap components so it shouldn't be price prohibitive to do so.

I'm just worried that it will happen again, since my other amp died the same way just a few months ago. I figure it's either the hot and muggy weather stressing the gear out, or something with my electrical supply. Do you know if either of those factors could cause this kind of failure?

Although they both died with similar symptoms , they haven't died from the same problem. Engl's advice suggests it's a common problem for their amps. The Ampeg is being less obvious, as it's working again , on its own accord.
Humidity can affect valve pins and pots and connectors in general. It can cause an oxidization build up causing bad contact or none at all [ and invisible to the naked eye.] Cleaning your valve pins and pots with some contact cleaner would be wise thing to do in your environment/climate.

How old are these amps ? That is a relevant factor determining component failure and why.
I tend to think your over thinking the cause of your problems.

 

[Punkrot]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

Engl's best guess is that "the rectifier diodes may have been damaged," and that the amp will work once they're replaced. [/QUOTE]Silly me, obviously not a Diode block
There's four diodes there and maybe only one or two have failed. None the less the others may be damaged and fail if not replaced. It would be best to replace all four. Diodes are pretty cheap components so it shouldn't be price prohibitive to do so.


Although they both died with similar symptoms , they haven't died from the same problem. Engl's advice suggests it's a common problem for their amps. The Ampeg is being less obvious, as it's working again , on its own accord.
Humidity can affect valve pins and pots and connectors in general. It can cause an oxidization build up causing bad contact or none at all [ and invisible to the naked eye.] Cleaning your valve pins and pots with some contact cleaner would be wise thing to do in your environment/climate.

How old are these amps ? That is a relevant factor determining component failure and why.
I tend to think your over thinking the cause of your problems.

The Ampeg is pretty old (turns 50 next year). But I had it overhauled by an excellent vintage amp tech back in Portland sometime around 2011 or 2012 (can't quite recall).

The Fireball 100 is fairly recent (2013 at the oldest, I think?). Since I got it secondhand, I really don't know. I'm sure I could pester Engl to tell me based on the model number.

I forgot to mention in my post that I cleaned all the pin connectors in the Engl with Deoxit after it stopped working (in case it was from humidity). I also tested connectivity on the preamp tube pins, and found them all to be okay.

Do you think my step-up transformer could be causing stress to the components in some way? The socket readings I got off the surge protector confuse the hell out of me.

Sorry to ask so many questions. I really appreciate your help!

 

[GoldenVulture]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

The Ampeg is pretty old (turns 50 next year). But I had it overhauled by an excellent vintage amp tech back in Portland sometime around 2011 or 2012 (can't quite recall).
Have you gone over this one with Deoxit ? if not , do so.
The Fireball 100 is fairly recent (2013 at the oldest, I think?). Since I got it secondhand, I really don't know. I'm sure I could pester Engl to tell me based on the model number.

I forgot to mention in my post that I cleaned all the pin connectors in the Engl with Deoxit after it stopped working (in case it was from humidity). I also tested connectivity on the preamp tube pins, and found them all to be okay.
This is obviously a component failure
Do you think my step-up transformer could be causing stress to the components in some way? The socket readings I got off the surge protector confuse the hell out of me.
No, I'd ignore most of those readings. The relevant and important ones are your Live and neutral at the power point and at the amp and they seem fine. If the step up transformer was going to cause problems [ which I doubt ] it would likely die or show symptoms of failure first

Sorry to ask so many questions. I really appreciate your help!

I'm going to find a schematic of the Ampeg if I can, and scrutinize it.
The Engl on the other hand seems pretty straight forward. Change the diodes.

 

[Punkrot]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

I'm going to find a schematic of the Ampeg if I can, and scrutinize it.
The Engl on the other hand seems pretty straight forward. Change the diodes.

Wow, thanks for the tips. I'll hit the Ampeg with Deoxit for sure.

And if you can find a schematic for the Ampeg, I'd be thrilled. That thing is almost grandpa status at this point (but it sounds so good)!

 

[GoldenVulture]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

The Engl: the diodes according to the schematic are

- 1N4007- -Standard Recovery Diode, 1 kV, 1 A, Single, 600 mV, 30 A

Very cheap and available.

 

[Darg1911]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

I would also be concerned with what caused the diodes to fail. I'd also check the filter caps. If it's a know problem, then I'm sure that Engl, or someone familiar with repairing these amps, would know the cause. May be some additional info online.

 

[Punkrot]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

I would also be concerned with what caused the diodes to fail. I'd also check the filter caps. If it's a know problem, then I'm sure that Engl, or someone familiar with repairing these amps, would know the cause. May be some additional info online.

I spent a lot of time digging around online before posting here (didn't wanna bother y'all if I didn't have to). I wasn't able to find much, but then again I also don't know how to search for this kind of stuff in German. English info on Engl amps is often fairly minimal.

 

[Punkrot]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

The Engl: the diodes according to the schematic are

- 1N4007- -Standard Recovery Diode, 1 kV, 1 A, Single, 600 mV, 30 A

Very cheap and available.

Wow, that's awesome — thanks!

You mentioned something about a higher amperage diode sometimes being a good fix… Should I try that, or just wait to see if these ones blow out again?

Also, do you think excessive distortion and/or bass makes these guys die faster? Because I keep the lead gain around 7, crank ALL THE BASS, and play with a baritone guitar tuned to drop A… :headbang:

 

[GoldenVulture]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

Wow, that's awesome — thanks!

You mentioned something about a higher amperage diode sometimes being a good fix… Should I try that, or just wait to see if these ones blow out again?

Also, do you think excessive distortion and/or bass makes these guys die faster? Because I keep the lead gain around 7, crank ALL THE BASS, and play with a baritone guitar tuned to drop A… :headbang:

For now , I'd just replace them with the same type as they're readily available and cheap.[$0.263 ea - http://au.element14.com/diodes-inc/...YYASABEgLeD_D_BwE&CAWELAID=120185580000393182 -]
Maybe put higher amperage ones in if 1N4007's fail in the near future
They purely rectify the heater power to three of the valves, they do nothing else. Nothing you do is likely to affect them.

 

[Joey Voltage]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

If you have access to a dmm, you can check to see if they are working correctly, most will have a diode tester. You can also measure across the heaters to ensure you have the correct potential. I would honestly replace them with a 1n5408 if you can, the current rating of the 1n400x series is little low for this purpose especially if the valves are running at 6Vdc, and not 12Vdc.

The Fireball 100 is fairly recent (2013 at the oldest, I think?). Since

Do you think my step-up transformer could be causing stress to the components in some way? The socket readings I got off the surge protector confuse the hell out of me.

Sorry to ask so many questions. I really appreciate your help!

You’ll only cause issues if your step up is causing secondary voltages to rise also. If you are just using it to step up your wall vac to feed the amplifier the vac the primary the power transformer is rated for (for example stepping up a 120vac wall supply to 230vac in order to run an amp that’s rated for a 230vac one) you should have no issues.

 

[Punkrot]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

If you have access to a dmm, you can check to see if they are working correctly, most will have a diode tester. You can also measure across the heaters to ensure you have the correct potential. I would honestly replace them with a 1n5408 if you can, the current rating of the 1n400x series is little low for this purpose especially if the valves are running at 6Vdc, and not 12Vdc.


You’ll only cause issues if your step up is causing secondary voltages to rise also. If you are just using it to step up your wall vac to feed the amplifier the vac the primary the power transformer is rated for (for example stepping up a 120vac wall supply to 230vac in order to run an amp that’s rated for a 230vac one) you should have no issues.

Good to know. I've been a bit worried about it. The surge protector is also powering my analog solid state stereo and related peripherals. No issues with any of that stuff.

I'll keep the beefier diodes in mind if the replacements blow out again.

 

[Punkrot]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

For now , I'd just replace them with the same type as they're readily available and cheap.[$0.263 ea - http://au.element14.com/diodes-inc/...YYASABEgLeD_D_BwE&CAWELAID=120185580000393182 -]
Maybe put higher amperage ones in if 1N4007's fail in the near future
They purely rectify the heater power to three of the valves, they do nothing else. Nothing you do is likely to affect them.

Super! I'll order some of these and give it a whack.

Also — just making sure I'm not a complete idiot — there's one of these per valve, right?

 

[GoldenVulture]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

Super! I'll order some of these and give it a whack.

Also — just making sure I'm not a complete idiot — there's one of these per valve, right?

No, it has nothing to do with the amount of valves. It's the amount of diodes it takes to produce a full wave DC voltage. The diodes are polar, as in they have a Positive and Negative end. This is important when replacing them. The diodes have to be replaced in the same positive/Negative orientation. The positive end is usually marked with a white/Silver band near the end, which circles all the way around the diode.

Positive

Negative [1N4007 looks like this]

If you do this fix yourself, make sure you note which way the diodes are mounted before you remove the old ones. I'm presuming they're mounted to a circuit board. If your unsure how to go about removing these , shoot me a PM.

As per usual, when working on amps, make sure your filter caps [ Large can capacitors ] are discharged and don't have it plugged in to anything [ power or otherwise ].

In your case , if it hasn't been plugged in for ages , the caps are probably discharged. You can check by using a multi meter set to a high DC voltage range and take a reading from the terminals of the caps.

 

[GoldenVulture]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

Here's a diagrammatic view of how the four diodes work.

 

[Punkrot]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

Here's a diagrammatic view of how the four diodes work.

Awesome! Thanks for all your help!

 

[67Mopar]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

Someone please check my math... If there is an issue with voltage drop (via faulty AC inverter), the amplifier would theoretically pull excess amperes to meet demand. I'm thinking the two main issues to consider here (if correct) is cathode stripping and diode failure. If this is the case, I would look at upgrading the voltage inverter.

 

[Punkrot]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

Someone please check my math... If there is an issue with voltage drop (via faulty AC inverter), the amplifier would theoretically pull excess amperes to meet demand. I'm thinking the two main issues to consider here (if correct) is cathode stripping and diode failure. If this is the case, I would look at upgrading the voltage inverter.

Most of that was Greek to me.

Not sure if this is helpful, but I'm starting to think that probably the ground at the socket is faulty, which is stressing my amps out. I'll be fixing that issue as well.

 

[GoldenVulture]

Re: Two Amps Died the Same Way — HELP!!

Re: Two Amps Died the Same Way — HELP!!

Most of that was Greek to me.

Not sure if this is helpful, but I'm starting to think that probably the ground at the socket is faulty, which is stressing my amps out. I'll be fixing that issue as well.

Not likely to cause any operational problems at all.

Your using a step up transformer , not an inverter, it's a bit irrelevant. [ 1000W step-up transformer. ] Plenty big enough to handle the draw of the amp and other things you have plugged in.