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The great resistor changing experiment

RichardH

RichardH

Bodging pleb
Just spent the last couple of hours happily meddling with the resistors in the feedback loop on the main gain stage of my 32.5. I'm recording the results, and will try and make some downloads available for those sad enough to be interested. Might be tricky keeping the quality good and the file size low - a 1 minute WAV is 10 meg!!
For those seriously interested, it may be better for me to burn a CD for you once I've done the lot.

So far I've just recorded the "stock" Naim resistors, and then swapped them out for Welwyn RC55s. Not actually been able to listen to the differences, as my daughter's bedroom is adjacent to the listening room, and she's not an early riser.

I've got some of the Vishay Dale RC60s, plus some bulk foils Les kindly sent me a while ago, so I should have a fairly good overview of the main contenders - I guess Holcos are the main absentee.

...And for those of you wondering how I managed to record the changes to the 321 boards when the line out doesn't run through said boards - I ran the preamp's output that would normally go straight to the power amp directly to the inputs of the PC (another good reason I've not heard the changes in sound yet). Careful volume twiddling needed to get the levels right, but seems to have worked a treat.

More later....
 
Well I thought that, but I put 3 ~10 meg wav files into a zip (total size 31.045Mb, and it came out at 28.149Mb - hardly compressed at all. Tried it with WinRAR and got it down to 19.6Mb - better, not as good as I was expecting, by any means.
 
Its difficult to compress wav files, photos and documents have a lot of redundant data so zip-type compression works a treat. The flac lossless compression is - well, lossless and db power amp converts them back in seconds.
 
Thanks, Chris - dbPowerAmp is my preferred converter anyway, but I'd not looked into other compression codecs.

I may as well go the whole hog and get some of the tant resistors Kit mentions, and I'll see if I can find some holcos cheap (any ideas, anyone?.

Hopefully the resultant files will give people an idea of how particualr resistors sound, and help them choose for their applications - and yes, I know they'll vary depending on the application, but a signature sound should show through.
 
I may as well go the whole hog and get some of the tant resistors Kit mentions, and I'll see if I can find some holcos cheap (any ideas, anyone?.
Click to expand...

IIRC Zanash, here or on Zerogain has a plentiful supply. A little known secret is that Rapid Electronics are clearing these, but only have limited stocks of certain, usually non-standard, values.

Some are older non-magnetic stock, some are the newer and not so good types with magnetic end-caps.

It's a bit if a gamble on the mag bit, but for the prices they are charging (90p for 5off, or 9.00 for 50 off, i.e. the same unit price) they are a good deal for 0.1% tolerance, low tempco precision resistors. Compare that to RC55's!

I note the part no.s and then ring them, as the stock situation isn't available on-line.

You can always make up values from series / parallel combinations too. Also, some values are only available in 50's, so look carefully!

www.rapidelectronics.co.uk

Andy.
 
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