Problem with PMC PRODIGY 1

[Al ears]

That’s a good point, as the gain with MC cartridges is enormous and any HF oscillation or spurious output will give tweeters are hard time.

That said, I’m still inclined to think there was a surge or spike given that both PMC tweeters blew simultaneously.

I have been using low output mc cartridges for ages and I have never had any issues with any of them affecting any of the tweeters in speakers I have used over the course of time.

 

[twinkletoes]

@rayolight

“When using my streamer, volume rarely goes above 2”
What? You must be joking right, no wonder pmc gave you a hard time!

I’ve never taken a volume knob past 11 on any amp and that’s loud! And you can physically see cones reaching there limits at that point . 2 o’clock that’s really loud and that will certainly blow tweeters and cones with a 2volt input and long before you get to 2 on the volume sweep.

Heck my current amp if I take it to 9 on the dial I’m at 100db peaks.

Come on you over did it and you know you did!
I’d heavily suggest when listening to 2 volt inputs like CDs and digital media you keep the volume well under 12 and possibly the no higher than 10 or 11

 

[rayolight]

@rayolight

“When using my streamer, volume rarely goes above 2”
What? You must be joking right, no wonder pmc gave you a hard time!

I’ve never taken a volume knob past 11 on any amp and that’s loud! And you can physically see cones reaching there limits at that point . 2 o’clock that’s really loud and that will certainly blow tweeters and cones with a 2volt input and long before you get to 2 on the volume sweep.

Heck my current amp if I take it to 9 on the dial I’m at 100db peaks.

Come on you over did it and you know you did!
I’d heavily suggest when listening to 2 volt inputs like CDs and digital media you keep the volume well under 12 and possibly the no higher than 10 or 11

You've completely misread what I said ,I said volume rarely goes from zero to 2 not round to 2 o clock.

 

[rayolight]

You've completely misread what I said ,I said volume rarely goes from zero to 2 not round to 2 o clock.

Just another point ,PMC didn't give me a hard time they were very sympathetic. The problem was with the importer. You should also bear in mind that a volume of 2 on a 50watt amp is considerably different to an amp of 250 watt. I have 2 amps with different outputs and the volume output per amp from the volume knob is completely different also it depends on the ohm rating of the speakers your driving if I am not mistaken.

 

[DougK1]

@rayolight

“When using my streamer, volume rarely goes above 2”
What? You must be joking right, no wonder pmc gave you a hard time!

I’ve never taken a volume knob past 11 on any amp and that’s loud! And you can physically see cones reaching there limits at that point . 2 o’clock that’s really loud and that will certainly blow tweeters and cones with a 2volt input and long before you get to 2 on the volume sweep.

Heck my current amp if I take it to 9 on the dial I’m at 100db peaks.

Come on you over did it and you know you did!
I’d heavily suggest when listening to 2 volt inputs like CDs and digital media you keep the volume well under 12 and possibly the no higher than 10 or 11

Volume knob position is no indication of volume output. Volume pots vary by manufacturer, some are maxxed by 11 o'clock, some 5 o'clock, or some are like my pot which just goes round and round with no end stop.

 

[nopiano]

I have been using low output mc cartridges for ages and I have never had any issues with any of them affecting any of the tweeters in speakers I have used over the course of time.

No, me neither, although I’ve not had a MC since around 2010. It was more that I’m not sure where else tweeter frazzling signals might come from, other than my hypothesis of a power surge or spike. I was more reflecting on PMC’s speculation as to the cause.

 

[rayolight]

I have been using low output mc cartridges for ages and I have never had any issues with any of them affecting any of the tweeters in speakers I have used over the course of time.

I'd be interested to know what increase in volume you need for your mc cartridge, say relative to a mm or cd

 

[twinkletoes]

Volume knob position is no indication of volume output. Volume pots vary by manufacturer, some are maxxed by 11 o'clock, some 5 o'clock, or some are like my pot which just goes round and round with no end

Come on dude this is stretch, amps are almost entirely delivering there entire volume with a 2 volt input at the 10-11 o’clock position.

Full sweep controls are very rare and almost entirely found on avr’s with digital pots.

Off the top of my head with all the amps I’ve owned and come across in 42 years I can count on one hand the amps with full sweep pots.

Text book overdriven. I’ve said my piece and I’ll leave it there. I’d say the OP has been very lucky

 

[rayolight]

Come on dude this is stretch, amps are almost entirely delivering there entire volume with a 2 volt input at the 10-11 o’clock position.

Full sweep controls are very rare and almost entirely found on avr’s with digital pots.

Off the top of my head with all the amps I’ve owned and come across in 42 years I can count on one hand the amps with full sweep pots.

Text book overdriven. I’ve said my piece and I’ll leave it there. I’d say the OP has been very lucky

You're still missing the point ,I didn't mention 2'o clock position ,I said from off position to plus 2 in other words hardly any turn of the volume knob Don't know where you get this 2 o clock position from,that's nearly two thirds turn on my volume control. So your totally wrong in your comments. And for the record my amp has almost a full sweep pot.

 

[rayolight]

So am I. Some sort of arcing or DC signal would be the reason two tweeters blow simultaneously. To be fair to PMC it doesn’t frankly sound like a manufacturing defect on the face of it. That said, they charge premium prices and probably want to retain goodwill, so might well fix them fre of charge through their local distributor or provide spares for you.

But I’d remove the switching box and see if you can test it, otherwise you’ll soon have two sets with blown tweeters!

Here is the link to the switching box be interested in your comments

Douk Audio VU102 2 Zone Amplifier / Speaker Selector Box with VU Meter Audio Switcher w/IR Remote

Features VU102 amplifier / speaker selector: two working modes (2-IN-1-OUT / 1-IN-2-OUT), with A/B channel switch button, convenient to compare the sound quality of 2 pair of different speakers or 2PCS power amplifiers without plugging in and out cables repeatedly to avoid wearing the contact...

doukaudio.com

 

[Al ears]

I'd be interested to know what increase in volume you need for your mc cartridge, say relative to a mm or cd

I don't need to increase the normal position of the volume control on my amplifier and you shouldn't with a decent phono preamp as it should be amplifying whatever output the cartridge has to line level.
The volume control on my amp stays the same, relatively, whether I am using my turntable or my CD player.

 

[rayolight]

I don't need to increase the normal position of the volume control on my amplifier and you shouldn't with a decent phono preamp as it should be amplifying whatever output the cartridge has to line level.
The volume control on my amp stays the same, relatively, whether I am using my turntable or my CD player.

Does this mean that the Musical Fidelity mx vynl recommended by whathifi mag is not up to it or is faulty as that is not the case,when for instance I have it connected to a hana ml or an Ortofon 2m Black.With the Hana I definitely have to increase the volume .

 

[Al ears]

Does this mean that the Musical Fidelity mx vynl recommended by whathifi mag is not up to it or is faulty as that is not the case,when for instance I have it connected to a hana ml or an Ortofon 2m Black.With the Hana I definitely have to increase the volume .

Perhaps it's a Gain issue with that mx vinyl.
if it can amplify that Ortofon to a 2v line output then it should be able to do the same with the Hana

 

[rayolight]

That's all the setting available

 

[rayolight]

That's all the setting available
View attachment 8194

Could this have something to do with the tweeters problem 🤔