Aura Evolution VA100 • Clean up & upgrade

Yep but not in the correct size to be snapped in ;)
Only the ALC10 do. If can go for bigger but remote & with wires to link it to pcb I'll go for Panasonic TSHA wich are cheap ! Or BC Vishay wich are bigger but more expensive... or... will se.
I'll go for Rubycon ZA to replace the Elgen 220/35, caps on the LM4562 supply lines.

About the rectifier, any gain to find here?
 
dead va100 on my desk...

hi

i was given a dead va100 mk I in perfect condition - it doesn't work, but there are no signs of damage visible on the PCB. fuses look OK.

fault finding/trouble shooting would be a lot easier if i had a schematic of the circuit...

any hints where i should start digging?

thx for help!

best, ©
 
i have only visually checked the PCB from above after taking the lid off. did the shorts occur directly on the (black anodized) heat sink or to the aluminum L-sheet attached to the heatsink and the FETs?

anything to watch out particularly when taking the PCB out?
 
i have only visually checked the PCB from above after taking the lid off. did the shorts occur directly on the (black anodized) heat sink or to the aluminum L-sheet attached to the heatsink and the FETs?

anything to watch out for particularly when taking the PCB out?
 
That's it, the L shaped aluminium under frame. And no nothing special, the whole chassis is quite minimal and bow and distorts so much!
Mine is now closed for years, useless as I don't need it but fixed. That was just that careless design and fitting in this fragile box.
About the whole Aura system the tonal balance is quite good but I find (beside my personal system on the Quad 11L) that it's with no depth att al and no space nor air between sound sources. It's a rough picture where my system is a real stage with other flaws. A bit less dynamic also. At least it's normal as the main stuff is more serious and more fresh ;)
No way to use it as main setup for me, I guess we all can't go forward!
 
Work In Progress

Well fellows,

here I go, fitted Rubycon ZA instead of the Elgen, bigger for the same ratings, and closer to the LM4562. The 100nF film caps that were in that place are gone. All the feedback given for the ZA are the same as the BlackGate: they work better alone.

Aslo fitted russian capacitors at the input, MKC are gone here and 0.444µF K40Y-9 (real PIO) sold as 0.470µF (wich is the MKC value). I've some Teflon caps to bypass them, will be perfect, almost overkill for... an OPAMP as buffer/preamp.

I've removed the phono ps via the resistors feeding them. If I have to use it/sell it I'll just have to put them back.
An externally hosted image should be here but it was not working when we last tested it.


I've also to fit my new big cans, RIFA PEH169 6800µF/63V:
An externally hosted image should be here but it was not working when we last tested it.


Even if they are given for 10 years on the shelf life I'll reform them:
http://www.vcomp.co.uk/tech_tips/reform_caps/reform_caps.htm

And as a side note my source is a Philips DVP5500S ( SACD, DVD & DivX ) with LM4562 & ZA and no more DC blocking caps. The ZA sounds a bit dry in their 100/16 form. If any BG 47/16 (Thomo?) then I'll go with these. Just average sound, nothing analog like like with my beloved modded CD53...).

At last a question:
will it be stupid to fit a new PSU to feed the opamps and the phono part?
http://www.selectronic.fr/article.asp?article_ref_entier=90.7966-3
They both are on the 50V lines and then go through 2K2 resistors (I suppose that make a voltage frop but don't know how to calculate it). The main thing is to choose for a new amp later (my beloved G&W TW-2006X...), go for that PSU add, feed the opamp with batteries, remove opamp for discrete or better opmap like LM4562...HA... maybe going that far will defo be stupid in this tiny integrated... And cost is a concern, right now it was free with the 6 caps not that exepensive (said 30€?).
 
It works... but

Yes it works, have so many noises here tonight no way to listen to music. Just had a try and... there is a problem (more annoying than real but... I'm not that sane and annoying means "can't sleep anymore" with me!).

I had the same before with my G&W TW-2006X:

before with plastic case MKC no problem, dead silent with volume to minimum.
With russian caps, K75-24 on the G&W, K40Y-9 on this Aura, it's slightly noisy, a kind of bzzzzz in the speakers. In both cases (even if the former one is no more a concern as the amp is sold) moving the cables with sound leading to caps makes its volume change. Touching the isolated case (metal) of these caps makes a huge humming...
Should I ground the cases? Leave it like that and find the less noisy route for the ALPS to Caps cables?

K75-24 in the G&W:
An externally hosted image should be here but it was not working when we last tested it.


K40Y-9 Aura:
An externally hosted image should be here but it was not working when we last tested it.