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Plinius 8150 Amp question


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Checking here if anyone is familiar with the plinius 8150 ? Do owners here keep the amp switched on all the time on standby mode ? I do read that instructions do require 72 hours until it reaches optimal sound , so any input would be great , picking up speakers tomorrow. 

Have had the amp on for 6 hours now and it’s very warm just how my sugden use to be ...

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I used to own the 8150.

Unlike the later 8200 amp the 8150 had a fairly high class A bias and ran hot! 

Even the knobs on the front panel would be quite warm, something I found disconcerting - especially in summer when ambient temps were higher meaning the amp ran hotter.

The top panel ran very warm-hot and under the amp, where the output transistors/heatsink were bolted to the bottom chassis, was scolding hot - as I found out when repositioning the amp!

The internal heatsinks only exacerbated things - ensuring that all the internals ran hot as well.

I probably had the amp for a couple of years and used to keep it powered up (as suggested by Plinius). I never had an issue, but running high internal temps like that can't be good in the longer term. 

IMO an amp running this sort of high bias in a fairly compact chassis should have external heatsinks to assist cooling. 

 

I later had an 8200P power amp (similar to the power amp section of the 8200 integrated), which had the same internal heatsink/chassis design but lower class A bias, and it ran much, much cooler.  

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The 8150 is a great amp - I had one for a couple of years and always regretted parting with it. I was advised by the salesman at the time to leave it off but fire it up for 30 minutes or so before listening for results. Plinius advise you to keep it on all the time but he could not detect any major changes and felt it was an unnecessary waste of electricity and put unnecessary hours on the amp. Worked for me.

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After a week I’m really enjoying the 8150 have it matched with focal Electra 1007s . Definitely a very liquid  sounding amp  , I have kept it on for a long period , but given the age I’m reluctant to. I have plugged my 1210m5g into the onboard phono , but only one channel is working , it maybe my tt earth wire as I had modified it recently and then changed it back to stock with original m5g rca cables ? the phono stage from one channel is very good , was so surprised actually.. will need to borrow a seperate phono to diagnose this. Defiantly happy with my new set up 

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2 hours ago, clappy said:

The 8150 is a great amp - I had one for a couple of years and always regretted parting with it. I was advised by the salesman at the time to leave it off but fire it up for 30 minutes or so before listening for results. Plinius advise you to keep it on all the time but he could not detect any major changes and felt it was an unnecessary waste of electricity and put unnecessary hours on the amp. Worked for me.

Best advise.  I have no idea why anyone would recommend any pieces of electronics to be idling on 24/7.  Not only it’s a waste of electricity but certainly will put hours on components like electrolytic caps and due to the high bias also places SS on notice. 

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25 minutes ago, Addicted to music said:

Best advise.  I have no idea why anyone would recommend any pieces of electronics to be idling on 24/7.  Not only it’s a waste of electricity but certainly will put hours on components like electrolytic caps and due to the high bias also places SS on notice. 

Fairly said which is why I was asking .. but I assume electricity wasn’t much of a problem back then ?  I won’t be leaving my amp on ...... no way .

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7 minutes ago, rocky500 said:

How do you go with ME products that sound there best after 3 days?

That would be the preamps. I don't understand the question.

 

7 minutes ago, rocky500 said:

Warm up would be a b... as you have plan well ahead when ever you want to have the best listening session. :)

 

Nope. As it is only the preamps that require a long warm-up period, as long as the preamps are plugged in, they are powered up and the power consumption is 4 Watts, then the heat generated is insignificant. No planning is required. 

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I have a 9200 and always turn it off when not in use as it otherwise runs hot even when just at idle pushing no signal. TBH i've always wanted to upgrade to a newer Plinius like the Hautonga or Hiato for one reason only, that they have a standby mode whereas my damned 9200 doesn't - other than that it's a beautiful piece of kit :)

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  • 1 month later...

Haven't owned the 8150 but I am using a Plinius Tautoro pre and SA Reference power amp, according to user's manual I leave the pre on stand by when not in use, but I always switch off the power amp after using it from the main power switch for couple of reasons: 

I found the SA Reference power amp doesn't require a long warm up time to sound good.

If I leave the power amp on stand by, it still gets warm, (According to it's manual, it's normal)

Not sure what I am doing would make any sense, commends are very welcome.

Edited by mlinvpp
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  • 3 weeks later...

I have an 8150 and do leave it on all the time except when I go away for a few days or more, but I turn it back on as soon as I get home again so it is ready for listening later. I find it sounds light & edgy when cold. Takes at least half an hour to an hour to start coming right. They do run hot, but that is what makes them so good! Turning off/on does stress the caps, but as my one was manufactured in '99 I had it serviced, caps replaced. Glad I did as the caps were budget 8500uf and 85 degree rated, down 10% on spec due to age. Tech put 105 degree 10000uf Elnas in it instead, no more worry. He also made a few other mods, better than before. Gorgeous amp to listen to, esp late at night on low volume.  I also use it as a preamp sometimes, I pull the 4 fuses out of the back to turn off the power amp section when I do, sounds even better. Would never let go of my 8150.

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5 minutes ago, Rayblo said:

I have an 8150 and do leave it on all the time except when I go away for a few days or more, but I turn it back on as soon as I get home again so it is ready for listening later. I find it sounds light & edgy when cold. Takes at least half an hour to an hour to start coming right. They do run hot, but that is what makes them so good! Turning off/on does stress the caps,

Incorrect. In any properly designed amplifier, switching on and off stresses nothing. In fact leaving an amplifier on continuously, causes premature wear on electrolytic caps. Not to mention the stress on your family finances. 

 

5 minutes ago, Rayblo said:

 

but as my one was manufactured in '99 I had it serviced, caps replaced. Glad I did as the caps were budget 8500uf and 85 degree rated, down 10% on spec due to age. Tech put 105 degree 10000uf Elnas in it instead, no more worry. He also made a few other mods, better than before. Gorgeous amp to listen to, esp late at night on low volume.  I also use it as a preamp sometimes, I pull the 4 fuses out of the back to turn off the power amp section when I do, sounds even better. Would never let go of my 8150.

105 degree C rated caps may last longer, but they too will not last forever. Always switch off when not in use. 

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Incorrect. The greatest stress on a capacitor is the initial energising. And of course no capacitor lasts for ever, but having higher temp rated caps will last longer between servicing. Sound quality is more important to me and this is in line with Plinius recommendation. 

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7 minutes ago, Rayblo said:

Incorrect. The greatest stress on a capacitor is the initial energising.

Cite your evidence of this claim. 

 

The real facts are more prosaic. Electrolytic capacitor manufacturers specify their products' life span as XXX hours @ XXX degrees C. Lower temperatures = longer life and higher temperatures = shorter life. 'Ripple current' rating must also be taken into account with capacitors subject to higher currents. 

 

7 minutes ago, Rayblo said:

 

 

And of course no capacitor lasts for ever, but having higher temp rated caps will last longer between servicing. Sound quality is more important to me and this is in line with Plinius recommendation. 

Higher temperature caps MAY last longer. It depends on the detail hidden in the ratings.  In a product operating at (say) 40 degrees C, a 105 degree C, 1,000 hour cap will not last as long as an 85 degree C, 20,000 hour cap. 

 

The devil, as usual, is in the detail. 

 

Either way, electrolytic caps (all of them) will last longer if the product is not permanently powered and operated at elevated temperatures.

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2 hours ago, Rayblo said:

Incorrect. The greatest stress on a capacitor is the initial energising. And of course no capacitor lasts for ever, but having higher temp rated caps will last longer between servicing. Sound quality is more important to me and this is in line with Plinius recommendation. 

I may just go with the 105 caps as you explained @Rayblo and now I do leave my 8150 on . I’m listening to music every day as soon I get home  4 hours per day .. l just make sure the windows are close so the hot air from outside doesn’t warm up the living room .. I’m really enjoying this amp  , it eats my preview sugden ?

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20 minutes ago, Diynamic said:

I may just go with the 105 caps as you explained @Rayblo and now I do leave my 8150 on . I’m listening to music every day as soon I get home  4 hours per day .. l just make sure the windows are close so the hot air from outside doesn’t warm up the living room .. I’m really enjoying this amp  , it eats my preview sugden ?

Just as long as you realise that Rayblo is incorrect. Leaving electrolytic caps to endure elevated temperatures accelerates wear on the components. And yes, I understand that the 8150 requires a warm-up period. A timer or remote switch-on system would be a better idea. You'll save money on electricity too. 

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4 hours ago, Zaphod Beeblebrox said:

Cite your evidence of this claim. 

 

The real facts are more prosaic. Electrolytic capacitor manufacturers specify their products' life span as XXX hours @ XXX degrees C. Lower temperatures = longer life and higher temperatures = shorter life. 'Ripple current' rating must also be taken into account with capacitors subject to higher currents. 

 

Higher temperature caps MAY last longer. It depends on the detail hidden in the ratings.  In a product operating at (say) 40 degrees C, a 105 degree C, 1,000 hour cap will not last as long as an 85 degree C, 20,000 hour cap. 

 

The devil, as usual, is in the detail. 

 

Either way, electrolytic caps (all of them) will last longer if the product is not permanently powered and operated at elevated temperatures.

Ok then, you can view this YouTube video from Pauls Posts for starters.  Paul McGowan pretty much covers this topic.  He is the owner of PS Audio in the US and is a veteran in the manufacture of high-end audio with 40+ years experience, manufacturing Class A, AB, D, MOSFET and hybrid vacuum tube designs.

 

In the case of my 8150, Plinius used 85 degree Marcons, a budget cap.  Other owners may open their amps up and find better caps than my one had.  It's whatever Plinius had on the shelf at the time maybe.  If one was to service their 8150 themselves they can put whatever they like in as they will probably know what they are doing.  If they take their amp to a HiFi service agent worth their salt and ask for audiophile cap upgrades I would imagine the service agent will put decent caps in if they appreciate audio, as my local audio repair guy did.  But a good place to start is to look for/ask for 105 degree audiophile grade caps.  You are right in that the other specs need to be considered and I agree.  What I am saying is that my audio repair guy makes his own high performance amps and does not buy in low grade caps.  He buys audiophile 105 degree caps and made a point of telling me what caps he installed and why.

 

When you buy a Plinius 8150 amp you are getting something special.  The 8150 was regarded by Neil Grader as one of the ten most significant amplifiers of all time.  Google it.  What makes it so good even today is excellent engineering and clever circuit design.  It's a Class AB amp and what contributed to making it so good is the significant biasing into Class A.  A byproduct of this design is the generation of heat.  But the heat is not a nuisance as such, as without it the amp would not be as good. It NEEDS to run warm to perform.  Turning it off is stopping you from getting the full enjoyment from it.  When I come home from a hard day (times vary) one of my favourite things to do is to stick on some good music and settle myself in the sweet spot.  Having to wait for it to warm up would be a real pain.  I made a personal decision that leaving it on and getting the enjoyment from it was more important than thermal aging and power consumption.  That's the price you pay for audiophile grade listening.

 

Take my Plinius SA-50 amps for example.  They are Class A/AB switchable. Most of the time I leave them in Class AB to limit thermal aging and lower power consumption.  But late at night when all the ambient noise quietens down I want the performance they offer and I switch them to Class A.  They get REALLY HOT, way more than my 8150.  Now the benefits of Class A do not come into effect straight away.  It takes about 2+ hours before I hear the silkiness, detail, transparency and sound stage depth that Class A has.  They have to heat up and settle into another level of performance.  Interestingly when I opened one of them up they had 85 degree caps in the DC blocking stage.  Some time I will get these serviced too for peace of mind as they are 25 years old now.  Hobbies typically cost you, not many hobbies make you money.

 

Don't be too concerned about the heat generated.  I was worried initially but then I realised it was normal.  Just make sure the heat can escape unhindered, and enjoy it!  My concern was the age of the amp as in my first post and having the amp serviced assured me that is was ready for another 20+ years of great listening.

 

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