Using the amp as it was designed to be run will have appropriate gain structure.
And it should be quick and easy to try.
Chris
Common sense isn't anymore!
The thing is, if it is a gain-structure issue would that not manifest itself immediately? How could it be great for months and then deteriorate?
Current Lash Up:
TEAC VRDS 701T > Sony TAE1000ESD > Krell KSA50S > JM Labs Focal Electra 926.
Location: London
Posts: 1,499
I'm Sam.
Maybe your neighbours have started using some equipment like a network over powerlines thing and it's effecting your mains but being away from the system has made you immediately notice it.
Well the NVA is completely passive and bufferless - all is can do is subract from the signal.
On top of that you could have a dirty switch contact somewhere in the NVA, and that can have some strange effects.
I've probably spent more time typing this reply than it would take you to rig the amp back up as an integrated ...
Chris
Common sense isn't anymore!
I recall you mentioning that you were not happy with the sound a while back Martin. It's possible Sam is on the right track and the mains have got 'dirty' as it were. Can you borrow a conditioner?
It is impossible for anything digital to sound analogue, because it isn't analogue!
I have had a similar situation with mine Martin and am trying to identify what was the last time it sounded really good.
My conclusion is that I have not used my system that much just recently and my house has not been heated to the same degree which as I have found particularly with valve amps has a negative effect on sound quality. This also applies to my speakers and cartridge.
Tomorrow however I intend to have along session using my system and will heat the room if necessary. I will let you know what the results are!
Like you I know when my system is really performing and so any drop in SQ is very noticeable.
Main system : VPI Scout 1.1 / JMW 9T / 2M Black / Croft 25R+ / Croft 7 / Heco Celan GT 702
Second System : Goldring Lenco GL75 / AT95EX / Pioneer SX590 / Spendor SP2
Location: Napier, New Zealand
Posts: 1,519
I'm Andrei.
Are you able to check capacitors? - esp in the crossovers. They are known to clap out eventually.
[COLOR=#a52a2a][B]Sources:[/B] [B]1[/B][/COLOR] PC & Wyred4Sound DAC-2 DSDse [COLOR=#a52a2a][B]2[/B][/COLOR] Oppo BDP105 [COLOR=#a52a2a][B]3[/B][/COLOR] Technics SL·1210 MK5 (Jelco 750D · Benz Wood). [COLOR=#a52a2a][B]Speaker Cable[/B][/COLOR] [COLOR=black]Nordost Frey.[/COLOR] [COLOR=#a52a2a][B]Interconnects [/B][/COLOR][COLOR=#000000]Oyaide[/COLOR][COLOR=black] & [/COLOR][COLOR=#000000]Geisha [/COLOR][COLOR=black]Silver.
[/COLOR][B][COLOR=#a52a2a]Phono Stage [/COLOR][/B][COLOR=black]Fosgate Signature V2. [/COLOR] [COLOR=#a52a2a][B]Preamp [/B][/COLOR][COLOR=#000000]Ayon Eris[/COLOR][COLOR=black]. [/COLOR] [COLOR=#a52a2a][B]Power Amp[/B][/COLOR] [COLOR=Black]ATC P1. [/COLOR] [COLOR=#a52a2a][B]Speakers[/B][/COLOR] Triangle Magellan Cello. [COLOR=#A9A9A9]Oh Sting, where is thy death?[/COLOR]
Thanks for your replies, folks.
Firstly I don't think the mains is the problem. I have had a balanced mains unit in the system quite recently and that did not noticably improve SQ although it did sound 'different'. Also sound through the TV is good, I was thinking just the other night how much better it sounds than the main system, albeit on a smaller scale. Mains would affect that too, right?
With the speakers being old, rare and consequently irreplacable I am loath to get the backs off and start messing about. If it does come to that I will have to take them down to Paul at RFC and get him to do a proper job on them.
However I have now been advised that it may well be an issue with the amplifier so I will be exploring that avenue tomorrow when I have a free day and can get a good run at it.
Current Lash Up:
TEAC VRDS 701T > Sony TAE1000ESD > Krell KSA50S > JM Labs Focal Electra 926.
I think that's a sensible first port of call Martin, having the amp checked out. The only common thing here seems to be the amp (ie change it and things improve). As Ali and others have said, it's worth cleaning all connections anyway. A little meths on a cloth or switch cleaning solution. RE crossovers...they don't tend to go overnight, but drift with time as electrolytics dry up. It's a gradual thing so unlikely to be those. Older voice-coils usually dont take kindly to over-amplification and were usually modestly rated to protect the winding insulation fro melting with heat (power). Again, if it were a voice coil issue, it would be apparent that you have one or more drivers out open circuit (easy to check with a multimeter so may be worth checking the DCR of your drivers). With speakers of that age, it is likely that where electrolytics are concerned, they might benefit from an inexpensive refresh, as testing them involves removing them anyway. It seems for now, the amp is the centre of attention though.