Hartke HA3500 issue...
 

Hi, men! They got two HA3500s on rehearsal base we play... And both shut down after an hour of my playing... Indication stays in working order, amp's compressor reacts... Then after some minutes the sound comes back... Then this issue repeats in every 5-10 minutes... While figuring out the malfunctioning part I pluged in in an amp's loop return... The same! Tech said it is my case only and no one complained! Did anyone have such an issue with HA3500, and maybe know the reason? Thanks!

P.S. And, yeah, that wasn't from the beginning... For a pretty long time I played 3-6 hour rehearsals without any issue. And every pedal in my pedal chain I'm sure works fine and was not changed before that troubles began. I'm concerned so much about it, cause looking forward to buy HA5500 and they (with HA3500) got a similar circuit and, I guess, reliability.

Much more info needed: cabs, impedance, eq settings, gain structures, etc. They are good amps by all accounts.

if it were a computer i would say that it/they are having thermal issues. check the vents and make sure any fans are spinning.

More info: cabs are Hartke XLs 4x10 & 1X15, 8Ohm both... I played active Ibanez Roadstar II RB-851 to Grey Stache (full drive, vol. at 10 o'clock) to VT Bass (drive at 3 o'clock, vol. at 10 o'clock), and to EHX Tube EQ (with slightly boosted high, mid and low broad bands, dont know center frequencies exactly, it's not graphic, but boosting is pretty modest - no booming and clipping were ever provided), it's output impedance is 82kohm (damn high!)... Then to amp: master on 3 digit, comp. on 2, preamps both on 4 (and I tried with tube on 0), eq almost flat - only 30hz is slightly down, and some khz sliders are slightly up. Also I tried to play with clean sound - the same! That's it... I hope it can help...

Yeah, I checked the vent, it's just fine... and I moved the stack about 1 meter from wall for better air circulation... That didn't help.

Are you getting good clean power to it ? Sometimes when an amp gets low voltage it will tend to draw more current and heat up which causes the shutdown.

Make sure you aren't playing through some skinny extension cords that are getting hot which means they are overloaded and likely causing a voltage drop.

Also make sure your speaker cables are good quality with adequate thickness and no shorts.

If all of that is OK then try using only one cabinet and see if that makes a difference.

My active bass got pretty hot signal, cords are ok,
since that issue occured I've fully changed my pedals & chord pack, except Tube EQ... The only thing in my chain that I can blame, because of it's enormous output impedance (82kohm)... Yeah, I'll try to play with my buffered reverb inserted between Tube EQ & the amp, to clear my suspicions

I don't think the output impedance of the TubeEQ is related to the problem.

Does the top of the amp feel very hot, hotter than other amps?

Do you have a meter for testing the wall power outlet? If the voltage is much higher or much lower than the range the amp was designed for, that could cause shutdowns.

Are there any refrigerators, neon signs, or other power-hungry appliances sharing the same wall circuit? It is possible for an amp to draw a big spike of current when you play hard, and if that happens at the same time as a beer cooler or air conditioner kicks in, there may not be enough current to share.

The amp probably has some circuitry to protect itself from power surges and drops, and it may be that some component of that protection has worn out from age or use, making the amp more likely to shut down.

But if wall circuit current is the reason, amp should shutdown like a reload, but it doesn't reload, only sound dissapears for about a couple of minutes, indication stays in working order, compressor's led keeps reacting to the signal. It always happens after about an hour of playing, and then repeats about every 10 minutes. And tech from this rehearsal base said this issue is only my case, and this is the reason why for the second year already they do nothing with this amp. Indeed, the strange case...

I've had the same thing happening to me on the HA 3500 combo and it turned out to be the fan though. The fan was toching the metal fan protector and stopped cooling. I think I checked it sometimes before noticing it. The longer I was looking for the cause the more things I started to blame for it but it didn't get me anywhere.
Eventualy I shipped it back to the store I got it from and they fixed it under warranty.
After the fix (too bad they didn't told me exactly what they did) it never gave me problems again.

So maybe check the fan again, who knows...

If you are the only one this happens to there at least two possibilities : 1) you are doing something different than the other guys or 2) something else is going on in the building when you play that doesn't happen when they play.

I recommend going to another band's rehearsal there. Watch what they do and try to figure out what is different.

I agree with bongomania. It sounds like it's a thermal (overheating) issue because the sound takes minutes to come back, where a shutdown due to a short will usually take just a few seconds for the sound to come back when the short is removed. You're running a 4 ohm load, which is acceptable for the HA3500, but it is also its most demanding load and is therefore the most heat producing, so if there is a AC power problem in your rehearsal room it could be just enough to trip the protection circuitry into thermal shutdown.

One of the most common things I've ever been told is, "This only happens to you" or "Nobody else has ever noticed or complained," when in fact it turns out not to be true at all. I'm not saying you were lied to, I'm just saying it has happened to me many times...

Hi.

Any amp that has been sold in the numbers HA3500 has, is bound to have seemingly large number of reported reliability issues.

AFAIK, with HA3500, 90% or so of those issues has been either with the fan or the tube.
Excluding obviously the FX loop issue that plagues all series FX loop amps regardless of the manufacturer.

The only real way to tell what's the problem is to take it to a tech or to bench it, but as these are rental space amps, very little chance of that happening I guess.

It is very, very unlikely that any of Your equipment is at fault, but don't let this experience discourage you from considering a HA3500 purchase.

There is a very minuscule chance that a malfunctioning pre-amp stage somewhere in the signal chain produces a DC offset into the signal that messes up with the amps protective circuit, but like I said, it is very rare.

Regards
Sam

I had a 3500 and it was notoriously overheating for no damn reason. I operated it in what I would consider an amp's designed conditions (nothing cranked, playing through the matching 4x10) and it would randomly shut itself down for awhile.

Heat issues. I removed it from the case (it was one of those 4x10 combos) and sat it on top, never had the problem again. IIRC, the 3500 has a fan or two on the bottom of the amp, which needs to breathe.

Since it was OK for 3 hours at a time previously, sounds like overheating (blocked or non-functional fan) or as other have suggested, low line voltage. Check the fan, check the voltage.

Hey it turns out I didn't have the same issue on my HA3500 like you have as I mentioned before in this topic.
I realised that last rehearsal with my band (1st time in our "new" rehearsal room) when the problem I did used to have came back.
After an our and a half the sound became very distorted and I mean really undesireable distortion. I gave the amp a moment to cool down (unplugged the instrument cable and kept the powerswitch on to keep the fan running) and after +5minutes everything sounded normal again. Another fifteen minutes of playing later: again the same problem.

The fan works normal now so that's not what causes it I think, I'm guessing it's the tube so we'll replace it in the near future. But I know I might be wrong about the tube.
Does anyone know what it could be?

(extra info: EQ is boosted in a wide upside down V only +5 at 500Hz and -1 at 30Hz and 30KHz, volume was set to 2/10 or maybe a tad more. Countour has low pass -7 and high pass +1, no compression, no pedals or anything.
I did build a case myself for the amp out of plywood but it leaves just as much room around the amp as the original HA3500+VX410 combo. I hooked it up to a Hartke transient attack Transporter 4x10" and yet it gave the same issue as 6years ago when I still used the original combo setup - amp mounted in the combo- )

Mine has done that five or six times but only after bar gigging it for 3 years. The culprit is the cooling fan, it was stuck from the smoke and once it was replaced there are no more problems

Actually, it could go that way. The old Marshall Major heads would blow if you put too hot an input into it; it would develop 1700 volts or more across the output transformer, which would blow up. I have one of those, and had to replace the transformer along with two sets of KT88s.

My guess is that, should a similar circumstance occur in a more modern amp like the Hartke, it will go into protect mode.

+1

Hi.

Actually, no.

The impedance mitchmatches very rarely produce nothing more than reduced dynamic range and/or raised noise floor.
Impedance by itself has nothing to do with the gain (hotness or lack of it) of two or more amplifier stages.


It has more to do with the distortion than simply just the gain.
UL taps tend to create resonance in the circuit when distortion increases beyond certain level.
And that's a "feature" of virtually all UL tube amps not just Majors, including the silverface Bassman 10.
The Hartke output section design is pretty much as far away as possible from that design.

Regards
Sam