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I had some issues with "fuzzy (piano) notes" with a pair of NVA A40 Mk2 amplifiers (both units).
It has come to my attention, that a small number of other users have the same / similar issue with their NVA amplifiers. The issue is very noticeable when you listen to music with distinct piano notes. There is a fuzz around the notes which becomes quite irritating after a while. I do not have the amplifiers anymore but I really am curious to know what was causing the issue. I am not aware that it is also present in mk1 models. It seems to be limited the newer mk2 versions (the ones with the huge heat sink :stalks:)
NVA is refusing to give me information on the subject, so I am turning to the online community to seek some enlightment.
Cheers all
:D
istari_knight
04-12-2013, 17:18
:lol: I can see this thread heading for the bin. http://theartofsound.net/forum/showthread.php?27569-Ban-on-all-discussion-of-Richard-Dunn-(NVA)-and-The-Hi-fi-Subjectivist&p=475513#post475513
Until it does... I would guess its oscillation of some kind ? Or could be quiescent current set too low that causes the exact problem you describe...
Arkless Electronics
04-12-2013, 17:20
:lol: I can see this thread heading for the bin. http://theartofsound.net/forum/showthread.php?27569-Ban-on-all-discussion-of-Richard-Dunn-(NVA)-and-The-Hi-fi-Subjectivist&p=475513#post475513
Until it does... I would guess its oscillation of some kind ? Or could be quiescent current set too low that causes the exact problem you describe...
+1
Your icon undermines your question.
:lol: I can see this thread heading for the bin. http://theartofsound.net/forum/showthread.php?27569-Ban-on-all-discussion-of-Richard-Dunn-(NVA)-and-The-Hi-fi-Subjectivist&p=475513#post475513
Not so, dude. As long as the topic of discussion centres on the amplifiers themselves, rather than who made them or his forum, then all is ok :)
Marco.
istari_knight
04-12-2013, 17:31
Not so, dude. As long as the topic of discussion centres on the amplifiers themselves, rather than who made them or his forum, then all is ok :)
Marco.
Cool :thumbsup: I thought it was a blanket ban [hadn't properly read the thread I linked to :doh:]
Sovereign
04-12-2013, 17:39
Your problem is very un NVA . I was listening to some large scale piano music last night and my NVA amps sounded big, bold and clear as a bell.
istari_knight
04-12-2013, 17:48
Your problem is very un NVA . I was listening to some large scale piano music last night and my NVA amps sounded big, bold and clear as a bell.
Are yours mk1 or mk2 ?
Sovereign
04-12-2013, 17:58
Well it's a TSS so it's the same circuit board with the massive heat sinks
the fuzz, if present can be heard by placing an ear close to the tweeter.. after that it is everywhere .. at first it was thought that it could be the speaker cables which were to close together (NVA cable incidentally). But that wasn't the cause. Relocation of amps (away from any HF), source change and a number of other interventions didn't stop the fuzz. The only thing that helped was to take the amps out of the chain.. go figure ? up until now I was led to believe that this case was an isolated one.. this however doesn't seem to be the true anymore.
istari_knight
04-12-2013, 18:41
Well it's a TSS so it's the same circuit board with the massive heat sinks Oh right, nice looking things those :)
Do they pre-date the mk2 range ? I would have expected the PCB's to have some subtle differences to the lesser models ? I know they use separate power supplies for the front end & L/R channels... Its not uncommon to see higher bias settings in the more expensive of two amplifiers that share the same core design.
From what I've seen all NVA amps use a fixed value resistor for bias setting... If the value of said resistor was calculated for the mk1 heatsinks you would end up with an underbiased amp if you then fixed that PCB to a much larger heatsink [IME.]
All pure speculation I must stress ! Either way its a relatively minor issue & I'm sure the designer/manufacturer will sort out any problem units which are by all accounts few & far between.
I might add that the amps where sent to the manufacturer to be checked but they where incapable of reproducing the issue and returned them.
istari_knight
04-12-2013, 19:26
In that case I don't know :confused: It would suggest that something in the vicinity of your system was causing the instability.
No I don't think so... I removed every possible source of instability. Reconfigured the system in every possible way, switched interconnects, turned off wifi, fridge (just joking), computers, router, streamer, phones...
but maybe it was the fridge after all.
;-)
julesd68
04-12-2013, 20:15
What did you do with the amps Rupert?
that is another story. suffice to say that I had to send them back to the manufacturer because one of the amps was DOA when I got them back from nva
Maybe it happened when Rupert was playing some 'fuzzy warbles': http://theartofsound.net/forum/showthread.php?18037-What-s-your-new-Fuzzy-purchases
:D
Marco.
great classic
Alex: What you got back home, little sister, to play your fuzzy warbles on? I bet you got little save pitiful, portable picnic players. Come with uncle and hear all proper! Hear angel trumpets and devil trombones. You are invited.
sorry but I really have to insert another smiley at this stage
;)
done !
PaulStewart
04-12-2013, 21:21
Loved the Hydraulic Reference in Alex's system. A J.A. Michell made one, crafted at the other end of Shenley Street, Boreham Wood from Elstree Studios, where the film was made. It's common knowledge, that John was a cinematographic model maker and knew Kubrick through making the spacecraft for 2001. Kubrick also owned a Reference TT, with a Vestigial Arm and ADC XLM cart.
Hi,
Quite some time ago, I bought an LP that I didn't particularly like.
I sent it back and got a refund. However, I'm a sad old git who just can't let things go and get on with life. Has anyone else had a similar experience?
( just in the interest of working out what the problem is/was of course )
:D
Guy.
At least the amps are returnable if they don't fit the bill for whatever reason. Pleanty of protection for mail order firms I believe. You tried them, found they didn't suit for whatever reason and I suspect you sent them back and were refunded? Best for all to leave it there eh?
Audioman
04-12-2013, 21:32
Wasn't the OP using something other than the recommended speaker cables IIRC?
The updated 306 you have will be carefully bandwidth controlled and pretty well bomb-proof into any load, limiting when it can't cope, so glad you have a solution that suits :) Don't forget that it inverts absolute phase (from memory)...
At least the amps are returnable if they don't fit the bill for whatever reason. Pleanty of protection for mail order firms I believe. You tried them, found they didn't suit for whatever reason and I suspect you sent them back and were refunded? Best for all to leave it there eh?
that is not the subject .. I am trying to find out if the amps had an intrinsic problem. Actually, it seems my query has been answered by the manufacturer himself.
so it is not a case of me not liking the amps it becomes a case of the amps having a design issue or at the very least being incompatible with power sources outside the UK.
I don't want to get into the gory details surrounding the comm with the manufacturer
Also, if you have these amps with the fuzz just send them in and don't waste hours trying to debug the problem
The updated 306 you have will be carefully bandwidth controlled and pretty well bomb-proof into any load, limiting when it can't cope, so glad you have a solution that suits :) Don't forget that it inverts absolute phase (from memory)...
yep , thanks for the info.
Spectral Morn
04-12-2013, 22:06
Hi,
Quite some time ago, I bought an LP that I didn't particularly like.
I sent it back and got a refund. However, I'm a sad old git who just can't let things go and get on with life. Has anyone else had a similar experience?
( just in the interest of working out what the problem is/was of course )
:D
Guy.
:offtopic:
Also, if you have these amps with the fuzz just send them in and don't waste hours trying to debug the problem
I'm really unclear on your motive for starting this thread, Rupert, but I don't see lots of people rushing in to agree with you. Most likely a one-off issue or, more likely, a mismatch with other components in your chain.
jandl100
05-12-2013, 07:50
I'm really unclear on your motive for starting this thread, Rupert
Really?
:eyebrows:
So, just to make sure I understand this; the OP bought an amp, which had a fault. He has returned the amp and got his money back. Is there anything to discuss? I bought a floor lamp which didn't suit, and am returning it today. No big deal.
So, just to make sure I understand this; the OP bought an amp, which had a fault. He has returned the amp and got his money back. Is there anything to discuss?
No, I don't think so, unless anyone has anything valuable to contribute.
The icon on the OP shows r100s motivation.
Gordon Steadman
05-12-2013, 11:47
This sort of thing annoys the hell out of me.
This is a clear, thinly disguised attack on a particular manufacturer for personal reasons. The said manufacturer has publicly acknowledged that there have been a small number of similar problems that he has personally investigated without finding a real reason. It is presumed to be a particular system problem.
As the OP has had his money back, I can see no reason to raise this, especially so long after the event - at least six months I understand.
I would delete this thread altogether.
I do agree, Gordon. Clearly, this thread had no constructive purpose.
Therefore, I will lock it and amend the thread title simply to 'NVA amplifiers', in order to protect NVA from any unwarranted adverse publicity caused by subsequent Google searches.
Marco.
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