Need help OOW Monoprice Cavalli LP

Hello everyone, first timer here!

So I bought Alex Cavalli's Liquid Platinum second hand (warranty is still going strong but Monoprice doesn't do service on these anymore, I'll get something back if I send the amplifier back to the seller, he sends it to the Monoprice, I get store credits, order something from Monoprice which could sell as a new product and then I'd have something in my hand after national and international shippings.

Let's then go to the problem which started all this: I bought PC88 tubes from my local retailer thinking I'm buying PCC88s (texts were wiped pretty much) and had slapped those in. Started the amp and before I could do anything just a hiss and just a hint of smoke I think, barely visible. Next panic hits and I put stock ones in and try the amp, it starts to power up like normal but stays on the red light.

Of course local tube retailer won't take any of this for himself, I should know what I'm putting into the amp, like I thought I did and by being new in this hoppy, didn't see from the tube wiring that "Hey! This is PC88, not PCC88 what I ordered, let's stop here!". Monoprice won't share circuit schematics of course, Cavalli having the ownership to those (so if you're listening, please share these with me for personal use only, I have only one local electric engineer who could check out this amp and he would do it by reading the schematics which are unavailable for me) and neither they will service it, just shop credits on the table (how much - don't know after a lots of shipping payments nationally and internationally).

I've sent a lot of emails for TV- and radio service shops but they a) tell me to send it to the place I ordered it b) are willing to check out it for pretty nice amount of money but no guarantees for service c) won't answer.

So, I'm pretty much circled by people who's 'hands are tied'. Only thing at the moment that could save me (what I can think of) is those schematics that I will not be seeing I would presume.

Here's link to some photos of the MOSFETs which are the only components I think that seem different than the counterparts. No smoke trails, nothing. But, here we go (there's some text on my language to my local electric engineer): https://imgur.com/a/nJf0iWG

Thank you for your answers already!

 

Wish that i could help but someone here may be able to.

Good luck

 

If you really want to fix it.
Avenson Audio are the official repairer for Cavalli amplifiers.

Your best bet is to ask them if they can help.
It will cost you in international shipping as they are located in the USA.

@dBel84 might be able to offer further advice.
I'd take anything he says as a hard truth.

 

What Marv said.

The Monoprice LP is a microprocessor controlled tube hybrid. I suspect you have blown the high voltage section of the power supply which is not as simple as just repairing the switch mode elements that make it up. Avenson may be able to repair and reprogram.

Good luck.. dB

 

Listen to @dBel84 and @purr1n

 

Thank you for your answers and the information you shared with me. The thing is that Monoprice is offering me (after international and national shippings) shop credits IF they think that warranty covers it. No service available. Also I payed about 300e for the amp. What I've heard, the warrant probably will be denied and I'd have to pay the shipments back too. I'm listening to @dBel84 and @purr1n about this case, also my local amp designer could probably help out since he has been involved with the same amp back in the day, doesn't hurt to show it to him because he won't take any payment just for check it out. Thank you everyone, this was the first forum I got seriously helped out!