Bugera Trirec Infinium

[Chris988]

Hello, I have a big problem with my Trirec and the guitar tech I brought it to is refusing to check the amp without schematics. I really don't know what to do now :/ I would thank you forever, if you could help me out with this...
Thanks in advance!
Sincerely, Chris

[DrGonz78]

Describe with your best ability the symptoms or the nature of the big problem you are having with this amp. Also, please fill out your profile to include the Country/City that you live. That information is useful in a few different ways and for one there might be a nearby tech from this forum that would service the amp.

[Chris988]

Thanks for your quick answer! I did fill out my profile now, sorry for that. The first channel is running as it's supposed to, but anytime i switch to channel 2 or 3 the output of the amp is dropping to a barely noticable level. Also it does some kind of sound dying out completely after a few seconds. The tubes aren't the problem, that's already been tested.

[Enzo]

I would look closely at each preamp tube to see that BOTH little heaters inside each is glowing. Just because the tube is "good" doesn;t mean the socket works. And a loss of heater will fade a sound out to zero.

And any tech without a schematic should know he can at least check voltages around a triode, problems are usually pretty obvious.

[Chris988]

I don't have the amp here now, but before i took it to the tech all heaters lit up, i dissassembled it from the case and removed the caps to see that correctly.

And I don't really know what the tech has done yet, besides checking tubes.

[bob p]

Getting schems for the Bugera Infinium series of amps is pretty tough. I've been asking around for a schematic for the V-22 Infinium and I've gotten nowhere. Behringer is very tight about distributing their schematics. If someone is not an authorized/contracted Behringer repair site then Behringer won't help them with schematics.

Unfortunately, Behringer's unwillingness to release the schematics on their Infinium circuit means that Behringer has cornered the market on servicing their amps. They know that independent shops can't afford to waste their time reverse engineering the circuit, and in the absense of doing that, Behringer controls which amps get repaired. By refusing to repair the amps, they can effectively force most people into the re-purchase cycle. I hate that.

The good news is that there are a lot of simple repairs that can be made without having the schematic. Maybe your local guy made the schematic requirement just because he doesn't want to mess with a Bugera amp.

When my V-22 stops working I'll make them fix it if it fails during warranty. Once it's out of warranty I think I'll probably just bypass the control circuitry on the amp and build a linear power supply to run the amp. To hell with them.

I notice that you're in Germany. That gives you a definite advantage over me. You're close enough that you can call Behringer for help. If they refuse to help then you can threaten them with throwing the amp through the window at their world headquarters. I once experienced a smilar problem with Raybestos/Brake Parts Inc. on some brand new parts that were defective. I got a "no support" response from Raybestos, solely because I had purchased the item through RockAuto. The Raybestos people changed their mind about "no support" when I told them that I was local and that if they refused to honor their warranty on a new product, then I'd be coming over to their office to throw the parts through their window. They shipped replacements the next day.

[Chris988]

Thanks for your advice, I'll call Behringer tomorrow and tell ask them for help. By the way, the throwing out of the window method also came to my mind cause i'm really angry

And the problem with my local tech is that he's refusing of measuring anything within the curcuit without the schematic unfortunately. I would have measured it myself if i had a bit more knowledge.

[bob p]

Good luck with Behringer. If you find a way to get an Infinium schematic from them, please try to get the V22 Infinium schematic as well! I'd love to have a copy.

[MarkusBass]

I often fix amps without schematics but in this case the circuit is assembled on a PC board painted with black silkscreen, which makes tracking the circuit extremely difficult. And, the amp is controlled by a microprocessor. As Enzo says, quite often the problems are basic and can be diagnosed without schematic but you never know. What does authorised service say (there must be authorised Bugera service in Germany)?
Based on your description, if this is not related to valves, I would look at relays that switch the channels. But this is just a wild guess - maybe I shouldn't suggest anything.

Mark

[DrGonz78]

I've been asking around for a schematic for the V-22 Infinium and I've gotten nowhere.

A bit off topic for a second... Just curious but is this the same amp schematic or is it a different version?

[Chris988]

Mark my local tech indeed said he thinks it's a relais, based on the symptoms, but as i said he's not willing to go any further. I didn't contact authorised service yet, because i would have to send it to them which would cost around 30€.

[MarkusBass]

Mark my local tech indeed said he thinks it's a relais, based on the symptoms, but as i said he's not willing to go any further.

Most probably, relays are "bypassed" with high value resistors (something like 3M3) and when the channel is changed but the relay does not have contact, you would get symptoms exactly as you described. But there also may be few other failures that give the same symptoms. What about tapping on the relays with some pencil? Or, in general, tapping the PC board with some wooden (isolated) stick? Maybe you will find the reason for the problem and you will ask your tech for payment for doing his job ? I know that fixing the amp without the schematic is difficult but life is also difficult. And your tech seems to be accepting only the easy jobs.

Mark

[bob p]

A bit off topic for a second... Just curious but is this the same amp schematic or is it a different version?

Different version. The "Infinium" models replaced the manual bias circuit with an auto-bias circuit that's under microprocessor control.

[J M Fahey]

Thanks for your advice, I'll call Behringer tomorrow and tell ask them for help. By the way, the throwing out of the window method also came to my mind cause i'm really angry

Not surprised at that, since the method seems to have been invented there
https://www.britannica.com/event/Def...of-Prague-1618

Sadly the last time it was used it started the Thirty Years War

[bob p]

I've visited Pražský hrad. There were actually two "defenestrations" that took place in Praha, both of which precipitated wars.

The first one was in 1419. There was discontent in the congregation of the Hussite church due to inequality between the peasants and the nobility, including the church prelates. A parish priest, Jan Želivský, led his congregation in a protest march to the town hall at Novoměstská radnice in Charles Square because the town council had refused to honor a prisoner exchange with the Hussites. Someone in the town council hall supposedly threw a rock from the town hall, which hit the priest. The result was that an angry mob stormed the town hall and seven officials got thrown out the window, killing them all. This event led to the Hussite Wars that lasted from 1419 to 1436.

The second defenestration (the one you mentioned) occurred in 1618. It is more popularly remembered because it is more recent, and because it led to the battle of White Mountain, sparking the 30 Years War.

One might ask how anyone survived the second defenestration, considering they were thrown out of the 3rd story tower windows. The answer is that they landed on a large pile of dung! No shit!

By any chance do you have Czech relatives, Juan? Just wondering how you might know these obscure facts. I know that many Czechs emigrated to Argentina in the 1930s, some of whom subsequently came to the USA.