Impulse!! [Archive] - The Art of Sound Forum

Stumpy

18-04-2012, 00:04

Some expensive bottles to eventually replace. Made on site? :stalks:

Lot of (Rated) power from not much glass.

Hmm, Chinese mains power transformers.......:eek:

I'm not familiar with the sound of either amp or speakers, and to be honest I'm not ever likely to be.
Thing is, if it works for you, enjoy! It doesn't matter what we think. :cool:

Congratulations!

kreacherx

18-04-2012, 01:56

your answers!?
a) lot of rated power from not much glass?
with valve u dont need loads of tubes unlike transistors??
whats wrong with chinese mains transformers?? as we know most of electrical is made in china therefore they should be more proficient than us at winding transformers?

I always respected this forum & its fair approach therefore your statement "...I'm not familiar with the sound of either amp or speakers, and to be honest I'm not ever likely to be...."
I regard as rather rude & dismissive!
ah well it takes all kinds I suppose!
"

Stumpy

18-04-2012, 05:20

Sorry I thought you asked for opinions?

The amps website specifies what seem to me like high power output figures for a single power valve per channel. Just seems unusually high to me being used to much lower figures with valves, thats all.

Plenty of threads on here and elsewhere discussing faulty power transformers and mains voltage mis-matches in Chinese amps. Hope yours is OK and continues to be. (By the way, we in Great Britain were winding transformers LONG before the Chinese thought to try and copy and undercut western manufactures! Seems you didn't know that?).

I don't see how my comment could be considered "Harsh, Rude or Dismissive" by most rational folk? I'm not going to be as lucky as you to own such gear, so I'll probably never get familiar with it. My loss and misfortune. I envy you your sheltered life if that seems rude!

I thought it was accepted practise to use smilies as I did, to qualify comments and add an amount of tongue in cheek humour to them? Did you not notice them? (:ner:)

Truth is the bottom line is like I said - "Thing is, if it works for you, enjoy! It doesn't matter what we think.

Congratulations! ".

Guess my opinions weren't congratulatory enough?

Martinh

18-04-2012, 05:33

I don't see how my comment could be considered "Harsh, Rude or Dismissive" by most rational folk? I'm not going to be as lucky as you to own such gear, so I'll probably never get familiar with it. My loss and misfortune. I envy you your sheltered life if that seems rude!

I thought it was accepted practise to use smilies as I did, to qualify comments and add an amount of tongue in cheek humour to them? Did you not notice them?

I thought you were rude and dismissive too, and continue to be so in your second post. Maybe I have a sheltered, irrational life as well.;)

David, Sounds like some nice equipment, do you have any photos to share?

Martin

StanleyB

18-04-2012, 06:08

Seems a very nice setup to me as well. Just add a Gator upgrade to the TC-7520 with say an AD826, and that valve amp is gonna sound mighty expensive.

Haselsh1

18-04-2012, 07:13

My own personal findings with Chinese valve amplifiers during 2006/2007 fully supports the words of Stumpy.

Ali Tait

18-04-2012, 07:17

If you are happy with the sound that's all that matters. It's always nice getting new kit, enjoy!

However, the comment about mains transformers and UK voltage is a valid one. I have a had a few Chinese amps through my hands and even ones touted as "UK Spec" still only had mains trannies rated at 230v, which aint enough. I am not familiar with your amp, but it may pay to check with the seller/manufacturer what the actual rating of the mains trannies actually is. Don't let them fob you off with assurances, get the facts!

The problem is, a lot of the Chinese kit uses trannies with two secondaries rated at 115v. This saves costs as 115v is fine for countries like America, but not ideal for the likes of us, as tying the two secondaries together gives 230v. It means they don't have to make different trannies for different countries.

It may be a problem for your amp long term, as if it does have 230v trannies, depending on what the voltage is where you live, the amp may be running on or over it's max rating. This is not good for long term reliability, as voltages will be over what they should be inside the amp, particularly if the design runs the power valves hard for more power.

If all this is the case, there's no need to panic, but I would definately recommend the use of a variac or bucking transformer to lower the voltage to 220 if you'd like the amp to last, but as I say, check to see what the rating of the mains trannies actually is. 220 or 230v is NOT enough, despite what they may try to tell you.

StanleyB

18-04-2012, 08:34

hifi_dave

18-04-2012, 09:13

today i went out & completely emptied every coffer i have -- I bought :-

MC368-BSE Ming Da Valve amp
A pair of Cabasse java speakers
together they sound out of this world!!

I still have :- my Audioquest Blue Speaker cable
my Beresford 7520Dac
my iMac

what is your opinion (not too harsh please)?

If you're happy, that's all that matters but did you listen to the Croft and Harbeth as we discussedd on the phone ? You might have been even happier..:scratch:

Marco

18-04-2012, 09:40

Hi David,

Congrats on your new system - you've got some nice kit there, particularly the Cabasse speakers, which are a really class act! :)

However, with respect, I think you're overreacted a little towards Paul's comment, as a result of misconstruing its tone. Unfortunately, this is the fallibility of the written word, and sometimes smilies don't help. His second reply was simply made out of frustration at you missing the point. Let's read again what he wrote originally:

I'm not familiar with the sound of either amp or speakers, and to be honest I'm not ever likely to be.

I didn't take that as a slur against the kit you've just bought, but quite the opposite, as a compliment, in the sense that he was congratulating you on the gear you've bought and stating that, as it was out of his price range, he was not ever likely to be familiar with it.

Perhaps Paul would confirm? What's certain for me, however, is that there was no malice in what he wrote, so perhaps you guys could kiss and make up? :grouphug:

In there too, of course, is a warning about the (sometimes) dubious quality of the transformers in Chinese valve amps, and often how they are incorrectly rated, electrically, for our 240V UK mains supply, despite stating otherwise in the advertising blurb!

Therefore, please take note of what Ali has written, and before plugging your amp into the mains supply (and connecting your lovely speakers to it) have it fully tested by an experienced UK electronics engineer (I'd recommend Anthony TD or Nick Gorham (lurcher), on this forum.

Chances are everything will be ok, but it's much better to be safe than sorry, as I'd hate to see you come back later and tell us a sorry tale of how your amp blew up and took out your new speakers with it......... :nono:

So please, matey, do the right thing and thus be sure to stay happy and safe!

Marco.

Gx Audio

18-04-2012, 09:40

Sound's like another happy Senso customer :-) genuinely nice guys in Truro

Ali Tait

18-04-2012, 09:57

Correct me if I am wrong, but don't the valves run off the regulated and rectified mains? Should the regulator then take care of any mains fluctuations?
And isn't the mains voltage across the EU now harmonized at 230V?

The mains trannie secondaries will be whatever the circuit calls for, perhaps 6.3v for valve heaters, 5v for a valve rectifier if it has one, and the HT, say around 3-400v ( dunno what valves are used in this amp). These voltages will only be correct if the trannie is run at it's rated input. If the trannie is specced at 220 or 230, running it on UK mains at 240v+ will mean the secondary voltages will be higher than they are meant to be. No Chinese amp I've seen has a power supply regulated in such a way as to keep the voltages within spec. Certainly none of the ones I've had.

As for the so called harmonisation, it's a pile of sh1t. Do us a favour Stan and check what your mains voltage is at the moment. Ours here is pretty steady at 240 to 242. I've known some folks to be as high as 253! Imagine what that is doing to a valve amp with 220v trannies...

Anyone who is happy and competent to measure their mains voltage care to share what it is please?

I'll be surprised if anyone is getting 230 or less.

Audioman

18-04-2012, 10:17

David. Congratulations on the new equipment. Did you buy the Ming-da through a UK seller or direct from China? If the second you should take note of the 'experts' here. The problems with Chinese amps are well known.

If it came through a UK importer it may well have been built specialy to UK spec. Best thing is to check with your dealer and don't be fobbed of by vague assurances. The difference in spec probably goes a long way to explain the difference in Chinese ebay prices and Chinese kit officialy sold here. I agree with Ali tate. Mains here is 240v nominal. The EU official voltage is based on a mean + or - variation. A typical Brussels botch up as mains in all Euro countries aren't the same.

hifi_dave

18-04-2012, 10:19

My voltage is usually 238, here in the sticks. At my last shop in St.Albans it was 242 - 252. Occasionally, because of this, certain products made more noise than they should and we were used as a 'bad as it gets' for some products.

Marco

18-04-2012, 10:24

If the second you should take note of the 'experts' here.

No need for the inverted commas, our resident qualified electrical engineers fully deserve the title! ;)

More seriously, even if the amp was bought from a UK dealer, unless the dealer can confirm categorically (and get it in writing, so you can sue him if it's not, and the amp blows up) that the amp has been FULLY tested, electrically, by qualified personnel, prior to being sold.

Trust me, you cannot rely on the majority of dealers being so thorough!

Marco.

Ali Tait

18-04-2012, 10:26

Just another point to note, I had a Yarland that was supposedly EU spec. That had 230v rated trannies, still not enough for the UK IMHO. Saying that, I also used to have a Mr Liang 845 amp. The trannies on that were 230, though were well specced and high quality, and as far as I know that amp is still going strong several years down the line.

anthonyTD

18-04-2012, 10:28

hi All,
the voltage precaution that have been mentioned by Ali is a valid one, Chinese equipment is getting better and better, however, the mains voltage issue must be adered to and checked, if your equipment states 230v you can be sure that actualy it needs 220v to be correct and at 230v a lot of the equipment is already being over run slightly [i have had a lot of it on my bench over the years and checked] the voltage here in the UK can vary wildly, i have measured between 238v and 244v at my house, at a friends works he has measured over 250v, so it realy is important to know what voltage your equipment needs to see to be absolutely sure it is not being seriously over-run, some equipment will take it for a good while before giving up, however, some fail quite spectacularly after a relatively short time.
Hope this helps.
Anthony,TD.

Ali Tait

18-04-2012, 10:32

Yes indeed, I have seen pictures of a Chinese valve amp that caught fire..

Marco

18-04-2012, 10:39

I've owned one!! Remember the Yaquin?? :eek:

Fizz...pop...BANG! Goodnight, Mary Ellen.... :lol:

Marco.

anthonyTD

18-04-2012, 10:46

Thats just one example Marco,
However, you have a valid point there, the Yaqins coming in with 220v rated ie; from Hong kong need only 207v on the primary's for everything on the secondaries to be correct, so as can be seen, if you run this equipment on upwards of 240v its not going to last very long.
A good compromise is a dedicated step down transformer, or a bucking type to lose at least 30v off the mains for this type of import.
Anthony,TD...

Audioman

18-04-2012, 10:49

Before we scare David to death. There is an official UK division of Ming Da since 2011. Therefore would expect UK spec and proper warranty + CE regs.

http://www.mingda.co.uk/

Worth chasing them up to check specification of your model David.

They state -

Beware of ‘grey’ imports - warranties on out-of-territory sales are not supported by Ming Da Valve UK - and they may not even be electrically suitable for other territories than the one for which they are supplied. All Ming Da amplifiers have linear power supplies, which should be used on the mains voltage and frequency for which they were supplied to avoid damage.

Martinh

18-04-2012, 10:56

From the Ming Da UK website:

All Ming Da amplifiers sold by Ming Da Valve UK are covered by a comprehensive 2 year warranty, with the exception of power output valves, which are covered for 12 months.

Beware of ‘grey’ imports - warranties on out-of-territory sales are not supported by Ming Da Valve UK - and they may not even be electrically suitable for other territories than the one for which they are supplied. All Ming Da amplifiers have linear power supplies, which should be used on the mains voltage and frequency for which they were supplied to avoid damage.

Sounds like a good company to me - I'd ask them to confirm that it's got UK transformers fitted though.

I love the fact that it's got a remote and those VU meters are nice.

Martin

anthonyTD

18-04-2012, 10:59

Before we scare David to death. There is an official UK division of Ming Da since 2011. Therefore would expect UK spec and proper warranty + CE regs.

http://www.mingda.co.uk/

Worth chasing them up to check specification of your model David.

They state -
HI Paul,
I completely agree, what started out as a guy wanting to share his delight with us about his new purchase has turned a little sour, however, its best to be safe than sorry and your sugestion is a very good starting point for anyone being put off or scared by what has been discussed here.
Realy sorry David.
Anthony,TD...

Marco

18-04-2012, 11:04

I absolutely agree - and that's not what was intended by my warning, but having myself experienced the woes of a Chinese amp going pop, I'm loathe for it to happen to anyone else!

If David contacts Ming Da, in the UK (who appear to be a reputable organisation), I'm sure he'll receive all the reassurance he needs :)

Marco.

Ali Tait

18-04-2012, 11:13

Yes indeed, sorry if I've put the willes up anyone as it were, just want to keep peeps safe.

Jonboy

18-04-2012, 11:52

I have had a pair of Ming DA 845 Se amps and matching pre amp for a few years, the pre amp has been fine but the power amps did not like uk voltage which is currently 250 volts here, they ran very hot and the sound was distorted, so i now run them on a variac with no more issues and the distortion went as well which i think was caused by the biasing going out due to the extra volts.

Nice amps by they way Dave but please check voltage as has been said before

Audioman

18-04-2012, 12:59

Martinh

18-04-2012, 14:22

Interestingly this is probably the company that makes Icon Audio products. Certainly their MC/MM phono stage is very familiar at a £200 saving. The amps do look very good value and worth an audition.

Jon. It does look like this brand has moves forward a bit in the last few years. Chinese are rapidly catching on to the required standards demanded by western audiophiles. It looks like David has bought himself a very nice amp for the asking price.

As a matter of interest, what would an "equivalent" UK made product cost, bearing in mind this has a RRP of £2000?

Martin

Jonboy

18-04-2012, 15:15

Interestingly this is probably the company that makes Icon Audio products. Certainly their MC/MM phono stage is very familiar at a £200 saving. The amps do look very good value and worth an audition.

Jon. It does look like this brand has moves forward a bit in the last few years. Chinese are rapidly catching on to the required standards demanded by western audiophiles. It looks like David has bought himself a very nice amp for the asking price.

Yes i'm sure that they also build Icon stuff so everything should be hunky dory, mine have some age to them but nicely made all point to point wiring underneath and heavy each mono weights in at around 22kg

Audioman

18-04-2012, 15:32

Yes i'm sure that they also build Icon stuff so everything should be hunky dory, mine have some age to them but nicely made all point to point wiring underneath and heavy each mono weights in at around 22kg

If they are not the current made for UK models it may be worth doing a check on the specs. The manufacturing company, Mei-Xing, have been doing Icon for some time so hopefully they benefited from UK input to design.

Paul.

Audioman

18-04-2012, 15:36

As a matter of interest, what would an "equivalent" UK made product cost, bearing in mind this has a RRP of £2000?

Martin

Difficult to say exactly. Probably 50% more to double. If you exclude Croft the prestige UK brands such as EAR and Audio Note would be considerably more.

Reffc

18-04-2012, 17:42

If the amp was sourced and bought via official UK importers, there should be no trouble whatsoever with it. They (Ming Da) make good kit for the money. I've taken the plunge myself and bought a Consonance Cyber 10, which is not only properly rated for UK voltage, but build quality and sound quality blows away any British made valve amp of the same type short of twice the cost. We may have been making transformers longer than the Chinese but that doesn't make our kit superior any longer, unless we're talking seriously expensive hand wound trannies.

Transformer winding practice in recent years has moved on. From an engineering point of view (something I am qualified to offer an opinion on) both the quality of the wire and the insulation in particular is FAR BETTER on many quality Chinese amps these days than they were on British kit from say 20 years ago, something worth remembering.

Most of the horror stories (a vast majority in fact) come from people who run 220 or 230v rated trannies at UK voltages. As has already been said, EU electrical supply harmonisation was a complete fudge, and a disgrace to even enter it in reality as it has caused quite a bit of confusion for no real practical purpose. Barmy. Providing your amp is a UK spec amp, then it is a) covered by a warranty and b) should be perfectly safe and long lived.

Congratulations David, an excellent sounding pairing and exceptionally good value in the scheme of things.

Marco

18-04-2012, 17:49

Useful information there, Paul, and very good to know. Cheers! :)

Marco.

kreacherx

18-04-2012, 21:54

Thank you most for your mostly practical reply, I took advice & rang Ming Da importers, who rang me back & we were discussing the Amp for an hour & a half!!... we discussed transformers & he assured me that the fault that was in previous amps (Icon Audio) have been rectified & as stated there is a 2yr guarantee on the product!
I also take the comment that a photo has been seen of a chinese amp catching fire but that does not mean that all chinese amps will catch fire!
I have also seen a picture of a house catchng fire :mental:
I am not upset by -ve comments if they are practical, after all I sat down & listened & it sounded beautiful!
Only by the statement ....I havent seen one & I dont want to see one.......???

anyway after all my life experiences I'm made of tougher stuff than that!:cool: