Big Overkill Amp Rebuild
I have an 'spare' amp, bought on a whim that is currently residing with a friend, a very capable hifi loving friend who has a soldering iron and knows exactly which end gets hot. What is more he is more than capable of constructing and or modifying almost any amplifier, and a lot more besides, so a simple check-up has become a rather more elaborate affair.
When rebuilt, it / they will be monoblocks with two 1000va transformers, so pretty hefty. Each (big fat) transformer weighs 7kg! So that's two 1000va transformers in each amp.
This is patently ridiculous overkill, but I sold all my spare accumulated HiFi stuff to make this project self-funding - if I'm going to make that kind of sacrifice I want it to be fun!
On the recommendation of my executive amplification consultant ^:)^ I have also bought some pretty fancy (and hyper expensive) smoothing capacitors - a set for each traffo. And some really trick bridge rectifiers (it was very interesting - and something of a bonus - to learn what it is they do).
So the whole thing is pretty exciting, I'll post more later when they are closer to being built (apparently we are waiting on some parts).
In a general sense, does anyone know what sort of difference larger power supplies should make to an amplifier?
Comments
I enjoyed going to the TSS as it not only did the 'bigger' thing but was so much better at the 'soft' stuff, like texture and low level detail. What I am wondering is if all that was down to the power supplies.
I am going with some nice hardwood front & sides, not too dear by comparison and potentially much more attractive IMO. Also, there is the faintest chance of a further rebuild in the years to come...
I am minded towards something like Zebrano. My first choice was American Black Walnut, but this can look really boring, and seeing as I'm not going to be able to hand pick my wood I'll take the stripes...
Ordered the Zebrawood now, too late to have second thoughts. It wont be too dear to have a couple of perspex top plates made up (with hole for ventilation), it might be fun to be able to peek inside.
It's not an unusual thing to modify an amplifier, just look at DIYAudio forums or Pink Fish Media, or HiFiWigWam, or AudioSmile (formerly ZeroGain), or Art of Sound...the only factor at play here is the original manufacturer of this particular amplifier. To my knowledge, no comment has been passed by this person regarding the rebuilding of Naim amps by end users with Avondale parts, or ID Design amps being rebuilt/uprated, or similar (there are loads of examples).
I am quite aware there will be no sympathy, far less support if the project goes wrong but I never expected, nor asked for any.
At the end of the day, I am not "plagiarising" anyone's design, nor am I out to provoke any kind of response (any more than I'm interested in reading these responses). I am simply having my NVA amp rebuilt - as hundreds of people do with their own amp of choice - for fun. The design of the amp is not changing, the circuit will be untouched as I want an improved amp with same qualities I value in NVA. This is because I really rate NVA, not, as I am told has been suggested, because I want to "knock NVA".
Why is it OK to do this with other amps, but not this one? Or for others to do this, but not me? Or on other forums, but not this one? So please dont be concerned, I'm not even going to read it, as I have no problem with it.
James/FAF*
Fellow Amp Fiddler.
We await your progress reports. :-)
My betting is that Alan may be on to something.
Before anything is made too permanent I am going to crack open my TSS amp and photograph the innards, just to make sure nothing much changes from the black box range to statement range (bar PS size/quality etc). The circuits I have in the rebuild are from a mid nineties A80, so there may have been recent changes. I'll pop them on photobucket or something so 'EAG' (Evil Amp Genius) can have decent look.
I'll post one or two of the pics if anyone is interested in electronicy stuff? Otherwise I won't, as I don't know what I'm looking at.
Here are a few shots:
Seriously, i'm getting nervous just looking at those pics - please put the base panel back on ASAP! :-0
So, EAG has informed me that the first pair of power supplies has been made. He hooked up one of the circuits and has run it into his test speaker for a couple of hours with no drama as yet, and all the magic smoke has (as yet) stayed inside where it belongs! WooHooo!
It's nice to know it works though.
I've read on a italian magazine (about dyiy audio) about a quite well know amp technician in italy, his name's Nardi (a technician for audionote) who didn't succeed in repairing a nva ap50 and he left only the shell , inside he built a gainclone...what a pity for the owner...
ciao!
s
I shall pass on your comments to Dr EAG (Evil Amp Genius), who is doing all the work here and deserves any credit should it actually work! The idea behind the bigger PS wasn't really 'more power' [/Clarkson], AFAIK.
As regards thermal limits, we already added more heatsinking to be on the safe side, as it seemed a bit marginal before. TBH I don't honestly know exactly where we are just now as I haven't been along to see for myself for a while, and real life is gloriously intrusive in the summer!
We did discuss an interesting alternative build a few weeks, but although I can see it might very well result in a better amplifier I don't think I can fund it right now. So this rebuild will continue at a leisurely and economical pace until EAG is satisfied with wot 'e 'as done. If that day doesn't arrive we might look at the alternative out of necessity.
Thanks Rob!